Plastic Fabrication

Plastic Fabrication: Methods, Benefits, and Frequently Asked Questions

What is plastic fabrication?

Plastic fabrication is any of several processes used for molding plastic into different sizes. These processes can help to increase product performance, help to reduce maintenance, or to manufacture components for nearly every industry globally. Industries from medical and pharmaceutical, to aerospace, to automotive, to construction, to agriculture all use plastic fabrication.

Plastic Fabrication Methods

There are several different types of plastic fabrication methods. Which method you use depends on factors such as the product or part itself, its application, and its size and shape. Some of the methods may not be as efficient for fabricating certain types of plastics, so it’s important to understand what you want your outcome to be and how to get to that outcome. When deciding which method to use, think about:

• the need for single plastics versus plastic compounds
• the intended proportion of plastic to non-plastic material in the product
• the role of plastic in your fabrication process (e.g., adhesion, lamination, base product)
• the dimensions and use of the final product

Let’s take a look at several of the most common plastic fabrication methods.

Plastic Welding: The most common method of plastic fabrication, this is the process of joining together two thermoplastics by melting the surfaces and pressing them together. The equipment used in plastic welding depends on the method and type of plastic. To learn more about the different types of plastic welding methods, check out plastic welding 101.

Compounding (or blending): This is the process of two or more plastics being melted to form a mixture (blend), and then they are made into new shapes, often improving the performance of the final product. Some common plastics used are basin resin and flame-retardants.

Plastic Lamination: This process is commonly used to improve the durability or aesthetics of a product by using heat and pressure to create a plastic barrier along the surface material. Synthetic resin and film are two of the most common plastics used for lamination.

Molding: This is the process in which plastic is formed into a specified shape through the use of heat and then is set to cool and harden around or within a mold. There are several types of plastic molding, but the most common types are blow molding, rotational molding, and injection molding.

Plastic Extrusion: This process is used to make plastic sheets, tubes, and pipes by melting plastic and making it into a pellet. This method can endure stress better than other types of fabricated plastics because extruded plastics don’t have seams.

Plastic Foaming: This process uses polystyrene and polyurethane to create plastic foam; it results in plastic insulators that can be used as an insulator for buildings.

Die Cutting: This process is an efficient method to cut plastic film and thin plastic sheets into finished parts. Some common plastics made are polycarbonate and polyester film.

Thermoforming: This process has thermoplastics being softened using heat and the reshaped according to product need. Tooling costs are comparatively low in looking at other fabrication methods, which is because the thermoformed parts don’t need to be treated at high temperature and pressures.

Plastic Fabrication Benefits

There are many benefits to fabricating plastic. First, just for using plastic instead of steel or metal, you’re saving a lot in costs. Plus, with the use of plastic, the high malleability makes it extremely versatile. Now let’s look at the benefits of the actual fabrication process.

Less expensive - Not only is the plastic material itself less expensive than other materials, the fabrication process is also more cost-effective because more parts can be made per hour, and other components that may be needed, such as stamping or casting for parts, all cost less to produce.

Ease of forming - Because of its high malleability and low melting point in comparison to other materials, you can form with relative ease simple and complex products from plastics.

Reduced finishing - Different from most metals, you can color plastics before fabrication, doing away with some post-fabrication procedures, such as painting.

Faster production - Fabricating plastic often entails fast cycle times and quick turnover rates.

Chemical resistance - Plastics are typically less prone to chemical reactions, such as rusting or oxidation, than metals are.

Longer life span - Thanks to the plastic fabrication process, it can be a one-time deal, meaning once it’s done, you won’t have to maintain it or do it again, which means the final product will last longer.

Plastic Welding: FAQs

Of the different types of plastic fabrication methods, plastic welding is the most commonly used. Plastic welding is a process of uniting in a molecular bond two compatible thermoplastics generally with the aid of heat. In other words, thermoplastics are joined together by melting the surfaces and pressing them together. When it comes to plastic welding, you may have some questions that we’re happy to answer.

What Types of Plastic Can Be Welded?

You can use any type of thermoplastic for welding, which is a plastic that becomes pliable at a specific temperature and will solidify when it cools. A few of the more common types include:

• Polypropylene
• High-density polyethylene
• PVC (polyvinyl chloride)
• CPVC (Chlorinated polyvinyl chloride)
• Polycarbonate
• ABS (acrylonitrile butadiene styrene)

Is Plastic Welding Easy?

Plastic welding may sound daunting, but it’s a pretty straightforward task that can easily be done at home with a plastic welding gun and a welding rod.

There are three main steps in plastic welding, which are pressing (ensuring sufficient pressure when pushing the plastics together), heating (achieving the right melt temperature), and cooling (length of time the join is allowed to cool before releasing the pressure).

• Pressing: The application of pressure, which is often used throughout both the heating and cooling stages, is used to retain the parts in the proper orientation and to improve melt flow across the interface.
• Heating: The purpose of the heating stage is to allow intermolecular diffusion from one part to the other across the faying surface (melt mixing).
• Cooling: Cooling is necessary to solidify the newly formed bond; the execution of this stage can have a significant effect on weld strength.

How Do I Weld Plastic?

Once you’re all set to start welding, here are some instructional tips:

1. Secure the plastic together by tack welding the ends. Using a tacking nozzle, run the tip of the nozzle along the weld line, which ensures a slight melting of the two plastics together, thus closing up the joint interface and preventing the plastics from moving as you complete the weld.
2. Trim the end of the welding rod using angle cutting pliers. By doing so, you’re increasing your chances of getting a very smooth weld without any plastic bubbling.
3. Insert the welding rod into a speed nozzle on your welding gun.
4. Move the tip of your welding gun over the plastic, touching just the edge of the nozzle to the plastic. Heat until you see the plastic begin to melt.
5. Be consistent in terms of pressure and pace. Move at a steady, deliberate pace so you can melt the plastic just enough to bind them without burning them.
6. Upon completion of your weld, wait at least 5 minutes for the plastic to cool.

What Do I Need to Think About Before Welding?

There are a few things you need to think about before you begin your plastic welding process.

• You’ll need to identify what heat temperature will work best for your project. You’ll probably need temps within the range of 200 and 300 °C (392 and 572 °F).
• Ensure the welding rod is the same material as the plastic to be welded. The end of the welding rod should be trimmed to a pencil-point form.
• Your welding gun should be the proper size for your project. Hand-held welding guns should not be used for thickness beyond 10mm.
• Consider using a welding kit because they are fully equipped, ensuring you don’t forget anything you might need mid-project process.

Plastic is everywhere and there are an unlimited number of things you can do with plastic. And when it comes to using plastic in a manufacturing process, or increasing product performance, or reducing maintenance operations, you may find yourself jumping into the plastic fabrication process. But the great news is that plastic fabrication is filled with many benefits, such as better cost, better reliability, and better ease of use than fabrication of other types of non-plastic materials. For your plastic fabric needs, our AWARD-WINNING welding tools will help you get the best final product. It’s crucial that you can depend on your supplier not only to provide the best products but to also provide guidance in the process if needed, and that’s what we here at Leister do for you. We are here to serve you; that’s our goal!