Liquid Silicone Rubber Injection Molding vs Traditional Silicone Molding Processes

Liquid silicone rubber (LSR) injection molding and traditional silicone molding are two common processes for producing silicone parts. Both provide benefits and drawbacks that should be considered when selecting the optimal technique.

LSR Injection Molding

Liquid silicone injection molding utilizes two component materials that are mixed and injected into steel molds under high pressure. The liquid silicone vulcanizes quickly into solid rubber parts with excellent dimensional consistency and minimal flash.

Benefits of LSR injection molding include

- High levels of precision and repeatability

- Ability to produce intricate, detailed part geometries

- Efficient cycle times and volume production capabilities

- Minimal waste generation compared to other processes

However, LSR injection requires high initial investments in equipment and molds. Complex parts may also require multi-cavity molds, further increasing costs.

Traditional Silicone Molding

Traditional silicone molding involves adding a catalyst to high consistency rubber materials and pressing or pouring them into molds. The silicone cures at room temperature into finished parts. This is a versatile process suitable for prototypes and small production runs.

Advantages of traditional silicone molding include:

- Lower equipment costs compared to injection molding

- Ability to use various silicone materials including HTV and addition cure

- Capable of large or simple part geometries

- Easy to change molds for new designs

However, traditional methods produce less consistent tolerances and are better suited for lower volume applications. Extensive labor is required to remove flash and finish parts.

Choosing the Best Method

LSR injection molding provides extremely high consistency and is ideal for large production volumes of complex parts. Traditional methods offer more flexibility for small batches or prototypes using different silicone formulations.

Considering part requirements, production quantities and budgets can determine which process delivers an optimal solution. With an understanding of both techniques, manufacturers can utilize silicone molding in the most effective way.