Plastic Fabrication: Definition, Purpose, How It Works, Advantages, and Examples

"Plastic fabrication" is the step in the design and manufacturing process when a selected shaping or molding method turns raw polymer materials into finished products. The end goal in the plastic manufacturing business is to select the right fabrication method for the economical production of a wide range of goods fit for service in applications from simple household items to sophisticated industrial components. The fabrication process typically entails some combination of cutting, molding, welding, and assembly steps to achieve the desired plastic shapes and sizes. 

Plastic materials are generally adaptable to a number of fabrication methods, allowing the design flexibility for the manufacturer to produce plastic parts which are affordable and light in weight. But plastic fabrication also has problems, such as potential toxicity of the raw materials, sensitivity to UV light, and lack of high temperature strength compared to metals. This article will discuss plastic fabrication, its purpose, how it works, advantages, and disadvantages.

What Is Plastic Fabrication?

The term "plastic fabrication" describes the process of creating, producing, and/or assembling custom-designed plastic products or high volume parts out of plastic or composite materials. Plastic fabrication includes a variety of processes, such as: 

1. Plastic extrusion

2. Plastic pultrusion

3. Plastic welding

4. Thermoforming

5. Injection molding

6. Rotational molding

7. Blow molding

8. Plastic CNC machining

9. Vacuum casting

10. Stereolithography

11. Fused deposition modeling

12. Selective laser sintering

These methods each has a different set of processes. Plastic's adaptability, cost-effectiveness, and light weight make it versatile, and for that reason, it is widely used.

What Is Plastic Fabrication Also Known As?

“Plastic processing” and “plastic manufacturing” are other terms for plastic fabrication. This phrase can refer to any or all of the steps that go into shaping and molding plastic materials into finished goods. 

What Is the Purpose of Plastic Fabrication in Manufacturing?

Plastic fabrication is used in manufacturing to create finished goods with specific forms and functions from raw plastic materials. Due to plastic's flexible nature and affordability, this process enables the production of a variety of items used in a variety of industries, including consumer goods, automotive components, medical devices, and electronics.

What Are the Industries That Use Plastic Fabrication?

The automotive, food, aerospace, electronics, medical, packaging, and consumer goods industries make use of one or more plastic fabrication methods to create finished products. The adaptability of plastic fabrication enables it to serve a variety of applications in these industries. Injection molding is a widely used plastic fabrication method in various industries. The process starts with molten plastic material injected into a mold cavity, where it cools and solidifies to form the desired shape. Additionally, the medical field employs injection molding to create items like syringes, IV components, and sterile medical equipment.

How Does Plastic Fabrication Work?

Plastic fabrication involves multiple processes, starting with design and planning, material selection, material preparation, forming and shaping, finishing and assembly, and concluding with quality control and inspection. There are several plastic fabrication methods, each with various processes. Listed and discussed below are three common methods:

1. 3D Printing: By constructing objects layer by layer from a computer model, 3D printing emerges as a highly adept method for crafting intricate designs and prototypes. This process involves creating a 3D model using software, selecting a compatible plastic filament—important when utilizing an FDM printer—preparing and loading the filament into the printer, and then sequentially extruding the model onto a build platform. The printed object undergoes polishing during finishing and assembly, followed by a final inspection to ensure accuracy and identify flaws.
2. Extrusion: Extrusion is a popular method for shaping plastic pellets into continuous objects like sheets and pipelines. Fundamental procedures include designing the required die form, choosing appropriate plastic pellets depending on their qualities, melting the pellets, and then running the molten plastic through the die to shape it. The operation is finished by cutting the continuous shape to the necessary lengths and checking for uniformity and flaws.
3. Plastic Injection Molding: The plastic injection molding process creates complicated pieces by pouring molten plastic into a mold. Plastic pellets are heated and injected into the mold after choosing the right material and designing the mold. There, they cool and solidify inside the mold's shape. After this, the object is taken out of the mold and thoroughly inspected for flaws, dimensions, and general quality.

What Is the Step-by-Step Process of Plastic Fabrication?

Each step of the plastic manufacturing process, from design to delivery, is essential for economically transforming raw polymeric materials into usable products.

1. Design and Planning

The first step in manufacturing a successful product is to understand the product requirements, including (but not limited to) size, dimensional tolerances, mechanical properties, and chemical and temperature resistance. A preliminary design, usually a 3D computer model, can then be created.

2. Material Selection

The first step in manufacturing a successful product is to understand the product requirements, including (but not limited to) size, dimensional tolerances, mechanical properties, and chemical and temperature resistance. A preliminary design, usually a 3D computer model, can then be created.

3. Material Preparation

Prepare the selected materials by extruding, molding, or cutting them into usable shapes.

4. Forming and Shaping

Shape the plastic materials into the desired product using methods like injection molding, thermoforming, or CNC machining.

5. Finishing and Assembly

Assemble subcomponents into final parts if necessary and add any necessary features. Other finishing processes that may be needed include: burr or flash removal, surface smoothing, painting, sealing, or curing. 

6. Quality Control and Inspection

Verify that the part meets all customer specifications by using statistical process control and inspection.

7. Packaging and Delivery

Deliver the finished products to the intended recipients in packaging that adequately protects the product from damage during transport.

Skipping any of the steps listed above may result in the production of plastic parts that are defective or incomplete. Each step is crucial to achieving success and meeting customer expectations.

Can Fabricated Plastic Parts Be Polished Using Acetone Vapor Smoothing?

Acetone vapor smoothing is a technique for reducing surface roughness and developing a polished appearance on fabricated plastic parts. The plastic product is exposed to acetone vapor, which dissolves the rough surface layer of the polymer and leaves behind a smoother surface. Acetone vapor smoothing works by thoroughly dissolving the plastic's outer layer and removing any surface flaws, focusing in particular on the high surface energy associated with asperities.

What Are the Materials That Can Be Used in Plastic Fabrication?

All plastics can be manufactured into final products using suitable fabrication techniques. The following materials are some of the ones that are commonly employed in the manufacture of plastics:

1. Acrylic (PMMA)

PMMA (polymethyl methacrylate, or simply acrylic) is a transparent thermoplastic that resists UV light and has excellent optical clarity. Its light weight and weather resistance makes it a popular choice for displays, signage, and lenses. Acrylic (PMMA) fabrication is best accomplished through techniques like CNC machining, laser cutting, and heat bending. Thermoforming works well too. These methods exploit acrylic's clarity, lightness, and adaptability for various applications such as displays, signage, and lenses.

2. Polycarbonate (PC)

Polycarbonate is especially well-matched with production techniques like injection molding, using its impact resistance to construct sophisticated safety gear, eyewear, and electronics components. This technology offers critical transparency and durability, surpassing alternatives like vacuum forming and machining in terms of speed.

3. Polyethylene (PE)

The versatile plastic polyethylene comes in a variety of densities, including HDPE (high-density polyethylene) and LDPE (low-density polyethylene). Due to its chemical resistance, flexibility, and affordability, it is used in pipes, household goods, and packaging. Extrusion, blow molding, and injection molding serve as optimal fabrication methods for harnessing the potential of Polyethylene (PE), encompassing diverse densities such as HDPE and LDPE. 

4. High-Density Polyethylene (HDPE)

HDPE is rigid and offers a high strength-to-weight ratio. It is widely used in bottles, toys, and pipes. Its resistance to chemicals and impact makes it suitable for demanding environments.

5. Polypropylene (PP)

Polypropylene, renowned for its chemical resistance and toughness, is often used in textiles, food containers, and automotive parts. It strikes a balance between toughness and affordability. Injection molding and thermoforming are both excellent methods for fabrication. While thermoforming is efficient for producing larger, less complex parts, injection molding produces intricate, small components.

6. Polyvinyl Chloride (PVC)

PVC is a flexible plastic that is widely used in medical equipment, vinyl flooring, and pipes. PVC decking is one of the applications of PVC, offering numerous advantages due to its composition of synthetic polyvinyl chloride instead of organic materials like wood pulp. Because it is synthetic, it is extremely resilient to water and can tolerate a variety of weather situations. It requires less upkeep than conventional wood decking, thus yearly sealing is not necessary. Additionally, it has a lifespan of at least 50 years.

7. Polyethylene Terephthalate (PET)

PET's optical clarity and good mechanical properties make it a top choice for beverage bottles and food containers. Its recyclability adds to its popularity as a sustainable packaging material.

8. Polyoxymethylene (POM)

Also known as acetal, POM is used in precision parts such as gears and bearings. This is due to its excellent mechanical properties and resistance to wear and chemicals. Blow molding is suitable for certain plastic materials, including POM. It's commonly used for producing hollow parts like bottles, containers, and certain types of POM components.

9. Polystyrene (PS)

Polystyrene is derived from the monomer styrene, and is a versatile polymer widely employed for its rigidity. Found in packaging, disposable cutlery, and insulation, PS is used in various applications. As a thermoplastic, it's solid at room temperature but can be melted for molding or extrusion at higher temperatures before being resolidified. This adaptability stems from its liquid hydrocarbon origin, derived commercially from petroleum.

How Much Does Plastic Fabrication Cost?

The cost of manufacturing plastic products depends on: the size of the part, the material it is made from, and the fabrication method used. Simple molds cost between $3,000 and $6,000, while more complex, large-scale, or high-volume molds can run between $25,000 and $50,000 or more. For exceptionally complex projects, costs may exceed $100,000. Plastic fabrication encompasses various methods beyond molding. Hobbyists can buy entry-level 3D printers for $200 to $500. For individuals with some experience, midrange solutions between $500 and $2,000 are suitable. Professionals wanting top-notch quality can purchase high-end 3D printers for $2,000 to $10,000. Industrial variants, priced between $10,000 and $100,000, are excellent for use in the automotive, aerospace, and medical industries.

What Are the Advantages of Plastic Fabrication?

Advantages of fabricating products from plastics include:

1. Plastics can be molded into various shapes and sizes for diverse applications.
2. Plastic components are light in weight, reducing transportation costs.
3. Polymers are resistant to corrosion, chemicals, and weather.
4. It is easy to create complex designs and features using plastics.

What Are the Disadvantages of Plastic Fabrication?

Disadvantages of fabricating products from plastics include:

1. Many plastics are not biodegradable, leading to pollution.
2. Certain plastics melt at relatively low temperatures, limiting their use in high-temperature applications.
3. Certain plastic formulations can be brittle, making them prone to cracking or breaking under stress or impact.
4. Exposure to sunlight can cause color deterioration in the finished plastic part.

What Are Examples of Fabricated Plastic Products?

Here are some examples of products fabricated from plastics:

1. Plastic bottles, containers, and bags.
2. Toys, kitchenware, and electronics casings.
3. Bumpers, dashboards, and interior components.
4. Syringes, IV bags, and surgical gloves.
5. Pipes, insulation, and window frames.

What Is the Quality Level of Fabricated Plastic Parts?

Products made of plastic can be of varying quality depending on the choice of material, the manufacturing process, and the design. Durability, resistance to the elements, and precise dimensions are all features of high-quality plastics. However, issues like brittleness, warping, or a shorter lifespan may result from the use of poor-quality materials or poorly controlled production techniques.

Are Fabricated Plastic Products Durable?

Yes, depending on factors like material choice, design, and manufacturing techniques, fabricated plastic products can be durable. High-quality plastics, sound engineering, and the right finishing processes can increase a product's durability and make it more resistant to abrasion, impact, and the elements. Less durable products may be the result of using inferior materials, poor manufacturing practices, or of misapplication of material when designing the product in the first place.

What Is the Difference Between Plastic Fabrication and Plastic Extrusion?

Plastic extrusion is a particular technique within the field of plastic fabrication, whereas plastic fabrication encompasses a wider range of techniques, including: shaping, molding, cutting, welding, and assembly of plastic components into finished goods. Plastic extrusion entails melting plastic and pressing it through a die to form continuous profiles with constant cross-sections. This process is often used for items like pipes, tubes, and window frames.

What Is the Difference Between Plastic Fabrication and Sheet Metal Bending?

Plastic fabrication refers to making products from plastics using any of a number of different manufacturing methods. One of the possible methods for making plastic parts is the bending of sheet plastic. Some examples of parts made by bending plastic sheets are signage, displays, covers and enclosures, and light diffusers.

Sheet metal bending is a particular manufacturing process applied to thin metals. In particular, in sectors like consumer goods and automotive, it offers versatility for producing intricate designs and one-of-a-kind items.

Sheet metal bending is used to reshape metal sheets to create desired shapes and angles. Construction and manufacturing sectors often use this method to create components like brackets, enclosures, and panels. Sheet metal bending, as opposed to plastic fabrication methods, involves working with metal materials, which offer improved strength, rigidity, and durability compared to plastics. 

Summary

This article presented plastic fabrication, explained it, and discussed how it works and its advantages. To learn more about plastic fabrication, contact a Xometry representative.

Xometry provides a wide range of manufacturing capabilities, including fabrication and other value-added services for all of your prototyping and production needs. Visit our website to learn more or to request a free, no-obligation quote.

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