Technical Specifications:
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Film Type - transparent, thin, Japanese paper, weight: approx. 8.5 g/m2
Hot Seal Adhesive - free of plasticisers
Thickness of Product - 50mm, after pressure sealing: 20-30mm
Auxiliary Agents - Magnesium carbonate and Magnesium hydroxycarbonate
Sealing Conditions in Press - Temperature:100OC - 120OC Pressure: approx. 7-9 kg/cm2
- Time:1 minute
- The acrylic acid estercopolymer adhesive provides good adhesion which remains intact even after repeated folding - unlike many PE sealing adhesives.
- Magnesium carbonate neutralises the acids which sometimes develop during the decomposition of old papers and which then migrate into the adhesive layer. the acids in sealed paper cannot be neutralised because the magnesium carbonate remains in the Adhesive. The pH value of paper including the adhesive is 9.6.
Characteristics of the hot sealing adhesive:
- age resistant
- colourless
- non-yellowing (applies only to paper backing and adhesive)
- good sealing of papers (not affected by repeated folding)
neutralises acid
- no fading or bleaching of colour prints or writing/marking inks after 4 weeks storage at 70OC. Colours containing plasticisers can fade, e.g. black ball point pen, but not blue or other colours.
Backing Paper:
- free of lignin
- free of hemicellulose
- high alpha cellulose content
- pH neutral
Blocking tendency:
- The hot sealing adhesive blocks at temperatures above 50OC. Possibly even at 35OC when under high pressure and high humidity. Rolls without masking paper must therefore be stored dry and cool.
Removal:
- The adhesive can be made soluble again through the application of acetone or heat. When using heat, be sure to allow the high temperature required to warm right through the adhesive. The sealing can then be removed.
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