A composite structure manufactured by adhesive bonding or extrusion lamination of at least two sheets of film, for example, polyester film, aluminium foil or polyethylene film. Sacks made of composite film materials with a polyester layer provide a good barrier against oxygen and moisture. Sacks made from such materials extend the shelf-life of food by reducing oxidation and microbial contamination.
BS EN 788 specifies the general characteristics, requirements and methods of test for tubular sacks made of composite film, for example, PET/Alu/PE. The tubular sacks may be used as vacuum or inert gas packages.
BS EN 788 applies to tubular sacks made of composite film, for example, PET/Alu/PE, for the packaging of foodstuffs with a net filling weight of up to 2 000 g and storage life of at least 1 year in tropical climates of 38 °C and 90 % relative humidity.
Note: The packaging surrounding filled tubular sacks is not covered by BS EN 788.
BS EN 788 on tubular sacks made of composite film is useful for:
Sacks are made of a composite film for use in food packaging do not cause any leakage of a packaged substance through pinholes formed on the wall of the sack, which in turn leads to contamination of the circumferential regions during the distribution thereof and which ultimately permits the stable dissolution of the content thereof in water.
BS EN 788 goes through the tests for the determination of the tensile stress at break and elongation at break of the composite film, adhesion of the composite film, oxygen permeability of the composite film, and heat-sealed seam strength of tubular sacks.
BS EN 788 provides you with guidance on the dimensions of the tabular sacks made of the composite film. Following the description of the dimensions, the method of measuring the dimensions and the dimensional designation of the sack, manufacturers will be able to design appropriate sacks for the transport of food aid and this will help you in protecting food against contamination from the storage environment.