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
  • Venting system of plastic injection mold introduction

    Venting system of plastic injection mold introduction

    Feb 27, 2022Hello everyone, thanks for attention. We’ve discussed about the temperature control system earlier, now we are going to talk about the mold venting information in following 11 articles, from the...view
  • Plastic injection mold runner system design points

    Plastic injection mold runner system design points

    Jan 9, 2022When designing the gating system, Firstly, we should consider making the plastic melt fill the cavity with core side quickly to reduce pressure and heat loss; secondly, it should be economically...view
  • Slider designing tips 1

    Slider designing tips 1

    Aug 3, 20221. After the slider core pulls out, the length of staying in the guide pin slot should not be less than 2/3 of the total length of the slider, for special cases, the slider slot can be partially...view
  • Design Tips of Vacuum Venting Mold

    Design Tips of Vacuum Venting Mold

    Mar 30, 2022There are some regular venting way which are parting surface venting, insert venting, insert pin venting and well-ventilated steel, but there is a special way is vacumm venting, it will need vacumm...view
  • What is the side parting and core pulling mechanisms with their function?

    What is the side parting and core pulling mechanisms with their function?

    May 31, 2022When there are holes, cavities or cores on the inside or outside of the injection-molded plastic parts that are different from the opening and closing directions of the mold, the plastic parts cannot...view
  • Direct gate of plastic injection mold runner system design

    Direct gate of plastic injection mold runner system design

    Jan 19, 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