Plastic Fabrication Overview: Custom Plastic Parts

Plastic fabrication is used for processing small or large plastic parts in low or large quantities by specific techniques and machinery. At Sungplastic, you can enjoy our one-stop service, including part design to finished product output. Read more about the specific processing and manufacturing services for plastics.

What is Plastic Fabrication?

Plastic fabrication is the process of shaping, forming, and assembling plastic materials into various products and components. This plastic fabrication process involves a range of techniques, such as molding, extrusion, thermoforming, and machining, to transform raw plastic materials into usable items. Plastic fabrication is a crucial aspect of modern plastics manufacturing and plays a pivotal role in the production of a wide array of everyday products, from packaging materials and consumer goods to automotive parts and medical devices.

Advantages of Plastic Fabrication

• • Cost-Effectiveness
    Plastic fabrication processes are often cost-effective due to the low material costs, high production speeds, and reduced labor requirements compared to other materials like metals.
  • Versatility
    Plastics can be molded into a wide range of shapes and sizes, making them suitable for diverse applications across various industries.
  • Rapid Prototyping
    Plastic fabrication techniques, such as 3D printing and injection molding, enable rapid prototyping and iterative design, reducing development time.
  • Low Weight and Corrosion Resistance
    Plastics are lightweight, making them advantageous in industries where weight reduction is critical, such as automotive and aerospace. Many plastics are naturally corrosion-resistant, reducing the need for additional protective coatings.

Applications of Plastic Fabrication

Plastic fabrication has become an integral part of our lives due to their versatility, durability, and cost-effectiveness.
Plastic fabrication is vital for numerous industries, including:

• • Packaging
    Plastic fabrication is essential for creating containers, bottles, and packaging materials used in the food and beverage, pharmaceutical, and cosmetic industries. These materials offer protection, convenience, and shelf life extension for products.
  • Automotive
    Plastics manufacturing are used extensively in the automotive industry for components such as dashboards, bumpers, interior trim, and fuel tanks. Plastic fabrication techniques are crucial for producing these parts efficiently and cost-effectively.
  • Construction
    Plastics manufacturing are used in construction for various purposes, including pipes, insulation, roofing materials, and decorative elements. Plastic fabrication ensures that these plastic components meet the required specifications.
  • Medical
    Medical devices and equipment often incorporate plastic parts due to their biocompatibility and ease of sterilization. Plastic fabrication is essential to produce precision components used in surgeries, diagnostics, and patient care.
  • Electronics
    Plastics manufacturing are found in electronic devices, from casings to connectors. Plastics manufacturing techniques help create intricate, customized components for electronics manufacturing.
  • Consumer Goods
    The production of consumer goods like toys, kitchen appliances, and household items heavily relies on plastic fabrication for molding and assembly.
  • Aerospace
    Lightweight and high-strength plastics are used in aircraft components. Plastic fabrication ensures that these components meet strict safety and performance standards.

Plastics Used in Fabrication

There are many various plastics used to manufacture various custom plastics parts or products. What’s more, with good properties and a wide range of applications, the cost of plastics are controllable and relatively low, which is becoming more and more popular in the manufacturing market.

Thermoplastics & Thermosetting Plastics

Plastics can be broadly categorized into two main groups: thermoplastics and thermosetting plastics.

Thermoplastics are plastics that can be melted and re-molded multiple times without undergoing significant chemical change. Common examples include polyethylene, polypropylene, and PVC.

Thermosetting plastics are plastics that, once cured or set, cannot be re-melted or reshaped without undergoing chemical degradation. Examples include epoxy resins and phenolic resins.

Commonly Used Plastic Materials

• • Polyethylene(PE)
    Polyethylene is a versatile thermoplastic known for its low cost, chemical resistance, and excellent electrical insulating properties. It is used in packaging, pipes, and various consumer products.
  • Polypropylene(PP)
    Polypropylene is lightweight, durable, and resistant to moisture, making it suitable for packaging, automotive components, and medical devices.
  • PVC (Polyvinyl Chloride)
    PVC is widely used in construction, electrical cables, and plumbing due to its rigidity and fire-resistant properties.
  • Acrylic (PMMA)
    Acrylic is a transparent thermoplastic known for its optical clarity and weather resistance. It is used in windows, signage, and decorative applications.
  • Polycarbonate(PC)
    Polycarbonate is a durable thermoplastic known for its high impact resistance. It is used in eyewear lenses, safety shields, and automotive components.
  • ABS(Acrylonitrile Butadiene Styrene)
    ABS is the plastic used to build Lego bricks. Fused deposition modeling (FDM) 3D printers use ABS filament to create objects using computer assisted manufacturing (CAM).
  • Polyethylene Terephthalate (PET or PETE)
    PET is another thermoplastic polymer and is used to create polyester. Some filament 3D printers use PET-based filaments.
  • Polystyrene (PS)
    Polystyrene is a lightweight plastic with good insulation properties. It can be clear (crystal) or foamed (expanded polystyrene, or EPS).
    Used in disposable tableware, packaging materials, insulation, and consumer products.
  • Polyamide (Nylon)
    Polyamides are strong, durable plastics with good chemical resistance. They come in various forms (e.g., Nylon 6, Nylon 66). Used in textiles, automotive components, and engineering applications.
  • Polyurethane (PU)
    Polyurethanes are versatile plastics with a wide range of properties, including flexibility and resilience. Used in foams, sealants, adhesives, and elastomers.
  • Polyethylene Glycol (PEG)
    PEG is a water-soluble polymer used in pharmaceuticals, cosmetics, and as a lubricant.
  • Polyvinyl Acetate (PVA)
    PVA is often used as a glue or adhesive and in paper coatings.

Characteristics and Properties of Plastics

Plastics exhibit a range of characteristics and properties that make them suitable for various applications.

• • Density
    Plastics can have low to high densities, impacting their weight and strength.
  • Thermal Conductivity
    Plastics are generally poor conductors of heat.
  • Chemical Resistance
    Plastics can resist chemical corrosion, making them suitable for harsh environments.
  • Electrical Insulation
    Many plastics are excellent electrical insulators.
  • Transparency
    Some plastics are transparent or translucent, while others are opaque.
  • Mechanical Properties
    Plastics can vary widely in terms of strength, flexibility, and toughness.

Understanding these properties is essential for selecting the right plastic material for a specific plastics manufacturing application, ensuring that the final product meets the required performance standards.

Plastic Fabrication Techniques

Plastic fabrication techniques offer a wide range of options for creating diverse plastic products with varying shapes, sizes, and properties. The choice of technique depends on factors such as the material, desired properties of the final product, production volume, and cost considerations.

Plastic Injection Molding

Plastic injection molding is one of the most widely used plastic fabrication techniques. It involves injecting molten plastic material into a mold cavity under high pressure and then allowing it to cool and solidify.
The process starts with the heating of plastic pellets or granules to their melting point. Once molten, the plastic is forced into a mold cavity by a hydraulic or mechanical press.
After cooling and solidification, the mold opens, and the finished part is ejected. This process is highly repeatable and can produce complex, precision parts with minimal waste.

Common products produced using injection molding include plastic housings for electronics, automotive interior components, medical syringes, and toys. Its ability to create intricate, high-precision parts makes it ideal for mass production.

Plastic CNC Machining

CNC (Computer Numerical Control) machining involves cutting and shaping plastic materials using computer-controlled precision machinery.
The process starts with a CAD (Computer-Aided Design) model, which is converted into G-code instructions that guide the CNC machine.
Various cutting tools, such as mills and lathes, are used to remove material from a solid plastic block or sheet, creating the desired part.

CNC machining is used for producing custom or low-volume parts that require high precision and tight tolerances. It is commonly employed in industries like aerospace, electronics, and medical devices for creating prototypes, specialized components, and intricate parts.

Extrusion

Extrusion involves forcing a molten plastic material through a die to create a continuous profile or shape.
The plastic material is first melted in an extruder, a machine with a screw-like mechanism that heats and pushes the plastic forward.
The molten plastic is then pushed through a specially designed die that imparts the desired shape.
After exiting the die, the plastic is cooled and cut into the desired lengths or shapes.

Extrusion is commonly used for creating plastic sheets, pipes, tubing, and profiles. PVC pipes, window frames, and plastic films are examples of products made through extrusion.
It is a cost-effective method for producing long, continuous lengths of plastic products.

Blow Molding

Blow molding is a technique used to create hollow plastic parts by inflating a heated plastic parison (a hollow tube) inside a mold cavity.
There are three main types of blow molding: extrusion blow molding, injection blow molding, and stretch blow molding, each with its variations.
The plastic is heated and shaped within a mold, with the help of compressed air, to take on the desired form as it cools and solidifies.

Blow molding is commonly used for producing plastic bottles, containers, and automotive components. It is known for its ability to create lightweight, hollow structures with good strength and durability.

Thermoforming

Thermoforming, whose main types are vacuum forming and pressure thermoforming, involves heating a flat plastic sheet until it becomes pliable and then forming it over a mold to create a specific shape.
The process includes three main steps: heating the plastic sheet, forming it using vacuum, pressure, or mechanical means, and cooling to solidify the shape.
After cooling, excess material is trimmed, leaving the final part.

Thermoforming is used to make a wide range of products, including packaging, disposable containers, automotive interior panels, and signage.
It is favored for its cost-effectiveness, especially in high-volume production.

Compression Molding

Compression molding is a technique where plastic material, typically in the form of pre-cut sheets or pellets, is placed into a heated mold cavity. The mold is then closed, applying pressure to compress the material and shape it.
It is often used for producing thermosetting plastics and composite materials, including items like appliance parts, electrical insulators, and automotive components.

3D Printing/Additive Manufacturing with Plastics

3D printing, also known as additive manufacturing, builds plastic parts layer by layer from a digital 3D model.
The process typically involves depositing melted plastic filament or resin onto a build platform, where it solidifies.

Various 3D printing technologies exist, including Fused Deposition Modeling (FDM), Stereolithography (SLA), and Selective Laser Sintering (SLS), each with its characteristics.
3D printing is used for rapid prototyping, custom manufacturing, and creating complex geometric shapes.
It finds applications in industries like aerospace, healthcare (for producing custom prosthetics and implants), automotive (for rapid prototyping), and consumer goods (customized products).

Reaction Injection Molding (RIM)

Reaction injection molding involves mixing two or more reactive liquid components, often polyurethane or other thermosetting polymers, and injecting them into a mold. The reaction between the components causes the material to solidify.
RIM is utilized for manufacturing items requiring high-strength, impact resistance, and complex geometries, such as automotive bumpers and body panels.

Compounding (or Blending) Plastic

Compounding is the process of mixing different plastic materials or additives together to create a customized plastic compound with specific properties. This technique allows manufacturers to tailor the characteristics of plastics to meet the requirements of particular applications.

Compounding is a type of custom plastic fabrication that combines two or more plastics into an amalgam before forming them into a single part.

Some common types of plastic compounds include:

• • • Polymer fillers (which are added to plastic to reduce costs and add certain properties).
    • Base resins (pure plastic which is mixed with fillers and other additives).
    • Pigment masterbatches (plastic with concentrated pigment, to be used instead of straight pigment).
    • Blowing agents (used to create plastic foam).
    • Flame retardants.
    • Purge compounds (which clean molding machines of leftover resin and dye).

Rotational Molding (Rotomolding)

Rotational molding is a method used to create hollow plastic parts. It involves placing a powdered plastic resin into a mold, which is then heated and rotated on two perpendicular axes. As the mold rotates, the plastic powder coats the inner surface of the mold, gradually melting and fusing together. This process is commonly used for producing large, hollow products such as tanks, containers, playground equipment, and automotive components.

Die-Cutting

Die-cutting is a versatile method for cutting flat plastic sheets or films into specific shapes using a die (a specialized cutting tool). It’s commonly used for producing gaskets, labels, and intricate plastic components. This technique is particularly useful for high-precision and high-speed production.

Ultrasonic Welding

Ultrasonic welding employs high-frequency sound waves to create a strong bond between plastic parts. The process involves placing the parts to be joined under pressure and subjecting them to ultrasonic vibrations, which generate heat and melt the plastic at the interface.
It’s often used in the assembly of electronic devices, medical equipment, and automotive components.

Plastic Laminating

Plastic laminating involves applying a layer of plastic film or sheet onto another material, typically paper or cardboard, to enhance its durability, appearance, or protective qualities. The plastic layer is bonded to the substrate using heat and pressure.
Common applications include laminated ID cards, signage, packaging, and printed materials.

Blister Packaging

Blister packaging is a specialized technique where plastic cavities (blisters) are formed over a mold to securely hold and display products. The plastic blister is typically sealed to a backing card. This method is commonly used for packaging small consumer goods like electronics, toys, and pharmaceutical products.

Factors Affecting Plastic Fabrication

When we process custom plastic parts, we need to know some of the influencing factors, so that we can improve our process and promote quality output of plastic parts or products.

Material Selection

Material selection is a crucial factor in plastic fabrication. The choice of plastic type and grade depends on the desired properties of the final product, including strength, durability, flexibility, and chemical resistance.
Engineers and designers must consider factors such as the material’s melting point, shrinkage rate, and compatibility with the chosen plastic fabrication method.
Material selection also involves evaluating the cost-effectiveness of different plastics, taking into account factors like material availability and production costs.

Design Considerations

The design of a plastic product significantly impacts the plastic fabrication process. Designers must consider factors such as part geometry, wall thickness, draft angles, and the presence of undercuts.
Well-designed products facilitate easier plastic fabrication, reduce the likelihood of defects, and minimize material waste.
Design for manufacturability (DFM) principles are essential to ensure that the design is optimized for the chosen plastic fabrication technique.

Temperature and Heating Methods

The choice of heating method and temperature control are critical aspects of plastic fabrication. Different plastics have distinct melting points, so heating must be precise to achieve the desired flow properties.
Temperature control is vital to prevent overheating, which can lead to material degradation, or underheating, resulting in incomplete or flawed products.
Heating methods can vary depending on the fabrication technique, including convection heating, radiant heating, or induction heating.

Mold and Tooling Design

The design and quality of plastic molds and tooling are pivotal to the success of plastic fabrication processes like injection molding, blow molding, and thermoforming.
Tooling design must account for factors such as mold material, cooling channels, venting, and gating systems.
Precision in tooling design ensures the production of high-quality parts with minimal defects.

Quality Control and Tolerance

Quality control measures are essential throughout the plastic fabrication process to ensure that parts meet specified tolerances and quality standards.
Inspection methods may include visual inspection, dimensional measurements, and non-destructive testing techniques like X-rays or ultrasonics.
Maintaining tight tolerances is particularly critical in industries like aerospace and medical devices.

How to Choose a Right Plastic Fabrication Process?

Choosing the right plastic fabrication method is crucial for ensuring the production of high-quality plastic parts that meet your specific requirements.
To make an informed decision, consider the following steps:

• • • Understand the Material Requirements
      Determine the type of plastic material that best suits your needs. Consider factors such as strength, flexibility, temperature resistance, chemical resistance, and cost. Different plastic fabrication methods may work better with specific materials.
    • Consider Production Volume
      The volume of parts you need to produce is a critical factor. Some plastic fabrication methods are better suited for high-volume production, while others are more suitable for prototypes and low-volume runs.
    • Evaluate Part Complexity
      Assess the complexity of the parts you need to fabricate. Some plastic fabrication methods, like injection molding and 3D printing, are better for intricate and detailed components, while others may be more suitable for simple shapes.
    • Budget and Cost Analysis
      Determine your budget for the project. Some plastic fabrication techniques have higher initial tooling costs but lower per-part costs for high-volume production. Consider the overall cost of production, including tooling, material, and labor.
    • Lead Time and Speed
      Evaluate the time constraints for your project. Some plastic fabrication methods, such as 3D printing and CNC machining, offer quicker turnaround times for prototyping and small runs, while others, like injection molding, may have longer lead times but higher production speeds.
    • Quality and Tolerance Requirements
      Consider the required quality and tolerances for your parts. Some plastic fabrication methods provide higher precision and tighter tolerances than others. Ensure that the chosen plastic fabrication method can meet your quality standards.
    • Tooling and Setup Costs
      Be aware of the tooling and setup costs associated with each plastic fabrication method. Injection molding and die-cutting, for example, typically involve higher initial tooling expenses.
    • Prototype and Test
      Whenever possible, create prototypes or small test runs to evaluate the performance and suitability of the chosen plastic fabrication method. This helps identify potential issues early in the process.

If you are uncertain about the best plastic fabrication method for your project, seek advice from Sungplastic, which is an expert plastic fabricators with experienced engineers and workers. We can provide valuable insights and help you make an informed decision.

As a custom plastic parts manufacturer, we provide many years of practical experience, and a professional design and manufacturing team, modern high-tech manufacturing equipment, as well as controllable market costs.
We are full of confidence and sincerity in your projects. Welcome to contact us.