In order to ensure the packaging effect, safety performance and user experience of the product, manufacturers and purchasers must conduct comprehensive and scientific quality inspections on plastic bags. So, what are the quality inspections for transparent self adhesive plastic bags?
1. Overview of common quality problems
During the production or transportation process, transparent self adhesive plastic bags may have the following problems:
Uneven thickness, affecting load-bearing and feel
Poor adhesive strips or residual adhesive problems
Unstable edge sealing, easy to crack or leak
Wrinkles, damage, bubbles on the bag body
Opaque, many impurities, pungent odor
Dimensional deviation, affecting assembly or display
Therefore, it is particularly important to establish a scientific quality inspection process.
2. Main items of quality inspection
1. Thickness test
Tool: electronic thickness gauge
Method: measure the thickness at multiple locations of the bag to ensure uniformity
Standard: if the nominal thickness is 50μm, the error should be controlled within ±10%
2. Dimension test
Tool: steel ruler, caliper
Method: check whether the bag length, bag width, pasting area, and folding edge dimensions are consistent with the design
Standard: the error should be controlled within ±2mm
3. Adhesion test of self-adhesive tape
Tool: manual pasting test + peel strength tester
Method: seal the bag mouth and repeatedly open it 3 times to evaluate whether it can still be firmly pasted
Standard: the seal does not debond, warp, bubble, or residual glue
4. Load-bearing test
Method: put in a certain weight of items, lift and let it stand for 1 hour, and check whether it is broken or the seal is loose
Standard: the product's nominal load-bearing must be reached or the safety load standard of more than 20%
5. Seal Strength & Leakage Test
Method: Inject an appropriate amount of air or water and then press the bag mouth by hand to observe whether there is air leakage or water seepage
Standard: The seal is complete, without air leakage or damage
6. Transparency & Impurity Check
Tool: Visual inspection + light box assistance
Method: Observe whether the bag body is clear, whether there are black spots, impurities, wrinkles
Standard: High transparency, no obvious particles, printing residues or foreign matter
7. Odor Test
Method: Smell the odor after opening the bag, and record whether the odor is pungent or has chemical residues
Standard: Food grade/environmental grade bags should have no odor or only a slight plastic odor
8. Printing Fastness Test (If printed)
Method: Hand rub test or wipe with alcohol cotton cloth to determine whether the printed pattern falls off or fades
Standard: The pattern is firm, resistant to friction and alcohol
