👋 Hello everyone – Ellie here from Sinclair & Rush!

Today’s blog takes a look at the variety of plastic manufacturing processes used in the industry—and right here at Sinclair & Rush. It follows up on last week’s poll, where we asked:
“How many plastic manufacturing processes are there?”
The multiple-choice options were: 1, 3, 5 or 6+.

Here’s how you voted:

• 30% chose 3

• 70% chose 6+

• 0% chose 1 or 5

It turns out most of you were spot on! There are indeed more than six widely used plastic manufacturing processes, and it’s great to see that so many of our followers already had an understanding of this.

When I first joined Sinclair & Rush, I’ll be honest—I had no idea just how many different methods existed to create plastic parts. It all depends on the material being used, the desired quality, the look and feel, and of course, the volume and production speed required. So let’s dive into some of the key methods we use across our UK, US, Australian, and Chinese facilities:

🔧 Plastic Extrusion

This process involves pushing heated material through a die to form a continuous shape—such as a tube. Using central pins and vacuum chambers, a wide variety of profiles can be created. Once cooled, the material is cut to length directly on the production line.

We introduced extrusion to our UK facility in 2016 to meet growing local demand. It’s a high-speed, efficient, and low-waste process, ideal for large volume runs.

🛠️ Vinyl Dip Moulding

A heated metal mandrel is dipped into liquid plastisol (PVC), which solidifies on contact. The part is then oven-cured and removed from the mould.

In the UK, we operate both small-batch rigs for prototyping and large-volume machines for industrial-scale production. Dip moulded PVC parts are flexible, durable, and cost-effective—perfect for a wide range of applications.

⚙️ Injection Moulding

Plastic granules are melted and injected into metal moulds at high pressure. Once cooled, the part retains the exact shape of the mould cavity.

While tooling setup is more expensive, this process allows for exceptional precision and repeatability—especially valuable for high-spec parts and large production runs.

♻️ Thermoforming

This involves heating a thermoplastic sheet and forming it over a mould. Thin-gauge thermoforming is often used for disposable retail packaging (e.g., salad boxes), while thick-gauge variants produce items like shipping trays, automotive fascias, and appliance panels.

🧽 Foam Extrusion

Similar to plastic extrusion, but using rubber compounds and foaming agents. The material is pushed through dies, then cured and shaped using high-speed grinders for a refined finish.

This is how our foam grips—available on our website—are made by our US team.

We hope this blog has given you more insight into the diverse world of plastic manufacturing. Each process plays a vital role in producing the high-quality components we supply worldwide.

💻 And to explore our full product range, head HERE

Thanks for reading—until next time!
— Ellie 😊