Plastic Injection Molding Manufacturer CNMOULDING Benefits Clients by Cutting Sales Costs

By taking advantage of Internet, CNMOULDING gets the edge in supplying the most cost-effective plastic injection molding products to customers from all over the world. Now CNMOULDING is providing an array of first-class products and services in automotive, home appliances and electronics

 Plastic injection molding products has been widely used in many industries and CNMOULDING promises customers direct benefits through its easy and definitive consumer approach module. The company's objective to become the "one stop shop" is facilitated through its 2000 sq meters workshop in China.  Powered by world-class infrastructure, a large and adroit workforce and a solid management team, the company has become a trusted supplier of plastic molds for many European and North American based companies. Furthermore, CNMOULDING claims to be the only China plastic molding injection company that offers complete cost analysis and full transparency to prospective buyers.

Company insiders indicate that the biggest plus of working with CNMOULDING is in the direct method of approach that the company adopts. As a top plastic injection molding manufacturer, CNMOULDING has earned its fame though innovation, quality control and cost-down.  According to their reports, CNMOULDING picks up direct consumer leads from the Internet and then tries to establish direct contact. Company officials have also, on several occasions, shown why the conventional way of marketing through trade shows is becoming obsolete. The company plans further expansion and the owners indicated that they are bringing more innovation in the manufacturing process to accelerate production and reduce downtime.

CNMOULDING has also made an elaborate effort to keep their price structure transparent for their international clients. While most similar companies would make every effort to conceal the numbers, CNMOULDING promises to give their clients a sneak peek into the pricing and profit structure.

The CEO of CNMOULDING recently addressed the local press. He laid great emphasis on the sales team of the company: "Most companies tend to carry out their sales through salespersons who exhibit an acute lack of product knowledge. At CNMOULDING, our sales manager deals with all the sales and effectively communicates the messages in and out of the company. We also make it a point to adhere to transparent pricing."

About the company

CNMOULDING is a leading direct plastic injection company based out of China. The company caters to both the Chinese and international markets.

More information about the company is available at www.cnmoulding.com

Injection Molding Adapts to a More Interconnected World

Plastic, rubber, and metal injectionmolding and, more recently, rapid molding techniques have been major contributors in global manufacturing. A variety of processes and equipment can be used, depending on volumes, materials and turnaround time, and whether parts are prototypes or finished ones. The rise of rapid molding for fast delivery of high-mix, low-volume products and prototypes, and new ways to make molds such as 3D printing, are changing the way design engineers use injection molding in product development and production planning.

Droduct manager for the cnmould service of fast-turn molding company cnmoulding molding services can be classified into three different types: traditional high-volume molders; a broad group of lower-cost, high-volume molding services typically located offshore; and rapid molders, a more recent phenomenon.

Traditional molders are usually full-service suppliers. "They are all about injection molding tools that last forever, and about speeding up injection," he said. "They do a lot of value-add services like assembly or painting." Tooling used by these services tends to be made of hardened steel; hundreds of thousands to tens of millions of parts are made from multi-cavity production molds.

Rapid molding is newer, and something Proto Labs helped pioneer. It serves the need for making multiple variations of a single product in somewhat lower volumes -- 25 to 1,000 units instead of 100,000 or more, said Barsness. These products and all their components must be prototyped exactly, in all those variations, using exactly the materials they will be produced with.

The resulting increase in SKU proliferation is caused by several colliding trends. First, globalization has produced effects, as described by Barsness. "Say you make a household product or a communications device, and you want to sell it around the world," he said. "Your market used to be the US, but now there's the Chinese market and other countries, like Brazil. Customers in those countries have different values and tastes, whether it's a car or a thermostat." Those countries also have different regulations, such as those for safety, and different specifications, such as for electrical voltage, which effect part variations.

Trends related to energy and environmental friendliness are also driving changes in product designs. "Lightweighting is major, especially in anything that moves," said Barsness." Also, LEDs are being used everywhere for their ability to reduce the power, size, and cost of lighting, and they can be packaged almost any way imaginable. On many of these LED-enabled products, the entire assembly can include five to 10 different injection molded parts.

A third set of changes is due to increases in product connectivity and automation. The Internet of Things has engineers putting sensors on just about anything, from household appliances to industrial products. "Now the design engineer has to get 10 different prototypes of 10 different products for 10 different countries, all of them have LEDs, and they've all got to talk to the Internet," Barsness remarked. This is where rapid molding services come in.

Rapid molding tooling is typically "soft," represented by aluminum instead of steel, for a much lower cost. Rapid molding, of course, has a much faster turnaround. A traditional molder, using a high-volume production mold, could typically take a few months to deliver entire part runs, but the average rapid injection molder delivers parts in 25 to 45 days. Proto Labs' service promises one to 15 days.

Before rapid molding begins, prototypes are also made with production-grade materials. Typically, a customer sends three to five iterations of a design, and Proto Labs cuts a different mold each time. The industries Proto Labs serves tend to be those with some regulation or a high amount of product churn.

Injection Mould design

The mould consists of two primary components, the injection mould (A plate) and the ejector mould (B plate). These components are also referred to as moulder and mouldmaker. Plastic resin enters the mould through a sprue or gate in the injection mould; the sprue bushing is to seal tightly against the nozzle of the injection barrel of the moulding machine and to allow molten plastic to flow from the barrel into the mould, also known as the cavity. The sprue bushing directs the molten plastic to the cavity images through channels that are machined into the faces of the A and B plates. These channels allow plastic to run along them, so they are referred to as runners. The molten plastic flows through the runner and enters one or more specialized gates and into the cavity geometry to form the desired part.

The amount of resin required to fill the sprue, runner and cavities of a mould comprises a "shot". Trapped air in the mould can escape through air vents that are ground into the parting line of the mould, or around ejector pins and slides that are slightly smaller than the holes retaining them. If the trapped air is not allowed to escape, it is compressed by the pressure of the incoming material and squeezed into the corners of the cavity, where it prevents filling and can also cause other defects. The air can even become so compressed that it ignites and burns the surrounding plastic material.

To allow for removal of the moulded part from the mould, the mould features must not overhang one another in the direction that the mould opens, unless parts of the mould are designed to move from between such overhangs when the mould opens (using components called Lifters).

Sides of the part that appear parallel with the direction of draw (the axis of the cored position (hole) or insert is parallel to the up and down movement of the mould as it opens and closes) are typically angled slightly, called draft, to ease release of the part from the mould. Insufficient draft can cause deformation or damage. The draft required for mould release is primarily dependent on the depth of the cavity: the deeper the cavity, the more draft necessary. Shrinkage must also be taken into account when determining the draft required. If the skin is too thin, then the moulded part will tend to shrink onto the cores that form while cooling and cling to those cores, or the part may warp, twist, blister or crack when the cavity is pulled away.

A mould is usually designed so that the moulded part reliably remains on the ejector (B) side of the mould when it opens, and draws the runner and the sprue out of the (A) side along with the parts. The part then falls freely when ejected from the (B) side. Tunnel gates, also known as submarine or mould gates, are located below the parting line or mould surface. An opening is machined into the surface of the mould on the parting line. The moulded part is cut (by the mould) from the runner system on ejection from the mould. Ejector pins, also known as knockout pins, are circular pins placed in either half of the mould (usually the ejector half), which push the finished moulded product, or runner system out of a mould. The ejection of the article using pins, sleeves, strippers, etc. may cause undesirable impressions or distortion, so care must be taken when designing the mould.

The standard method of cooling is passing a coolant (usually water) through a series of holes drilled through the mould plates and connected by hoses to form a continuous pathway. The coolant absorbs heat from the mould (which has absorbed heat from the hot plastic) and keeps the mould at a proper temperature to solidify the plastic at the most efficient rate.

To ease maintenance and venting, cavities and cores are divided into pieces, called inserts, and sub-assemblies, also called inserts, blocks, or chase blocks. By substituting interchangeable inserts, one mould may make several variations of the same part.

More complex parts are formed using more complex moulds. These may have sections called slides, that move into a cavity perpendicular to the draw direction, to form overhanging part features. When the mould is opened, the slides are pulled away from the plastic part by using stationary “angle pins” on the stationary mould half. These pins enter a slot in the slides and cause the slides to move backward when the moving half of the mould opens. The part is then ejected and the mould closes. The closing action of the mould causes the slides to move forward along the angle pins.

Some moulds allow previously moulded parts to be reinserted to allow a new plastic layer to form around the first part. This is often referred to as overmoulding. This system can allow for production of one-piece tires and wheels.

Two-shot injection moulded keycaps from a computer keyboard

Two-shot or multi-shot moulds are designed to "overmould" within a single moulding cycle and must be processed on specialized injection moulding machines with two or more injection units. This process is actually an injection moulding process performed twice and therefore has a much smaller margin of error. In the first step, the base color material is moulded into a basic shape, which contains spaces for the second shot. Then the second material, a different color, is injection-moulded into those spaces. Pushbuttons and keys, for instance, made by this process have markings that cannot wear off, and remain legible with heavy use.

A mould can produce several copies of the same parts in a single "shot". The number of "impressions" in the mould of that part is often incorrectly referred to as cavitation. A tool with one impression will often be called a single impression (cavity) mould. A mould with 2 or more cavities of the same parts will likely be referred to as multiple impression (cavity) mould. Some extremely high production volume moulds (like those for bottle caps) can have over 128 cavities.

In some cases multiple cavity tooling will mould a series of different parts in the same tool. Some toolmakers call these moulds family moulds as all the parts are related. Examples include plastic model kits.

About Injection mold History

In 1847 Jöns Jacob Berzelius produced the first condensation polymer, polyester, from glycerin (propanetriol) and tartaric acid.[4] Berzelius is also credited with originating the chemical terms catalysis, polymer, isomer, and allotrope, although his original definitions differ dramatically from modern usage. For example, he coined the term "polymer" in 1833 to describe organic compounds which shared identical empirical formulas but which differed in overall molecular weight, the larger of the compounds being described as "polymers" of the smallest. According to this (now obsolete) definition, glucose (C6H12O6) would be a polymer of formaldehyde (CH2O).

The first man-made commercial plastic was invented in Britain in 1861 by Alexander Parkes. He publicly demonstrated it at the 1862 International Exhibition in London, calling the material he produced "Parkesine." Derived from cellulose and nitric acid (nitrocellulose), Parkesine could be heated, moulded, and retain its shape when cooled. It was, however, expensive to produce, prone to cracking, and highly flammable.

In 1868, American inventor John Wesley Hyatt developed a plastic material he named Celluloid, improving on Parkes' invention by plasticizing the nitrocellulose with camphor so that it could be processed into finished form and used as a photographic film. Together with his brother Isaiah, Hyatt patented the first injection moulding machine in 1872. This machine was relatively simple compared to machines in use today: it worked like a large hypodermic needle, using a plunger to inject plastic through a heated cylinder into a mould. The industry progressed slowly over the years, producing products such as collar stays, buttons, and hair combs.

The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903, which was much less flammable than cellulose nitrate. It was eventually made available in a powder form from which it was readily injection moulded. Arthur Eichengrün developed the first injection moulding press in 1919. In 1939, Arthur Eichengrün patented the injection molding of plasticized cellulose acetate.

The industry expanded rapidly in the 1940s because World War II created a huge demand for inexpensive, mass-produced products.In 1946, American inventor James Watson Hendry built the first screw injection machine, which allowed much more precise control over the speed of injection and the quality of articles produced.[9] This machine also allowed material to be mixed before injection, so that colored or recycled plastic could be added to virgin material and mixed thoroughly before being injected. Today screw injection machines account for the vast majority of all injection machines. In the 1970s, Hendry went on to develop the first gas-assisted injection moulding process, which permitted the production of complex, hollow articles that cooled quickly. This greatly improved design flexibility as well as the strength and finish of manufactured parts while reducing production time, cost, weight and waste.

The plastic injection moulding industry has evolved over the years from producing combs and buttons to producing a vast array of products for many industries including automotive, medical, aerospace, consumer products, toys, plumbing, packaging, and construction.

Examples of polymers best suited for the process

Most polymers, sometimes referred to as resins, may be used, including all thermoplastics, some thermosets, and some elastomers. Since 1995, the total number of available materials for injection moulding has increased at a rate of 750 per year; there were approximately 18,000 materials available when that trend began. Available materials include alloys or blends of previously developed materials, so product designers can choose the material with the best set of properties from a vast selection. Major criteria for selection of a material are the strength and function required for the final part, as well as the cost, but also each material has different parameters for moulding that must be taken into account.[10]:6 Common polymers like epoxy and phenolic are examples of thermosetting plastics while nylon, polyethylene, and polystyrene are thermoplastic.[1]:242 Until comparatively recently, plastic springs were not possible, but advances in polymer properties make them now quite practical. Applications include buckles for anchoring and disconnecting outdoor-equipment webbing.

Injection molding of CNMOULDING

Injection moulding (injection molding in the USA) is a manufacturing process for producing parts by injecting material into a mould. Injection moulding can be performed with a host of materials, including metals, glasses, elastomers, confections, and most commonly thermoplastic and thermosetting polymers. Material for the part is fed into a heated barrel, mixed, and forced into a mould cavity, where it cools and hardens to the configuration of the cavity. After a product is designed, usually by an industrial designer or an engineer, moulds are made by a mouldmaker (or toolmaker) from metal, usually either steel or aluminum, and precision-machined to form the features of the desired part. Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers which do not melt during the injection moulding of some lower temperature thermoplastics, can be used for some simple injection moulds.

Parts to be injection moulded must be very carefully designed to facilitate the moulding process; the material used for the part, the desired shape and features of the part, the material of the mould, and the properties of the moulding machine must all be taken into account. The versatility of injection moulding is facilitated by this breadth of design considerations and possibilities.

Process characteristics

Injection moulding uses a ram or screw-type plunger to force molten plastic material into a mould cavity; this solidifies into a shape that has conformed to the contour of the mould. It is most commonly used to process both thermoplastic and thermosetting polymers, with the former being considerably more prolific in terms of annual material volumes processed. Thermoplastics are prevalent due to characteristics which make them highly suitable for injection moulding, such as the ease with which they may be recycled, their versatility allowing them to be used in a wide variety of applications,8–9 and their ability to soften and flow upon heating. Thermoplastics also have an element of safety over thermosets; if a thermosetting polymer is not ejected from the injection barrel in a timely manner, chemical crosslinking may occur causing the screw and check valves to seize and potentially damaging the injection moulding machine.

Injection moulding consists of high pressure injection of the raw material into a mould which shapes the polymer into the desired shape. Moulds can be of a single cavity or multiple cavities. In multiple cavity moulds, each cavity can be identical and form the same parts or can be unique and form multiple different geometries during a single cycle. Moulds are generally made from tool steels, but stainless steels and aluminum moulds are suitable for certain applications. Aluminum moulds typically are ill-suited for high volume production or parts with narrow dimensional tolerances, as they have inferior mechanical properties and are more prone to wear, damage, and deformation during the injection and clamping cycles; however, aluminum moulds are cost-effective in low-volume applications, as mould fabrication costs and time are considerably reduced. Many steel moulds are designed to process well over a million parts during their lifetime and can cost hundreds of thousands of dollars to fabricate.

When thermoplastics are moulded, typically pelletized raw material is fed through a hopper into a heated barrel with a reciprocating screw. Upon entrance to the barrel the thermal energy increases and the Van der Waals forces that resist relative flow of individual chains are weakened as a result of increased space between molecules at higher thermal energy states. This process reduces its viscosity, which enables the polymer to flow with the driving force of the injection unit. The screw delivers the raw material forward, mixes and homogenizes the thermal and viscous distributions of the polymer, and reduces the required heating time by mechanically shearing the material and adding a significant amount of frictional heating to the polymer. The material feeds forward through a check valve and collects at the front of the screw into a volume known as a shot. A shot is the volume of material that is used to fill the mould cavity, compensate for shrinkage, and provide a cushion (approximately 10% of the total shot volume, which remains in the barrel and prevents the screw from bottoming out) to transfer pressure from the screw to the mould cavity. When enough material has gathered, the material is forced at high pressure and velocity into the part forming cavity. To prevent spikes in pressure, the process normally uses a transfer position corresponding to a 95–98% full cavity where the screw shifts from a constant velocity to a constant pressure control. Often injection times are well under 1 second. Once the screw reaches the transfer position the packing pressure is applied, which completes mould filling and compensates for thermal shrinkage, which is quite high for thermoplastics relative to many other materials. The packing pressure is applied until the gate (cavity entrance) solidifies. Due to its small size, the gate is normally the first place to solidify through its entire thickness. Once the gate solidifies, no more material can enter the cavity; accordingly, the screw reciprocates and acquires material for the next cycle while the material within the mould cools so that it can be ejected and be dimensionally stable. This cooling duration is dramatically reduced by the use of cooling lines circulating water or oil from an external temperature controller. Once the required temperature has been achieved, the mould opens and an array of pins, sleeves, strippers, etc. are driven forward to demould the article. Then, the mould closes and the process is repeated.

For thermosets, typically two different chemical components are injected into the barrel. These components immediately begin irreversible chemical reactions which eventually crosslinks the material into a single connected network of molecules. As the chemical reaction occurs, the two fluid components permanently transform into a viscoelastic solid. Solidification in the injection barrel and screw can be problematic and have financial repercussions; therefore, minimizing the thermoset curing within the barrel is vital. This typically means that the residence time and temperature of the chemical precursors are minimized in the injection unit. The residence time can be reduced by minimizing the barrel's volume capacity and by maximizing the cycle times. These factors have led to the use of a thermally isolated, cold injection unit that injects the reacting chemicals into a thermally isolated hot mould, which increases the rate of chemical reactions and results in shorter time required to achieve a solidified thermoset component. After the part has solidified, valves close to isolate the injection system and chemical precursors, and the mould opens to eject the moulded parts. Then, the mould closes and the process repeats.

Pre-moulded or machined components can be inserted into the cavity while the mould is open, allowing the material injected in the next cycle to form and solidify around them. This process is known as Insert moulding and allows single parts to contain multiple materials. This process is often used to create plastic parts with protruding metal screws, allowing them to be fastened and unfastened repeatedly. This technique can also be used for In-mould labelling and film lids may also be attached to moulded plastic containers.

A parting line, sprue, gate marks, and ejector pin marks are usually present on the final part. None of these features are typically desired, but are unavoidable due to the nature of the process. Gate marks occur at the gate which joins the melt-delivery channels (sprue and runner) to the part forming cavity. Parting line and ejector pin marks result from minute misalignments, wear, gaseous vents, clearances for adjacent parts in relative motion, and/or dimensional differences of the mating surfaces contacting the injected polymer. Dimensional differences can be attributed to non-uniform, pressure-induced deformation during injection, machining tolerances, and non-uniform thermal expansion and contraction of mould components, which experience rapid cycling during the injection, packing, cooling, and ejection phases of the process. Mould components are often designed with materials of various coefficients of thermal expansion. These factors cannot be simultaneously accounted for without astronomical increases in the cost of design, fabrication, processing, and quality monitoring. The skillful mould and part designer will position these aesthetic detriments in hidden areas if feasible.

Factors plastic mold defects and improve methods

Plastic products in the commissioning and production processes are all types of injection defect occurs, cause of the defects are many, processing of raw materials, injection molding machines, injection molding process, the production environment and other factors, the most important factor is - mold.

Here we focus on the reasons of all kinds of plastic molds product defects and some improved methods for mold.

1. Size does not match the size requirements of drawings, product development, processing, basic use, the product size is wrong, simply can not assemble and use. Therefore, to ensure the product size is the most fundamental, but also the greatest difficulty and workload. Molds mainly from the following aspects to ensure product dimensional accuracy:

2. Choose a reasonably accurate shrinkage, in addition to material suppliers parameters, but also must consider the flow direction of the product shape and plastic; • The design of the mold, according to the requirements of accuracy class product, the product is converted into the mold parts tolerance tolerance, while leaving the safety margin repair mode;

3. part design, it will be an important product dimension is reflected in the size of the parts diagram, labeling tolerances, and detection and control;

4. improve the machining accuracy and surface quality, and controlled;

5. rational design of cooling system (mold temperature control). First, a variety of techniques trial, select one closest to the product size requirements of the process, and the stability of this process down. Then according to product size, to repair the die size. For non-critical dimensions or does not affect product assembly and function of size, can be communication and consultation with the client, whether concessions release.

2. The product is unstable in the case of molds and raw materials, and injection molding process remain unchanged, after injection molding products out, not only is the appearance or size, or that other aspects vary greatly, resulting in product sometimes qualified sometimes scrapped. In this case, the mold can not make any amendments, in particular dimensions, because no one can refer to the reference, so to ensure the stability of the product formed, it is the basic condition subsequent modification mode.

2.1 Cause:  mold parts deformation;  mold parts guide and positioning allowed;  mold temperature control system is uneven or unstable;  moving parts of the gap is too large, resulting in per-action deviates;

2.2 improve Opinions:  increase mold guiding and positioning mechanism, such as a fine positioning.  reduce mold part gap.

3. burrs (burrs) flash, at the sub-surface and juxtaposition line position, the extra plastic, foil or hairy. In the injection molding production, the most frequent problem, the position appears greater. Any set of molds, more or less will have some flash, a little bit higher product requirements, will require repairs. In this regard, we will increase the workload after the process; the same time, will increase the risk of product quality. Therefore, no flash each injection enterprises injection will be lowering the efficiency of an important issue.

3.1 Cause:  mold steel hardness is not enough, easy to wear; insufficient strength, easily deformed;  lack of precision mold parts processing, assembly clearance;  die not wearing good, especially sub-surface location, closure is not tight or way that is force;  mold plane falls within the foreign substance or metal inserts

3.2 improve Opinions:  at the design stage, preferred high hardness steel, such as hardened steel;  at the design stage to ensure that the size of the part of sufficient strength enough;  improving mold machining accuracy;  reconfiguration mode, reducing typing surface gap;  Die regular cleaning maintenance;  clean up the parting foreign body, keeping the mold closed well.

4. sink marks (indented) products relatively thick wall thickness or wall thickness mutation region, because the material accumulation, shrink larger, resulting in surface pitting. Generation of sink marks, mainly in product design is not very reasonable, so we have to communicate with customers at the time of the pre-analysis of proposed amendments. While in the mold structure optimization aspects to do.

more information http://www.cnmoulding.com/plastic_injection_molding_china.htm  

Plastic Injection Molding Manufacturer CNMOULDING Benefits Clients by Cutting Sales Costs

By taking advantage of Internet, CNMOULDING gets the edge in supplying the most cost-effective plastic injection molding products to customers from all over the world. Now CNMOULDING is providing an array of first-class products and services in automotive, home appliances and electronics

SHANGHAI, China, August 30, 2015  -- Plastic injection molding products has been widely used in many industries and CNMOULDING promises customers direct benefits through its easy and definitive consumer approach module. The company's objective to become the "one stop shop" is facilitated through its 2000 sq meters workshop in China.  Powered by world-class infrastructure, a large and adroit workforce and a solid management team, the company has become a trusted supplier of plastic molds for many European and North American based companies. Furthermore, CNMOULDING claims to be the only China plastic molding injection company that offers complete cost analysis and full transparency to prospective buyers.

Company insiders indicate that the biggest plus of working with CNMOULDING is in the direct method of approach that the company adopts. As a top plastic injection molding manufacturer, CNMOULDING has earned its fame though innovation, quality control and cost-down.  According to their reports, CNMOULDING picks up direct consumer leads from the Internet and then tries to establish direct contact. Company officials have also, on several occasions, shown why the conventional way of marketing through trade shows is becoming obsolete. The company plans further expansion and the owners indicated that they are bringing more innovation in the manufacturing process to accelerate production and reduce downtime.

CNMOULDING has also made an elaborate effort to keep their price structure transparent for their international clients. While most similar companies would make every effort to conceal the numbers, CNMOULDING promises to give their clients a sneak peek into the pricing and profit structure.

The managerof CNMOULDING recently addressed the local press. He laid great emphasis on the sales team of the company: "Most companies tend to carry out their sales through salespersons who exhibit an acute lack of product knowledge. At CNMOULDING, our sales manager deals with all the sales and effectively communicates the messages in and out of the company. We also make it a point to adhere to transparent pricing."

About the company

CNMOULDING is a leading direct plastic injection company based out of China. The company caters to both the Chinese and international markets.

More information about the company is available at 

www.plastic-injectionmoulding.com  

About CNMOULDING

Shanghai CNMOULDING TECHNIC CO.,LTD , CNMOULDING offer plastic injection molding service and specializes in various plastic moulds for. automotive, home appliances, electronics ,as well as general industrial OEM applications. Our company covers an area of more than 2000 square meters workshop, surrounded with convenient  transportation . At present, our group reaches to more than 100 employee and capital assets to more than 8 million RMB. Our capacity is 40-50 sets mould per month.

CNMOULDING’s mission is to be professional, trustworthy and creative toolmaker and injection molding supplier, We always keep Layout at the top level, introduce modernized management system, Go in for zero default. Make sure quality and techniques in the highest way. Therefore, We dedicate to make innovation and progress continually to be your better partner. enhance our technology and accumulate experience in mold building ,injection molding, print and paint  ,etc.

Why Choose Us?

1,We provide direct factory price and make cost transparent.

As you know there are more than 5000 trading companies in China, but Some of them concealed their property very well, It is hard to tell for a foreigner. normally they will take profit 30%.so we show the detail cost in our website, Most traders can’t quote the price with this level. but these price are normal price for us and have proper profit.

2,We focus on providing one stop service for small and middle size company.

We are a middle size mold making and injection molding company, it is also one reason for good price. We don’t need to pay for the huge administration fee compare to big factory. We got ISO9001-2008 certificate, it insure our quality same as big factory. As everyone know china mold is much cheaper than USA or Europe but injection molding will be more expensive, because the resin price in China is 50% higher or double. But if you only produce 1,000-50,000 pcs. then China will have big advantage. Moreover we can make print, paint and assembly in house.it also save a lot!

3,Our Sales Manager have rich experience in engineering.

Most of company will arrange sales girls to contact customer, they are lack of mold knowledge ,just transfer e-mail and said some holiday words but will get good commission(3-5% total price, of course the cost will be calculated in their quotation).our Sales Manager will handle the job for both sales manager and project manager. It will make sure our professional service get through the whole process and the communication is more efficient.

CNMOULDING PRODUCES INJECTION MOLDING EQUIPMENT FOR VARIOUS USES

Almost every household material that is made out of plastic requires the process of injection molding. Only professionals can create such products and one should make a proper research before purchasing equipment for injection molding process. There are various websites selling plastic injection materials and one of them is CNMOULDING.

Before buying a product one can have a look at the experience of the company and the reviews of their previous customers. The present CNMOULDING industry involves both screw type machines and plunger type machines. The screw type injection molding is common among the customers and most of the clients are on the lookout for the screw type machines. The molding of plastic is different for different products depending on the type of plastic. Each product is different and one needs to be aware of his requirements before purchasing the product.

A company with good standards and certification can produce such products and one cannot expect to get quality injection molding machine from an amateur. CNMOULDING follows a very complicated process to make sure that the customers get quality equipment. The buyers can have a look at the quality control process of the company by visiting this link http://www.chinamoldmaker.org/equipment/mold-equipment/. Having a look at the injection molding process will helps the buyers in understanding the quotation process and the pricing structure of the company. This also helps in making a proper research on the experience of the company and one can be rest assured that they are with an experienced company.

The process followed by professioanls makes sure that the plastics can be re-used and recycled and this helps in reducing wastage. They have an eco-friendly process that helps in reducing wastage. There are huge amount of customers who like to use eco-friendly processes and go with the ones who follow a greener process that reduces wastage. CNMOULDING is one of those companies that focuses on reducing wastage and makes sure that these CNMOULDING processes are done in an environmentally friendly manner.

The products on the website also include automotive products, door closers, covers, iPhone cases and much more. People can have a look at all the products and compare them according to their needs. Once the buyers get the products that meet their requirements and budget they can make sales enquiry through the website. The process of injection molding makes production processes much easier and faster. It reduces errors during production processes and makes sure that it is done in a cost effective manner.

About CNMOULDING:

Website:http://www.cnmoulding.com

CNMOULDING is a company based in China that has been producing various injection molding equipment. They have been in this field for a long time now and sell products around the world. The buyers can have a look at the FAQ section and the industrial processes followed by the company on their website. One can make product enquiries through the above mentioned website.

Common types of plastics, advantages and disadvantages, the main defect (b)

PS material (polystyrene) (General Purpose Polystyrene GPPS, commonly known as: PS; high impact polystyrene HIPS, commonly known as: super glue is not broken) for the production of insulating transparent pieces, decorative pieces, and chemical equipment, optical instruments, etc. ʱ??

Forming characteristics: 1. amorphous material, moisture absorption is small, without fully dry, difficult to break down, but the thermal expansion coefficient, easy to produce internal stress, good mobility, can bolt or plunger-type injection molding machine.

2. to use high melt temperature, high mold temperature, low injection pressure, injection time extend help to reduce stress. Prevent shrinkage and deformation. Chemical and physical properties: Most commercial use of PS are transparent, non-crystalline material. PS has very good geometric stability, thermal stability, the optical transmission characteristic, electrical insulating properties and a very slight hygroscopic tendency. It is resistant to water, dilute mineral acids, but can be strong oxidizing acids such as concentrated sulfuric acid corrosion and can be expanded and deformed in some organic solvent. Typical shrinkage between 0.4 to 0.7%.

POM (POM, commonly known as: steel) heat-crystalline plastic, melting point of 165 to 175 degrees, the nature of the nearest metal.

Advantages: 1 has high mechanical strength and rigidity.

2. The highest fatigue strength.

3. High environmental resistance, resistance to organic solvents.

4. Resistance to repeated impact resistance.

5. wide temperature range (-40 to 120 degrees).

6. good electrical properties.

7. good recovery.

8. The self-lubricating properties, good wear resistance.

9. excellent dimensional stability.

Disadvantages: 1. process if prolonged high temperatures can lead to thermal decomposition.

2. No self-extinguishing.

3. antacid poor.

4. forming a large shrinkage.

Chemical and physical properties: POM is a tough elastic material, even at low temperatures are still very good creep properties, geometric stability and impact resistance. POM homopolymer materials have both copolymer material. Homopolymer material has a very good extension strength, fatigue strength, but not easy to process. Copolymers have good thermal stability, chemical stability and ease of processing. Both homopolymer material or copolymer materials are crystalline materials and are not easily absorb moisture. The high crystallinity of POM cause it has a fairly high shrinkage, can be high up to 2% to 3.5%. For a variety of enhanced materials have different shrinkage.

 PVC (polyvinyl chloride) Chemical and physical properties: Rigid PVC is one of the most widely used plastic materials. PVC material is a non-crystalline materials. PVC material in actual use, often by adding stabilizers, lubricants, auxiliary processing agent, pigment, impact agents and other additives. PVC material is not easily flammable, high strength, resistance to climate variability and excellent geometric stability. PVC of oxidants, reducing agents and strong acids have a very strong resistance. However, it can be concentrated oxidizing acids such as concentrated sulfuric acid, concentrated nitric acid corrosion and does not apply to contact with aromatic hydrocarbons, chlorinated hydrocarbons occasions. PVC melt temperature during processing is a very important process parameters, if this parameter incorrectly will cause the material to decompose problems. PVC is rather poor flow characteristics, the process is very narrow range. Especially high molecular weight PVC material more difficult to process (this material is usually added to lubricants to improve the flow characteristics), so commonly used are low molecular weight PVC material. PVC contraction rate is very low, typically 0.2 to 0.6%.

PE (polyethylene)

A. is the largest output, the most should be the plastic in the world, with its output accounting for 30% of world plastics production.

B. The structure of long chain-like structure or a branched structure, a crystalline polymer type song.

C. odorless and tasteless flammable white powder, the appearance of floating white.

D. excellent electrical insulation properties, high frequency cable insulation should be made.

E. having high chemical stability.

F. good low temperature properties, good air permeability, can make agricultural films, bags.

PP (polypropylene, commonly known as the pleated plastic) is the most common plastic produce a heat-resistant, high yield strength, high bending labor life. Shrinkage greater resistance to impact strength with temperature changes. Insufficient rigidity. Flammable Chemical properties of stability, good dielectric properties, better engage in chemical erosion resistance, the ability to soak 80 degrees below the inorganic acid, lye, salts, and many organic solvents, water absorption is also minimal. At the melting point has good mobility, good molding properties Chemical and physical properties:. PP is a semi-crystalline materials. To be more rigid than PE and has a higher melting point. Since the type of PP homopolymer temperature is higher than the above 0 ℃ very brittle, so many commercial PP material is added 1-4% ethylene random copolymer or a higher ratio of clamp-stage ethylene content copolymer. PP copolymer-based material has a lower heat distortion temperature (100 ℃), low transparency, low gloss, low rigidity, but have a stronger impact strength. PP ethylene content increases strength increases. PP Vicat softening temperature of 150 ℃. Due to the high degree of crystallinity, the surface rigidity and scratch resistance properties of this material is very good. PP environmental stress cracking problem does not exist. Generally, the use of glass fiber, metal additives or thermoplastic rubber modified PP. MFR PP turnover ranges from 1 to 40. Low MFR PP material better impact properties but extend lower strength. MFR for the same material, copolymer-based homopolymer type intensity ratio is higher. Since the crystal, PP contraction rate is very high, typically 1.8 to 2.5%. And shrinkage direction uniformity than PE-HD material is much better. 30% of glass additive can shrink rate fell to 0.7%. Homopolymer and copolymer PP material has excellent resistance to moisture absorption, resistance to acid corrosion, anti-solubility. However, it aromatic hydrocarbons (such as benzene) solvents, chlorinated hydrocarbons (carbon tetrachloride) solvents is not resistance. PP did not like PE still has oxidation resistance at elevated temperatures.

PPE ethylene polypropylene chemical and physical properties: In general, PPE or PPO, commercially available materials generally mixed with other thermoplastic materials such as PS, PA and so on. These hybrid materials are generally still call it PPE or PPO. PPE or PPO hybrid has better processing characteristics than the pure material. Change characteristics depending on the mixture as a ratio of PPO and PS. Mixed with PA 66 of the mixed material has a stronger chemical stability at high temperatures. Moisture absorption of this material is very small, its products have excellent geometric stability. PS material mixed with non-crystalline, and mixed with the PA of the material is crystalline. Glass fiber additives can make the shrinkage rate decreased to 0.2%. This material also has excellent electrical insulating properties and low coefficient of thermal expansion. The viscosity depends on the mixture ratio of the material, PPO rate increase will result in increased viscosity.

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Common types of plastics, advantages and disadvantages, the main flaw

Plastic is a resin as a main component, at a certain temperature and pressure molded into a certain shape, and at room temperature can be maintained given the shape of the high molecular weight organic material. Plastic light weight, high strength. Usually density 0.9-2.3g / mm³ is 1 / 8-1 / 4, 1/2 of aluminum, iron and steel excellent electrical insulation properties, good chemical stability, anti-friction wear resistance, light transmittance and protective properties Good, good damping silencer performance. After heating the surface of the plastic according to the performance into thermosetting plastics and thermoplastics. Occur at a certain temperature over a period of time of heat, pressure or added hardener chemical reaction and hardened, hardened plastic chemical structure changes, hard, insoluble in solvents, no longer softened after heating, such as temperature: thermosetting plastic Features too high to decompose. Such as Bakelite (commonly known as bakelite), epoxy plastic (EP) and the like. Thermoplastic Features: biological state change hair after being heated to soften or melt into a sticky fluid state from a solid, but can harden after cooling from solid, and the process can be repeated many times. The molecular structure of the plastic itself is not changed. Plastics such as polyethylene (PE), polyvinyl chloride (PVC).

PC material (polycarbonate)

Advantages: 1 has high strength and elastic modulus, high impact strength, wide temperature range.

2. High transparency and freedom of dyeing

3. good fatigue resistance

The excellent electrical characteristics

5. low mold shrinkage, good dimensional stability.

Disadvantages: 1. hydrolysis resistance

2. chemical resistance, notch effect

3. The problem is easy to produce finished poorly designed internal stress.

Chemical and physical properties: PC is a non-crystalline engineering materials, with a particularly good impact strength, heat stability, gloss, inhibit bacterial properties, flame retardant properties and fouling resistance. PC de gap estimated impact strength in Iraq (otched Izod impact stregth) is very high and very low shrinkage rate, usually 0.1% to 0.2%. PC has good mechanical properties, but poor flow characteristics, so the injection molding process more difficult this material. PC quality in the selection of the material, we should expect the final product as a benchmark. If the plastic parts require high impact resistance, then use a low turnover rate of PC material; the other hand, you can use the high turnover rate of PC material, which can optimize the injection molding process.

Material ABS (acrylonitrile - butadiene - styrene copolymer, commonly known as: super glue is not broken)

Advantages: 1. hard, easy extrusion

2. Flame

3. easy to dye

4. Impact

5. The surface resistance

Disadvantages: 1. poor solvent resistance

2. Low Dielectric strength

3. Low stretch rate

Forming characteristics: 1. amorphous material, liquid medium, moisture large, must be fully dry, glossy plastic surface should take time to preheat the drying 80-90 degrees, 3 hours

2. should take high melt temperature high mold temperature, high precision mold, mold temperature should take 50-60 degrees, high-gloss heat-resistant plastic parts, mold temperature should take 60-80 degrees.

Chemical and physical properties: ABS is, butadiene and styrene of three monomers synthesized from acrylonitrile. Each of the monomers having different characteristics: acrylonitrile high strength, thermal stability and chemical stability; butadiene have toughness and impact resistance properties; styrene easy processing, high-quality finish and high strength. Morphologically, ABS is an amorphous material. Polymerization of three monomers produces a terpolymer having two phases, a styrene - acrylonitrile continuous phase, and the other is a polybutadiene rubber dispersed phase. The properties of ABS depends on the ratio of the monomers and the molecular structure of the two phases. This allows great flexibility in product design, and the resulting market hundreds of different quality ABS material. These different quality materials offer different characteristics, such as moderate to high impact resistance, from low to high finish and high heat distortion characteristics. ABS material with superior ease of processing, appearance, low creep and excellent dimensional stability and high impact strength.

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Characteristics of transparent plastic material commonly used in the injection molding process and (b)

(IV) injection molding process should pay attention to the issues (including the requirements of the injection molding machine)

In order to reduce internal stress and surface quality defects in the injection molding process should pay attention to the following aspects of the problem.

a) should be used as the special screw with a separate temperature control nozzle of the injection molding machine;

b) injection temperature plastic resin does not decompose under the premise, to use the high humidity injection;

c) Injection pressure: generally higher in order to overcome the melt viscosity of the defect, but the pressure is too high will produce stripping difficulties caused by internal stress and deformation;

d) Injection speed: In the case of filling meet, generally should be low, it is best to use a slow-fast and slow multi-stage injection;

e) dwell time and molding cycle: to meet product filling, no depression, the case of the bubble; should be kept short to minimize melt residence time in the barrel;

f) screw speed and back pressure: Under the premise of quality to meet the plastics should be as low as possible to prevent degradation of the possible;

g) Mold temperature: cooling products good or bad, a great impact on the quality, so the mold temperature must be able to precisely control the process, if possible, some good mold temperature should be high.

Issue (5) other aspects of

Because you want to preventing the deterioration of the surface quality, minimize the use of general injection molding release agent; when the use of regrind shall not exceed 20%. Except for the outside pet, after the products should be treated to eliminate stress, pmma should at 70-80t hot air circulation drying 4 hours; pc should be in clean air, glycerol. Liquid paraffin and other heating 110-135 ℃, time according to the product, the highest need more than 10 hours. The pet must biaxial stretching step, in order to obtain good mechanical properties.

Third, transparent plastic injection molding process

(A) process characteristic transparent plastic: In addition to these common problems, also have some processes transparent plastic properties, are summarized as follows:

1, process characteristics pmma the pm-ma viscosity, somewhat less liquidity, and therefore must be high temperature materials, high injection pressure injection job, which affect the injection temperature is greater than the injection pressure, but the injection pressure is increased, it will help to improve shrink products rate. Injection wide temperature range, the melting temperature of 160 ℃, decomposition temperature of 270 ℃, material temperature and therefore wide adjustment range, the process better. Therefore, to improve mobility, we can proceed from the injection temperature. Poor impact resistance, good abrasion resistance, easy to draw flowers, easy to rattle, it should raise the mold temperature, improve the condensation process, to overcome these deficiencies.

2, the technical characteristics of pc pc viscosity, high melting temperature materials, poor mobility, must therefore be at a higher temperature injection (between 270-320 ℃), the material temperature adjustment range is relatively narrow, technology is not as good as pmma. Injection pressure has little effect on liquidity, but the viscosity, still larger injection pressure, corresponding to prevent stress, dwell time should be as short as possible. Shrinkage, dimensional stability, but a large internal stress, easy to crack, it is appropriate to raise the temperature rather than pressure to improve fluidity, and improving the mold temperature, mold structure and to improve the post-processing to reduce the possibility of cracking. When the low injection speed, the gate prone to defects such as corrugations, radiation nozzle temperature to be controlled separately, mold temperature is higher, the flow channel, gate resistance is smaller.

3, the technical characteristics of pet pet molding temperature is high, and the material temperature adjustment range is narrow (260-300 ℃), but after melting, good liquidity, so the process is poor, and often at a nozzle extension to be added to the anti-flow devices. Mechanical strength and performance after the injection is not high, we must in order to improve performance and modified by stretching step. Precise mold temperature control, to prevent warping, distortion of the important elements back to back this proposal hot runner mold. Official high mold temperature, otherwise it will cause poor surface gloss and stripping difficulties.

Fourth, transparent plastic parts defects and solutions

 (A) silver streaks: from filling and condensation process, the internal stress anisotropy effects of stress generated by the vertical direction, so that the resin flow occurs on orientation, while non-current orientation and produce different refractive index and raw silk flash pattern, when After its expansion, may make the product cracks. In addition to the injection molding process and mold note, the best products for annealing. As pc material can be heated to above 160 ℃ holding 3-5 minutes, then natural cooling can be.

(B) bubble: Master in moisture and other gases within the resin did not break out, (in the mold condensation process) or because of insufficient filling, excessive condensation condensing surface and form a "vacuum bubble."

(C) the surface gloss difference: mold roughness, on the other hand the condensation too early, so that the resin can not copy the state of the mold surface, all of which make the surface uneven produce small concave strike, leaving the products lose their luster.

(d) shock pattern: refers to intensive ripple from the center sprue formed, the reason because the melt viscosity is too large, front-end material has been condensed in the cavity, then break through this material and condensing surface, leaving the surface shock pattern ʱ??

(E) white, fog halo: mainly due to the fall in the dust in the air into raw material or feedstock caused by too much moisture.

(f) white smoke, black spots: mainly due to the plastic barrel, due to local overheating of the machine and produce resin cylinder formed by the decomposition or deterioration.

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Characteristics of plastic commonly used in transparent materials and injection molding process (a)

Because plastic is light weight, good toughness, molding and easy. Low cost, and therefore in the modern industrial and household products, more and more plastic instead of glass, especially for optical instruments and packaging industry, develop rapidly. However, due to its transparency requirements better, higher abrasion resistance, impact toughness is better, so the plastic components, injection of the process technology, equipment, molds, they have made a lot of work to ensure that they be used instead of glass plastic (hereinafter referred to as transparent plastic), good surface quality, so as to achieve the requirements of use.

Currently on the market transparent plastic commonly used are poly (methyl methacrylate) (commonly known as acrylic or Plexiglas, codenamed pmma), polycarbonate (code pc). Polyethylene terephthalate resin (codenamed pet), transparent nylon. as (acrylonitrile-styrene copolymer), polysulfone (codenamed psf), of which we have the most contact is pmma, pc and pet three plastic, because of space limitations, the following three plastic as an example to discuss Characteristics of transparent plastic and injection molding process. A transparent plastic properties of transparent plastics must first have a high transparency, and secondly to have a certain strength and wear resistance can impact resistance, heat resistance and better, excellent chemical resistance to water absorption should be small, the only way to use , and can meet the requirements of transparency and long-term deformation

Second, transparent plastic injection molding process should pay attention to common problems

Transparent plastic due to high light transmittance, a necessary requirement the plastic surface strict quality requirements, can not have any markings, pores, whitening. Halo fog, black spots, discoloration, poor gloss and other defects, and thus the entire injection molding process for raw materials and equipment. Mold, and even product design, we must pay great attention to and propose strict and even special requirements. Second, because the transparent plastic, mostly high melting point, poor mobility, so as to ensure the surface quality of the products, often in machine high temperature, injection pressure, injection speed and other parameters for fine adjustments to make when both full of plastic injection molding, without It will produce internal stress caused by deformation and cracking products.

Here its preparation of raw materials. Requirements for equipment and tooling, raw material injection molding process and product handling aspects, to talk about the matter should be noted.

Preparation and drying (a) the raw material at any point because it contains impurities in plastics, are likely to affect the transparency of the product, so the storage, transportation, feeding process, we must pay attention to the seal, to ensure a clean raw material. Especially raw materials containing water, can cause deterioration of raw materials is heated, so be sure to dry, and at the time of injection, the feeding must use the drying hopper. Also note that the drying process, the air inlet should preferably be filtered, dehumidified to ensure that does not contaminate raw materials.

(Ii) Clean barrel, screw and its annexes to prevent contamination of raw materials and there are old material or impurities in the screw and accessories depression, especially poor thermal stability of resin exist, so before use, screw cleaning agents are applied after the shutdown clean all parts, so that it can not stick with impurities, when there is no screw cleaning agent, available pe, ps and other resin cleaning screw. When the temporary shutdown, in order to prevent material at high temperatures to stay a long time, causing degradation should be drier and barrel temperature decreases, such as pc, pmma, etc. barrel temperature should be reduced to below 160 ℃. (Hopper temperature for pc should be reduced to below 100 ℃)

(C) the issue in the mold design should pay attention (including product design) in order to prevent back flow of poor or uneven cooling caused by bad plastic molding, surface defects and deterioration in general in the mold design should note the following points. a) wall thickness should be uniform, stripping slope be large enough;

b) should be gradually transition. Smooth transition to prevent any sharp corners. Produce sharp edges, especially pc product must not have a gap;

c) gate and runner as large, chunky, and the location of the gate should be set according to the contraction condensation process, if necessary add cold material well;

d) the mold surface should be smooth, roughness low (preferably less than 0.8);

e) vent grooves must be sufficient, and when the exhaust gas in the air and melt;

f) In addition to pet, the wall thickness of not too thin, usually not less than 1mm.

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Plastic product classification (according to the physicochemical properties of classification)

Classified by physicochemical properties

    According to a variety of different physical and chemical properties of plastic, you can put plastic into thermosetting plastics and thermoplastic plastics types.

    ⑴ thermosetting plastics

    It refers thermosetting plastics under heat or other conditions can be cured or with insoluble (melt) plastic characteristics, such as phenolics, epoxy plastic. Thermosetting plastic was divided formaldehyde cross-linking and other cross-linking of two types. When heated to soften, harden when cooled, can repeatedly soften and harden and maintain a certain shape. Soluble in certain solvents, having a fusible soluble nature. Thermoplastics with excellent electrical insulation properties, in particular polytetrafluoroethylene (PTFE), polystyrene (PS), polyethylene (PE), polypropylene (PP) has a very low dielectric constant and dielectric loss, should for use as a high-frequency and high-voltage insulation material. Thermoplastic easy molding, but low in heat resistance, easy to creep, with the degree of creep under load, the ambient temperature, the solvent, the humidity varies. To overcome these weaknesses thermoplastics, meet the need of space technology, new energy development and other fields, countries are developing melt molding heat-resistant resin, such as polyether ether ketone (PEEK), polyether sulfone (PES) , polyarylsulfone (PASU), polyphenylene sulfide (PPS) and the like. To them as a matrix resin composite material having high mechanical properties and chemical resistance, thermoforming and welding between energy, interlaminar shear strength is better than epoxy resin. As with PEEK as a matrix resin and carbon fiber composite materials, the fatigue resistance than epoxy / carbon fiber. Its good impact resistance, excellent creep resistance at room temperature, process, and can be used continuously at 240 ~ 270 ℃, it is an ideal high temperature insulation material. It has high strength and hardness at 200 ℃ with PES as a composite material matrix resin and carbon fibers, at -100 ℃ can still maintain good impact resistance; non-toxic, non-flammable, fuming at least, radiation resistance Well, the key components for the spacecraft is expected to use it, but also molding into a radome and the like.

    Formaldehyde-crosslinked plastics include phenolics, aminoplasts (such as urea - formaldehyde - melamine - formaldehyde, etc.).

    Other cross-linked plastics include unsaturated polyesters, epoxy resins, diallyl phthalic acid resins and the like.

    ⑵ thermoplastic plastic

    Refers to thermoplastic plastics can be repeatedly softened by heating and hardened by cooling of the plastic, such as polyethylene, polytetrafluoroethylene or the like within a specific temperature range. Thermoplastic plastic was divided hydrocarbons, vinyl containing polar gene engineering, cellulose and other types. After thermo-forming insoluble infusible form a cured resin molecules by the linear structure of its cross-linked into a network structure. Thermal decomposition will again strengthen damage. Typical phenolic thermosetting plastic, epoxy, amino, unsaturated polyesters, furan, polysiloxane and other materials, as well as newer polyethylene phthalate and propylene carbonate plastic or the like. They have high heat resistance, heat easily deformed and so on. The disadvantage is that the mechanical strength is generally not high, but by adding fillers, made of laminate or molding material to improve its mechanical strength.

  Phenolic resin as the main raw material of thermosetting plastics, such as phenolic molded plastic (commonly known as Bakelite), with a durable, dimensionally stable, resistant to other chemicals in addition to strong base effects and other characteristics. According to different purposes and requirements, the addition of various fillers and additives. Such as requiring high insulation performance of varieties, can be mica or glass fiber as filler; to resistant varieties, may be asbestos or other heat-resistant filler; species such as seismic requirements, various appropriate fiber or rubber filler and a number of toughening agent to produce high toughness materials. Further aniline may also be used, epoxy, polyvinyl chloride, polyamide, polyvinyl acetal-modified phenolic resin, etc. to meet the requirements of different applications. It can also be made with phenolic resin phenolic laminate, which is characterized by high mechanical strength, good electrical properties, corrosion resistance, easy processing, widely used in low-voltage electrical equipment.

  Aminoplast have urea formaldehyde, melamine-formaldehyde, melamine urea formaldehyde. They have a hard, scratch-resistant, colorless, translucent, etc., can be added to products made of bright color pigment, commonly known as Bakelite. Because of its oil, affected by the weak base and an organic solvent (but not acid), long-term use at 70 ℃, short-term resistant to 110 ~ 120 ℃, can be used electrician products. Melamine formaldehyde plastic plastic hardness than urea formaldehyde, have better water resistance, heat resistance, arc resistance, arc resistant insulating material can be used.

  Epoxy resin as the main raw material of thermosetting plastic varieties, many of them with a bisphenol A type epoxy resin as a base of about 90%. It has excellent adhesion, electrical insulation, heat resistance and chemical stability, shrinkage and water absorption, good mechanical strength and other characteristics.

  Unsaturated polyester and epoxy resins can be made of glass steel, it has excellent mechanical strength. Such as unsaturated polyester, glass, steel, good mechanical properties, low density (only 1/5 to 1/4 of steel, aluminum, 1/2), easily processed into a variety of electrical components. Electrical and mechanical properties of plastics to phthalate acrylate resin are better than phenolic and amino thermoset plastic. It is hygroscopic small, products dimensional stability, good moldability acid and boiling water and some organic solvents. Molding plastic suitable for manufacturing complex structure, both have high temperature insulation parts. Usually long-term use in the temperature range of -60 ~ 180 ℃, the heat levels up F grade to H level, higher than the phenolic and amino plastic heat resistance.

  Polysiloxane structure in the form of silicone plastic used more often in Electronics & Electrical Technology. Silicone laminated plastic over glass cloth as reinforcement material; silicone molded plastic over glass fibers and asbestos packing, for the manufacture of high temperature, high or submersible motors, electrical appliances, electronic equipment parts. Such plastics are characterized by a small dielectric constant and tgδ value, by the frequency of small, for electricians and electronics industry corona resistance and arc discharge even cause decomposition, the product is capable of conducting silica rather than carbon black ʱ?? Such materials have outstanding heat resistance, can be used continuously at 250 ℃. The main disadvantage of polysiloxane is low mechanical strength, adhesiveness small, oil poor. Has developed a number of modified silicone polymers, such as plastics, polyester-modified silicone technology has been applied in the electrician. Some plastic both thermoplastic and thermosetting plastics. Such as polyvinyl chloride, usually thermoplastics, Japan has developed a new type of liquid PVC is thermosetting molding temperature of 60 ~ 140 ℃; Lund plastic American called Alex, both thermoplastic processing features, there are the physical properties of thermoset plastics.

    ① hydrocarbon plastics. Is a non-polar plastics, crystalline and non-crystalline points, crystalline hydrocarbon plastics include polyethylene, polypropylene, non-crystalline hydrocarbon plastics, including polystyrene and the like.

    ② vinyl plastic containing polar gene. Fluorine plastic, most non-crystalline transparent body, including polyvinyl chloride, polytetrafluoroethylene, polyvinyl acetate and the like. Most vinyl-based monomer may be polymerized using a free radical catalyst.

    ③ engineering thermoplastics. Including polyoxymethylene, polyamide, polycarbonate, ABS, polyphenylene oxide, polyethylene terephthalate, polysulfone, polyether sulfone, polyimides, polyphenylene sulfide and the like. Polytetrafluoroethylene. Modified polypropylene or the like are also included in this range.

    ④ thermoplastic cellulose-based plastics. It includes cellulose acetate, cellulose acetate butyrate, celluloid, cellophane and the like.

Third, according to the processing method of classification

    According to the different kinds of plastic molding methods can be divided into membrane pressure, lamination, injection, extrusion, blow molding, reaction injection molding plastics and other types of plastic.

    Membrane pressure, mostly plastic processing performance and general properties similar to solid plastic plastic; laminated plastic means of fabric impregnated with resin, the laminated, hot materials incorporated as a whole; injection, extrusion and blow mostly plastic properties and processability of thermoplastics with generally similar plastic; means capable of molding plastic under no pressure or little pressure, poured in a mold shaped article can harden into a liquid resin mixture, such as MC nylon; Reaction Injection plastic material with a liquid, the membrane cavity injection pressure, and allowed to react solidified into shaped articles of plastic, such as polyurethane or the like.

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Plastic products category (by using the characteristics of classification)

First, by using the characteristics of classification

Plastic Product Categories

    According to name different types of plastics used feature, usually plastic into common plastics, engineering plastics and specialty plastics three types.

    ① GE Plastics

    Generally refers to the production of large, versatile, forming a good, cheap plastic. GE Plastics has five varieties, namely polyethylene, polypropylene, polyvinyl chloride, polystyrene and ABS. They are thermoplastics.

    ② plastic

    Generally it refers to can withstand external force, has good mechanical properties and resistance to high and low temperature properties, good dimensional stability, can be used as plastics engineering structures, such as polyamide, polysulfone and the like.

    In turn divided into general-purpose engineering plastics engineering plastics and special engineering plastics into two categories.

    General engineering plastics include: polyamides, polyoxymethylene, polycarbonate, modified polyphenylene ether, thermoplastic polyester, ultra high molecular weight polyethylene, methylpentene polymer, vinyl alcohol copolymer.

    Special engineering plastics have crosslinked non-crosslinked type of points. Crosslinked include: polyamino bismaleamic, poly triazine, crosslinked polyimide, heat-resistant epoxy resin and other means. Non-crosslinked include: polysulfone, polyether sulfone, polyphenylene sulfide, polyimide, polyether ether ketone (PEEK), etc.

    ③ special plastic Dongguan, Dongguan website design Dongguan website construction site promotion site optimization Dongguan Dongguan high Po site construction Liaobu Dongguan Dongcheng site construction site construction site construction Dasan Dongguan Shijie Shilong Dongguan website construction site construction site construction Houjie Dongguan Ridge Hill site construction Zhangmutou Tangxia site construction site construction site construction Maoming Maoming Maoming site design site promotion Shenzhen printing stickers printed Shenzhen, Dongguan, Dongguan printing business card printing

    Generally refers to a special function, it can be used for plastic aviation, aerospace and other special applications. Such as fluorine plastic and silicone has outstanding high temperature, self-lubricating and other special functions, reinforced plastics and foams with special properties of high strength, high damping, these plastics are all areas of specialty plastics.

    a strong plastic: reinforced plastic material in the shape can be divided into granular (eg Gaisu reinforced plastics), fibers (such as glass fiber or glass cloth-reinforced plastic), the sheet (such as mica reinforced plastics) three. Press material can be divided Burkina reinforced plastic (such as rags to enhance or asbestos reinforced plastics), inorganic mineral-filled plastic materials (such as quartz or mica filled plastic), fiber reinforced plastics (such as carbon fiber reinforced plastics) three.

    . b Foam: Foam can be divided into rigid, semi-rigid and flexible foams three. Rigid foam no flexibility, compression great hardness, only up to a certain stress was deformed, not restitution after stress relief; soft foam full flexibility, compression hardness is small, it is easily deformed, stress relief after energy restitution, residual deformation small; hard between his soft foam semi-rigid foam between flexibility and other properties.

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