Flexible packaging food testing method - Database & Sql Blog Articles

Kaixin micro test

Test - lowercase jpg

Test probe PH-5H

With the rapid development of the modern fast-moving food industry, plastic composite flexible packaging has gradually replaced traditional glass and metal packaging. This shift is driven by the need for lightweight, durable, and cost-effective solutions that meet the demands of today's consumers.

Modern flexible packaging serves as a key component in food consumption. It not only captures consumer attention with its attractive design but also plays a critical role in maintaining product quality throughout storage, transportation, and sale. The performance of these materials directly affects freshness, spoilage prevention, and ease of handling.

To ensure effectiveness, it is essential to address these challenges in an economical and efficient manner. Quality control of food packaging has been well-established in many foreign countries for decades. Although China started later, the industry has grown rapidly and now garners significant attention from manufacturers, suppliers, and end-users alike.

A key feature of plastic flexible packaging is its ability to prevent the entry of external substances or the loss of internal contents—this is known as sealing. Proper sealing ensures the integrity of the package, preventing leaks, contamination, and deterioration. For food packaging bags, ensuring strong sealing performance is crucial for extending shelf life, maintaining cleanliness, and preserving food quality. As a result, sealing tests have become a top priority in the food production industry.

1. Barrier Test

Barrier properties refer to the ability of packaging materials to resist the passage of gases, liquids, and other substances. These properties are vital in determining food quality and shelf life, making them a central focus in many packaging tests. For example, in dairy packaging, oxygen permeability significantly impacts the shelf life of milk. Studies show that for fresh milk packaging, if the oxygen permeability is between 200–300, the refrigerated shelf life is about 10 days. If it’s reduced to 100–150, the shelf life extends to around 20 days. When oxygen permeability drops below 5, the shelf life can exceed one month.

For cooked meat products, both oxygen and moisture barriers are important. Moisture barrier properties help maintain product color and prevent drying out. In the case of fried foods like instant noodles and puffed snacks, barrier properties are equally critical. These packages must prevent oxidation and rancidity, often using vacuum aluminum-coated films. Testing shows that such materials should have oxygen permeability below 3 and moisture permeability under 2.

PET bottles used in beverage and beer packaging also require strict barrier performance. Some air-conditioned packages even demand control over carbon dioxide permeability. Overall, the importance of barrier testing in quality control is growing, aligning with global trends toward high-performance flexible packaging. Common testing equipment includes gas permeability testers, moisture permeability meters, oxygen permeability meters, and container/film oxygen permeability meters.

2. Strength Test

Strength testing evaluates the mechanical performance of packaging materials, including tensile strength, tear resistance, heat seal strength, and composite strength. These properties are essential for ensuring the durability and reliability of packaging during handling and transport.

Standardized physical indicators guide the evaluation of material strength. Common testing instruments include thickness gauges, seal testers, tensile testing machines, tearing testers, heat sealers, friction testers, torque meters, and impact and pressure resistance testers. These tools help assess various aspects of packaging performance, ensuring compliance with industry standards.

As new flexible packaging products and materials continue to emerge, material property evaluation becomes increasingly important. Advances in testing and control technologies provide valuable support for quality assurance, process optimization, and material research. Digitalization in packaging quality control helps manufacturers follow guidelines, users make informed decisions, and food packaging quality control becomes a practical and evidence-based practice rather than empty talk.