Injection Molding


Injection molding is one of the most commonly used methods for manufacturing plastic parts due to its ability to produce precision parts in a timely and cost-effective manner. At Sinclair & Rush, we specialize in manufacturing high-volume, tight-tolerance caps, plugs, closures, and grips.

What is Injection Molding?

The basic injection molding process involves "injecting" heated plastic resin into cavities. The process can be used to manufacture parts in a wide variety of plastic materials in virtually any shape or size. Given the nature of our business, Sinclair & Rush facilities tend to utilize high-speed presses with robotic sprue extractors and outbound conveying technology that allow us to manufacture parts in the most productive manner possible.

Business Units Supported

Our injection molding facilities primarily support our GripWorks business unit, but also supports our StockCap and VisiPak business units. All of these business units feature complete product lines of grips, plastic caps and plugs, as the well as the ability to design and manufacture custom items for our clients worldwide. As nearly all of the products we produce for these business units are small, precision-engineered items, our systems, presses, mold making processes, and automation are all tailored to these types of products.


To effectively serve our clients and support our global business, injection molding operations are strategically located throughout the world.


With over 50 years of design experience and extensive expertise with Creo and NX design and manufacturing software, our engineers have designed parts ranging from caps and plugs to complex industrial closures and components. Our team can assist in all aspects of the process, from concept and prototyping to production and quality assurance.

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