Plastic Extrusion, Process, Materials & Applications

Blog, Tuesday, September 13, 2022

Plastic Extrusion, Process, Materials, and Applications

Finding the right manufacturing process for your finished product is essential. When getting a part or product to market, you have to be concerned with lead times, costs, and the quality produced. With many manufacturing companies moving overseas, lead times and quality can be unpredictable, leaving you with problems regarding product delivery. The good news is there is a plastic manufacturing company that understands the problems and pains that can come with the plastic production process. CBM Plastics has experienced professionals who know the ins and outs of custom plastic profile extrusion and other plastics manufacturing processes. They know the importance of quality and timeliness and strive to meet and exceed their client’s needs. The company is U.S.-based, meaning lead times and shipping times are lessened, allowing you to get your parts and products when you need them. Find out more about how CBM’s plastic extrusion process can be the solution to your plastic product and parts needs, or contact us today to get started.

How Are Plastic Extrusions Made

The high-volume manufacturing process, plastic extrusion process utilizes raw plastics that will be heated and melted down to form one continuous profile. The thermoplastic material can consist of granules, pellets, flakes, or powders and is transferred from a hopper into the extruder. Mechanical energy generated by heaters and rotating screws along the barrel of the heater will cause the molten plastic to be forced into the die. The polymer will be shaped in the die and hardened during the cooling process, forming the final part or product.

What Are the Steps of the Plastic Extrusion Process?

Plastic extrusion is a continuous process that involves a few simple parts, including:

  • A hopper
  • The feed throat
  • A barrel
  • A breaker plate
  • A feed pipe
  • A die
  • The cooling system


Each of the parts work together to perform the extrusion process.

Step 1

The raw material will be solid in the hopper, which will feed through the feed throat by gravity into the extruder barrel.

Step 2

After entering the barrel, the material will be heated to a molten point in one of the three heaters located in the extruder. For example, if gradual heating is required, then the barrel will be cooler by the feed throat and get hotter towards the die.

Step 3

The melted plastic will then come out of the barrel and base through a screen that will remove contaminants and impurities from the material. The screen pack is reinforced by the breaker plate.

Step 4

The material will continue through the feed pipe and be pushed through the custom-created die, which will have an opening designed to produce the desired profile shape.

Step 5

Once the desired profile is reached, the extrusion process will be completed, and the product will be cooled along cooling rolls or in a water bath where it will harden.

How Do the Parts of a Plastic Extrusion Machine Work?

While a plastic extruder machine has a simple design at first glance, several parts within the machine facilitate the process and help you achieve the desired result. To understand how the machine works, it is essential to know each part’s role in the production process.


The screw design and function are crucial for the plastic extrusion process. The energy created by the screws is what heats the thermoplastic material to prepare it for the extrusion process. The screws are located along the barrel and typically have three different zones that assist with the heating process.

  • The feed zone is the part of the screw design where the material is fed.
  • The melting zone is the second area, and it is the area where the plastic is melted.
  • The final zone is called the metering zone, where the last bits of plastic will complete the melting process, and a uniform temperature will be achieved.

Temperature Control

The temperature control elements are critical to maintaining the proper temperature in the barrel, which will prevent the degradation and weakening of the plastic as it moves through the extrusion process. The temperatures will be controlled all the way through the extruder through the use of heaters, fans, and cooling systems.


While all of the components in an extruder are vital to the extrusion process, the die is the part responsible for the final product’s shape. The die will form the shape of the profile, but the profile can then be extended to varying lengths as needed, unlike the injection molding process, where the confines of the mold will determine the shape and size.

Why Use Plastic Extrusion?

Plastic extrusion can be the best manufacturing process for several reasons. From efficiency to shorter lead times, below are some of the best reasons to choose plastic extrusion for your product manufacturing needs.

  • Shorter lead times: Since creating the die takes minimal time, lead times are shorter, allowing you to produce high volumes of product in a shorter time.
  • Lower cost: Tooling costs can be high with injection molding and thermoforming. Since a simpler, less expensive die is used, the overall cost of production is lower.
  • It is versatile: Profile extrusion allows for a lot of versatility as products using this process can be created with complex designs, varying thicknesses, and various colors and textures. You can also put in additives to help change the properties of the product, making it more durable or fire-resistant.
  • Alterations are easy: Since the material is still hot after the extrusion process, it can continue to be manipulated once it exits the extruder. Different dies, rollers, and shoes can be changed out to alter the shape quickly and easily.

What Materials Are Used for Plastic Extrusion?

You can use a wide variety of thermoplastics for the plastic extrusion process. The material will be heated to a melting point but not so high that it compromises the integrity of the plastic, which allows more types of plastics to be used.

While many types of plastics will work for plastic extrusion, some of the ones most commonly used include:

What Is the Difference Between Plastic Extrusion and Plastic Injection Molding?

The plastic profile extrusion process is designed for a two-dimensional, continuous linear shape to be developed. Molten plastic will be pushed through an extruder through a die shape and manipulated to the correct length during the cooling process.

Injection molding is designed to produce a three-dimensional shape that is not continuous and is bound by size to the size of the mold. Melted plastic will be injected into the 3D mold, where it will cool and then be removed.

What Are Plastic Extrusion Applications?

Extruded products can be used in various industries and applications, from construction and building to automotive. Some of the most popular applications for the use of plastic extruded parts and products include:

  • Tubing and pipes: Since plastic extrusion produces a continuous profile, it is the most cost-effective method for making pipes and tubes, such as gutters and PVC pipes.
  • Profiles for windows and doors: Plastic extrusion can be used in several home construction applications, including door and window frames. With a wide variety of plastics able to be used and additives that can improve the properties of the plastics, extruder products can be made to be weather and flame-resistant, which is ideal in home construction.
  • Blinds: Blinds are created using identical profile pieces created from thermoplastics, most commonly polystyrene. This continuous profile makes their products ideal for plastic profile extrusion.
  • Wire insulation: Thermoplastics are commonly used in electrical applications due to their thermal stability and insulation properties. Since the insulation for wiring is a 2-dimensional continuous shape, extrusion is the perfect manufacturing option.
  • Weatherstripping: Weatherstripping products, such as draft excluders, are commonly produced using plastic extrusion methods. Using rubber polymers, weatherstripping can be easily created and perform its function well using this process.
  • Windshield wipers: One application where plastic extrusion is used in the automotive industry is producing windshield wipers. They can be created using plastic extrusion alone or in a co-extrusion process using natural and synthetic rubber.

Why CBM When Choosing an Injection Molding Company?

When searching for the best custom plastic extrusion company to produce your final product or part, look no further than CBM Plastics. A leader in the plastics industry, CBM plastics has the right solution for your plastic manufacturing needs. The U.S. location of their facility means that you will have greater control over the quality of your plastic manufacturing run and better control over the shipping. Get started on your next plastic project today by calling CBM Plastics to find the best solutions.