New protective film for foamed sandwich panels

Extreme heat resistance is the key to higher efficiency.

  • POLIFILM PROTECTION has developed an innovative process film for the production of sandwich panels with a rigid foam polyurethane core up to 20 cm thick.
  • The film is heat-resistant up to 160°C, whilst the special water-based acrylic adhesive formulation provides temperature resistance of up to 180°C.
  • Freshly produced hot panels do not fuse together when stacked. 
  • No other protective film in this market segment can offer similar properties. 

POLIFILM PROTECTION has developed a temporary protective film for polyurethane rigid foam core sandwich panels, commonly used for the insulation of cold stores and refrigerated warehouses. This unique film engineered for this application area can withstand temperatures of up to 160°C and prevents freshly produced panels from fusing together when stacked. 

Sandwich panels typically consist of an upper and a lower painted metal skin and an insulating core made of rigid polyurethane foam. Before production, the skin layers are laminated with a protective film that must withstand all of the processing steps: from profiling and preheating, the application of the polyurethane core and its exothermic foaming reaction through to the cutting and stacking of the finished panels.  

The Challenge: Extreme Heat Resistance 

The foaming and curing of the polyurethane mixture poses a particular challenge as the energy released generates extreme heat in the panels. Even thinner panels can reach temperatures of up to 100°C whilst panels typically made for refrigerated storage conditions having an insulated core of up to 20 cm thick, can reach temperatures of up to 160°C during production. Any protective film used must be able to withstand these temperatures without peeling or melting whilst ensuring that the hot, freshly cut panels can be stacked together at the end of the production line, without the protective films fusing together.

Tailor-made solution for PU foamed sandwich panels

With this new temperature resistant protective film which has been perfectly engineered for sandwich panels with a rigid foam PU core up to 20 centimetres thick, POLIFILM PROTECTION provides a tailor-made solution for these process requirements: The heat-resistant film made of polypropylene has a particularly high melting point of 160°C. Despite the poor wetting properties of polypropylene in general, POLIFILM PROTECTION have succeeded in equipping the film with a special water-based acrylic adhesive which also boasts a temperature resistance of up to 180°C.

There are several advantages for producers of foamed sandwich panels when using this film: Firstly, the new protective film guarantees uninterrupted and efficient production. Even after a comparatively short cooling phase, it prevents the stacked panels from fusing together. Secondly the scrap rate is reduced as the panels are no longer damaged when they are separated. Lastly, the surface of every PU sandwich panel is optimally protected from the start of production to the end of the construction work ensuring customer satisfaction.

“With our special film, manufacturers of PU sandwich panels ensure the quality of their products and improve their processing speed and reliability - production becomes noticeably more efficient.  No other protective film on the market currently offers this added value,” explains Fulvio Camerini, Technical Director of the Italian production & development site of POLIFILM PROTECTION.