Reasons for making the exhaust system of the injection mold

The gas in the injection mold includes not only the air in the cavity, but also the air in the gate and the decomposition gas generated by the plastic melt, and the steam which caused by plastic in high temperatures. During injection molding, these gases should be exhaust in time, otherwise there will be some issues as following:


1. Defects such as flow mark, water mark, and weld marks will be formed on part surface;

2. Defects such as bubbles and loose tissues inside the plastic parts, which will lead to insufficient filling inside plastic part;

3. It is difficult to fill the plastic melt or flash locally;

4. The gas generates high temperature under high temperature and high pressure, causing local carbonization and burnt marks on the product;

5. Reducing the filling speed of the plastic melt, not only the molding cycle is prolonged, but the melt temperature decreases quickly after injection speed dropped, the residual stress will increase, if the injection pressure is increased, and the possibility of warping deformation of the plastic part after demolding will increase, if the material temperature is increased in order to reduce the injection pressure, it will cause the plastic to crack.

   

图片1.png

    

Properly making the exhaust slot can reduce the injection pressure greatly, reduce the injection and the holding time, and reduce the clamping pressure, thereby improving the production efficiency, reducing the production cost, and the energy consumption of the machine. For transparent plastic parts or plastic parts with strict surface requirements, we should be careful with the mold exhaust system design.


Tags: Injection Mold | Injection Mold Supplier | Injection Mold Factory | Mold Factory | Mold Supplier | Injection Molding |
Related News about USM Injection Mold
  • Conformal cooing channel of plastic injection mold

    Conformal cooing channel of plastic injection mold

    Feb 23, 2022The conformal cooling gate is a new type of mold cooling gate based on 3D printing technolog, because of its processing characteristics, the conformal cooling gate can fit the shape of the product...view
  • The sub gate of the plastic injection mold runner system

    The sub gate of the plastic injection mold runner system

    Jan 26, 2022In order to get the best injection quality, the gate type must be selected carefully, the coommon gate tyeps are: direct gate, side gate, pin-point gate, sub gate,valve gate of hot runner etc. Among...view
  • Limitations of gas-assisted injection molding technology

    Limitations of gas-assisted injection molding technology

    Apr 25, 2022Gas-assisted injection molding technology has obvious advantages in thick wall thickness and pipe parts, but this technology still has many limitations, which are mainly reflected in the following...view
  • Plastic injection mold runner system design

    Plastic injection mold runner system design

    Jan 16, 2022The gate is the connecting part between the runner and the cavity, and is also the end part of the injection mold gating system, the molten plastic enters the cavity and core side through the gate...view
  • Main application of gas-assisted molding technology

    Main application of gas-assisted molding technology

    Apr 7, 2022Gas-assisted molding has a particularly obvious effect on the material saving of tubular and rod-shaped plastic parts, such as car handles, seat armrests, window frames, and wood-like furniture, the...view
  • Slider designing tips 2

    Slider designing tips 2

    Nov 22, 20239. The molding parting surface of the slider molding should be made as a shut-off surface as possible, and the width of the shut-off part should be at least 8mm, and do not make a shut-off surface;...view