Aluminium Blister Foils
Hard aluminum foils is the push through lidding material that is most widely used in Europe. The foil usually has a thickness of about 25 micron. However this may in time be reduced to 15 micron. The hardness of the aluminum facilitates push through opening. Usually only the print-primer side features a printed design, but occasionally the side with the heat-sealing lacquer can also be printed. A double coat of heat-sealing lacquer (a heat sealing primer and the actual heat-sealing lacquer) has become the standard for lidding materials.
The heat-sealing primer ensures optimum adhesion of the heat-sealing lacquer to the aluminum foil. Then the heat-sealing lacquer can be perfectly matched to the formed films. If the heat sealing primers are colored then the heat-sealing lacquer applied over the primer can protect the packaged product from coming into contact with the pigments. If additional printing is required on the side of the heat sealing lacquer, the only alternative is to apply two coats of the lacquer. This is necessary because the printing inks must be between the heat-sealing primer and the actual heat-sealing lacquer.
Foil Composition | Al.Foil Thickness (mm) | 0.025 | 0.02 | | Tolerance (mm) | +/- 8 % of al foil | | | Density (GSM/CC) | 2.71 | 2.71 | | Al.Foil Wt (GSM) | 68 | 54 | | Pin Hole In Al.Foil (NO/SQM) Max | 8-12 | 12-15 | | Al.Foil Surface | Matt / Bright | | | Temper | Hard Temper | | | Primer (GSM) Max | 1.5 | | | Heat Seal Lacquer | 3-4 GSM (Standard) | | | | 6-8 GSM (Special) | |
Printing Properties | Colour | 1-3 Colour as Per Design Prc on Both Side | | Ink Adhesion | To Pass Scotch Test | | Printing Surface | Non HSL Side | | Registration | +/- 0.025mm | | Other Properties | Resistance to Water, Heat, Abrasion |
Operating Condition | Temperature o C | 150 o C - 155 o C | | Pressure | 2 KG/SQ.CM | | Dwell Time | 1SEC |
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