Bags nine main function requirements for plastic film, lack of a all not line

Whether single bag or composite bags, bags for the appearance of the plastic film, specification and errors, transparency and glossiness are basic requirements. Professional manufacturer of flexible packaging packaging today with us one by one to understand the packing bag of plastic confidentiality of the nine main function requirements. 1, the appearance of the surface of the plastic film should be flat and smooth, without buckling or only a small number of pleats, no obvious uneven, black, impurities, crystal point and rigid block, no defects such as stripe, flecked, critical reinforcement, without bubble, pore and fracture, aluminum plating film of aluminized layer should be uniform, there is no obvious light bars, the phenomenon such as surface of Yin and Yang. In addition, the membrane surface clean clean, no dust, oil, etc. 2, specification and deviation of plastic film width, thickness and deviation shall conform to the requirements, and shall be uniform thickness, the thickness of the horizontal, vertical deviation is small, and the deviation distribution more uniform. In addition, aluminum plating film of aluminum plating layer thickness also should comply with the requirements. 3, transparency and gloss for transparent plastic film, the requirements for its light transmittance is higher, the general should reach more than 92%. But about not transparent plastic film, white film, for example, insist on the high whiteness, good opacity. In addition, the plastic film should also has good iuster. 4, physical function, physical and mechanical properties of the plastic film including tensile strength, crack percentage elongation and tear strength, impact strength, etc. , in addition, aluminum plating film on aluminum plating layer of the healthy and vigorous degree also should conform to the requirements. 5, moisture transmission said plastic material under certain conditions through the amount of water vapor, for example, the relative humidity is 90%, the temperature of 30 ℃, the thickness is 25 um within 24 h of plastic film per square meter of water vapor through quality, from a certain extent, it represents the moisture resistance of membrane material, amount of all kinds of thin film materials is different, this also will determine the use of the category. 6, oxygen permeability said plastic material under certain conditions through the amount of oxygen, for example in the relative humidity is 90%, temperature is 23 ℃, the thickness is 25 um within 24 h of plastic film through the oxygen volume per square metre. All kinds of thin film materials of oxygen permeability is also different. 7, geometry size stability, plastic film must have certain how much size stability, otherwise, the expansion rate is too big, in the process of printing and composite by mechanical force or by the heat effect is easy to produce telescopic deformation, not only affects the overprint precision, also can appear buckling and bending problems, serious impact on product quality and produce power. 8, the chemical stability of plastic film to contact in the process of printing and composite ink and some organic solvents, adhesives, these are all chemicals, therefore, it is necessary for plastic film are exposed to these chemicals has surely resistance, resistance to avoid influenced by it. 9, such as two-way stretch polypropylene film surface tension and the surface tension of the low density polyethylene film reached 3 requirements. 8× 10 - More than 2 n/m, nylon, polyester and polyester film plating aluminum film surface tension also have corresponding standards. In general, it is necessary for plastic film before printing or compound by surface treatment to improve its surface tension, and able to smoothly and composite printing.