What are the five major factors affecting silicone molding?

What are the five major factors affecting  silicone molding?

What are the five major pitfalls in silicone molding? How many have you encountered?

 Molds are made, equipment is adjusted, but products still suffer from bubbles, insufficient material, sticking, burrs, and cracks... 

The yield rate is low, and 90% of failures stem from these five "failures" 

① Bubbles – Hollow pores hidden inside, resembling a honeycomb when cut open.

 Incomplete venting, damp raw materials, insufficient venting frequency.

Ensure materials are dry, optimize venting channels, and vent multiple times during mold closing.

② Insufficient Material – Edges and corners are never filled, resulting in the entire mold being scrapped.

 Inaccurate material weighing, clogged runners, insufficient clamping force.

Standardized weighing, smooth runner design, and regular press calibration.

③ Sticking to the mold – Demolding is like tearing flesh, leaving black marks on the mold.

 Insufficient release agent, incomplete vulcanization, and scratched mold.

Spray the compound evenly, monitor temperature and time closely, and polish the mold frequently.

④ Burrs (flash) – Long "whiskers" on the parting line, requiring arduous trimming.

Large mold gap, too thin rubber compound, excessive material input.

 Clean the mold surface to check precision, control the amount of material input, and select rubber of appropriate viscosity.

⑤ Cracking – Cracking after a short period of use renders the product unusable.

Poor tear resistance of the raw material, repeated stress, over- or under-curing.

Select good raw rubber, follow the vulcanization curve, avoid over- or under-curing.