Intro to Injection molding - Brass knurled thread Bergek CNC

ABS plastics are one of the five major synthetic resins: Its impact resistance, heat resistance, low-temperature resistance, chemical resistance, and excellent electrical performance, but also has easy processing, product size stability, good surface gloss, and other characteristics, easy to paint, coloring, but also can be surface spray metal, electroplating, welding, hot pressing, and bonding, and other secondary processing, Widely used in machinery, automobile, electronic appliances, instrumentation, textile and construction, and other industrial fields, is a very wide range of thermoplastic engineering plastics.

ABS plastic molding features:

1, amorphous material, medium fluidity, high moisture absorption, must be fully dry, surface gloss plastic parts must be preheated for a long time drying 80-90 degrees,3 hours;

2, suitable for high material temperature, high mold temperature, but the material temperature is too high easy to decompose (decomposition temperature is >270 degrees). For high precision plastic parts, mold temperature suitable for 50-60 degrees, high gloss. Heat resistant plastic parts, mold temperature suitable for 60-80 degrees;

3, if you need to solve the water clamp, you need to improve the fluidity of the material, take high material temperature, high mold temperature, or change the water level and other methods;

4. If heat resistant or flame retardant materials are formed, plastic decomposition will remain on the surface of the mold after 3-7 days of production, resulting in a shiny surface of the mold. It is necessary to clean the mold in time and increase the exhaust position on the surface of the mold;

5, the cooling speed is fast, the mold pouring system should be thick, short as the principle, it is appropriate to set up the cold hole, the gate is suitable for large, such as direct gate, disk gate or fan gate, but should prevent the increase of internal stress, when necessary, can use the adjustment gate. The mold should be heated, wear-resistant steel should be selected;

6, the material temperature has a great influence on the quality of plastic parts, material temperature is too low will cause lack of material, surface luster, silver disorder, material temperature is too high easy to overflow edge, silver dark strip, plastic parts change color bubbles;

7, the mold temperature has a great influence on the quality of plastic parts. When the mold temperature is low, shrinkage, elongation, impact strength, bending, compression, and tensile strength are low. When the mold temperature is more than 120 degrees, the cooling of plastic parts is slow, easy to deform and stick, demolding is difficult, and the molding cycle is long.

8, forming shrinkage rate is small, easy to melt cracking, stress concentration, so molding should be strictly controlled molding conditions, molding plastic parts should be annealed;

9, the melting temperature is high, the viscosity is high, the shear action is not sensitive, for more than 200 grams of plastic parts, should be used screw injection machine, the nozzle should be heated, should use open type extension nozzle, injection speed in high speed.

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