Plastic Fabrication Services: A Guide to Die Cutting and Solvent Welding

Plastic fabrication services cover a lot of ground, from forming a plastic sheet into a three dimensional shape to cutting flat components to exact specifications to joining two finished parts into one. When a project calls for something other than an injection molded part, these fabrication methods are often the answer, especially for lower volume runs, larger parts, or projects that need a fast turnaround without the cost of hard tooling.

As a trusted plastic injection molder, Metro Plastics works alongside its sister company, Emco Plastics, to offer a full range of plastic fabrication services, including die cutting and solvent welding. Below, we cover how each process works, where it fits into a project, and how to know which service makes sense for your parts.

What Are Plastic Fabrication Services?

Plastic fabrication services describe the range of processes used to shape, cut, and join plastic sheet, rod, and tube stock into a finished part. Unlike injection molding, which uses molten plastic injected into a hard tool, fabrication starts with material that is already in a solid form and builds the part from there.

This category includes forming processes like thermoforming, which involves molding a heated plastic sheet around a mold to create the desired shape. We cover thermoforming in more detail, along with its close relative vacuum forming, in our blog on custom plastic fabrication. For this post, we’re focusing on two other plastic fabrication services that come up just as often: die cutting and solvent welding.

What Is Die Cutting?

Die cutting is a fast and economical plastic fabrication method that involves cutting components out of a plastic sheet using a custom die. Think of it like using a cookie cutter on a rolled out sheet of dough. The die is a specially crafted tool designed to pierce the material and produce a part with a precise two dimensional shape.

Because the die is built to the exact shape needed, die cutting services can turn out consistent parts quickly, which makes this process well suited to projects with tight timelines or higher part counts. Die cutting works on a wide range of stock materials as well, including vinyl, PETG, and polycarbonate, so it can support many different applications without a change in equipment.

A few reasons die cutting comes up often in plastic cutting services:

• Speed. Once the die is made, parts can be cut in a fraction of the time other cutting methods require.
• Cost. Die cutting tooling is generally less expensive than the hard tooling used in injection molding.
• Repeatability. Every part cut from the same die comes out with the same shape and dimensions.
• Material flexibility. The process works across a variety of plastic sheet materials, along with other substrates like foam and rubber.

What Is Solvent Welding?

Solvent welding uses liquid polymers and solvent chemicals to permanently join plastic components. Rather than relying on a mechanical fastener or an adhesive layer sitting on top of the material, a solvent or solvent blend is applied to soften the mating surfaces of two thermoplastic parts. As the solvent evaporates, the surfaces fuse together at a molecular level, creating a bond that becomes part of the material itself.

This approach to plastic bonding has a few advantages over other joining methods. Because there is no mechanical fastening involved, stress does not concentrate at a handful of points the way it can with screws or rivets. That helps produce a joint that is both durable and hermetic, meaning it can hold up to pressure or fluid without leaking. Solvent welding can also achieve a low visibility or even invisible seam, which matters for clear or cosmetic parts like acrylic displays and enclosures.

Solvent welding is one of several methods Emco Plastics uses to join thermoplastics. For applications that call for a different joining approach, our team also offers other plastic welding services and can help determine which one fits your part.

Die Cutting and Solvent Welding: How They Work Together

Die cutting and solvent welding often show up in the same project, just at different stages. A part might start as a flat sheet that gets die cut into its final two dimensional shape, then get solvent welded to another die cut piece to form a finished assembly. Point of purchase displays, enclosures, and signage frequently follow this exact path, where individual panels are cut to precise dimensions and then bonded into a single structure.

Understanding where each process fits helps when you are scoping out a new part:

• Die cutting handles shaping a sheet into a flat, two dimensional component.
• Solvent welding handles joining two or more of those components into an assembled part.
• Together, they can replace processes that would otherwise require injection molding, machining, or mechanical fasteners.

Choosing the Right Plastic Fabrication Services for Your Project

Deciding between die cutting, solvent welding, thermoforming, or another value added service usually comes down to what the finished part needs to do and how it will be produced.

Does the part start as a flat shape?

If your part is fundamentally two dimensional, such as a gasket, spacer, or panel, die cutting is often the most direct and economical route.

Will the part be assembled from multiple pieces?

If your finished product is made up of separate components that need to become one solid piece, solvent welding is worth considering, particularly for clear plastics like acrylic where a clean seam matters.

What material are you working with?

Not every plastic is compatible with solvent welding, and material choice can also affect die cutting speed and edge quality. Our engineers can review your material spec and part drawings to confirm compatibility before you commit to a process.

What volume are you producing?

Die cutting tooling is relatively inexpensive to produce, which makes it a strong option across a wide range of production volumes, from prototypes to ongoing runs.

Does the part need a three dimensional shape first?

If your component needs to be formed into a mold shape before it can be cut or joined, you may need thermoforming or vacuum forming as an earlier step. Our custom plastic fabrication blog walks through how that process compares to drape forming.

None of these questions have a single right answer for every project, and many parts benefit from combining more than one plastic fabrication service. Our engineers are available to review your drawings and help map out the right combination of processes for your budget, timeline, and performance requirements.

Contact Metro Plastics for Plastic Fabrication Services

Whether your next project calls for die cutting, solvent welding, thermoforming, or another one of our plastic fabrication services like CNC machining, cut-to-size, or edge finishing, Metro Plastics and Emco Plastics have the equipment and experience to help you get there. Contact us today to talk through your part requirements and find the right plastic fabrication company for the job.