Views: 1 Author: Site Editor Publish Time: 2022-12-12 Origin: Site
In the process of injection mold design, the design of small gate is often used. The pressure drop caused by the increase of flow resistance during the molding of small gate can be compensated by increasing injection pressure within a certain range. According to many years of injection mold experience, injection mold using small gate design has the following advantages, Xiaobian will elaborate on each advantage.
1. The injection mold using small gate design will reduce the viscosity, enhance the fluidity, conducive to mold filling.
There is a large pressure difference between the two ends of the small gate of the injection mold, which leads to the decrease of the apparent viscosity of the melt and the enhancement of the fluidity, which is conducive to the mold filling. This feature of the small gate is very useful for thin-walled products or products with fine patterns, as well as plastics such as polyethylene whose viscosity is sensitive to shear rate.
2. The injection mold adopts the design of small gate to make the melt at the gate freeze timely during the pressure retaining process, so as to properly control the feeding time.
In the process of injection molding, if the size of the gate is large, the pressure holding and feeding time will continue for a long time, especially in the vicinity of the gate will cause great feeding stress, resulting in the final warping deformation of the product. If a small gate is used, it is possible to adjust the volume of the small gate by mold test or mold repair, so that the melt at the gate can freeze timely during the pressure retaining process, so as to properly control the feeding time.
3. The injection mold using small gate design can shorten the molding cycle, improve production efficiency.
Injection mold because of the small gate volume is small, freezing fast, so the production of some products, can be frozen at the small gate without the need to be cured inside the product, as long as the external curing layer has enough strength and stiffness, the product can be released, so as to shorten the molding cycle, improve production efficiency.
4. The injection mold adopts the small gate design to balance the feeding speed of each mold cavity in the multi-mold cavity, which is conducive to the balance of the pouring system.
If the small gate is used in the non-equilibrium pouring system with multi-mold cavities, the flow resistance of the gate to the plastic melt will be much greater than that of the flow passage. The small gate can balance the feed speed of each mold cavity in the multi-mold cavity, which is conducive to the balance of the pouring system.
5. Injection mold using small gate design Using small gate is not only conducive to the solidification system and product separation, but also conducive to product dressing.
If large gate molding products are used, appropriate tools or machine tools are often required to finish the products to remove gate scars when the surface quality of the products is high. However, this trouble can be avoided by using a small gate. In addition, the scar after the removal of small gate is small, the use of small gate is not only conducive to the separation of the coagulant and the product, but also conducive to the product dressing.
Although the small gate of injection mold has the above advantages, too small gate will cause great flow resistance, resulting in the extension of feeding mold filling time. Reducing the cross-sectional area of the gate is often used in injection mold, but it may increase the melt shear rate, which will lead to a significant decrease in the apparent viscosity of the melt. On the contrary, it may be more conducive to mold filling than the large-section gate. The mission of Fansstar is to master the core technology of injection molding production, communicate and analyze the technology before injection molding with customers from the production needs of finished products, so as to make the injection mold delivery time short, long life, rapid mass production and finished product quality excellent! If you need injection molding, please contact us!