How Can You Glue Silicone Together?

Silicone rubber is one of the most challenging substrates to bond, and there are only a few adhesives that can make a strong bond? From our mass production experience, I see there are 4 ways to gule the silicone together. Please get the below details to see it:

  • Silicone Co-injection molding
  • Silicone Over-molding
  • Bonding – Use the gule by hand
  • Bonding- Use the LSR by hand

1. Silicone Co-Injection molding

Co-injection is a polymer injection technology in which different polymers are injected into the same mold. This specialized process can be used to improve part performance and cost while minimizing cycle time and production volume. Co-injection can be used to extend shelf life, improve production efficiencies, and allow for greater design flexibility depending on the materials used and the application.

Co-injection molding involves the injection of two dissimilar materials. Because of this, co-injection has some special advantages, as well as some potential molding problems. The Co-injection analysis helps you overcome the potential problems and leverage the advantages, by helping to optimize process control strategies and enhance part quality.

Silicone Co-Injection molding :

Co-injection Silicone molding allows two different silicone materials (solid silicone rubber and liquid silicone rubber) to be combined into a single products stream. This specialized process can be used to enhance products’ color performance and reduce cost without any penalty to cycle time or production volume. Depending on the materials selected and the application, Co-injection can be used to improve production efficiencies and allow for greater design flexibility. Co-injection dripping molding can be used for a wide range of applications across any industry including Consumer Electronic(Cute phone case, iPod case, Ipad case), and baby products(baby toy, baby feeding).Promotional gifts(Colorful products include: keychains, fashion accessories and gifts)

The Co-injection Silicone molding process:

Dispensing Dripping the liquid silicone rubber to the pattern of the mold with the Dispensing Dripping machine:

Heat the liquid silicone rubber and let them mold first.

Put the solid silicone rubber in the silicone mold and then molding.

You can get a colorful co-injection silicone molding products with many colors without any glue.

2. Silicone Over-molding:

Silicone Overmolding is a process where a single part is created using two or more different materials in combination. Typically the first material, sometimes referred to as the substrate, is partially or fully covered by subsequent materials (overmold materials) during the manufacturing process.

  1. Silicone Over Silicone-First a silicone substrate is molded. Then another silicone is molded onto or around the substrate. The silicone could differ in color and/or hardness.
  2. Silicone Over Plastic – First a rigid plastic substrate is molded. Then a soft Silicone is molded onto or around the substrate. This is often used to give a soft grip area to a rigid part.
  3. Silicone Over Metal-First a metal substrate is machined, cast or formed. Then, the substrate is inserted into a silicone compression molding tool and the silicone is molded onto or around the metal. This is often used to capture metal components in a silicone part. That is today’s process that we would like to show.

2.1: Liquid silicone rubber over injection molding:

Make the green leaf first. Then over-molding the purple grape outside.

2.2: Solid silicone rubber over-molding

The white plate should be compression molding first, Then over-molded the pink color. 

3. Bonding – Use the Gule by hand

Sometimes, because the structure of the silicone goods. When we hope to get the function of the goods. We may need to use glue. Check the below silicone 3D cartoon on the silicone bottle sleeve.

As we all know: Silicone rubber is one of the most challenging substrates to bond, and there are only a few adhesives that can make a strong bond. One option that has been successful in other silicone rubber applications is 3M™ Scotch-Weld™ Plastic & Rubber Instant Adhesive PR100 with 3M™ Scotch-Weld™ Instant Adhesive Primer AC79.

The basic steps are

  1. apply the primer to both parts,
  2. let it dry completely,
  3. apply the instant adhesive as soon as the primer is dry.

4. Bonding- Use the LSR by hand

When we make the silicone bag, especially the bag for shortage the food. We may not use glue for bonding. We use the Liquid silicone rubber to do the bonding. 

4.1:Two pieces of silicone bag before the LSR bonding:

4.2: The Silicone shortage reuseable bag after the liquid silicone rubber bonding:


From the above 4 information, you will see, only the Third way, we may use in our daily life. Others, all need the Professional equipment.

ZSR Group has rich experience in producing Custom silicone products with FDA or LFGB Approved standards with bonding or glue. We have the FDA register list number 3011147430.

Any Silicone products or Silicone projects need technical support, you also can custom Silicone products at ZSR Group. We will support your Silicone products from idea to life

The silicone overmolding bowl making video

Make the orange collar first, then with the blue body overmolding the orange collar.