Composite Film & Backsheet

Introduction of Composite Film & Backsheet

Thermoplastic polyester film (e.g. BO-PET film) is a film material with excellent performance, affordable price and very wide range of applications. In the photovoltaic industry, it is often used as the intermediate layer of photovoltaic backsheets and is the backbone material. The material has good mechanical stiffness, strength, heat resistance and electrical insulation; at the same time as the intermediate layer of the backsheet, special emphasis is also placed on its need for hydrolysis resistance, generally to achieve the autoclave PCT 48 hours of cooking grade (or double 85 aging 2000 hours). If used as a transparent frontsheet, it may need to achieve a higher PCT rating. In the non-photovoltaic industry, particularly in outdoor building materials such as colour steel, colour aluminium, light tiles and HPL protection panels, super-resistant polyester films are also urgently needed by the industry. In fact, there are many other members of the thermoplastic polyester family, such as PXT, PBT, PCT, PPT, PETG/PCTG, TPEE, PEN and LCP, etc. Some of these polyesters, after appropriate modification and upgrading, can become the so-called super weather-resistant polyester, such as PCT grade can be as high as 96 hours or more.

Hangzhou Fumotech (hereinafter referred to as Fumotech) has developed highly efficient formulation technologies for hydrolysis resistance and ultraviolet (UV) aging resistance. On the one hand, the customised production of BO-PET film with Fumotech's proprietary Semi-IPN weathering coating (Fluorina® coating) enables the production of high-performance front and backsheets. On the other hand, Fumotech has also developed new polyester films with ultra-high PCT grade, up to 96 hours grade for transparent products and 120 hours grade for opalescent products. On this basis, Fumotech has also launched innovative products such as super reflective polyester film (92% visible light reflectivity), all-black infrared high reflective polyester film (85% UV reflectivity), flame retardant polyester film and radiation-cooling polyester film in recent years. In order to closely address customers' pain points, Fumotech has also developed pre-coating technology (BondStronTM coating) for polyester films. Some of these pre-coatings can well participate in the co-curing of thermosetting resins, such as unsaturated polyester (UPE), epoxy resin (EP), melamine resin (MCA) and polyurethane resin (PUR). These ultra-resistant polyester films, when used as a top layer, can substantially improve the weather aging resistance of thermosetting resins, and are particularly effective in preventing problems such as yellowing, cracking and chalking.