Injecting molding is an affordable and common process for manufacturing custom silicone products. It is widely used to produce things ranging from medical equipment to kid’s toys, household and kitchen appliances, vehicle parts, and more. All these parts are strong and light.
Sometimes, the injection-molded custom silicone products need help. Inefficient ergonomics, slippery area, vibration proof, and low impact are reasons you need a second mold. It helps to add grip better cover or sleeve.
Some manufacturers choose to add the two different molded components using an adhesive or screw, but it may take time and money. However, there is a process of overmolding that works as a quick solution.
What is rapid overmolding?
The process uses a chemical bond to fix two parts permanently. It avoids hassles, eases product designs, and boosts the specifications of injection-molded parts.
It works by positioning a previously molded part back into the press and adding a liquid silicone rubber into it. The dual process needs some molds to work as the substrate and complete the overmolded product.
It also needs a human to load the substrate and unload the end product. Before choosing an overmolding project, you should consider these elements:
- Principles: The mold-ability principles apply to all overmolding.
- Material: There are two materials involved, substrate and overmold; both should be compatible.
- Bonding: A good bond between the two materials is essential for overmolding.
When talking about bonding, in a good overmold part, the overlay cannot be removed and is tried; it will tear down. Getting a good chemical bond may not be possible every time. Hence, companies often use an overmold gasket crafted with a soft sealing material. After the cover is bonded, the gasket cannot go anywhere.
Principles of overmolding
- Both materials have suitable draft angles, the equal thickness of walls, and smooth transition lines.
- The thickness of the overmold should be less or equal to the substrate.
- The melting temperature of the overmold should be less than the substrate
- If chemical bonding doesn’t work, mechanical interlocks can be used.
- Texturing the substrate and overmolded part often offers a better grip and appealing surface.
Overmolding is an amazing way to enhance the physical specification of a product and its looks. Like any other injection molding service, you can produce it in bulk.
If you have a bulk quantity to produce, you can choose rapid overmolding. It allows resting prototypes for material compatibility and bonding before investing in both materials and serves as a piece of bridge equipment till molds are ready.
Rapid overmolding is a complicated procedure compared to standard injection molding, so the tooling cost gets slightly higher than two molded and assembled parts. However, it offers higher quality and long-lasting products.
If you have any particular custom material, color, or size requirement, you can approach NewTop for all your queries. Get customized silicone products at the best price in any quantity you want. You can also get real samples to choose from. Look for the best silicone mold as per your needs and order now!