Are you concerned about whether the packaging you are about to purchase for your company's products will meet the required quality standards? However, with the naked eye, you can only inspect the appearance, dimensions, colors, and designs of packaging bags, without being able to determine their actual properties. So, let BMP Group introduce some methods for packaging quality control in the laboratory in the following article!

Microbiological Criteria for Packaging Quality

Packaging used for food and consumer goods currently available on the market is commonly made from plastic materials such as Polyethylene (PE) and Polypropylene (PP). Packaging may consist of multiple layers that completely enclose a product or cover only part of it. Below are some microbiological criteria for packaging quality that you should understand when conducting quality control:

• Dry residue in heptane at 25°C for 1 hour: 150 µg/mL.

• Dry residue in 20% ethanol at 60°C for 30 minutes: 30 µg/mL.

• Dry residue in water at 60°C for 30 minutes: 30 µg/mL.

• Dry residue in 4% acetic acid at 60°C for 30 minutes: 30 µg/mL.

Learn more: International Certifications and Standards in the Packaging Industry

Packaging may consist of multiple layers that completely enclose a product or cover only part of it.

You may also be interested in: Single-Layer and Flexible Laminated Packaging: Structures, Classification, and Applications

Methods for Packaging Quality Control in the Laboratory

Selecting packaging samples that meet quality requirements is essential for businesses. Therefore, BMP Group introduces several laboratory methods for packaging quality control that businesses can refer to and apply:

Related article: What Is Flexible Plastic Packaging? Differences Between PVC, PE, PP, and Common Packaging Plastics

Testing the Tensile Strength of Packaging

Tensile strength refers to the force required to break a material per unit of cross-sectional area. Polyester films and oriented PP films typically have high tensile strength values of over 400 kp/cm². Cellophane reaches 600 kp/cm², while LDPE ranges from 100 to 200 kp/cm². Therefore, you should use a tensile testing machine to measure the tensile strength of food packaging.

Testing the Elasticity of Packaging

Elasticity is an important factor in determining the quality of flexible plastic packaging. It represents the ability of packaging to return to its original dimensions and shape after being subjected to deformation. The elasticity of packaging can be checked manually by hand.

Elasticity is an important factor in determining the quality of flexible plastic packaging.

Testing the Tear Strength of Packaging

Tear strength plays an important role in determining the intended applications of packaging products. In practice, some food packaging products with low tear resistance are highly valued, such as potato chip bags. PE packaging has high tear strength, whereas Cellophane and polyester films have lower values. Therefore, the most effective method for measuring the tear strength of packaging is to use a packaging tear tester.

Testing the Impact Resistance of Packaging

Impact resistance is a particularly beneficial property when businesses package heavy products or goods in plastic films. It is also important when packaging products in large containers that may be subjected to impact forces throughout transportation.

An effective method for testing the impact resistance of packaging is to drop a specified weight onto the packaging. You can then measure the relative force required to puncture or break the material.

Testing the Stiffness of Packaging

For certain packaging applications involving plastic films, stiffness can be an important property. It is also particularly important for bottles and other containers where rigid packaging requires specific thickness values and maximum strength. In laboratories, packaging stiffness is generally determined by measuring and calculating the degree of deformation when the packaging is stretched.

Testing the Heat Resistance of Packaging

The heat resistance of product packaging is demonstrated through the melt flow index and heat-seal strength. These include:

Melt Flow Index: This refers to the flow rate of thermoplastic material under a specified temperature and pressure, as it passes through an opening of a specific size over a defined period. The melt flow index indicates the amount of material, measured in grams, that flows through the opening in 10 minutes. Businesses can test this property using a plastic melt flow index tester.

Heat-Seal Strength: This is the force required to separate two heat-sealed surfaces from each other in a perpendicular direction. PE packaging has high heat-seal strength, while Cellophane has a lower value.

The heat resistance of product packaging is demonstrated through the melt flow index and heat-seal strength.

Testing the Moisture Resistance of Packaging

Moisture resistance is an important factor when businesses need to determine whether a plastic film is suitable for packaging different types of goods. Some products need protection against moisture from the external environment, while others require protection from moisture originating inside the packaging. Therefore, you can test the moisture resistance of packaging in the laboratory using a water vapor permeability tester.

Conclusion

We hope the information above helps businesses understand effective methods for packaging quality control. If you have any further questions, please contact BMP Group for timely consultation.