Flexible packaging color temperature humidity control requirements

Due to the nylon membrane after moisture absorption and moisture absorption caused a series of negative consequences, so environment has certain requirements for flexible packaging color. General should be stored in 23 ℃, & plusmn; About 3 ℃, 60% dry humidity difference in RH± 5% RH ideal, nylon membrane cannot be placed directly on the floor, open, in order to avoid moisture absorption be affected with damp be affected with damp. And poor production environment of dry and wet is generally not more than 75% RH, if 80% RH should stop production, Especially the composite production) In order to avoid adverse for led. If the drive task must be put into production, can be used in production to add put the fan and dehumidifier, strengthen the indoor air circulation, make the production reproduction under environment humidity to 70% RH. All in all, must be careful to use when humidity is over 70% RH, in the use of low temperature or humidity is big, be sure to open the printing and the preheating equipment of compound machine, nylon membrane preheating first, drying on the nylon membrane on the surface of the water, for printing, composite production run smoothly; At the turn of the winter and spring season due to temperature change is bigger, to pay attention to in using the mixed solvent for effective adjustment along with the change of the temperature, prevent solvent evaporation too fast or too much residual solvent quality accident. Workshop environment control can maintain humidity was 50% ~ 60% RH, summer temperature in the 20 ~ 22 ℃ best, this is because the printing workshop in the process of production will produce large amounts of heat release, control the temperature and humidity is the first condition of guarantee the quality of printing. In the dry and solvent-free composite process, different types of two-component polyurethane adhesive for the sensitivity of water and alcohol. Beyond the scope of could not stem the phenomenon. If the sensitivity is beyond the scope of, ( The higher the) Flexibility is the worse, after composite products are sometimes hard and brittle. Can seriously affect the effect of compound, therefore, this is because the NCO group is contained in solvent-free polyurethane adhesive, can and active hydrogen reaction, these reactions will consumes isocyanate, to participate in the glue solution reduced the volume of reaction, and gives off carbon dioxide at the same time, make the rubber contains bubbles, very adverse for composite, surface not stem or adhesive strength will also decline. Response to the nylon membrane, cellophane and moisture absorption sex very strong material, residual solvents and humidity in the air after printing to strictly control. In family of nylon membrane, the PA6 film bibulous rate is maximum, saturated water absorption can reach 9%, two-way stretch nylon membrane be affected with damp be affected with damp after moisture absorption in addition to the wrinkle, also horizontal elongation, vertical shortening, and as the humidity increases and elongation, elongation of up to 1. 5%. As humidity at 75% RH, transverse elongation 0. About 37%, and the longitudinal & ndash; 0. 28%; If humidity to 85% RH, the transverse elongation 0. 5%, vertical & ndash; 0. 38%. The nylon membrane stress - after moisture absorption - Strain curve changes significantly. Nylon membrane after moisture absorption, will not be a larger influence on corona effect, but large influence on adhesion of printing ink and adhesive. General nylon membrane when the moisture content over 3% will not only influence the adhesion of printing ink and adhesive, at the same time also can make the film feel stiff, surface yellowing and affect the appearance. So for flexible packaging color should pay special attention to, in case of be affected with damp be affected with damp nylon membrane moisture absorption. Author: Chen Mengjie