Packaging and Appearance Inspection
Packaging Appearance: Inspect the packaging for any damage, ensuring there are no tears or leaks in the container. This is a fundamental step to ensure that the adhesive remains uncontaminated and unspoiled during transportation and storage.
Packaging Labeling: The outer packaging of adhesive paper should clearly and completely indicate the adhesive name, model, quantity of packaging, weight, manufacturer's name, production batch number, production date, shelf life, and other information. For flammable and explosive products, a hazard warning label should also be present. Additionally, an instruction manual should be included within the box, and the shelf life should provide at least 5 months of usable duration.
Section II: Adhesive Appearance and Physical Property Inspection
Color and Condition: The color and condition of adhesive for mounting papers should comply with standards based on the type of adhesive. For example, mounting adhesive may be a milky white liquid, water-based lamination adhesive a white slightly blue liquid, oil-based lamination adhesive a colorless or slightly yellow transparent thick liquid, and adhesive for sealing boxes may be a milky yellow thick gel. Additionally, the adhesive should not exhibit clumping, impurities, or other signs of deterioration.
Viscosity: Measure the adhesive's viscosity using a viscometer or rotational viscometer to ensure it falls within the specified range. Different types of adhesives have varying viscosity requirements; for instance, water-based lamination adhesive may have a viscosity between 17-19S (425), oil-based lamination adhesive between 1000-3000 mPa.s, and adhesive box glue between 1600-600 mPa.s.
Odor: Check for a strong smell, ensuring the adhesive meets environmental and safety standards.
III. Performance and Functionality Testing
Bond Strength: Evaluate the adhesive performance by testing the bonding strength of the lamination samples. The bonding strength should be greater than or equal to the substrate strength. If the substrate strength is above 300N/m, the small bonding strength of the sample should be tested at 3N/cm; if the substrate strength is below 300N/m, the small bonding strength of the sample should be tested at 1N/cm.
Adhesion Interface: Ensure the adhesion interface is smooth and even, without any bubbles, delamination, or spots. Additionally, any residual adhesive should be evenly distributed across the sample surface.
Tear Test: After drying the mounted product, the base paper and face paper should not separate.
Coating Test: Conduct coating tests on areas with brighter and thicker ink layers, observing if the ink is effectively transferred to the film. Separation or detachment of the film from the ink is not permitted. Additionally, perform convex or embossing tests to check for bubbling or delamination under high temperatures.
Box Adhesion Test: Conducted impact and tearing destructive tests, requiring that 80% or more of the cardboard fibers in the box break during the test.
Aging Test: Place the product in a high-temperature environment for a certain period, then remove it to observe for issues such as delamination, bubbling, creasing, or yellowing of color.
Freezing Test: Place the product in a low-temperature environment for a certain period of time, then remove it to observe for issues such as adhesive separation, bubbling, or delamination.
Section 4: Other Inspections
Spots and Impurities: Inspect the product surface for any spots, impurities, or defects.
Curl and Bow: Inspect products for any bowing, curling, or other deformation issues.
Uniform Coating: Inspect for even coating application to avoid quality issues caused by uneven coatings.
