What is Injection Molding?

Injection molding is process by which sealing devices and components are produced. A whole range of materials can be used in injection molding, from metal to plastic, and even glass. Injection molding allows for a consistent product, but it is imperative that the initial mold design is perfectly suited for the product’s needs.

How it Works

Not all injection molding systems are the same, but there are some procedures that are general to the injection molding process. The material for the component is heated until it is melted and then forced into the mold cavity. Once in the cavity, the material is allowed to cool and harden, maintaining the shape of the mold, creating the desired product. To account for shrinkage, holding pressure must be kept at proper levels. Coolant is also important in certain molding processes, allowing the material to cool at the correct rate.

What it’s Used For

Injection molding is one of the most common manufacturing methods for plastic products, as it creates a uniform product, and is especially useful for mass production of high quantity items. While it’s easy to imagine injection molding being used for small parts such as bottle caps, mechanical components, and electronics; injection molding can be used in large applications as well, such as entire car body panels. Chances are any plastic parts that make up the things you own were injection molded.

Molds

Perhaps the most complex and important part of the molding process are the molds themselves. Molds can be made from a range of materials, usually determined by the economics and requirements of the part being made, including hardened steel, pre-hardened steel, aluminum, and other alloys. Molds are typically expensive to design and make, as they are highly specialized and require extreme precision. The number and complexity of cavities in the mold will determine the cost of the mold, and it’s best to eliminate excess material as this can negatively impact production cost.

Molds are typically made of two plates with indentations and raised areas shaping the desired product. In order for the molten material to travel through the mold, there are “runner” channels through which the liquid flows. Some molds, for smaller parts, are designed in such a way that a single injection of material can yield several parts, making for a more efficient process. These molds can be made to create different or identical parts, so one mold can either perform the same job multiple times or produce a variety of related products in one “shot.”

Any defects in the mold will cause issues with the end product. If the mold is incorrectly sized then the material will warp, blister, or stick to the mold when it has finished the cooling process.

Real Seal’s Molds

Real Seal is an expert in injection molding, offering a wide range of materials for use in state of the art molds. Computer controlled mechanization and consistency ensure a superior product. They have created products ranging from 0.05” to 27” in diameter and have maintained customer tooling for two decades in many cases. If you require custom tooling, Real Seal provides this service on site, typically using insert style retrofitting into established basis, lowering your costs. Since these steps are all done by Real Seal, you can be assured of their consistency and conformity. Contact Real Seal for all your manufacturing needs.