Where does the gas generated during injection molding come from? What are the hazards?

Injection mold is a technical work, and exhaust is also a more important problem, because hot gas is easy to be generated during molding and pouring. If it is not discharged from the mold cavity in time, it is easy to affect the quality of the mold. Therefore, exhaust during injection mold is also a more strict work.

1. Source of gas

(1) Air is left in the mold cavity itself;

(2) Some raw materials contain water that has not been removed by drying and evaporate into steam at high temperature;

(3) Gas produced by high temperature decomposition of some unstable plastics during injection molding;

(4) Some additives are volatile gases produced in plastic materials or through mutual chemical reactions.

2. Hazards of poor exhaust

If the injection molding Abrasives do not exhaust the air in time, it is easy to cause some damage to the quality of the object. Generally, there are the following manifestations:

(1) In the process of injection molding, the melt will replace the gas in the cavity. If the gas is not discharged in time, it will lead to difficulty in filling the melt, resulting in insufficient injection and unable to fill the cavity;

(2) Under a certain degree of compression, the removal of unobstructed gas will form high pressure in the cavity and penetrate into the plastic, resulting in quality defects such as pores, voids, tissue thinning and cracking;

(3) Since the gas is highly compressed, so that the temperature in the cavity rises sharply, so that the surrounding melting decomposition, burning plastic parts and partial burning carbonization phenomenon. It is mainly found in the confluence of two molten grid flanges;

(4) Due to the poor gas emission, the melt velocity entering each cavity is different, which is easy to form flow marks and melt marks, and reduce the mechanical properties of plastic parts;

(5) Due to the obstruction of gas in the cavity, the filling speed is reduced, the forming cycle is affected, and the efficiency of tax collection and management is reduced.



About Huizhou Dj Molding Co., Ltd

Dj Mold is a China mold maker of plastic molds- injection mold, die casting moulds, plastic blow molding, rotational molding, medical plastic injection molding, two shot plastic injection molding, insert molding, overmolding, metal injection molding, micro injection molding, powder injection molding, ceramic injection molding, liquid injection molding, husky injection molding, household mold, casting mold, die mold tool, custom molds, china moulds, rapid prototyping tooling, plastic prototyping tooling, punch press tooling, die and tooling for mobile/ cell phone parts, automotive parts, vacuum cleaners, rechargeable tools, telephones, copiers, computers, multimedia speakers, and many other electronic products and household appliances. And also a plastic product manufacturer, mold manufacturer China– plastic parts, plastic water tank, plastic balls, plastic containers, plastic buckle, plastic anchor, plastic hanger, plastic spoon, plastic pipe fitting, plastic tumble, plastic tableware, plastic cups, plastic bottles, plastic tray, plastic cosmetic container, plastic case, plastic food container, plastic chairs, plastic caps, plastic cap closure, plastic tubes, plastic water pipes, plastic knobs, plastic tubing, plastic utility boxes, plastic racks and so on.

Person: James Yuan
Company: Huizhou Dj Molding Company Limited
Add:  LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China
Tel: 86-752-6682869
Email: [email protected]

Site: https://www.jasonmolding.com/custom-injection-molding/

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