Views:82 Author:Site Editor Publish Time: 2019-02-12 Origin:Site
Two Main Methods of Molding Silicone-- Compression Molding and Liquid Injection Molding(LIM)
There are two main methods of molding silicone components:liquid silicone injection molding(LIM) and compression molding
Liquid silicone injection molding (LIM) is an injection molding method of liquid silicone rubber(LSR), which uses High Consistency Rubber (HCR) that is also called gum stock, and LIM uses a high viscosity liquid silicone rubber.
Liquid Silicone Rubber consists of two parts, part A and part B. Only one part contains the platinum catalyst. The Part A and B tubes are connected to a dispensing machine that seals the material and uses pressure to pump the material from the original containers into the machine.
The reason why LSR need to add platinum catalyst is that the process time is very short, so don’t have enough time to vulcanize completely to make sure 100% FDA grade. To add platinum catalyst can accelerate vulcanize process and kill harmful substance to achieve 100% food safety.
LIM is the a good choice for the Medical Industry because the pails/drum kits of uncured LSR are loaded and sealed into the dispensing machine which can be injected or cured without human contact.
Liquid Silicone Rubber Injection Molding Manufacturing Process:
What’s the process of compression molding? Add pigment to silicone directly by labor. Mix silicone and added pigment in a two-mill roll. But this labor process has possibility for contamination of silicone. And after pigment is added and worker will weight the silicone according to the approximate size and configuration of the product. Then can place the weighted silicone directly into the mold cavity. The silicone material will be compressed between top and bottom plates in about 170-200°C temperature and be melt and cured.
Compression molding is cheaper compared with LSR injection molding. As compression molding has the use of fillers that are added to the silicone to lower the cost of material for manufacturing.
Compression molding is the simplest form of silicone rubber molding, but it is also an open-air labor intensive process. This allows for the possibility of contamination to get into the silicone. Compression molding also has the use of fillers that are added to the silicone to lower the cost of material for manufacturing.
Compression molding is the simplest molding methods, but it is also an open-air labor intensive process, which may cause contamination to get into the silicone.