Have you ever wondered how large pieces of plastic – such as the galley and window shields of airplanes, interior panels and bumpers of cars, hospital beds, large office printers, ATM machines – are made? How about the smaller pieces of plastic like test-tube racks in laboratories, blister pill packaging, and food containers? They all have something in common: plastic thermoforming.
What is Plastic Thermoforming?
Plastic thermoforming is a process of making plastic parts which involves the heating of plastic sheets until they become pliable and susceptible of being shaped into desired forms. Hence the words ‘thermo’ and ‘forming’.
Why is Plastic Thermoforming important?
While plastic thermoforming can make many types of plastics in different sizes and thickness, from thin plastic wrappings to large and thick plastic parts, it is especially important to a product’s design. Specifically, to enclosure design and weight.
Enclosure design is one of the most important components to a product, and usually also the most time-consuming and costly. Plastic thermoforming becomes an important process to consider in product design as the parts thermoforming is able to produce can be very large, or small, for enclosure purposes.
The thermoforming process can also create very aesthetic plastic, such as those with colors or textures, without needing additional polishing or painting (both of which can otherwise be cost-adding elements).
Plastics made via thermoforming may be used as an alternative material for products where weight matters. If you consider parts such as those used in cars and airplanes, weight becomes a sensitive factor. As such, thermoformed plastic provides a light weight yet sturdy alternative to sheet metal products.
How does Plastic Thermoforming work?
Plastic thermoforming – be it vacuum thermoforming, pressure thermoforming or mechanical thermoforming – begins by heating a sheet of plastic (thick or thin depending on the specifications of the final product) to make it highly pliable.
The pliable sheet of plastic is then placed over a mold – which has been inversely designed & engineered to the desired plastic product – and pulled towards the mold via a suction effect (vacuum thermoforming). At the same time, a downward pressure (pressure thermoforming) or a plug (mechanical thermoforming) can be used to apply additional pressure above the plastic sheet to give further accuracy to the molding process and better aesthetics to the plastic part.
After the heated sheet of plastic inherits the shape of the mold and becomes the desired plastic product, it is then rapidly cooled and trimmed. The plastic is now ready for use!
What are the advantages of plastic thermoforming when compared to plastic injection molding?
The advantages of plastic thermoforming can be seen from: tooling, lead-times, part size & complexity, and aesthetics of the plastic.
Tooling here refers to the process of mold creation. In comparison to plastic injection molding, the tooling costs for plastic thermoforming is significantly lower, and the mold itself is faster to make since only a one-sided mold is needed. Once made, the tool can be used for a life-time, making it very suitable for producing large volumes of plastic parts.
Given the relative rapidity of tooling, thermoforming also provides more leeway for fine-tuning the design of the product, and creating savings in tooling investment.
As the tooling process is much quicker than that of plastic injection molding, the ultimate lead-time for plastic thermoforming is also much shorter.
Part size & complexity
Plastic thermoforming can create large pieces of plastic parts that plastic injection molding is unable to produce. Plastic thermoforming can create part sizes of up to 10” x 18” and could consolidate multiple parts into a single large part. Plastic injection molding on the other hand can only create small parts with minimal consolidation.
Aesthetics of plastic
Thermoformed plastic is quite aesthetically pleasing, as textures and patterns can be predesigned into the tool. At the same time, it is also aesthetic enough for use even when unpainted. Plastic injection molding in comparison would need additional finishing for the product.
Moreover, Season is capable of twin sheet forming which allows for contrasting colors to appear in one piece part, allow for differences in thickness, hollow parts & internal reinforcements, and multiple textures and wall sizes.
Is thermoformed plastic sustainable?
Thermoforming in itself is a process, as such the sustainability of a thermoformed plastic part depends on the material that has been used to produce it, whether additional chemicals are added to the part and what the part is ultimately used for.
Some thermoformed plastics however could be recycled and reproduced as resin for further use. The material ABS for example is recyclable, and tends to be used to produce more long-lasting products such as toys and luggage rather than single-use plastic products.
Other materials, especially those with high stencil strength such as Lexan, Kydex and Boltaron, tend to also be more rigid and sustainable. These plastics in particular are often used in aerospace programs.
Plastic Thermoforming at Season Group
At Season, plastic thermoforming is one of our manufacturing capabilities. From sourcing plastics, reverse engineering, to in-house tooling (i.e. the making of molds for specified parts/products) and fine-tuning products, Season provides a one-stop-shop service to plastic thermoforming.
In fact, our Malaysia site has one of the largest thermoforming machines in Malaysia and Southeast Asia. We are even AS9100 certified for thermoforming, which makes us quite a reliable supplier for customers from the aerospace and defense industries.
Season is also capable of assembling your thermoformed plastic parts. Be it a small plastic component or a large case, it can be assembled with the rest of its parts at Season, even when it involves components of other materials.
Plastic thermoforming is a choice plastic process, especially if you’re looking to produce large, bulky plastic parts. The process has low tooling costs, a short lead time, and produces aesthetic, textured parts that are choice for enclosure design.