The Plastic Extrusion Process
The plastic extrusion process is wide and varied, and can take many different forms, including:
- Single extrusion
- Tubing extrusion
- Coextrusion: Used to create plastic layers of varying thickness in the extrusion process
As might be expected, different applications require different types of plastics and in different shapes and sizes, which in turn requires a specialized manufacturing process. One type technique used to create different shapes out of plastic is called plastic extrusion. The plastic extruding process begins in the form of tiny plastic pellets. These premade plastic pellets are first shipped to the manufacturing facility, where additives such as colorants and UV inhibitors are then added as needed. The raw plastic materials go through a very specialized process as explained below before the finished product can be used in various products.
Plastic products take many forms known as plastic profiles. They all start as raw material called resin. In the plastic extrusion process, resin beads are melted down and filtered for uniform consistency. In order for the resin to be pushed through a die cut for the final product shape, the melt temperature must be reached. This continuous process has many steps necessary as listed below:
1. The first step in this process is to place the resin granules directly inside the extruder’s hopper. Different applications may require different types of additives such as colorants, UV inhibitors, and anti-oxidants. These are also added to the hopper, before the resin is gravity-fed through the ‘feed throat into the barrel of the extruder. Inside the barrel is a long, rotating screw which directs the resin forward towards the die. It begins to melt as a result of the high temperatures, which depending on the type of thermoplastic being used, can range from 200 to 275 degrees.
2. Next, the molten plastic flows from the hopper down through the feed throat. This dispenses them onto a large spinning screw operating within a heated barrel.
3. The beads then pass through the barrel on the screw while being heated to the melting temperature that is required for that type of plastic. When it reaches the end of the screw, the plastic is thoroughly mixed and has a a thick consistency. The plastic extrusion process can be used to create basic shapes like plastic sheeting and piping, but it can also be used to create more advanced shapes using a custom die.
4. The plastic sheet flows across a screen and a breaker plate. The screen pack removes any contaminants or inconsistencies in the plastic. Then, the breaker plate changes the motion of the plastic from rotational to longitudinal which gets it ready for the die process.
5. The final step involves the die for an individual plastic profile. This is more than just a hollowed-out shape of the final product. It is designed so that the plastic flows smoothly and evenly from the cylindrical profile of the extruder into the final profile shape. Cooling rolls help to make the plastic keep it’s final form.
Why Is This Process Necessary?
Plastic extrusion is used to produce a large range of products on the market today, from building materials to consumer products. Pipes, tubing, window frames, electrical covers, fence, edging, and weather stripping are just a few of the common items made by plastic extrusion.
One of the largest benefits that plastic extrusion and injection molding offers is continuous production. Provided with enough raw materials, machines used to extrude plastic don’t have to stop, because the entire process moves at the same pace without any stopping.
Through innovative research and development, we are able to design products that meet your specific needs and reduce cost by eliminating assembly and extending functionality. Our focus on technology allows us to generate an in-depth analysis of your single plastic extrusion application in order to ensure you receive the very best value in tooling design, manufacturing, and material selection.
Materials That Can Be Extruded
- Nylon (nylon 6, nylon 6/6, nylon MDS)
- Polyethylene, low and high-density
- Acetal (copolymer)
- Polypropylene (different variations of polymer)
We can form these materials into sheets, strips, rolls, or coils depending on your needs. You can also choose from a wide array of colors when creating your final product, although color capacities can vary by manufacturer.
Before starting a plastic extrusion project, you need to ensure your project’s tolerances match the capabilities of the material being used. Material thicknesses vary tremendously, which could result in varied outcomes. Contact us today with any questions you may have about plastic extrusions.
Choosing Plastic Types
Choosing the right plastic material for each individual profile is very important. Dozens of materials can be extruded and each is chosen for a different set of properties. Polyethylenes, PVCs, and polypropylenes vary greatly in molding and cooling temperature. They also have different strength, integrity, ability to withstand chemicals, and production cost.
PVC products and polystyrene products are often chosen for their low cost and high dimensional stability. Although they don’t have the temperature resistance needed for other applications. Polypropylene products have exceptional chemical and moisture resistance, but have different strengths and melting temperatures. It is important to contact us so we can discuss the right plastic type for your project.
The Benefits of Plastic Extrusion
There are many benefits of plastic extrusion and it can transform the way your business interacts with plastic manufacturing. The plastic extrusion process is continuous and can establish a high-volume output. This is ideal for businesses that find themselves with high demand during specific times of the year or if the output of the company has grown quicker than its internal equipment can handle.
Plastic extrusion is perfect for parts that are consistent in wall thickness. It is also ideal for any plastic profiles that are longer or wider than those created by other forms of plastic manufacturing. Plastic films, rods, bags, piping, weather stripping and wire insulation are just some of the products that are created successfully by plastic extrusion.
Frequently Asked Questions
Q: How many plastic extrusion and tubing projects does Plastic Extrusion Technologies take on?
A: We average approximately 100-120 new plastic extrusion and tubing projects every year and take pride in every product we produce for our clients.
Q: What kind of engineering experience do you have?
A: Our staff has over 30 years of engineering experience, equipping us with the knowledge and capability to fully serve all of your extruded plastic engineering needs.
Q: Can Plastic Extrusion Technologies trouble shoot and provide solutions to help me achieve a cost effective end product?
A: Yes. Our team of experts will work with you to provide the most cost effective solutions to meet your needs and budgetary goals.
Do many firms require the services of a company that works with extruded plastic? More than you might think! Everyone from window manufacturers to adhesives producers use the types of extrusions produced by Plastic Extrusion Technologies. If you are looking for a plastic extruder with over 100 years’ experience, contact us today. We would be happy to answer any questions you might have and meet your business’s needs.
Plastic Extrusion Technologies supplies plastic extruded products to companies all over the United States. Below are some of the locations where we have recently served:
- Dallas, TX
- Columbus, OH
- New York, NY
- Miami, FL
- San Diego, CA
- Detroit, MI
- Boston, MA