GB719664A - Improvements in or relating to cheese package - Google Patents

Abstract

Cheese is enclosed in a grease-resistant moisture-proof wrapper consisting of an outer base sheet and an inner continuous film of a composition comprising 3-40 per cent polyethylene of mol. wt. at least 12,000, e.g. 18,000-20,000, 25-50 per cent solid polyisobutylene of mol. wt. at least 60,000, e.g. 100,000-140,000 and 10-72 per cent petroleum wax, e.g. microcrystalline wax of m.pt. 155-160 DEG F or paraffin wax of m.pt. 130-132 DEG F. The film and backing sheet may be applied to the cheese separately, or the film may be a coating on the backing sheet (see Group VIII). The base sheet, which may be regenerated cellulose, rubber hydrochloride, polyvinyl alcohol, or paper impregnated with microcrystalline, or a mixture of microcrystalline and paraffin, waxes has an oxygen permeability of not more than 250 c.c./sq. m./24 hrs. at 45 DEG F and 760 mm., and a carbon dioxide permeability which is, say, greater than 270 c.c./sq. m./24 hrs. at 70 DEG F and 760 mm. The film has a gas permeability in excess of the base sheet, and the wrapper inhibits moisture loss, is peelable from the cheese, and permits carbon dioxide generated by the cheese to escape while preventing the entry of oxygen in amount sufficient to effect surface flavour. Specifications 481,426, 481,427, [both in Group VIII], and 496,870, [Group XVII], are referred to.