Why do "TPE-coated ABS, PC, PC/ABS materials have bubble delamination"
Source：德創化工Time：2020-04-10Hits：3991
At 9:30 p.m. on April 10, 2020, I received a call from Mr. yang. Mr. yang is now making a PC/ABS material with TPE coating. since there are always bubbles in the product during the injection process, we found me through the internet. then we will make a brief analysis of the bubble problem in the forming of TPE coating. we often hear customers' reaction to the peeling of the gate or the peeling of the product during the injection process, especially when making rubber coating products. this phenomenon is especially serious. let's talk about the peeling, delamination, cracking, poor adhesion and other problems of TPE products.
Cause Analysis of Bubble Delamination in TPE Coating Material;
In this case, there are two reasons for the peeling and delamination of the rubber coating:
1. Compatibility of compounding system
SBC-based TPE composites contain many components, which form different phase structures during blending and plasticization. Each phase structure aggregates into a whole by physical cross-linking network. However, insufficient compatibility of each phase separation will become the root cause of material delamination.
2. Forming Speed Shear Rate
In some cases, too high a shear rate may lead to phase separation. In this case, the smaller gate size of the product for aesthetic purposes resulted in a higher TPE fluid shear rate at the gate position during injection molding. It is normal for TPE materials with poor compatibility to have peeling and delamination under the action of high shear rate.
3. Countermeasures
Not only in this case, other TPE products have the same reasons and solutions for peeling and delamination during injection molding.
(2) Strengthen the compatibility of TPE blending system;
(2) During injection molding, the injection speed and pressure should be appropriately reduced to reduce shear friction;
(3) Adjust the size and position of the glue inlet of the mold when necessary (for example, increase the size of the glue inlet appropriately).
