◆ FAQs — HIMACS Thermoforming

Thermoforming is the process of heating HIMACS sheets until they become flexible enough to be moulded into curved or three-dimensional shapes. Once cooled, the material retains the new form with excellent structural integrity, enabling creative and functional designs that maintain HIMACS’ durability and seamless appearance.

The recommended heating range is typically 150–170°C, depending on sheet thickness and colour. Temperatures below this may cause insufficient flexibility, while higher levels can result in surface blistering, colour change, or loss of mechanical strength.

Sheets should be placed in a dedicated thermoforming oven that distributes heat evenly on both sides. The material must be heated gradually to reach uniform temperature throughout its thickness. Localised heating methods, such as heat guns or open flames, are not recommended as they cause uneven softening and deformation.

Heating time varies depending on sheet thickness, size, and oven performance. As a general guideline, allow one minute per millimetre of thickness once the oven has reached the target temperature. For example, a 12 mm sheet typically requires about 12 minutes to achieve full flexibility.

Use heat-resistant moulds made from materials such as MDF, aluminium, or plywood treated for high-temperature applications. The mould must be perfectly smooth, clean, and free from dust, as any surface imperfection may transfer to the HIMACS sheet during forming. Apply a suitable release film or paper if needed.

After shaping, allow the material to cool slowly and uniformly while still in the mould to prevent warping or internal stress. Forced cooling with fans or cold air is not recommended. Cooling should continue until the sheet reaches room temperature and regains rigidity before removal.

Most HIMACS colours are suitable for thermoforming. However, dark or heavily pigmented colours may require extra attention to heating and cooling times to prevent visual inconsistencies or surface distortion. Always conduct a small-scale test before large-batch production.

The achievable bending radius depends on the sheet thickness:

• 12 mm sheet: minimum inside radius ≈ 150 mm

• 9 mm sheet: minimum inside radius ≈ 75 mm

• 6 mm sheet: minimum inside radius ≈ 30 mm
  Reducing thickness allows for tighter curves, but excessive bending can lead to whitening or cracking.

• Always pre-clean sheets to remove contaminants.

• Avoid overheating or uneven heating zones.

• Ensure proper ventilation in the oven area.

• Do not stack multiple sheets during heating.

• Handle the softened sheet with heat-resistant gloves to avoid surface marks.

Yes. Once cooled and stabilised, thermoformed parts can be bonded using standard HIMACS adhesives. Proper edge preparation and sanding are essential to achieve invisible seams and maintain structural strength.

In areas exposed to heat (e.g., near cooktops), bevel the reinforcement strip edges to 45° to reduce stress points. Ensure full adhesive coverage and a tight bond. Smooth and sand all edges to prevent cracks or delamination due to thermal expansion.

HIMACS sheets must be stored at room temperature for at least 24 hours before thermoforming to ensure dimensional stability. If sheets were transported or stored in cold conditions, allow sufficient time for acclimatisation. Always remove the protective film, inspect the surface for defects, and cut oversized by 25 mm to 7% to compensate for shrinkage during forming.

Pre-processing such as drilling, machining, or joining before thermoforming can cause cracking, distortion, and uneven forming due to stress concentration and thermal inconsistency. Only essential cutting and minimal machining should be performed prior to heating. All other fabrication work must take place after thermoforming to preserve material integrity.

Reference points are alignment marks placed on both the HIMACS sheet and the mould. They ensure precise positioning during forming, improve repeatability, and simplify post-forming trimming and assembly. For best results, use at least three clearly visible reference points and verify alignment before heating begins.

To maintain consistent colour and surface finish, ensure uniform oven temperature and cleanliness. For small heating areas, use a helper piece to maintain even pressure between heating plates. When flat and thermoformed parts are part of the same project, heat both simultaneously to achieve uniform pigment response and texture.

Begin forming immediately after removing the sheet from the oven while it is still flexible. Ensure the mould is clean, positioned correctly, and clear of obstructions. Allow the formed sheet to cool naturally on the mould until it reaches about 60°C. Avoid forced cooling, which can cause cracking or shape distortion.

After forming, trim to final dimensions using a handheld router or CNC machine depending on complexity. Consider creating a duplicate mould for trimming to avoid damaging the original. For surface finishing, use soft-backed sandpaper and follow the official HIMACS Finishing Guidelines for consistent sanding and polishing quality.

Yes. In vacuum pressing processes, areas under high stretch may experience material thinning. To maintain strength, plan mould design carefully and reinforce or support thin sections after forming. Avoid forming sharp internal corners, which may lead to cracks or long-term material fatigue.

• Always plan and document the full thermoforming process.

• Operate within the recommended temperature and radius limits.

• Use only ovens and moulds designed for uniform heat distribution.

• Keep the workshop environment stable (15–25°C).

• Follow validated procedures for consistent, high-quality results.