Flexible Liquid Packaging Bag Manufacturers

How do soft liquid packaging bag manufacturers ensure strong bonding and good sealing between multiple layers of composite materials?

Material selection:
Choose a multi-layer composite material with high adhesion and sealing properties. These materials should have good heat sealing properties and be able to form a strong seal at the appropriate temperature and pressure.
Consider the chemical compatibility of materials to ensure they will not react with packaging contents or cause degradation.
Process Optimization:
Optimize heat sealing process parameters such as temperature, time and pressure. These parameters should be adjusted based on the physical properties of the selected composite material to achieve optimal bonding and sealing.
Through scientific methods such as orthogonal or DOE (designed experiments), test the heat sealing strength under different conditions and select the optimal parameter combination.
Regularly verify the bag making process to ensure process stability and product quality.
Equipment maintenance:
Choose high-quality heat sealing equipment and molds to ensure they have precise temperature control and pressure distribution.
Perform regular maintenance on equipment and molds, including cleaning, inspection and repairs, to ensure they are in good working order.
Heat treatment is performed on the mold to increase hardness and reduce damage to the membrane material. The edges of the mold should be rounded to reduce friction and damage to the composite material.
Operation control:
Strictly implement operating procedures to ensure that operators operate in accordance with specified process parameters.
Provide training to operators to improve their skills and awareness and ensure they understand how to properly operate equipment and maintain product quality.
Quality Inspection:
Strict quality testing is carried out on the packaging bags produced, including sealing test, adhesive strength test, etc.
Use professional testing equipment and methods to ensure the accuracy and reliability of testing results.
Trace and correct unqualified products to avoid similar problems from happening again.
Adhesive options:
Choose an adhesive with good compatibility with the composite material to ensure that the adhesive can fully penetrate between the multiple layers of composite materials to form a strong bonding layer.
The adhesive should have excellent weather, chemical and temperature resistance to ensure that it does not open or degrade during storage and transportation.
Production process control:
During the production process, ensure that the composite material is kept dry, clean and free of contamination before bonding.
Control the tension of composite materials to avoid stretching or deformation during bonding.
During the bonding process, ensure that the adhesive is evenly applied on the surface of the composite material to avoid missing or uneven coating.
Packaging design optimization:
According to product characteristics and storage requirements, the design of the packaging bag is optimized to ensure that the packaging bag can withstand internal pressure and external impact.
Set up a reasonable opening and sealing structure on the packaging bag to facilitate users to open and reseal the packaging bag.

What performance tests do soft liquid packaging bag suppliers need to do on soft liquid packaging bags?

Sealing performance test:
Hot water test: Immerse the sealed sample bag into hot water of (60±2)℃ and observe whether continuous bubbles are generated within a specific time to evaluate the sealing property of the packaging bag.
Decompression retention ability test: Evaluate the decompression retention ability of the packaging bag by pumping air until the pressure difference between the inside and outside of the package is 20-30kPa, observing the pressure recovery rate, or observing whether the packaging film is tightly attached to the contents under specific conditions.
Pressure retention test (inflation test): evaluates the ability of the packaging bag to maintain pressure after inflation.
Vacuum chamber test: The packaging bag is evacuated in a vacuum chamber and its leakage is observed to evaluate its sealing performance.
Heat sealing strength test: For polyethylene blown films for liquid packaging, heat seal two films in the same direction together, and then cut the sample strips for tensile testing to evaluate their heat sealing strength. This helps ensure that the bag will not break due to poor heat sealing during transportation and use.
Compression strength test: Use equipment such as electronic tensile machines to test the pressure resistance of packaging bags to ensure that they can withstand a certain amount of pressure without breaking or deforming.
Puncture resistance test: Evaluate the resistance of the packaging bag when punctured by sharp objects to ensure that it can withstand a certain degree of external impact in actual use.
Friction coefficient test: Test the friction coefficient between packaging bags and different surfaces to evaluate their sliding performance during transportation, stacking, etc.
Drop test: simulate the drop impact that the packaging bag may suffer during transportation to evaluate its impact resistance and breakage rate.