The Different Types of Plastic Fabrication

Blow moulding

Plastic fabrication is the process of manufacturing and manipulating plastic materials to create a diverse range of products and components. With its versatile properties and applications, plastics have become an integral part of various industries, including automotive, aerospace, medical, electronics, and construction. 

Are you in search of a reliable, high-quality custom plastic fabrication provider? Look no further than Johndec Engineering Plastics WA. With our extensive experience and expertise in a wide range of plastic fabrication techniques, we’re here to help you find the perfect solution for your project, no matter how complex or intricate. Don’t wait any longer—contact Johndec Engineering Plastics WA today, and let’s bring your vision to life! 

Injection Moulding 

Injection moulding is one of the most widely used methods of plastic fabrication. The process begins with the heating of plastic pellets in a barrel, where they are melted and mixed. The molten plastic is then injected into a mould cavity under high pressure. 

Once the plastic cools and solidifies, the mould is opened, and the finished product is ejected. The mould can be made from various materials, such as steel or aluminium, depending on the desired production volume and part complexity. 

Advantages 

  • High production rates and efficiency—it’s a continuous process, allowing for high production rates and increased efficiency, making it ideal for large-scale manufacturing of plastic profiles 
  • Excellent repeatability and precision 
  • Ability to produce complex shapes and intricate details 
  • Low per-unit cost for high-volume production 

    Limitations 

    • High initial tooling and equipment costs 
    • Limited material options, as not all plastics are suitable for injection moulding 

      Applications 

      • Plastic bottles and containers 
      • Toys and action figures 
      • Automotive components and housings 
      • Medical devices 

      Blow Moulding 

      Extrusion blow moulding is a two-step process that begins with the extrusion of a parison from a plastic resin, such as high-density polyethylene (HDPE), polyethylene terephthalate (PET), or polypropylene (PP). The parison is extruded vertically downwards between two open mould halves. 

      Once the parison reaches the desired length, the mould closes around it, capturing the plastic at the bottom and forming a seal. Air is then blown into the parison through a blow pin, inflating it to take the shape of the mould cavity. After cooling and solidifying, the mould opens, and the finished product is ejected.

      1. Extrusion blow moulding: In this technique, the parison is extruded vertically from a plastic resin, such as polyethylene or polypropylene. The mould closes around the parison, forming a seal at the bottom. Air is then blown into the parison, inflating it to take the shape of the mould cavity. Once cooled, the mould opens, and the finished product is ejected. This method is commonly used for producing plastic bottles, containers, and large hollow parts.

      2. Injection blow moulding: This process begins with the creation of a parison through injection moulding, where a core rod forms the internal shape. The parison is transferred to a blow moulding station, where it is inflated by blowing air into it. This method allows for high precision and is suitable for small, intricate hollow components like pharmaceutical bottles and medical devices.

      3. Stretch blow moulding: Similar to injection blow moulding, stretch blow moulding includes an additional stretching step during inflation. The parison is mechanically stretched in the axial direction, enhancing the material’s strength, clarity, and barrier properties. This results in thinner, stronger, and lighter products, making it an ideal choice for high-quality PET bottles and other packaging applications. 

      Advantages 

      • Suitable for manufacturing hollow, lightweight parts 
      • Good for producing products with uniform wall thickness 
      • Low tooling and equipment costs compared to injection moulding 

      Limitations 

      • Limited complexity and precision compared to injection moulding 
      • Slower production rates due to the multiple steps involved, such as extruding or injecting the parison, inflating it, cooling, and ejecting the final product 

      Applications 

      • Plastic bottles and containers (e.g. beverage, detergent, and cosmetic containers) 
      • Fuel tanks 
      • Sporting goods, such as balls and bats 

        Rotational moulding 

        Rotational moulding, or roto-moulding, is a unique plastic fabrication method employed to create hollow objects by heating a mould containing plastic material and rotating it around two perpendicular axes. This rotation ensures the plastic material evenly coats the interior of the mould, resulting in a hollow product with uniform wall thickness. 

        Advantages 

        • Ideal for producing large, hollow products with complex shapes 
        • Low tooling and equipment costs 
        • Minimal waste, as excess material can be reused 

        Limitations 

        • Slower production rates compared to other methods 
        • Limited material options and design complexity 

          Applications 

          • Large tanks and containers 
          • Playground equipment 
          • Kayaks and canoes 

          Thermoforming  

          Thermoforming is a versatile plastic fabrication process in which a plastic sheet is heated until it becomes pliable and then shaped using a mould or die. The plastic is subsequently cooled and trimmed, resulting in the final product. This process is suitable for producing large, thin-walled, and complex parts with precise details. 

          1. Vacuum forming: In this thermoforming technique, a heated plastic sheet is placed over a mould, usually made from wood, aluminium, or composite materials. The air between the sheet and the mould is vacuumed out, causing the plastic to conform to the mould’s shape, forming the desired product.  

          Once the plastic cools and solidifies, it is removed from the mould and any excess material is trimmed. Vacuum forming is a cost-effective method that is suitable for producing large, simple parts with moderate detail, such as packaging, trays, and automotive components. 

          2. Pressure forming: Pressure forming is similar to vacuum forming but offers more precise detail and better surface finishing. In this process, the heated plastic sheet is placed over a mould and compressed air is applied to the backside of the sheet. The air pressure forces the plastic against the mould, ensuring a tighter fit and more accurate reproduction of the mould’s details. 

          This technique is ideal for producing parts with intricate designs, textured surfaces, and sharp corners. Applications include medical device enclosures, electronic housings, and high-quality consumer products. 

          Advantages 

          • Rapid prototyping and production capabilities 
          • Lower tooling costs compared to injection moulding 
          • Ability to produce large parts with minimal material waste 

          Limitations 

          • Limited to relatively simple shapes and shallow draw depths 
          • Less precise than injection moulding, with lower repeatability 
          • Not well-suited for high-volume production 

          Applications 

          • Packaging materials, such as blister packs and clamshells 
          • Automotive parts, including dashboard components and interior trim 
          • Medical device enclosures and trays 

            Extrusion moulding 

            Extrusion is a continuous plastic fabrication process that involves forcing heated plastic through a die, creating a consistent, long profile. The extruded profiles can be cut into desired lengths and used for various applications. 

            1. Single screw extrusion: Single screw extrusion is the most common type of extrusion process. It utilises a rotating screw within a barrel to push the molten plastic through a die, forming a continuous profile. The screw has three main zones: the feed, compression, and metering zones, which help convey, compress, melt, and ensure a consistent flow of molten plastic into the die. 

            2. Twin screw extrusion: Twin screw extrusion uses two intermeshing screws that rotate in the same or opposite directions. This design provides better mixing, melting, and conveying capabilities, especially for heat-sensitive, high-viscosity, or filled materials. 

            Advantages 

            • High production rates and efficiency 
            • Continuous profiles with consistent cross-sections 
            • Wide range of material options—it can process a wide variety of materials, including thermoplastics, thermosetting plastics, elastomers, and even metals 

              Limitations 

              • Limited to producing long, linear shapes 
              • Lower precision and surface finish compared to other methods 

              Applications 

              • Pipes, tubes, and hoses 
              • Window frames and door profiles 
              • Plastic sheeting and film 

              Compression moulding 

              Compression moulding is a well-established plastic fabrication process used to create a variety of products, from large, flat components to moderately curved parts. In this method, preheated plastic material, often in the form of a preform or sheet, is placed into a heated mould cavity. Pressure is applied, forcing the plastic to conform to the mould’s shape. 

              Advantages 

              • Good for producing thick, heavy parts—ideal for manufacturing large, heavy, and thick-walled components 
              • Suitable for high-temperature and high-strength materials 
              • Low residual stress in the final product 

              Limitations 

              • Slower production rates compared to other methods 
              • High labour and energy costs 
              • Limited to relatively simple shapes 

              Applications 

              • Automotive panels and body components 
              • Large containers and pallets 
              • Electrical housings and enclosures 

              Learn even more about the plastic fabrication process here. 

              Conclusion 

              Plastic fabrication is a versatile field that offers a wide array of techniques to create products and components for various industries. Each method has its unique advantages and limitations, making it crucial to choose the right process based on your project’s specific needs and requirements. 

              At Johndec Engineering plastic manufacturer Perth, we specialise in custom plastic fabrication and are committed to helping you find the perfect solution for your project. Our experienced team will guide you through the process, ensuring the best results tailored to your unique application. Don’t hesitate to reach out to us and let Johndec Engineering Plastics WA bring your vision to life. Contact us today to discuss your plastic fabrication Perth project and discover the difference our expertise can make.