Precision injection molding and the common points of precision injection molding

Precision injection molding and the common points of precision injection molding

The characteristics of precision injectionmolding is: the size of the injection molded parts with high precision, small tolerance. To achieve the requirements of precision injection conditions must be met:

(1) the mold material is better, rigid, cavity dimension precision and template between positioning accuracy is higher, lower surface roughness.

(2) to adopt precision injection molding machine.

(3) to adopt precision molding process. (

4) to choose suitable for precision injection molding process of the material. Commonly used precision injection molding materials have several: POM, POM = CF (carbon fiber), PNM = GF (glass fiber), PA \ FRPA66 (enhanced PA), PC, etc.

Precision injection process can ensure the size precision injection molding is the important way to control the shrinkage of injection molded parts, including: thermal contraction, disguised contraction of molded parts, orientation and compressed contraction and elastic recovery.

Common injection molding features are: precision is not high, the size of injection molded parts are typically can be assembled into standard, requirements for the appearance of the injection molded parts is relatively high, if necessary, may use the second processing (oil, for example) to improve the appearance of defects. Ordinary injection molding don't need to use special precision injection molding machine, also do not need to specially designated materials, general common thermoplastics can be used to production. So ordinary injection molding technology is widely used in modern plastic industry.

more information www.chinamoldmaker.org  www.plastic-injectionmoulding.com

electrical and electronic engineering plastics application

electrical and electronic engineering plastics application

Compared with general plastics, engineering plastics has more excellent mechanical properties, electrical properties, chemical resistance, heat resistance, abrasion resistance, dimension stability, etc; Compared with metal materials, engineering plastics has the advantages of light weight, small energy consumption when molding. Engineering plastics has become the world's plastics industry developing the fastest growing materials

In Asia, engineering plastics are mainly used in electrical industry, more than 50%, and in Europe and the United States, engineering plastics are mainly used in automotive industry. From 1998 to 1998 China engineering plastics consumption annual average increase rate of 26% (see chart 1). Is expected in the next few years the growth rate of 15% ~ 18%. As China's electrical products exports increased year by year, the dosage of the engineering plastics is on the rise. Although the current domestic product technology content and added value is very low, but this does not affect the huge demand for engineering plastics manufacturing. Under cost pressure, requirement for material localization is more and more obvious, which provides a broad prospect of application for engineering plastic.

Commonly used on electrical and electronic engineering plastics

1. The PA (nylon)

PA is characteristic of good toughness and high mechanical strength, wear resistance, but easy bibulous deformation. Mainly used in the manufacture of machine tools in electrical and electronic appliances, air switches, connectors, all kinds of coil skeleton; Tape recorder, video camera, video camera, DVD, OA equipment, machine core, skeleton, supporting parts, gear, wheel; As well as the cable bracket, brace, gear, wheel; And the cable sheath, household appliances, small appliances, etc.

2. PC (polycarbonate)

The advantage of PC is transparent, high impact strength, good mechanical strength, size stability. Drawback is not resistant to solvents, easy to produce stress cracking. Mainly used in the transparent parts of the electrical appliances (such as window, shell, panel, etc.).

PC/ABS alloy is more used in electrical appliances shell, display case, mobile phone shell, shell, batteries, laptop charger shell; Cable connector, OA equipment and small home appliance products.

3. The POM (POM)

POM has superior mechanical properties. Wear resistance and size stability, resistance to chemical corrosion, fatigue resistance, but poor thermal performance, flammable easy decomposition, notch sensitivity. Mainly used in electrical appliances, instrument structure, all kinds of gear, CAM, driving wheel, the recording tape axis core, floppy disks, the doors of machine tool electrical appliances.

more information www.chinamoldmaker.org www.plastic-injectionmoulding.com

What is called a precision injection molding

What is called a precision injection molding?

Precision injection molding, strictly speaking, refers to by injection molding machine equipment to produce the dimension precision of plastic products, can achieve below 0.01 mm, usually between 0.01 ~ 0.001 mm a way of injection molding production. "Precision injection molding" this concept, main is different from the conventional injection molding, with the rapid development of polymer materials and microelectronics technology, highly integrated electronic circuit, make industrial equipment parts gradually for the development of high-performance, high precision, lightweight, miniaturization and miniaturization. This precision plastic parts for compliance with the requirement of high precision, and at the same time have good machinery, mechanical properties and dimensional stability, etc, in machinery, electronics, instrumentation, communications, automotive and aerospace instrumentation and other industries fields, replaced the part precision metal parts and has been widely applied. By the definition of precision injection molding, precision plastic pieces of the size of the tolerance range is very narrow. And, in fact, the plastic molding industry recognized, when the size of the plastic parts of tolerance is under 0.1 mm, or size of plus or minus tolerance is under 0.1 mm parts, precision molding, can be called the size tolerance of parts reach micron grade, may call it super precision injection molding.

Plastic key features

Plastic key features:

① most plastic lightweight, chemically stable, will not rust;

② good impact resistance;

③ has good transparency and abrasion resistance; ④ insulation, and low thermal conductivity;

⑤ general formability, good color, low processing costs;

⑥ most plastics poor heat resistance, thermal expansion, easy to burn;

⑦ poor dimensional stability, easily deformed;

⑧ most plastics poor low temperature resistance, low temperature brittle;

⑨ easy to aging;

⑩ certain plastics soluble in solvents.

Plastics can be divided into two types of thermosetting and thermoplastic, the former can not be re-shape to use, which can be repetitive.

Plastic polymer structure, there are two basic types:

The first is a linear structure, a polymer compound having such a structure is called a linear polymer compound;

The second body structure is a polymer compound having such a structure is called a polymer compound body. Some polymer having a branched chain, a branched polymer known as belonging to the linear structure. Although some polymer intermolecular crosslinking, but crosslinking less known network structure, body structure belongs.

Two different structures, showing two opposite properties. A linear structure (including the branched chain structure) of the polymer molecules due to the presence of a separate, and therefore, flexibility, plasticity, can be dissolved in a solvent, the heating can be melted, the hardness and brittleness of smaller features. Since there is no independent body structure of polymer macromolecules exist, so there is no elasticity and plasticity, can not dissolve and melt, only swelling, hardness and brittleness. Polymer plastic has the two structures, made ​​by the linear polymer is a thermoplastic plastic, a polymer made ​​by the body are thermosetting plastics.

Compared with other plastic materials

<1> resistance to chemical attack

<2> shiny, partially transparent or translucent

<3> is a good insulator mostly

Light <4> weight and sturdy

<5> can be processed easily mass-produced, inexpensive

<6> versatile, multi-utility, easy coloring, and some high-temperature plastic is also divided into pan with plastic and plastic, the main purpose is to define the breadth, such as PE, PP cheap, available in a variety of different types of production of the machine. Plastic is more expensive, but raw material stability

And physical properties are much better, in general, it also has two characteristics of rigidity and toughness.

Plastic advantages:

  1, most of the plastic of the corrosion resistance, strong acids, bases and the reaction is not.

2, low-cost plastic.

3, durable, waterproof, lightweight.

4, easy to be made ​​into different shapes of plastic.

5, is a good insulator.

6, the plastic can be used in the preparation of fuel oil and fuel gas, which can reduce oil consumption.

Disadvantages of plastic

1, the recycling of waste plastics, classification is very difficult and economically viable.

2, plastic is easy to burn, produce toxic gases when burned. Such as polystyrene produced during combustion of toluene, a small amount of this substance can cause blindness, vomiting and other symptoms of inhalation, PVC burning will produce toxic hydrogen chloride gas, in addition to burning, is a high temperature environment, will lead to plastics decompose toxic ingredients, such as benzene and so on.

3, the plastic product is made ​​of petroleum refining, petroleum resources are limited.

4, the plastic can not be natural decomposition. 

more information www.plastic-injectionmoulding.com www.chinamoldmaker.org 

Injection operator processing requirements

Injection operator processing requirements

A, plastic product quality requirements

1, the injection forming of product, must ensure that the product structure is complete, there is no less material, more material phenomena.

2, product surface bright, uniform chromaticity, full.

3, product surface is not filled with flowers, impurities, defects such as black spots.

4, the product shape neat, there is no deformation, distortion, and the internal products are obvious bubble phenomenon.

5, the product can cooperate with relevant parts is normal, without external force cannot be separated.

6, the assembled product to need, after assembling the operators need to introspection, to ensure that products meet quality requirements. There is no

Not installed in place, packing, and have a fracture phenomenon.

Second, the plastic products trimming

1, the product of the inlet with trimming knife cutting, cutting mouth who can not have express white appearance.

2, when trimming knife trimming, forcibly when repairing products shall repair products outside introversion, resistance force direction is not allowed to have another hand

Block.

3, product trim on the handle of the strength should be uniform, can guarantee a hard cut products as much as possible, long group of front, middle

Not stagnation, a fix to the end, to ensure that after trimming the edges of the beautiful appearance.

4, the surface of the product by trimming does not allow defects wavy lines and uneven.

5, to remove the inlet area, trimming should level off, allow the phi 10 from minor scratches, trimming to improper

Other parts are not allowed to have should be trimming undeserved cause scratch defect.

6, to put front height is greater than 0.2 mm should be handled for trimming (unless adjust injection parameters to solve), especially in the production

Product outline on the edge of the phi front must be removed.

7, for different products, it is suggested that should use different types of trimming knife, to ensure product quality, improve the efficiency of trimming. 8, don't allow should trim other qualified on the surface of the damage caused by improper operation (such as good surface scratch, cut, etc.).

Three, product storage and handling

1, product stacked on the pallet height should not exceed 1.2 mm, the number of the same specifications each building products must be the same, with winding mode finally. For small products in the turnover box, bottom in turnover box height should be 10 cm, turnover box the loading weight of not more than 25 kg.

OEM PVC Plastics Injection Molding

OEM PVC Plastics Injection Molding

The molded products’ material can be PP, PA, POM, ABS, PET, PC, PE, PA66+GF, PVC, TPE,PC+ABS and so on.

Mold base adopt the standard of LKM / HASCO /DME etc.

Mold material:P20, 738, 738H, 718, 718H, NAK80, 2344, 8407, SKD61, S136 etc.

Surface treatment of the mold: polishing and grain surface

Cavity type: single cavity or multiple cavities

Runner system: hot runner and cold runner

Dimension of the mold: can be made by customers designs

Mold life: 300,000 shots

Designed software: UG, CAD, PROE

Mold process: CNC / Cutting / Carved / EDM/Milling/Threading/Drilling, etc.

Arrangement type: I-section / Straight Body Mould

Project developing procedure:DFM—- 2D structure design—-3D design—–mold machined and processed—-testing –delivery

Injection molding is a manufacturing process for producing parts from both thermoplastic and thermosetting plastic materials. Materials is fed into a heated barrel, mixed and forced into a mold cavity where it cools and hardens to the configuration of the cavity.

Injection molding is widely used for manufacturing a variety of parts from the smallest component to entire body panels of cars.

It can be used from home appliance to electronic parts.

CNMOULDING Mold is competent in offering a wide scope of injection molding service to customers. We can meet your specific requirements in terms of material, size, complexity and volume.

The advantages of CNMOULDING injection molding are:

1. high molding speed adapted for mass production.

2. multiple choices of thermoplastic material, can provide a variety of useful properties.

3. large productivity for mold threading, undercutting, holes drilling

4. within 24 hours reply and timely reply

5. competitive price and reasonable designs