1, to prevent the transfer layer color have any requirements on the paper moisture content?
Answer: the bottom paper moisture content is exorbitant, indoor temperature and humidity is not stable, easy to transfer paper deformation, shape of concave and convex edges falbala phenomenon.Transfer of the moisture content of paper as the change of storage time and storage temperature, will be released in different degrees.And transfer the product moisture release of excess, paper fibers will be relatively hard and brittle.After die cutting indentation indentation in hardening of the paper fibers are different degree of damage.To control the transfer paper moisture content 6% commonly, printing workshop temperature control in 18 ~ 25 ℃, humidity control in the 60% plus or minus 5% advisable.
2, to prevent the transfer layer color have any requirements on adhesive coating amount?
A: aluminum transfer paper surface adhesion, mainly depends on the early adhesive dry stick performance and the amount of coating.Coating weight also directly affects the size of the detonation phenomenon of color, coating quantity too little, infiltration of adhesive paper quantity is little, transfer layer is not easy to completely strip, aluminum thin film layer after drying, not easy to resist strong pressure;Coating amount is too large, paper and composite membrane and extruded easily, if improper adjustment, oven temperature is a membranous, with connecting fastness of aluminum layer is not strong.
Should choose different according to different paper coating weight, for example, the quantitative 225 g/m2 of single-side coated white cardboard, its surface finish, high fiber arranged closely, better stiffness, instant absorption performance is poor, on the surface of the paper glue volume shoulds not be too big, general control in 1.5 ~ 2.0 g/m2;For surface finish more bad of the paper, glue quantity is 2.0 ~ 2.5 g/m2.
3, to prevent the explosion transfer layer of color on the drying system of why to ask?
Answer: the length of the drying system with 12 ~ 16 m the most appropriate, temperature for at least three groups, 4 set of best.Ventilation, convulsions to relatively large, hot air blows directly composite good paper on the back, and bake, temperature according to different machine speed adjustment.The speed is slow, the corresponding low temperature, and temperature are comparatively high.Optimal deployment of temperature of oven is: speed during 100 ~ 125 m/min, bake, temperature range of the first set to 100 ℃, temperature range of the second set at 110 ℃, the temperature range of the third set at 110 ℃, the temperature range of the fourth set at 90 ℃.
4, to prevent the explosion transfer layer of color on the adhesive performance of why to ask?
Answer: at present, the domestic use of transfer paper mostly wet transfer way, besmear is to transfer adhesives on the surface of the aluminum level or paper that transfer film, composite membrane and transfer paper or again, after drying oven to offline stripping or attachment detachment of compound, transfer directly.
For wet transfer way, at the beginning of the dry to use water-based adhesives, dry performance, film forming performance, water resistance, water is not easy to dissolve after drying), solvent resistance, ultraviolet radiation resistance, friction resistance, high strength and pressure resistance, high temperature resistance and so on are required.For the specific requirements of the main performance is as follows.
(1) on the properties of adhesive initial dry requirements: composite paper after baking oven, after the adhesive should be in a certain temperature under the condition of dry film, and after the initial dry with paper and adhesive transfer fastness of aluminum layer adhesive is enough to make transfer completely stripping aluminum layer.
(2) the adhesive viscosity requirements: the current domestic production of paper production equipment is more, there are dry compound stripping, wet type compound stripping paper, film coating or coating, either way the production transfer paper, control of the adhesive viscosity are more important.Adhesive of low viscosity, speed too fast, through and extruded phenomenon often occurred in the composite roller, and affects the bonding strength of the gel.High viscosity, such as adhesives, the speed too fast, the uneven coating, affect the aluminum layer transfer, stripping is not completely.So we need according to the different way of compound, drying methods, coating method to select the suitable adhesive viscosity.
(3) on the properties of film forming requirements: transfer paper adhesive can't fully dry, but after its membrane adhesion force of 80 n, adhesion bonded aluminum layer reached the standard of 50 n pull.Film forming properties of the adhesive can directly affect the explosion transfer paper color rate, film adhesive with good sex of goo can enhance the flexibility of paper surface, folding resistance, but also reduces the rate of color.
(4) on the properties of solvent resistant requirements: transfer paper, aluminum layer is divided into the bottom paper, adhesives, varnish several layers of structure, etc.After the film adhesive solvent corrosion resistance is generally poor, its corrosion resistance time and corrosion resistant performance, mainly rely on glue adhesion agent adding anti-corrosive agent.Intaglio printing use from non-beryl point polarity solvent for hybrid material, corrosion resistance is strong, but volatile speed is faster, in 65 ~ 90 ℃ under the condition of high temperature and ventilation can instantly volatilization, membrane structure for adhesive will not cause too much damage.