Fish muscle and other edible parts are rich in protein, low fat and polyunsaturated fatty acids. They can regulate and improve the structure of human food and supply nutrients necessary for human health. Canned fish is convenient to eat , Nutrient-rich, easy to carry, and therefore favored by consumers. Canned fish meat generally uses tinplate cans, glass cans, composite film cooking bags or other packaging materials containers.
Heat-sealing strength, also called heat-sealing strength or sealing strength, is an index for evaluating the sealing strength of heat-sealed parts of food packaging. If the heat-sealing effect is significantly stronger than the composite fastness, the heat-sealed part is prone to be difficult to be unsealed, but the composite material is peeled and delaminated. If the heat-sealing strength is insufficient, problems such as openings, air leaks, and broken bags may occur in the finished packaging, which not only reduces the brand image of the product, but also causes quality problems such as mold and bag expansion in the canned fish, which seriously affects the competitiveness of the company's products and the company. Diminishing returns. Therefore, the aluminum-plastic composite film for canned fish meat in food enterprises should have excellent heat-sealing strength to ensure the sealing performance of product packaging.
Test methods and instruments
The chinese test standards for the heat-sealing strength of plastic film packaging bags mainly refer to QB / T 2358 "Test method for heat-sealing strength of plastic film packaging bags". The test can be completed by Link Testing Instruments Co., Ltd. independently developed and designed LTS-05 intelligent electronic tensile tester.
Test principle: The sample is clamped between the two chucks of the clamp, and the two chucks make relative movements. The force value during the test is collected through the force value sensor located on the moving chuck and the built-in displacement sensor of the machine. Changes and displacement changes, so as to calculate the heat seal strength, tensile strength and other performance indicators of the sample.
Test sample and test process
Test sample: aluminum-plastic composite film packaging for canned fish provided by a food factory.
(1) From the four heat-sealed edges of the packaging bag, cut out 10 test strips with a width of 15 mm and an unrolled length of 100 mm.
(2) Set the parameter information such as sample width and test speed.
(3) Clamp the two ends of the test strip to the two clamps, and the long axis of the test strip should coincide with the center line of the two clamps.
(4) Click the Start Test option to start the test. The instrument automatically records the force value during the test and calculates the test results.
Test results and analysis
The average heat seal strengths of the upper, lower, and side seals of the aluminum-plastic composite film package tested in this paper are 26.119 N / 15mm, 328.087 N / 15mm, and 68.206 N / 15mm.
From the above test results, the heat seal strength values of the upper and lower edge seals are low, and leakage or damage may occur at the two edge seals during the circulation and transportation. It is recommended that the manufacturer's production link and before leaving the factory Testing of heat seal strength and sealing performance should be strengthened. In addition, the project testing of product barrier performance and pressure resistance performance should be strengthened.