How to thermoform solid surface with a vacuum membrane press

To thermoform solid surface with a vacuum membrane press, heat the sheet evenly, place it on the mold and lower the membrane. The vacuum then holds the sheet against the mold until it cools. The makers' guides quoted below put the forming temperature between 130 and 175 °C, depending on the brand, and heating time depends on sheet thickness and oven type.

This guide covers the equipment, the step-by-step process, the temperatures, times and bend radii published by the leading solid surface makers, and the problems fabricators run into most. For press basics, see our vacuum press buyer guide.

Why solid surface can be thermoformed

Solid surface is a mineral-filled resin sheet, usually acrylic-based, used for worktops, washbasins and reception desks. It softens when heated, becomes rubbery at forming temperature and keeps its new shape once it cools on a mold. That makes it possible to produce curved fronts, integrated basins and 3D panels from flat sheet instead of joining several pieces.

Solid surface brands you can thermoform

Several manufacturers make solid surface, including Corian®, HI-MACS®, Krion®, Kerrock® and Betacryl®. The process is the same for all of them: heat the sheet evenly, form it over a mold under vacuum and let it cool under pressure. What changes is the temperature, the heating time and the minimum radius, which vary by brand, grade and sometimes colour. Always follow the data sheet for the exact sheet you are forming.

Our thermoforming ovens, vacuum membrane presses and thermoforming stations are suited to solid surface from all of these brands. Corian®, HI-MACS®, Krion®, Kerrock® and Betacryl® are trademarks of their respective owners.

Equipment you need

• A heating unit. A platen (hot plate) oven heats sheet much faster than an air-circulating oven, and Corian® recommends one. Air-circulating ovens also work but are slower. Whichever you use, it must heat the whole blank uniformly. Corian® advises against infrared ovens for solid surface. See our thermoforming ovens.
• A vacuum membrane press. It pulls a flexible silicone membrane over the hot sheet, which presses it evenly against a single-sided mold, even on curved and 3D shapes.
• Molds. Molds are usually wood-based or synthetic and CNC-cut; composite or metal molds suit high volumes. Add alignment features so the blank is easy to position.
• Temperature measurement. Use a contact thermocouple, an infrared thermometer or temperature-indicating labels to calibrate the oven and check the blank.
• Protective equipment. Wear insulated thermal gloves and gauntlets. Hot sheet causes burns on contact with bare skin.

For an overview of the materials and machines we supply for this sector, see solid surface applications.

Step by step: forming solid surface with a vacuum membrane press

1. Condition the sheet. Heating times assume sheet at normal room temperature. If sheet is stored somewhere colder or warmer, bring it into the shop the day before.
2. Prepare the mold. Have the mold, lubricant (wax or talc, if used), thermometer and safety equipment ready before heating starts. A preheated mold gives more working time and a more consistent first part.
3. Preheat and calibrate the oven. Let the oven stabilise at the set temperature. Run a scrap sample with a thermocouple to confirm how long your oven takes to heat your sheet thickness.
4. Heat the blank. Set the temperature and time from your sheet maker's guidance. For example, Corian® gives 150–165 °C and about one minute per millimetre in a platen oven, HI-MACS® gives 155–175 °C, and Krion® gives around 160 °C for about 10 minutes plus one minute per millimetre. The full figures are listed below.
5. Check the temperature. Scan the surface with an infrared thermometer to confirm the blank is evenly heated. If the oven was set above the target sheet temperature, let the blank rest briefly so the core and surface even out.
6. Transfer to the mold. Work quickly, because the blank starts cooling as soon as it leaves the oven. Large blanks are floppy, so have enough people to handle them safely.
7. Pre-shape and apply vacuum. Position the blank, pre-shape by hand or with helper pieces if needed, then lower the membrane and draw the vacuum. Pressing on the membrane by hand helps control wrinkling.
8. Cool slowly under vacuum. Keep the part on the mold until it reaches the maker's release temperature: about 82 °C for Corian®, 60 °C for HI-MACS® and below 45 °C for Krion®. For 12 mm sheet this usually takes 30 to 60 minutes, depending on room and mold temperature. The membrane usually reads a few degrees cooler than the sheet.
9. Trim and finish. Remove the part, then trim and finish it once it has cooled.

Temperatures, times and bend radii by brand

These are the figures each maker publishes for its standard sheet. They can vary with oven design, blank size and room conditions, so calibrate your own equipment with scrap pieces before forming a real part.

Corian®

• Platen oven setting: 150–165 °C. The oven must be able to heat uniformly up to 200 °C.
• Platen oven heating time: about 1 minute per mm (6 mm: 6 minutes; 12 mm: 12 minutes).
• Air-circulating oven heating time: about 5 minutes per mm (6 mm: 30 minutes; 12 mm: 60 minutes).
• Air-circulating oven maximum setting: 205 °C. The sheet itself should not exceed 177 °C.
• Rest after heating: 1–2 minutes so the core and surface temperatures equalise, especially if the oven was set above the target sheet temperature.
• Cool in the mold to: about 82 °C (up to 30–45 minutes for 12 mm sheet).
• Minimum inside radius for 2D bends: 25 mm for 6 mm sheet, 76 mm for 12 mm, 127 mm for 19 mm.
• 3D forms: local stretch should not exceed 10%.

Source: Corian® thermoforming guide (PDF).

HI-MACS®

• Heating temperature: 155–175 °C. Never exceed 204 °C, which can cause discolouration, burning or cracking.
• Heating time: 6–20 minutes for 6 mm sheet and 12–30 minutes for 12 mm, adjusted for workshop temperature and oven performance.
• Cooling: keep the part under pressure on the mold until it has cooled to 60 °C, which takes about 40–60 minutes at room temperature.
• Minimum inside radius for 2D bends: 20 mm for 6 mm solid colours and 50 mm for 12 mm solid colours. Granite, patterned and some special colours need larger radii, while the 12 mm Ultra-Thermoforming grade goes down to 6 mm.

Source: HI-MACS® thermoforming fabrication guidelines.

Krion®

• Heating temperature: around 160 °C. Simpler shapes with wider radii can be formed at 130–150 °C.
• Heating time: about 10 minutes plus one minute per millimetre. That is roughly 16 minutes for 6 mm and 22 minutes for 12 mm in an air-circulating or double-sided oven, and roughly 20 and 30 minutes in a single-sided oven.
• Cooling: about 40 minutes in the membrane press, until the sheet is below 45 °C.

Source: Krion® guide to thermoforming solid surface.

Krion® has also been formed on our equipment in published research. In 2025, researchers at the University of Málaga studied double-curved Krion® K-Life 1100 parts for children's play spaces. They formed them on a Global Duo Standard, the predecessor of today's Duo Cross-Flow and Duo Industrial thermoforming stations, using a base mold only and no counter-mold. The sheet was heated at 160 °C for 22 minutes, followed by 40 minutes in the station's heated chamber.

Source: Ventura Blanch, Shahdadpuri Aswani and Hernández Vílchez, "Thermoforming of Non-Developable Surfaces: Challenges in the Manufacture of Solid Surfaces, the Case of Krion K-Life", Applied Sciences 2025, 15(1), 363.

Kerrock®

• Heating temperature: 160 °C ± 10 °C in a hot-air oven or heated press. Do not exceed 170 °C, which can damage the surface; too low a temperature can make the sheet crack or turn pale at the bend.
• Heating time and minimum radius: about 16 minutes and 25 mm for 6 mm sheet, 19 minutes and 50 mm for 9 mm, 22 minutes and 90 mm for 12 mm, and 30 minutes and 120 mm for 18 mm.
• Easy Shaping (ES) sheet: made for tighter radii and deeper draws such as washbasins. A 12 mm ES sheet goes down to a 12 mm outer radius.
• Preparation and cooling: cut the blank at least 20 mm oversize, because the edges cool faster and distort, and cool the part evenly in the mold or membrane press.

Source: Kerrock® processing instructions (2024).

Other brands

Betacryl® and other solid surface brands follow the same process. Ask your sheet supplier for the thermoforming data sheet and start with scrap tests to set the temperature and time on your own oven.

Common problems and how to avoid them

• Material caught on a sharp edge. If the sheet gets trapped between the membrane and the edge of a female mold, it cannot draw into the cavity. Bevel cavity edges and remove sharp corners.
• Wrinkling or poor fill in tight areas. Pre-shape by hand or with helper pieces, and press on the membrane by hand as the vacuum draws down. A little wax or talc can help the sheet slide.
• Torn membranes. Silicone membranes can tear on sharp corners or where they must bridge a large gap. Round off corners, fill gaps and use helper pieces so the membrane stretches less.
• Parts cooling too fast. Metal molds conduct heat quickly and can chill the sheet before it is fully formed. They often need to be heated.
• Stress and later cracking. Uneven or spot heating and fast cooling leave stress in the part. Heat and cool the whole blank evenly.

Choosing equipment for solid-surface production

All of our thermoforming ovens are suited to heating solid surface: the Compact, Professional and Industrial thermoforming ovens and the heating bar. An oven is paired with a vacuum membrane press for forming. Our three thermoforming stations are also suited to solid surface, and they combine heating and vacuum pressing in one machine: the Duo Cross-Flow, Duo Industrial and Duo Professional. The right combination depends on your sheet thicknesses, part sizes and volume.

As an example, the Duo Industrial lists solid surface among its materials. It has a 2500 × 1000 mm heating area with an anodised aluminium heating platen up to 180 °C, a 2540 × 1420 mm press area, a PT100 sensor integrated in the worktop, automatic cycles by time and/or temperature, and an oil-free 100 m³/h rotary-vane pump reaching up to 8.5 t/m² (150 mbar abs.).

Frequently asked questions

What temperature do you thermoform solid surface at?

It depends on the brand. Corian® gives an oven setting of 150–165 °C in a platen oven and a maximum sheet temperature of 177 °C. HI-MACS® gives 155–175 °C and a maximum of 204 °C. Krion® gives around 160 °C, or 130–150 °C for simple shapes with wide radii.

How long do you heat solid surface before forming?

It depends on thickness, oven type and brand. In a platen oven, Corian® suggests about one minute per millimetre: 6 minutes for 6 mm and 12 minutes for 12 mm. HI-MACS® gives 12–30 minutes for 12 mm, and Krion® about 10 minutes plus one minute per millimetre. Air-circulating and single-sided ovens take longer.

What is the minimum bend radius for solid surface?

For 2D bends, Corian® gives a minimum inside radius of 25 mm for 6 mm sheet, 76 mm for 12 mm and 127 mm for 19 mm. HI-MACS® gives 20 mm for 6 mm and 50 mm for 12 mm solid colours. Patterned and granite colours usually need larger radii, so check the data sheet for your colour.

Can one vacuum press form every solid surface brand?

Yes. The oven and the vacuum membrane press do the same job whatever the brand: heat the sheet evenly and hold it against the mold while it cools. You change the temperature, heating time and cooling point to match each maker's data sheet.

Can you thermoform solid surface without a vacuum press?

Yes. Simple bends can be formed on clamped or two-sided molds. A vacuum membrane press applies even pressure over the whole part, which makes it well suited to single-sided molds, curves and 3D shapes such as basins.

Should I use a platen oven or an air-circulating oven?

Both work. Platen ovens heat much faster: Corian® gives about one minute per millimetre, compared with about five in an air-circulating oven. Air-circulating ovens need careful calibration, because large blanks disrupt the airflow. Krion® notes that single-sided hot plate ovens take longer than double-sided ones.

Talk to us about your solid-surface process

Tell us your material, part size and production volume, and we will recommend the heating and pressing setup that fits your process.

• Contact Global Vacuum Presses for sizing and a quote.
• Or see our solid surface applications page.