Methods for Handling Burrs and Flow Marks in Fully Encapsulated Injection Molding Liquid Silicone Rubber

Many customers report that using liquid silicone rubber for injection molding results in a particularly high scrap rate, which is difficult to control! Issues such as bubbles, burrs, flow marks, etc., often occur. Such problems are certainly unacceptable. These technical challenges have been resolved by Dongguan Hongfenghao Technology Co., Ltd. Contact: 13711884298 Wu Haiping, Technical Consultant: 13058520516 Wang Zhanfeng, Exclusive: Hongfenghao Wu Haiping

In fact, the main cause of burrs in fully encapsulated injection molding liquid silicone rubber is related to mold precision—specifically, insufficient precision in the parting line between the upper and lower molds, leading to significant dimensional errors. The quality of mold precision directly impacts the product qualification rate!

Solutions:

1. The parting line between the upper and lower molds needs to be polished with an oilstone; adding cryogenic deflashing can also help.

Causes of Flow Marks and Burrs in Injection Molding Liquid Silicone Rubber:

Ensure the correct selection of injection molding liquid silicone rubber raw materials and related additives, such as: Is the silicone ordinary or platinum-cured? Is the color masterbatch a pigment or a pre-dispersed agent? Since flow marks are related to silicone mixing, reducing mold temperature and ensuring thorough mixing can minimize or eliminate flow marks.

Causes of Burrs: 1. Excessive material weight; 2. Too many venting cycles, high mold temperature, etc. Solutions: The mold parting line needs to be polished with an oilstone; adding cryogenic deflashing can also reduce burr formation.