Injection molding is an excellent technology for combining molding and vulcanization as well as offering the free choice of color. For injection molding to work efficiently, it is essential to have the right tooling to ensure that even after manufacturing large quantities, products require only minimal post-production work.
It is important to consider the planned product volume, as the proper tooling can be a significant cost. In this article we describe
Requirements for injection molding tools
Vulcanization can involve temperatures of up to 200°C and pressures in excess of 200 MPa. Therefore injection molding tools must withstand high pressures and temperatures.
The tooling also needs to spread the material evenly, reducing the amount of waste. Accurately machined tools help to reduce the excess trim, but at the same time, technical trim is necessary to ensure product integrity.
Good tool surface quality ensures a uniform product texture. It is also important that the tool is compatible with the injection molding machine, typically consisting of not only the mold but also the pressure system and the mold clamping system.
What should the injection molding tool be made of?
A common method for prototyping is using silicone injection mold, however, for mass production more durable and reliable material is required. Mass-production injection molds are therefore typically made from steel or aluminum.
Aluminum molds are cost-effective to make and require less work to achieve the right shape and finish. However, they are more suitable for making products in the thousands as they have lower dimensional accuracy and wear out more quickly in use.
Steel injection molds are more costly to produce as they require accurate and patient machining on suitable machines. However, they provide a uniform surface finish, have high dimensional accuracy, and, above all, are extremely durable, and wear slowly, making them suitable for mass production runs up to millions of units.
During product design, it is crucial to consider the
- expectations of the product,
- number of units, and
If injection molding is an economically suitable process, then specifying the physical and chemical aspects of the mold is part of the product design process. Specialist companies and machine shops are available to manufacture the designed mold.
Injection mold tooling requires a significant investment, but the product quality provided by a good tool and the ability to produce high volumes at high speeds result in a substantial return on investment.
The molds are durable and can be stored while other products are being made on the injection molding line.
Injection molding of rubber products by SIC
At SIC, we have been injection molding rubber products for decades. The technology enables efficient production of cones, automotive parts, balls, seals, and other industrial rubber products for a wide range of industries. We offer our customers a wide range of colors.
Using proven technology, we reliably manufacture rubber products to the highest quality standards. Contact us for the injection molding of rubber products, whether prototyping, medium or large series production: we are at your service.