PURPOSE: To produce a curt-free high quality patterned Al foil by specifying the size and dimensions of a pattern shape of a patterned Al foil as a packaging material, respectively.
CONSTITUTION: At the time of producing a patterned Al foil used for packaging food, chemicals, etc., and having fine patterns or a patterned laminated Al foil prepared by laminating the foil on paper, plastic film, etc., the thickness of an Al foil is regulated to ≤70μm and this Al foil is pressed to form a square- shaped pattern which consists of high ridge lines 1, low ridge lines 2, original Al foil planes 3, and inclined planes 4, 5 connecting them and in which pitch is regulated to 20-200mesh. At this time, a relation of h2/h1=0.1 to 0.6 is provided between the height h1 of the high ridge line 1 of the pattern with respect to the foil plane 3 and the height h2 of the low ridge line 2. Moreover, the high ridge lines 1 are formed in a direction orthogonal to a curl direction when the direction where curl is liable to occur is previously found, or, the high ridge lines 1 are formed in a direction forming an angle of inclination of about 45 degrees with the machine direction of the foil when the curl direction is not fixed.
Next Patent: ALUMINUM ALLOY FOR FORGING AND HEAT TREATMENT THEREFOR