What are common problems for silicone molding?

Silicone Molding, also known as silicone compression molding or rubber compression molding, is a very common processing technique for manufacturing silicone rubber parts, which is feeding solid silicone raw material mixed with vulcanizing agent in the mold, through a certain period of high temperature and high pressure vulcanization to forming silicone rubber parts to a required shape. Silicone Molding is more economical and cost-effective in mold cost than transfer molding and liquid silicone rubber injection molding.

Silicone Molding exist common problems:

Silicone Molding exist common problems during process due to some factors, exhausting, curing time, temperature and pressure, silicone material compound, etc. The problems will directly impact the quality of silicone molded products and production cost. Thus we need to find out solutions in time for these problems, so as to make qualified production and save production cost.

Silicone Stickiness:

Silicone Stickiness is one of common problems during compression molding, which will cause difficult ejection from mold tool, low production efficiency, high rejection rate. waste silicone material, thus the production cost will greatly increase. Also mold tool is broken easily. Here, we will talk some details about why silicone is easy to stick to mold during Silicone Compression Molding.

Some possible factors on silicone stickiness on mold tool:

1. Ratio of mixing raw material: Improper Ratio of Vulcanizing Agent and Silicone Raw Material: When we roll and mix silicone raw material with vulcanizing Agent for compression molded production, we need to add raw material and vulcanizing Agent in proper proportion.

2. Vulcanizing Agent: Vulcanizing Agent is not stirred and mixed evenly: We need to control sufficient time for rolling and mixing material, based on working instruction.

3. Hardness: Shore A of silicone compound is too low and thus material is too soft. If the Shore A of product lower, we suggest to choose LSR Injection Molding for manufacturing.  

4. Release agent: Don’t spray release agent on mold tool during compression molding production: The worker should spray release agent on mold surface first and then place silicone compound, finally close molds for curing process and forming the required shape of product.

5. Polished treatment: Polished treatment can cause Bright & Shiny Mold surface, thus silicone material adhere to mold during compression molded production.

6. Mold temperature: We can move on curing production only when the mold temperature is up to the required value. If mold temperate is lower than required, silicone material will adhere to mold.