Plastic fabrication can make or break the quality of a product, and getting the right fabricator is important.
Here we look at what is plastic fabrication, the different ways in which plastic is fabricated, and what goes into creating plastic parts.
What is plastic fabrication?
Plastic fabrication is the process of creating plastic parts, from design through to creation and assembly. It’s a pretty broad term that encompasses various methods of creating the plastic materials themselves as well as the components they’re shaped into.
Not all plastic parts serve the same purposes, so they cannot all be made in the same ways nor use the same materials. Therefore, plastic fabrication service providers typically offer a range of different fabrication disciplines.
Is plastic easy to fabricate?
Different plastics have different strengths, capabilities, and material properties that can make them relatively easy to work with, or much more challenging.
Certain plastics like acrylics and nylons are easy to cut and form using machine tools, and can be thermoformed. Even tough plastics like polycarbonate can be machined with relative ease.
Generally speaking, plastic fabrication is simple with the right tools and expertise. A good working knowledge of individual plastics properties is essential to ensure the finished product is as expected and fit for purpose.
Poor application of a fabrication method to certain plastics could produce undesirable outgassing, unstable geometry and an easily breakable design, or a poorly finished part that doesn’t serve its purpose.
What are the different kinds of plastic fabrication?
Fabricating plastics can be achieved using a number of different methods. Some of these methods are used to create whole parts from plastic material with no extra assembly required. Other methods are used to create composite pieces and to assemble separate plastic parts together.
What fabrication processes are used with plastics?
Methods of plastic fabrication include:
In injection moulding, plastic pellets are melted and extruded into a metal mould, then cooled. The plastic pellets are fed into a plasticising unit, which houses a screw insert that mixes the material to ensure it’s thoroughly melted whilst also feeding it forwards and acting as a screw conveyor.
Injection moulding can be used to mass produce identical parts at a high rate, though the need to have a mould created specifically to your desired shape presents a step in the process that demands extra cost and time than substrative methods.
Plastic machining uses CNC tools to cut and shape blocks of plastic into their desired forms, or to add finishing touches to formed parts. Plastic CNC machining uses tools such as drills, milling tools, and engravers to subtract material, and path that the machine follows is coded in for absolute accuracy.
Plastic machining is fantastic for complex part geometries and tight tolerances. It also creates parts that are common in industry such as thick, strong pipe sections and threaded parts designed to screw together.
Often called ‘rotomoulding’, this is similar to injection moulding in that a mould is used with molten plastic that assumes the shape of the cavity. The difference with rotational moulding is that the plastic is put in the mould in its solid form, then heated until melted and the mould itself is rotated to coat the inside with the plastic.
Because the rotation aims to coat the walls of the mould with a layer of molten plastic, this fabrication method is best used for hollow parts. It’s a less expensive process because no pressure is required and it creates uniform thickness in part walls. However, it is more time-consuming partly because of the need to cool the entire mould before removing the finished part.
Thermoforming involves heating plastic to shape it again. The difference it bears from rotational and injection moulding is that a plastic sheet is heated until its pliable as opposed to melting plastic pellets.
Once the plastic sheet has reached its glass transition temperature, the plastic is stretched and formed using a mould. The plastic is cooled and trimmed as necessary.
Thermoforming is commonly used for thinner, lighter objects like plastic cups and blister packs.
When two or more thermoplastic components need to be fused together, plastic welding can be used. Although typically thought of as a technique for metals, welding can indeed be done with plastics.
Plastic welding is ideal when adhesives and other joining methods wouldn’t be suitable, and to create composite parts with no seam leaving a weakness.
There are various 3D printing methods used with plastics including fused deposition modelling (FDM), selective laser sintering (SLS), stereolithography (SLA), and more that vary by manufacturer.
FDM involves heating plastic filament and extruding it in layers according to a CAD file, like those used with CNC machining. SLS uses polymer powder heated by a laser, again building in layers. Methods like SLA use liquid resin and UV light or lasers to instantly cure the resin and build up the part that way.
3D printing has uses in industry and manufacturing, but it can be expensive to run and doesn’t meet the high throughput needs that other plastic fabrication methods can meet.
How can plastic fabrication help your business?
If you need plastic parts made or assembled, plastic fabrication services can help your business by taking the stress out of the process.
Plastic fabrication may be more affordable and more efficient than buying readymade plastic items for your business, and the ability to work with a plastics fabricator to decide on custom design, ergonomics, or branding is invaluable.
If you need plastic fabrication services today, get in touch with GA Profiplast. We offer a wide range of services to meet your needs and create bespoke plastic parts. Get in touch today to find out more.