Food packaging and contact materials testing

The testing methods for food packaging and contact materials involve multiple aspects, including the testing of physical properties, chemical properties, and hygienic properties. The following is a detailed description of these testing methods:

1. Physical property testing
Physical property testing mainly evaluates the basic properties of food packaging and contact materials in actual use, including tensile strength, tear strength, thickness, oxygen permeability, water vapor permeability, heat deformation temperature, abrasion resistance, adhesion, light transmittance, etc.

Tensile strength and tear strength: The samples are tested by a tensile testing machine and tear testing machine, and the maximum tensile force and tear strength are recorded to evaluate the strength and durability of the material.
Thickness measurement: The thickness of the packaging material is measured using a thickness gauge to ensure that it is within the specified range.
Oxygen and water vapor permeability: Using the corresponding tester, the rate at which oxygen and water vapor permeate the packaging under certain conditions is measured to evaluate the barrier properties of the material.
Heat deformation temperature: The degree of deformation of the packaging material is measured at a specific temperature to evaluate its high-temperature resistance.
Abrasion resistance: The wear resistance of the printed pattern is evaluated through a friction test to ensure that the safety of the food will not be affected by wear during use.
Adhesion: Use tape to stick the printed surface and observe the adhesion of the ink to ensure that the printed pattern will not fall off.
Transmittance: Use a spectrophotometer to measure the transmittance of the packaging material to evaluate its transparency.
2. Chemical performance testing
Chemical performance testing mainly evaluates the harmful substances that may exist in food packaging and contact materials, including heavy metals, plasticizers, bisphenol A (BPA), organic content, etc.

Heavy metal migration detection: The packaging is exposed to simulated food contact liquid, and then the heavy metal content in the solution is analyzed, such as lead, cadmium, chromium, nickel, etc.
Plasticizer detection: Use chromatography and other methods to detect the plasticizer content in the packaging material, such as phthalates (DOP, DBP, etc.).
Bisphenol A (BPA) detection: Commonly found in polycarbonate plastics, bisphenol A is a potential endocrine disruptor that is harmful to human health.
Organic content detection: Detect the organic content in the material, such as volatile organic compounds (VOCs), etc.
3. Sanitary performance test
The sanitation performance test mainly evaluates the microbial contamination of food packaging and contact materials, including the total number of bacteria, coliform bacteria, molds and yeasts, etc.

Microbial testing: Cultivate and count microorganisms on the surface of the packaging to evaluate its hygienic condition.
Solvent residue test: Determine the solvent residue in the packaging material by gas chromatography to ensure that it will not migrate into the food.
4. Other test items
In addition to the above test items, food packaging, and contact material testing also include positive pressure sealing tests, negative pressure sealing tests, high-temperature cooking tests, corrosion resistance tests, biodegradability tests, etc.

Sealing test: Evaluate the sealing performance of the packaging through positive pressure sealing test and negative pressure sealing test to ensure that it will not leak during use.
High-temperature cooking test: Place the packaging under high-temperature cooking conditions, observe its performance changes, and evaluate its ability to resist high-temperature cooking.
Corrosion resistance test: Test the corrosion resistance of the material in acid, alkali, and other environments, especially for metals and coating materials.
Biodegradability test: Observe the degree of biodegradation of packaging materials in a specific environment to evaluate its environmental performance.
In summary, the testing methods for food packaging and contact materials involve multiple aspects, including the testing of physical properties, chemical properties, and hygienic properties. In practical applications, appropriate testing methods should be selected according to specific circumstances to ensure the safety and quality of food packaging and contact materials.