The characteristics of PVA membrane
PVA membrane products belong to the green environmental protection material. Relevant departments of the measured PVA biological oxygen consumption ( 生化需氧量) Much smaller than starch. In terms of degradation mechanism, PVA with water and biological degradation of material properties, gel first dissolve in water to form liquid infiltration in the soil, can increase the soil mass of viscosity, permeability and water retention, especially suitable for sandy soil reconstruction. In PVA material in the soil can be * * to decompose in the soil, biodegradable to CO2 and H2O. Water-soluble
PVA solvent is water, but water solubility is largely influenced by degree of polymerization, especially controlled by the alcoholysis degree. Alcoholysis degree at 0. 88, in room temperature of 20 ℃ room temperature water almost completely dissolved. With increased solubility of alcoholysis degree dropped substantially, completely alcoholysis PVA dissolved in the water. The water soluble PVA membrane associated with thin film thickness and the temperature of water. Strength and weatherability
PVA film good toughness, tensile strength, tear strength in all kinds of thin film first, the two-way tensile strength is superior, the good weather resistance, long service life. All kinds of film strength performance in the following table:
demoulding and metal plating
PVA membrane of hydrophobic strong plastic low affinity, the polarity of small organic material to take off the membrane ( Stripping) Good performance.
PVA membrane can be in 1. 33 * 10 ~ 266 * 10 pa vacuum aluminum plating, its products in 30 ℃ water soak for 24 hours, the coating will not shed.
PVA membrane permeability and pt are similar, is a kind of high humidity of thin film, packing heat, wet goods will not produce the droplets. According to JIS - Z1503 measurement data in the following table:
PVA membrane under dry conditions have excellent oxygen resistance performance, it is various kinds of resin film in low oxygen transmission coefficient. (there are many hydroxyl groups on the PVA molecules - - 哦) , are in a damp environment these hydroxyl groups and water molecules to form hydrogen bond, lead to changes in PVA * * state structure, make the barrier property of PVA drops greatly. With the rise of relative humidity, the amount of oxygen through the obvious rise. PVA membrane permeability of water and ammonia has strong, but the oxygen, nitrogen, hydrogen, helium, argon and carbon dioxide has excellent barrier property, under the condition of atmospheric oxygen blocking rate is about 1000 times that of the commonly used polyethylene film, polypropylene film 300 times. Using PVA membrane can remain intact packaged product ingredient and the smell of itself.
a lot of plastic film have very strong charge, the PVA membrane with hardly static electricity. Using PVA membrane in the process of packaging products, not because of static electricity and cause its plasticity reduced or electrostatic dust. Printing performance
PVA film with excellent water and ink printing, this is the existing plastic film can only use the ink printing incomparable advantages, can be used in water transfer printing, such as glass, ceramics, electrical shell, auto parts and so on irregular surface color printing. PVA membrane polarity is strong at the same time, when the printing don't electric spark processing, widely used in * * on the printing industry, such as water transfer printing membrane substrate. Hot sealing sex
water soluble packaging film has good heat sealing, suitable for resistance high frequency heat sealing, heat sealing and heat sealing strength is related to such conditions as the temperature and humidity, pressure, time, generally greater than 200 g/cm2.
oil resistance and solvent resistance of the
PVA membrane has good oil resistance, Vegetable oil, animal oil, mineral oil) , resistance to organic solvents and carbohydrate, etc. * * base but strong alkali, strong acid, chlorine and other substances that can react with PVA ( Such as borax, boric acid, some dyes, etc. ) , this kind of material is not suitable for using PVA film packaging.
keep incense and prevent sublimation
PVA membrane of incense and prevent packaging sublimation of better performance, using PVA film packaging, not only can maintain the fragrance of packing materials, but also can prevent the packing materials affected by the smell.
the above is about the introduction of the characteristics of PVA membrane, the hope can help to you.