Characteristics of plastic protective film

  • Plastic protective film is a kind of protective film produced with plastic materials as raw materials. Many friends do not have a lot of contact with plastic protective films in life, so there is relatively little understanding of plastic protective film, but in our lives There are still many products that are closely related to the use of plastic protective film. As one of China's well-known protective film suppliers, Xinhao suggests that you should learn more about plastic protective film.

    plastic protective film

    1. Specifications and deviations

    The width, thickness and deviation of the plastic protective film should meet the requirements, and the thickness should be uniform, with small deviations in the horizontal and vertical thickness, and the deviation distribution should be relatively uniform. In addition, the thickness of the aluminized layer of the aluminized film should also meet the requirements.

     

    2. Transparency and gloss

    For clear plastic protective film, its light transmittance is required to be higher, and it should generally reach 92% or more. For opaque plastic protective films, such as white film, high whiteness and good opacity are required. In addition, clear plastic protective film should also have good gloss.

     

    3. Appearance

    The surface of the plastic protective film should be flat and smooth, with no folds or a small amount of live patch, no obvious unevenness, black spots, impurities, crystal spots and rigid blocks, no stripes, spots, violent tendons, etc., no bubbles, Pinholes and cracks, the aluminized layer of the aluminized film should be uniform, and no obvious bright stripes, yin and yang surfaces, etc. are allowed. In addition, the surface of the protective film is required to be clean and free of dust, oil, etc.

     

    4. Physical and mechanical properties

    Because plastic protective sheeting is subject to mechanical forces during printing and lamination, the protective film material must have a certain degree of mechanical strength and flexibility. The physical and mechanical properties of the plastic protective film mainly include tensile strength, elongation at break, tear strength, impact strength, etc. In addition, the firmness of the aluminized layer on the aluminized film should also meet the requirements.

     

    5. Geometric dimensional stability

    Plastic protective sheeting must have a certain degree of geometric dimensional stability, otherwise, its expansion rate is too large, and it will easily produce expansion and contraction under the action of mechanical force or heat during the printing and lamination process, which will not only affect the accuracy of overprinting, but also cause wrinkles. , Curling and other issues, seriously affecting product quality and production efficiency.

     

    6. Chemical stability

    Plastic protective sheeting is exposed to inks, adhesives, and certain organic solvents during the printing and laminating process. These are all chemical substances. Therefore, the plastic protective sheeting must have certain resistance to these chemical substances in contact with it, so as not to Affected by it.

     

    7. Moisture permeability

    Indicates the amount of water vapor transmitted by the plastic protective sheeting material under certain conditions. For example, when the relative humidity is 90% and the temperature is 30°C, the water per square meter of a plastic protective sheet with a thickness of 25um in 24 hours The quality of steam, to a certain extent, represents the moisture resistance of the film material. The moisture permeability of various film materials is different, which also determines its application range.

     

    8. Oxygen permeability

    Indicates the oxygen permeability of the plastic protective sheeting material under certain conditions. For example, when the relative humidity is 90% and the temperature is 23°C, the oxygen permeation by a square meter of plastic protective sheeting with a thickness of 25um in 24 hours volume of. The oxygen permeability of various protective film materials is also different.

     

    9. Surface tension

    In order to make the printing ink and the composite adhesive have good wettability and adhesion on the surface of the plastic protective film, the surface tension of the protective film is required to reach a certain standard, otherwise it will affect the ink and adhesive on the surface. Surface adhesion and adhesion, thereby affecting the quality of printed matter and composite products. For example, the surface tension of the two-way polypropylene protective film and the low-strength polyethylene protective film is required to reach 3.8x10-2N/m, and the surface tension of the nylon protective film, polyester protective film and polyester aluminized film is generally required to reach 45x10. -2N/m or more. Generally speaking, the plastic film must undergo surface treatment before printing or laminating to increase its surface tension, and printing and laminating can be carried out smoothly.

     

    Recommended reading:

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