ABS plastic

(Acrylonitrile-butadiene-styrene)

English name: Acrylonitrile Butadiene Styrene

Specific gravity: 1.05 g/cm3 Molding shrinkage: 0.4-0.7% Molding temperature: 200-240 C Drying conditions: 80-90C 2 hours

Material properties

1. Good overall performance, high impact strength, chemical stability, good electrical properties.

2. Good welding with 372 organic glass, made into two-color plastic parts, and can be chrome-plated and painted on the surface.

3. There are high impact resistance, high heat resistance, flame retardant, reinforced, transparent and other levels.

4. The fluidity is slightly worse than HIPS, better than PMMAPC, and good flexibility.

Suitable for making general mechanical parts, wear-reducing and wear-resistant parts, transmission parts and telecommunication parts.

Molding performance

1. Amorphous materials have medium fluidity and high moisture absorption. They must be fully dried. Plastic parts that require gloss on the surface must be preheated and dried for a long time at 80-90 degrees for 3 hours.
2. It is advisable to use high material temperature and high mold temperature, but the material temperature is too high and it is easy to decompose (the decomposition temperature is > 270 degrees). For plastic parts with higher precision, the mold temperature should be 50-60 degrees, and for high gloss and heat-resistant plastic parts, the mold temperature should be 60-80 degrees.
3. If you need to solve the problem of water marks, you need to improve the fluidity of the material, use high material temperature, high mold temperature, or change the water level, etc.
80-90 C 2 hours

4. If forming heat-resistant or flame-retardant materials, plastic decomposition products will remain on the mold surface after 3-7 days of production, resulting in mold
The surface is shiny, the mold needs to be cleaned in time, and the exhaust position needs to be increased on the mold surface.

PS plastic

(Polystyrene)

POM plastic

(Polyoxymethylene)

English name: Polyoxymethylene (Poly formaldehyde)

Material properties

Excellent electrical insulation (especially high-frequency insulation), colorless and transparent, light transmittance second only to organic glass, colorability and water resistance, good chemical stability, average strength, but brittle, prone to stress cracking, not resistant to benzene, gasoline and other organic solvents.

Suitable for making insulating transparent parts, decorative parts and chemical instruments, optical instruments and other parts.

Molding properties

1. Amorphous material, low moisture absorption, no need for full drying, not easy to decompose, but large thermal expansion coefficient, easy to produce internal stress. Good fluidity, can be molded by screw or plunger injection molding machine.

2. It is suitable to use high material temperature, high mold temperature, low injection pressure, and extend the injection time to reduce internal stress and prevent shrinkage and deformation.

3. Various forms of gates can be used, and the gates are connected to the arc of the plastic part to avoid damaging the plastic part when removing the gate. The demoulding slope is large and the ejection is uniform. The wall thickness of the plastic part is uniform, and it is best not to have inserts. If there are inserts, they should be preheated.

PMMA plastic (plexiglass)

(Polymethyl methacrylate)

English name: Polymethyl Methacrylate

Specific gravity: 1.18 g/cm3 Molding shrinkage: 0.5-0.7% Molding temperature: 160-230 C Drying conditions:

70-90 C 4 hours

Material properties

Excellent transparency, high strength, certain heat and cold resistance, corrosion resistance, good insulation, and comprehensive performance exceeds polystyrene, but it is brittle and easily soluble in organic solvents. If used as a light-transmitting material, its surface hardness is slightly lower and it is easy to scratch.

Suitable for making transparent insulating parts and parts with general strength.

Molding performance

1. Amorphous material, high moisture absorption, needs to be dried, not easy to decompose, medium fluidity, prone to poor filling, mold sticking, shrinkage, welding marks, etc.
2. High pressure injection is recommended, and high material temperature and high mold temperature are taken without defects to increase fluidity, reduce internal stress, and improve transparency and strength. The surface of the mold casting system should be smooth, with a large demoulding slope and uniform top. At the same time, an exhaust port is set to prevent blistering.

English name: Polystyrene

Specific gravity: 1.05 g/cm3 Molding shrinkage: 0.6-0.8% Molding temperature: 170-250 C Drying conditions:
Specific gravity:
1.41-1.43 g/cm3 Molding shrinkage: 1.2-3.0% Molding temperature: 170-200 °C Drying conditions:

Square

Material properties

Good overall performance, high strength and rigidity, good wear resistance, low water absorption, good dimensional stability, but poor thermal stability, easy to burn, easy to age in the atmosphere.
Suitable for making wear-resistant parts, transmission parts, and chemical, instrumentation and other parts

Molding performance

1. Crystallized material, narrow melting range, fast melting and solidification, crystallization occurs when the material temperature is slightly lower than the melting temperature. Medium fluidity.
Low moisture absorption, no drying treatment is required.
2. Low friction coefficient, good elasticity, and wrinkle-like surface defects are easy to occur on the surface of plastic parts.
3. Very easy to decompose, the decomposition temperature is 240 degrees. Irritating and corrosive gases are generated during decomposition. Therefore, mold steel should be made of corrosion-resistant materials.

PP plastic

(polypropylene)

PE plastic

(polyethylene)

Material properties

Low density, strength, stiffness, hardness and heat resistance are better than low-pressure polyethylene, and can be used at about

100 degrees. It has good electrical properties and high-frequency insulation and is not affected by humidity, but becomes brittle at low temperatures, is not mold-resistant and is prone to aging.

Suitable for making general mechanical parts, corrosion-resistant parts

and insulating parts

Molding properties

1. Crystalline material, low hygroscopicity, prone to melt rupture, and easy to decompose when in contact with hot metal for a long time.

2. Good fluidity, but large shrinkage range and shrinkage value, prone to shrinkage holes, dents, and deformation.

3. Fast cooling speed, the pouring system and cooling system should slowly dissipate heat, and pay attention to controlling the molding temperature. The material temperature is low and the directional

is obvious. It is especially obvious at low temperature and high pressure. When the mold temperature is lower than 50 degrees, the plastic part is not smooth, and it is easy to produce poor welding and marks. It is easy to warp and deform above 90 degrees.
4. The thickness of the plastic wall must be uniform, avoiding missing glue and sharp corners to prevent stress concentration.

English name: Polypropylene

Specific gravity: 0.9-0.91 g/cm3 Molding shrinkage: 1.0-2.5% Molding temperature: 160-220 C Drying conditions:

Material properties

Corrosion resistance, electrical insulation (especially high-frequency insulation) are excellent, can be chlorinated, irradiated
modified, and can be reinforced with glass fiber. Low-pressure polyethylene has a high melting point, rigidity, hardness and strength, low water absorption, good electrical properties and radiation resistance; high-pressure polyethylene has good softness, elongation, impact strength and permeability; ultra-high molecular weight polyethylene has high impact strength, fatigue resistance and wear resistance.

Low-pressure polyethylene is suitable for making corrosion-resistant parts and insulating parts; high-pressure polyethylene is suitable for making films, etc.; ultra-high molecular weight polyethylene is suitable for making shock-absorbing, wear-resistant and transmission parts.

Molding performance

1. Crystalline material, low moisture absorption, no need for full drying, excellent fluidity, fluidity is sensitive to pressure, high-pressure injection is suitable for molding, uniform material temperature, fast filling speed, and sufficient pressure holding. Direct gates should not be used to prevent uneven shrinkage and increased internal stress. Pay attention to the selection of gate positions to prevent shrinkage holes and deformation.
2. Large shrinkage range and shrinkage value, obvious directionality, easy to deform and warp. The cooling speed should be slow, the mold should be equipped with cold material holes, and there should be a cooling system.