PVA film processing technology
4. 1 on PVA CP melt blowing it must be fully dry before, otherwise, in the melt blowing bubbles easily, at the same time, because the molecules of the PVA acetyl heated, easy hydrolysis reaction with water molecules, acetic acid small molecules generated will completely evaporate under 118 ℃, affect the appearance and intrinsic quality of membrane, can't even film.
4. 2 processing temperature on the mechanical behavior of blown film < br /> PVA molecules containing a large number of hydroxyl groups, the formation of intramolecular and intermolecular hydrogen bond, make its melting point close to the decomposition temperature, therefore, the temperature has a significant effect on the quality of PVA film < br /> charging period of temperature at 134 ℃ temperature control effect is better. Compression Duan Ruguo temperature is too high, may result in decomposition of PV material. Metering section if the temperature is too high, easy to lower melt strength, difficult to film; If temperature is too low, the tubular membrane formed through the ring head hard blow stretching.