Thermoplastics

  • A Comprehensive & Simple Guide to Understanding, Using, and Buying Thermoplastics

    With thousands of variations across the planet, thermoplastics are one of the most versatile materials on earth. They are found in all kinds of applications, from everyday household objects like mixing spoons in the kitchen, right up to aircraft parts, and they’re even used in parts of the International Space Station!

    As with all materials, thermoplastics can be subject to breakages and faults. In this article we’ll discuss how to know what kind of thermoplastics you have and what would be the best way to repair that material so you can continue to use it. Additionally, we offer plastic welding rods to buy online, as well as offer a range of custom solutions and ask that you call to discuss your specific needs and requirements for a custom quote.

    What Are Thermoplastics?

    There’s a huge variety of plastic products and materials on the market but thermoplastics are unique in their ability to be molded and reformed almost infinitely.

    Thermoplastics are a material, usually a plastic polymer, that can be cooled and heated several times without any change in the thermoplastic’s chemical or mechanical properties.

    As the name would suggest, thermoplastics react to heat, meaning that when they are heated they lose their form and may even become molten (liquid). When they’re cooled they become hard and strong. This means that thermoplastic is useful in a wide range of everyday uses: automobile parts, shampoo bottles, bulletproof vests, storage containers, and toys to name a few.

    Thermoplastics vs Thermosets

    It’s easy to get confused between thermoplastics and thermosets, but here is a brief rundown of what both polymers are and how they differ:

    • Thermoplastics - Can be heated up, reformed, and reshaped almost indefinitely to be reused and repaired easily. Thermoplastics have a low melting point, but they are relatively strong when cooled.
    • Thermosets - Can only be heated and formed once before changing their chemical makeup. Thermosets have a higher melting point but they get stronger as they cool down.

    What are The Advantages of Thermoplastics?

    Due to their versatility, thermoplastics have a huge list of advantages over thermosets and other plastics.

    The number one advantage to thermoplastics is that they can continually be remelted and reformed, this means that manufacturers will see less wastage, and recycling thermoplastic products are usually fairly easy

    If you’re looking to make a prototype or a product that requires a high impact value, thermoplastics are a perfect choice.

    Types of Thermoplastics and Their Uses

    Thermoplastics come in a number of different styles and resins; these may include:

    • Polycarbonate - tough and transparent, used in many engineering applications due to its high heat resistance and stability.
    • Acetal Copolymer Polyoxymethylene - Easy to process low melting plastic with high strength.
    • Acetal Homopolymer Polyoxymethylene - Great strength and good for high repeated impact products.
    • Acrylic (Polymethyl Methacrylate) - A versatile plastic used in place of glass in many applications such as visors, window panes, lights, lenses, etc
    • Nylon - A strong plastic often used in place of cotton thread (and woven into fabric sheets) in fabrics such as parachutes, ropes, and stockings.
    • Polyvinyl Chloride (PVC) - A hard and versatile plastic found in such applications as drain pipes and guttering but also in more flexible thermoplastic uses in place of fabric (such as clothing).
    • Teflon (Polytetrafluoroethylene) - Known as a very tough plastic used for coating on metal pipes and cookware.

    Can Thermoplastics be Welded?

    Due to how thermoplastics behave when heated, they can be easily welded to join two pieces or to repair a fault. Usually, this involves using a thermoplastic rod to create a smooth join.

    What is the melting point of plastic?

    • PP - Roughly 266F.
    • PVC - Roughly 185F.
    • HDPE - Roughly 267F.
    • HMW HDPE - Roughly 267F.

    How to Tell What Kind of Plastic You Want to Weld

    When it comes to welding, you’ll need to do the ‘burn test’ to determine the type of plastic you want to weld as each behaves differently:

    • Polyethylene - No smoke with a bluish flame.
    • Polypropylene - Not a lot of smoke, orange flame, and not a lot of smell.
    • Acrylics - Black sooty smoke that smells sweet.
    • PVC - No flame.
    • Polyurethane - Black smoke with a very active and spluttering flame.

    How to Select The Right Plastic Welding Rod?

    When welding plastic together, a welding rod will be required to ensure a smooth and strong join that will last. It’s uncommon for rods to be made from different types of plastics to the ones that you are welding, this means your first step is to identify your plastic-type using the burn test detailed above. Remember, to ensure a strong plastic weld you’ll want to make sure you are welding the same plastic together.

    Once you know the plastic you’re using, you’ll want to do a small test, melt the end of the rod and weld it to a small piece of the plastic. If the rod is secured and won’t come off, you’re using the right rod for your weld.

    Having quality welding equipment is vital for this process to happen correctly and safely. answer any questions you may have.

    We offer four types of plastic welding rods for direct purchase right from our online store.

    • HDPE plastic welding rods
    • PVC plastic welding rods
    • PP plastic welding rods
    • HMW HDPE welding rods

    In addition to the above thermoplastics types for sale we also provide custom orders. Contact the team at Heatgun.com on (1-800-241-4628) or drop us a message and we’ll be happy to discuss your needs and specifications to provide you with a custom quote.