Book Cover hydrosol coating quality control point analysis
Cover machine, used to make book covers , etc., which is essential hydrosol film , then, explain this knowledge
In books and other printed materials cover the surface covered with a layer of polypropylene plastic film, used to improve the surface brightness , it has a moisture-proof , anti-fouling , folding function, after the film prints look bright , luxury, taste value greatly improved.
Plus hydrosol bonding performance, the ink layer can produce good affinity . No use of organic solvents, printed paper, ink without erosion , will not wrinkle , loss sticky, stripping . Both the production site and storehouse eradicated fire hazards, ensure safety in production. No use of organic solvents , no harmful gases volatile pollution, in line with national environmental requirements , clean production environment, protect human health . And be able to just finish printing ink is not completely dry lamination printed matter , saving time , shorten the processing cycle . But also because of its light performance , without causing bleeding of ink pigment and color, no discoloration due to aging and yellowing . Hydrosol cheap, coated with less cost, hydrosol now largely replaced hot-melt adhesive resin used .
However, due to operational use and other reasons, after the film 's products often appear not bright or blistering , wrinkling and other phenomena . Now talk about common problems in the operation process .
1 . Temperature Control
In the rain or the rainy season , if the temperature regulation is inappropriate, coated products is no light. On silica gel rollers obvious water vapor, which is a lot of paper absorbs moisture caused. Then hot roller temperature is adjustable to 40 degrees Celsius. If the temperature is too high , it will blister. Some hydrosol laminating machine without heating device , you need to increase the baking lights before lamination to make glue dry, reduce foaming .
2 . Pressure Control
In the film thickness should be adjusted according to the paper , the general in 5Pa. If the pressure is too general produce film and paper wrinkle deformation .
3 glue control
Plastic volume control is by spin coating on the plastic drum roller and size of the gap control , as well as an increase in the scratch film . Large amount of light plastic film blowing pressure , pressure for a small amount of glue . The amount of glue to master , both to cover prison uniform, without producing crystal point . If the glue is too large, it will make the product does not shine. Gluing process should pay attention , we must prevent the glue solidified tiny particles and impurities remain in the plastic tray. If you are stuck scraping the film , will produce a white offset, linear cause blistering . Before turning on the use of alcohol -based solvent cleaning roller and plastic bucket, if the roller is not clean , it will cause needle bulbs. Gum containing impurities , can be diluted with water , precipitation of impurities , when the diluent to reduce adhesive waste.
4 roller cleaning
When the paper feed separation occurs , the gel will be directly rolled over silica rollers , resulting in accumulation , easy to make products wrinkled, or affect the brightness of the drum should be cleaned regularly and kept clean . Drum itself usually will not wrinkle , need to be replaced.
5 . Temperature and humidity control
Ambient temperature and humidity changes, moisture absorption paper produce " flouncing " when coated paper wrinkle easily , keep the temperature and humidity balance. Heating roller temperature is too high , the paper tight side will wrinkle, be requested to control the temperature.
6 feeding control
Skewed paper feeding causes wrinkling , the operation should seriously make feeding level service , the pressure on both sides of the same. At feeding time , for each sheet are laminated 3mm, and controls the amount of glue , to prevent the phenomenon of excess glue . Such products can be reduced to each other after the film adhesion . If the connection wrinkled or from vacuoles, should be maintained temperature and humidity equilibrium conditions , due to increase pressure on the bonding level service and reduce foaming .
7 film roll control
Roll of film on both sides to prevent inconsistencies resulting elastic fight wrinkles .
To select the first line on both sides of the elastic membrane , and then adjust the tension across the membrane to balance and prevent wrinkle . In the film to make use of wool is expected to open the book size plus size width of the film, such as the big 16 format , try using 44Omm wide film without using 460mm wide film , which can save costs by 4%. 16 format using 780mm wide film , try trimming, reducing the amount of plastic , save with plastic.
8 Printing Do not use additives to control the amount of powder
Try not to use the printing process additives , because easy to dry , after the film foaming . And the need to control dusting usage. In the film before you arrange for someone to erase dusting on the cover , reduce flooding or blister film phenomenon , the product light.
9 . Machine speed control
In the coating process, do not arbitrarily change the speed of the host , too fast , glue meet the requirements, when a slight increase in speed, glue and too large. If the speed is set too low , reducing the amount of glue , easy blistering. In order to ensure consistent glue , laminating machine can speed by 60% of the maximum speed limit , so that each class is run under the specified speed , the implementation of data management, in order to reduce unnecessary losses.