Backing for Blister Packaging

Application Description

Strong, heat sealable film for the back of APET and PVC blister packs.


DuPont Teijin Films material selected and why

Mylar® 850 or Mylar® OL both perform on reel-fed blister packaging machines, even when contamination is present in the seal are.

Product Description

Mylar® 850 is a co-extruded, one side heat sealable polyester film. It can be heat sealed to itself and heat seals well to thermoformed APET/CPET trays and APET coated board. It also heat seals to various other substrates including PVdC, PVC, paper and aluminium foil, but will not seal to polyolefines. The plain (non heat-sealable) surface of Mylar® 850 exhibits the properties of a standard polyester film. Mylar® 850 is available in thicknesses of 15, 20 and 30 micron.

Typical Applications

Mylar® 850 is an excellent film for lidding to APET/CPET trays, either as a single web (Fig.1) or as part of a laminate (Fig. 2). Such packages are often used for dual ovenable ready meals. Mylar® 850 can also be used on Form-Fill-Seal machines and blister packs; its excellent aroma barrier properties make it ideal for packaging aromatic products such as air fresheners and toilet blocks.

Practical Information

Mylar® 850 has an exceptionally wide heat seal range, from 140°C to 220°C, with outstanding hot tack properties. Either fin seals or overlap seals may be made on conventional packaging equipment. The sealable surface of Mylar® 850 also acts as an excellent 'prime' for water-based latices. The film can thus be PVdC coated from an aqueous dispersion by converters without a primer to produce a high barrier laminating film. The plain surface of Mylar® 850 can be printed or metallised in the same way as plain polyester film, although the sealable surface makes handling of the film during conversion more critical. Mylar® 850 can withstand temperatures down to -70ºC and food can be heated/cooked in this film at typical heating conditions of 220ºC for 30 minutes. The heat seal surface of the film is normally wound on the inside of the reel (Mylar® 850i).