You are printed base paper or basement membrane, its surface must be clean, dry, level off, without dust, no pollution, the nonpolar, surface density smooth materials such as PE, for its surface tension is low, only 29 ~ 31 mn • m - 1, but also ahead of corona treatment, make its surface state changes, surface tension increased to 40 mn • m - 1, or at least 38 mn • m - 1 above, so, printing ink to achieve certain fastness.
2 cups the requirement of printing ink
Used in paper cups of the printing ink printing requirements better fastness, prints have good acid and alkali resistance, water resistance, heat resistance, light fastness, won't because of these factors effect happens fade, discoloration, fall off phenomenon; The other printed matter to have good scratch resistance and gloss, half extinction sex and extinction sex.
Paper cups printing technology (except general printing technology outside of the supplementary)
1 ink composition: ink components must comply with the food hygiene law and the corresponding food packaging hygiene standards.
2 residual solvent: control residual solvent quantity is less, in order to prevent the prints produce stink, printed matter back smearing, solvent adhere to sealing in base material or the basement membrane, can cause heat sealing bad, form sealing place bonding bad or for bonding bad made roll * * * * mouth phenomenon.
3 drying temperature: ink drying temperature too much, the temperature is too high time base membrane surface will produce peroxide, cause heat sealing bad. But also to prevent the printing ink dry bad, in order to avoid stink.
4 ink and ink solvent selection: choose as far as possible the printing ink solvent can make PE film swelling or solvent water, in order to prevent the prints crimp; As far as possible choose contain can plasticize free carrier ink, in order to prevent ink film and PE film because of temperature change and produce different shrinkage rate, forming a print crimp. Curly prints the die cut into segment will produce warping, give a paper cup cup of delivery and roll opening molding difficult.
5 the environment temperature and humidity: shop humidity is too high can form prints crimp, after printing roll film higher temperature can occur between up and down two film adhesion, will also affect the processing sequence of after paper cup forming.
Paper cups processing performance
According to the paper cups processing performance and use performance, decided the paper cup base paper must have the following technical requirements:
1 strong resistance to water performance: made of paper cup without water seepage, slack phenomenon.
2 easy processing formability: when making paper cups in order to avoid manufacture process in paperboard and wrinkle phenomenon, and forming after the paper cups not changeful form, request paper cups base stiffness, high smoothness, thickness properly, easy to machining molding.
3 paper surface exquisite sex: requirements control base demand printing surface or tube membrane of PE to printing the surface roughness value, to meet the requirements of paper cup surface printing surface exquisite and sex.
4 high whiteness: do not use fluorescent agent in the premise of base paper to keep the corresponding paper whiteness, in order to ensure printed pattern clear beautiful.
5 high safety and health sex: paper cups base paper and paper cups products regularly send the local national sanitation epidemic prevention system for health safety testing, in order to ensure the use of user security, paper cups base paper accord with "food wrapping base health standard" (GB 1 1680), paper cups paper accord with "food wrapping polyethylene molding product health standard" (GB/T 9687), and at the same time, products (including special plastic particles) still need to send agencies lZDA quality testing, in order to ensure the health and safety to the provisions of the state on the sanitary standard and conform to the requirements of customers abroad.
conclusion
Paper cups of food packaging materials, direct and population contact, in health must conform to the hygiene standards, paper cups made continuous molding processing of heat sealing performance and printing in PE membrane surface, which require in the printing technology must be mixed into and paper cups performance adapt to the ink composition, residual solvent quantity, moderate dry conditions and so on.