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Extrusion Thermoplastic Process

Thermoplastics are plastic materials that can be melted (and re-melted) for subsequent processing operations. As these materials melt at higher temperatures and harden at cooler temperatures, they can be heated, formed, mixed with additives, and cooled into their final shape. Manufacturers use operations, such as extrusion, injection molding, and thermoforming, to transform thermoplastics into finished goods.

For over 75 years, Inline Plastics, Inc. has been an industry leader in custom plastic extrusions. Our company specializes in over 20 different thermoplastics, providing them in a wide range of shapes and profiles, including tubing and rods.

With over seven decades of experience in producing custom plastic extrusions, we understand the benefits of using thermoplastics to manufacture consumer, commercial, medical and industrial parts, such as:

  • Affordability. Thermoplastics are easily melted and formed into complex and custom designs. The speed and ease of thermoplastic forming operations, make thermoplastics suitable for large production runs.
  • Energy Efficiency. Both manufacturing and processing operations for thermoplastics requires very little energy.
  • Versatility. As a whole, thermoplastic materials demonstrate a wide variety of properties, with each thermoplastic offering its own set of unique characteristics.
  • Metal alternatives. Thermoplastics serve as suitable lightweight alternatives for other materials, such as metal.

How Are Thermoplastics Made?

There are three key processes used to transform thermoplastics from raw materials into finished products. Those processes are:

Granule Manufacturing

Thermoplastic granules are the raw materials which undergo manufacturing processes to become finished products. The chemical compositions of these materials are largely dependent on the type of thermoplastic being produced. However, they are all formulated to preserve the properties characteristic of thermoplastics: malleability and recyclability. Some of the most common chemicals used to create thermoplastic granules include acrylics, cellulosics, nylons, and polyurethanes.

During the granule manufacturing process, the chemicals are mixed together in a large, heated pot. Coloring pigments may be added to the mixture before it cools. During the cooling process, the material is split into granules, which are easier to inventory, inspect, transport, and measure.

Granule Melting

After the thermoplastic granules are produced and delivered to the manufacturing facility, they are subjected to further processing operations. The granules can be mixed or separately added to a melting vessel, which slowly heats the pellets and melts them into a formable plastic liquid.

Injection Molding

Injection molding is just one of the methods by which melted thermoplastics are formed into finished parts and products. During injection molding operations, manufacturers inject metal molds with the viscous liquid. The liquid fills the hollow shape of the mold and, after a sufficient cooling period, is ejected as a set plastic form.


Plastic extrusion is the process of transforming solid plastic into a shaped product. In contrast to injection molding, which is an intermittent discontinuous process, extrusion is a continuous manufacturing process. Typically, plastic is melted down and pressed into the desired shape and then cooled before experiencing other potential secondary extrusion sub-processes, such as blown, sheet or cast film, profile, pelletizing and more.

What Are Thermoplastics Used For?


Thermoplastics are used across a wide range of industries. In addition to their ability to hold intricate designs and forms, these materials have unique attributes—such as weathering and impact resistance and long-term color retention—that make them ideal for long-term industrial use. They commonly find application in:

  • Car parts
  • Containers
  • Lenses
  • Medical devices
  • Pipes
  • Signs
  • Windows

Our Thermoplastic Materials

At Inline Plastics, we specialize in a wide variety of thermoplastics. Some of our most popular plastics include:

  • Acrylonitrile Butadiene Styrene (ABS), which is tough and has high impact strength
  • Acrylic, which is resistant to chemicals and impact
  • Copolymer & Homopolymer (Polypropylene), which is stiff and tough
  • Ester & Ether (Polyurethane), which is resistant to UV radiation and is ideal for medical applications
  • Ethylene Vinyl Acetate (EVA), which is flexible and has good memory retention
  • Flexible Polyvinyl Chloride (PVC), which is ideal for medical and industrial applications
  • Polycarbonate, which offers high impact strength, good electrical properties, dimensional stability, high rigidity, and excellent clarity
  • Polyethylene (HDPE), which has good electrical properties and resistance to stress cracking, chemicals, and abrasion
  • Polyethylene (LDPE), which has good durability and excellent toughness and electrical properties
  • Polystyrene (Crystal), which has low impact strength and good clarity, stiffness, and printability
  • Polystyrene (High-Impact), which exhibits good stiffness and cost-effectiveness
  • Rigid PVC (Polyvinyl Chloride), which comes in exterior grade and interior grade varieties

While we do specialize in the materials mentioned above, our materials are not strictly limited to the ones listed. We possess over 30 different thermoplastic materials that can be made to your exact specifications. Feel free to call us at 909.923.1033 or visit our contact us page for more information regarding our thermoplastic materials.

Request A Quote From Inline Plastics Today

Thermoplastics are ideal for the manufacture of a wide range of industrial, commercial, medical and consumer parts and products. At Inline Plastics, we can provide custom-tailored thermoplastic materials for your company’s next project.

To learn more about our custom plastic capabilities or to receive a quote for your project, request a free quote today.