Abstract
Pet food is specialized in providing food for pets and small animals, and is a high-grade animal food between human food and traditional livestock and poultry feed. Its main nutrients are proteins and fats, which are easy to absorb moisture and agglomerate or be oxidized and decomposed by microorganisms under the action of certain temperature, oxygen and moisture, resulting in the loss of nutrients and even deterioration, so it is required that the barrier performance of the pet food packaging should be good. This paper utilizes GBPI's self-developed N530 2.0 Gas Transmission Rate Tester to test the oxygen transmission rate of dog food bags sent by customers, and introduces the testing instrument, testing principle, testing process, etc., which provides an effective solution for monitoring the oxygen barrier performance of pet food packaging bags.

With the development of the economy and the improvement of people's living standards, more and more people have pets. People use pets as a support for their feelings and to meet our emotional needs, corresponding to the rapid development of the pet food industry, the market competition is gradually fierce, the importance of pet food packaging has gradually come to the fore. Cat food / dog food packaging bags selected plastic material should have a barrier, heat resistance, sealing, able to prevent food deterioration. General selection of multi-layer plastic composite, common materials include PET/AL/PE, PET/NY/PE, PET/MPET/PE, PET/AL/PET/PE, PET/NY/AL/PE, PET/NY/AL/RCPP, high-temperature dry distillation bags for wet food, soft canned food packaging.

Like other foods, pet food has a shelf life. During the shelf life, pet food needs to ensure that no spoilage or loss of nutrients occurs. Pet food nutrients can meet the needs of pet growth, but also is a good natural medium for microbial growth. If the packaging material has poor barrier properties, the oxygen and moisture that passes through the packaging can lead to the growth of microorganisms. Under the action of microorganisms, the nutrients (proteins, fats, etc.) in the pet food will be decomposed, which not only affects the sensory of the pet food, but also loses the nutritional value of proteins, fats and other original substances. The growth of microorganisms is mainly due to three factors: temperature, oxygen, moisture, oxygen is the main external cause of rancidity, so the pet food packaging must have a good barrier performance to the outside world of oxygen, in order to effectively ensure the quality of pet food in the shelf period. This paper utilizes     GBPI's self-developed N530 2.0 differential pressure gas permeability tester to test the oxygen barrier performance of dog food packaging bags sent by customers to provide technical references for relevant pet food package production and use of enterprises to select the oxygen barrier performance test equipment and test methods.

Test Principle: N530 2.0 Gas Transmission Rate Tester adopts the principle of differential pressure method. The treated specimen is placed between the upper and lower chambers, the vacuum pump is used to evacuate the whole gas circuit system, and then an atmospheric pressure of experimental gas is added to the upper chamber to form a constant pressure difference between the upper and lower chambers. Under the action of pressure gradient, the gas permeates through the film from the upper cavity to the lower cavity, and the system can calculate the gas permeability and other barrier performance parameters of the specimen through the pressure change of the lower cavity.

01 Test Sample

The customer provided dog food packaging bags, its main component to PA as the main barrier function resin multi-layer co-extruded film, bags, sample A's structure PE / Tie / PA / TIE / PE, sample B's structure for PA / Tie / PE / TIE / PA / Tie / PE.

02 Testing Process

(1) Cutting the sample: Take the neat and pollution-free sample to be tested and place it on the cutting table, and use the special sampler to cut the test sample.
(2) Sample: Press the button to open the pneumatic chamber cover, evenly apply a circle of sealing grease on the chamber, put the filter paper in the middle of the chamber, then put the cut sample on the chamber coated with sealing grease, smooth it out clockwise and cover the test chamber cover.
(3)Turn on the instrument control software, set the test pressure, temperature and other experimental parameters.
(4) In the software running under the setup interface, select the measurement mode, fill in the test sample name, test standards, test units and other experimental information.
(5) After setting the test information, start the test.
(6) After the test is finished, the instrument pops up a prompt message that the test has been completed, and automatically calculates and displays the test results.
03 Test Results