1、 Acrylonitrile butadiene styrene (ABS) (milky white, translucent)

advantage:

1. Good mechanical and thermal properties, milky white translucent, high hardness, easy to metal plating surface;

2. Fatigue resistance, stress cracking resistance and high impact strength;

3. Resistant to acid and alkali corrosion;

4. It is easy to form and modify.

Disadvantages:

1. Poor weather resistance; 2. Poor heat resistance; 3. Low tensile rate.

Main application scope: machine cover, cover, instrument case, electric hand drill shell, fan impeller, radio, telephone and TV shell, some electrical parts, automobile parts, machinery and conventional weapon parts.

Modified ABS copolymer:

Adding ABS into PVC can improve its impact toughness, flame retardancy, aging resistance and cold resistance, and improve its processability.

The impact strength and heat resistance of ABS can be improved by blending ABS with PC; MBS plastic, commonly known as transparent ABS, can be prepared by replacing acrylonitrile component in ABS with methyl methacrylate.

ABS/NYLON：

Heat and chemical resistance, good fluidity, low temperature impact and low cost;

It is mainly used for automobile body guard board, engine room components, connector and power tool shell.

ABS/PVC：

PVC increases fire resistance, reduces cost and ABS provides impact resistance;

It is mainly used for components of household appliances and transaction machines.

ABS/PC：

It can increase the dimensional stability of ABS, improve the low temperature and impact resistance of PC, and reduce the cost;

It is mainly used for typewriter shell, word processor, computer equipment shell, medical equipment components, small household appliances components, electronic equipment components, automobile headlamp frame, tail lamp cover, food plate.

ABS/SMA：

Increase heat resistance, fluidity and good coating performance;

It is mainly used for electronic components, covers and household appliances.

mould design 

1. Exhaust. In order to prevent the defects such as poor exhaust, burning and fusion joint during mold filling, it is required to set up an exhaust groove with a depth of no more than 0.04mm;

2. The wall thickness is between 0.8 mm and 3.2 mm, and the typical wall thickness is about 2.5 mm, and above 3.8 requires structural foaming;

3. The minimum fillet is 25% of the thickness and the most appropriate radius is 60% of the thickness;

4. Shrinkage: 0.4% - 0.7%, generally 0.5%;

5. Stiffener: height < 3T width 0.5T rib spacing > 2T demoulding angle: 0.5 ° - 1.5 °;

6. The height of the column stiffener is 4T, which can reach 90% of the height of the column, the width is 0.5T, and the length is 2T. The outer diameter of the column is twice the inner diameter.

2、 Polyethylene (PE)

advantage:

1. Soft, non-toxic, transparent and easy to dye; 2. Impact resistance, drug resistance, good insulation.

Disadvantages:

1. It is not easy to eject and fit; 2. High coefficient of thermal expansion; 4. Poor temperature resistance.

Purpose:

HDPE is mainly used in occasions with certain hardness and toughness, such as water pipe, gas pipe, industrial chemical container, heavy packing bag and shopping bag, shampoo bottle, etc.

LDPE is mainly used in insulator, hose, tape, film and agricultural film.

Minimum wall thickness 0.5mm (LDPE), 0.9mm (HDPE) (0.5-7.6mm, generally 1.6mm)

Shrinkage: 2% for HDPE 1.5% - 3.5%, 1.5% for LDPE 1.5% - 3%.

3、 Polypropylene (PP)

advantage:

1. Translucent, rigid, ductile, high bending strength, fatigue resistance and stress cracking resistance;

2. Light weight, non-toxic, tasteless, high temperature resistance, good insulation. （0.9G/cm3）

Disadvantages:

1. It is easy to be brittle and not easy to join under 0 ℃;

2. Poor weather resistance, easy to be decomposed and oxidized by ultraviolet rays;

3. Large shrinkage (1% - 3%), poor dimensional stability, not suitable for making high-precision parts.

Wall thickness: 0.6mm-7.6mm, generally 2mm.

Purpose:

Chemical container, washbasin, pipeline, pump impeller, joint, rope, packing belt, transparent bottle, insulating material, automobile accessories.

Mold design:

1. The molding shrinkage rate is large, so when choosing the gate position, the melt should be filled in the mold cavity in a more balanced flow order to ensure that the shrinkage of the products in all directions is consistent;

2. For the products with hinge, attention should be paid to the selection of gate position, and the flow direction of melt should be perpendicular to the axis line of hinge;

3. Due to the good fluidity of PP, the depth of exhaust groove should not exceed 0.03mm.