PROFESSIONAL BLOG
SEPTEMBER 27, 2023 • 8 MIN READING
Vacuum forming: Efficient production of larger products in small and medium-sized product series
Vacuum forming is an efficient process for producing covers and components for machines – but what is it exactly, and how does it work?
Geir Bergh
Head of Office, Plexx
What is vacuum forming?
Vacuum forming is a plastic molding technique used to create a variety of products and components. Vacuum forming uses heat and vacuum to shape a thermoplastic sheet. The forming tool in the machine determines the shape and function of the sheet.
Vacuum forming provides a unique surface quality as the product only comes into direct contact with the forming tool on one side. This opens up many possibilities for design and geometric solutions. In addition, the process has limited environmental impact, and excess materials are 100% recycled.
How does the process take place?
Here are some of the biggest advantages of choosing thermoplastics as a material in product development and industrial production:
01
Tool
Først lages et positivt eller negativt verktøy. Formverktøyet er en eksakt kopi av det ønskede sluttproduktet og bestemmer geometri, detaljer og overflate.
02
Heating
A thermoplastic sheet, typically 1–15 mm thick, is heated by top and bottom heat to a temperature where it becomes soft and flexible – without melting completely.
03
Pre-blowing
The hot, soft sheet is inflated. The mold tool is then moved up against the plastic material (positive tool) or the plastic down into the tool (negative tool).
04
Vacuum forming
When the heated platen comes into contact with the mold, the air is drawn out between the plastic and the tool. The vacuum sucks the plastic tightly against the mold, forcing it to take on the geometry of the tool.
05
Cooling
The plastic is quickly cooled with air, becomes rigid and retains its shape. The finished part is demolded and sent for cutting and finishing.
"Vacuum forming provides a unique surface quality as the product only comes into direct contact with the forming tool on one side – it opens up many possibilities for design and geometric solutions."
The tool determines the geometry and surface
The forming tool is the heart of the process. We design and machine aluminum tools tailored to each project, ensuring that tolerances, radii and surfaces are exactly as they should be – even for components with large dimensions.
Low tooling costs compared to injection molding make vacuum forming particularly suitable for small and medium-sized series of larger parts.
Advantages of plastics in technical applications
Thermoplastic materials are used in the vacuum forming process. Engineering plastics have several advantages in technical installations compared to traditional materials:
Low weight
Plastmaterialer er generelt lettere enn metall – det reduserer vekten på sluttproduktet, forenkler håndtering og senker fraktkostnader.
Corrosion resistance
Plast er motstandsdyktig mot korrosjon og reagerer ikke med fuktighet eller kjemikalier på samme måte som tre eller metall.
Flexibility in design
Plastic can be molded into a variety of shapes and sizes with relative ease, giving designers great freedom to create unique geometries.
Low maintenance
Plastic products require little maintenance and are resistant to rot, corrosion and many chemical influences.
Cost-effective
Plastic materials are often cheaper to produce than metal, and vacuum forming makes it cost-effective – even in medium-sized series.
Durability
Plastic can withstand harsh environmental conditions such as UV radiation, salt and aggressive environments when the right material is chosen.
Environment
We are ISO 9001 and 14001 certified. Own regeneration plant at all our factories – all production waste is ground up and incorporated into new panels.
Vacuum forming at Plexx/Opido
Plexx/Opido has extensive experience with vacuum forming for a number of large and small customers throughout Europe. We don't just deliver finished products - we work closely and consultatively with the customer so that we jointly arrive at the best solution.
For example, for Thermocold, which has been making cold rooms and cooling units for 35 years, we have supplied vacuum-formed details and plastic parts for use in cooling units, cold rooms and wine cabinets.
Questions and answers
Vacuum forming is a plastic molding technique in which heat and vacuum are used to shape a thermoplastic sheet over a mold tool. The tool determines the shape, and because the plastic is only in direct contact with the tool on one side, the product is given a distinctive surface quality.
We typically vacuum form thermoplastics in thicknesses from 1 to 15 mm. The thickness is selected based on strength, stiffness and application requirements — from thin covers to large, load-bearing components.
A positive tool gives the best detail reproduction on the inside of the product, while a negative tool gives the best surface on the outside. The choice depends on which side is visible and which details are most important.
Tooling costs are significantly lower than with injection molding, while the method allows for large dimensions. This makes vacuum forming particularly cost-effective for series from a few to several thousand units.
Excess material from trimming and edging is 100% recycled. We have our own regeneration facilities at all our factories, and the waste is ground up and sent back to our panel manufacturers for the production of new panels.
Among other things, we have supplied vacuum-formed plastic parts to Thermocold, which has been manufacturing cold rooms and cooling units for 35 years. The parts are used in their cooling units, cold rooms and wine cabinets.
Plexx/Opido has extensive experience in vacuum forming and supplies to large and small customers throughout Europe. All of our subsidiaries and affiliates are ISO certified.
Do you have a challenge you would like to discuss?
We advise you so that together we can find the optimal solution – from material selection to finished product.