Optimal machine settings are following:
- not down, well connected stamps in good conditions;
- the stamps must have been fixed without tension and must be of equal thickness over the entire length;
- minimised glue application by adjusting the distance/opening between the dosage and lick rollers;
- the distance between the stamp and the lick roller must be the same as the thickness of the stamp.
Window material can be divided into two groups: glassine window or synthetic window.
Glassine window material can also be glued with the standard Paramelt side seam adhesives. Glassine is a thin, hard, short fibre, transparent paper type. Glassine is obtained by high milling grade and a refining process; the paper grammage is about 40 g/m². Glassine is much more sensitive to variations in humidity than normal paper. This often results in wrinkling around the window perimeter. The advantage of glassine is its easy gluing.
Synthetic film used is usually polystyrene, which can be subdivided into half matt and crystal clear (fully transparent) film. Sometimes polypropylene film is used, but this is more difficult to cut. Thickness of the film is approximately 35 µm. A disadvantage of synthetic films is that it is difficult to glue.
Due to the differences in expansion of materials under the influence of moisture, wrinkling often occurs around the perimeter of the window. This can be reduced by:
- using an adhesive with a high solid content;
- applying the adhesive in a grid rather than full coverage (thus lowering amount of glue applied).
Our product line in window patching adhesives is:
- Enziflex: co-polymer dispersion specially developed for different machines, paper and application systems.
