POLIFILM PROTECTION continues to expand its range of next generation specialist film solutions. The experts within have developed a coextruded protective film for thermoforming polycarbonate sheets that can withstand even a 14 day pre-drying process at temperatures of around 100°C.

The application is unique in the market and makes the manufacturing process of products such as skylights more consistent, more profitable, faster and more energy efficient. 

Thermoformed polycarbonate is the material of choice for many products including skylights for mobile homes, shopping centres or offices. The thermoforming process is demanding because polycarbonate absorbs and retains moisture from the ambient air.

POLIFILM PROTECTION's new protective film solution for thermoforming PC sheets.

Before thermoforming, the plastic must be dried in a special oven to ensure a residual moisture content of less than 0.01%. This prevents such quality issues as bubble formation which can occur during forming and moulding.

Easily removable after extensive drying cycles

To ensure such plastic sheets are thoroughly protected, POLIFILM PROTECTION has developed a tailor-made protective film solution. It has very good temperature resistance and can remain on the surface during extended drying cycles of up to 14 days, whilst exposed to drying temperatures of around 100°C.

Following which, the film can easily be removed without the risk of residues due to the speciality of the adhesive system maintaining its peel strength properties.

As with all coextruded films, the adhesive is integrated into the protective film. Easy and residue-free removal is assured every time, without risk of reworking operations.

Furthermore, the film allows simultaneous drying of stacked polycarbonate sheets, without the risk of the sheets themselves welding together, which can then be easily separated once the process is complete thereby accelerating processing times and increasing efficiency.

With conventional protective films, the polycarbonate sheet must be cooled to room temperature before the film can be removed. In contrast, the new protective film can be removed from the sheet immediately after pre-drying, whilst the sheet is still at a temperature of around 80°C. There is no need to interrupt the production process to wait for the sheet to cool.

Additionally, if the polycarbonate sheet undergoes thermoforming immediately after the protective film is removed, the residual heat retained by the sheet reduces the energy required for the forming process.

In case the thermoforming process in question allows, the protective film can even be left on the sheet after pre-drying, only needing to be removed after the thermoforming process is complete, thus providing even more protection and enhancing process efficiency.

“The new protective film ensures quality, reduces rejection rates, speeds up production processes and saves energy at the same time – a combination of positive benefits that are not available from any other protective film provider in the market,” said Avi Niv, CEO of COEX CAST, POLIFILM PROTECTION's development and production site.