[China Packaging Reuters (Author: Labthink Technology Co., Ltd.) with the economic development and people's living standards, more and more pet into the family more, Correspondingly pet food industry The rapid development. Just like the ordinary food industry, pet food industry also has corresponding requirements for product safety and quality. Like other foods, pet foods have shelf life for a certain period of time. During the shelf life, pet foods need to be protected from deterioration or nutrient loss. The quality of packaging has an important impact on the shelf life of pet foods, and the quality control of packaging materials and packaging is a major issue that pet food manufacturers must face. This article aims to briefly describe the quality control methods for pet food packaging.
Pet food packaging
The main pet food packaging in the market includes two major categories: metal cans for packaging wet foods and multi-layer bags for packaging dry pet foods.
Pet foods are packaged in a variety of forms for packaging pet foods of different specifications. The common packaging styles on the market today mainly include: aluminum and steel cans, aluminum foil trays, composite film flexible packaging, paper bags, card boxes, multi-fiber composite containers, and disposable packaging and other convenient packaging. Among the materials used for pet food flexible packaging include: PET, AL, PE, OPP, CPP, CPPP, VMPET, BOPA, RCPP, etc.
Quality control of pet food packaging
For pet food manufacturers, the use of suitable packaging materials is crucial to ensure the shelf life of the product. Therefore, strict quality control of packaging materials and packaging is required.
As we all know, the breeding of microorganisms requires a certain environment. The three most important factors are ambient temperature, oxygen and moisture. Oxygen is the main cause of rancidity. The lower the oxygen content, the less likely the rancidity is, and the moisture can provide microorganisms with an active environment to accelerate the hydrolysis of fat and shorten the shelf life of food. During the shelf life, the oxygen and moisture content of the package is more dependent on the integrity and barrier properties of the pet food package.
Therefore, the quality control of pet packaging is mainly controlled from both the barrier properties of the materials and the integrity of the packaging.
Barrier control of packaging materials
During the shelf life, oxygen and moisture in the complete pet food package are mainly derived from the oxygen and water vapor that penetrates through the package. Barrier property refers to the hindrance of the packaging material to the permeation of gas or liquid molecules through the material. Labthink chooses seven pet food packaging materials commonly used in the market: PET, PET+CPP, BOPP/CPP, BOPET/PE, OPP/PE/CPP, BOPET/VMPET/LDPE, and aluminum-plastic composite film, respectively. Over-rate and water vapor transmission rate were tested, analyzed and compared. The greater the oxygen transmission rate, the worse the oxygen barrier property of the material; the greater the water vapor transmission rate, the worse the moisture resistance of the material.
Oxygen permeability test:
The Labthink OX2/230 Oxygen Transmission Rate Test System was used for this measurement. The instrument uses the equal pressure test principle. During the test, the specimens were first equilibrated in a standard environment (23±2° C., 50% RH) for 48 h, and the round specimens were taken from the unfolded portions. The pre-treated sample is placed in the middle of the upper and lower chambers of the OX2/230 Oxygen Transmission Test System. At this time, the sample is divided into upper and lower chambers. The upper chamber is a flowing high-purity oxygen, and the lower chamber is a flowing high-purity nitrogen. During the test, the oxygen molecules pass through the sample and enter the lower chamber. The high-purity nitrogen gas is brought to the oxygen sensor and detected by the oxygen sensor. The oxygen gas concentration and the oxygen permeability of the sample are calculated. This test uses 23°C, 50% RH test conditions.
Moisture permeability test:
In addition to oxygen, the penetration of moisture in the air can also accelerate the deterioration of pet foods. This measurement uses Labthink blue light W3/030 water vapor transmission rate test system. The test instrument belongs to the weighing method test. Select the equalized flat sample as the oxygen barrier test. Place the sample in a moisture permeable cup equipped with the instrument. Place a proper amount of distilled water that has been distilled twice into the cup. Humidity difference. During the test, the humidity difference between the two sides of the sample is controlled by controlling the humidity in the test chamber. The water vapour permeability of the sample was calculated by the weight reduction of the moisture permeable cup during the test test. This test uses 38°C, 90% RH measurement conditions.
Analyzed and compared the test results of the barrier properties of the pet food packaging of the seven structures, it can be found that the pet food packaging of different materials, due to the different materials of the composite layer, there is a difference in oxygen barrier. Among the samples tested, aluminum-plastic composite films, BOPET/VMPET/LDPE, and PET/CPP composite films have low oxygen transmission rates, and their corresponding pet foods have a longer shelf life, which is closely related to the high barrier properties of packaging. Related.
The composite membrane improves the water vapor transmission rate of the pet packaging material. The PET bag has poor moisture resistance and is not conducive to the storage of pet food. The pet food of the package has a short shelf life.
In summary, the barrier properties of packaging materials are extremely critical to the shelf life of pet foods. Manufacturers should pay attention to the selection of packaging materials with high barrier properties of composite plastic flexible packaging, aluminum plastic composite materials or tinplate materials. The choice of material must not only consider its oxygen barrier and moisture resistance, but also consider the influence of the environment on the barrier properties of the material. For example, EVOH and PA materials are extremely sensitive to environmental humidity. At room temperature and low relative humidity, the moisture resistance of these two materials is good, but in a high humidity environment, the moisture resistance will be greatly reduced. Therefore, this material should not be selected as a packaging material.
Packaging integrity testing
Through the detection of the integrity of the package, the pet food can be effectively packaged for quality control, thereby avoiding problems such as packaging damage during the production, transportation or storage of the pet food package, and ensuring the shelf life and product quality of the pet food.
1, the overall sealability test of pet food packaging
Sealing performance test can determine the overall integrity of pet food packaging, can be divided into positive pressure test and negative pressure test two methods.
Labthink Languang LSSD-01 leak and seal strength tester can test the heat seal strength, burst pressure, seal leakage and overall compressive performance of pet food packaging, which is a positive pressure test. LSSD-01 has three methods of rupture test, creep test and creep to rupture test. During the test, the sample is filled with air, and the maximum rupture pressure of the test sample can be determined by testing the maximum pressure when the test sample is broken; the sealing quality of the pet food package can be tested through the creep test, the creep to the rupture test, Found a weak part of the seal.
Labthink MFY-01 Sealing Tester is a negative pressure test. The instrument is designed according to GB/T 15171 standard. The test principle is to place the sample in a vacuum tank and vacuum the vacuum tank to make it immersed in water. The pressure difference between the inside and outside of the sample is generated, and the expansion of the sample or the gas overflow in the sample is observed. Based on this, the sealing performance of the sample is judged. MFY-01 can test the sealing performance of the whole sample. Through MFY-01, it can detect various pinholes, inconspicuous cracks and sealing quality of packaging materials.
2. Peel strength and heat seal strength test of pet food packaging bags
By using Labthink Languang XLW series intelligent electronic tensile testing machine to inspect the peel strength of the packaging bag, the composite quality of the composite packaging bag can be intuitively determined. During the test, the packaging bag is cut into strips and the composite layer is pre-stripped. The pre-striped sample is clamped on the upper and lower fixtures of the equipment and peeled off by the instrument to record the maximum stripping force required for stripping the composite layer. Value and calculate peel strength. If the peel strength is too low, it means that the composite quality is poor, and the packaging bag cannot achieve a good quality expectation that the multi-layer material will be dispersed and act as a barrier, and the package will easily break when dropped, and the barrier performance will be lower than expected.
The heat seal strength represents the strength of the package seal. Using XLW series intelligent electronic tensile testing machine can quickly and easily check the sealing strength of pet food flexible packaging bags. Simply take a sample of a sufficient length in the vertical direction from the package and the heat-sealed area, center the sample on the heat-sealed area, open it to 180°, and clamp the two ends of the sample to the upper and lower fixtures of the device. On the top, the maximum force at which the heat seal was separated was tested and the heat seal strength was calculated. If the heat-sealing strength is too low, seal cracking and pet foods are likely to be scattered during handling, resulting in contact between pet food and oxygen and moisture in the air, and the food is susceptible to mildew.
3, pet food packaging bag piercing force, tearing force
The piercing force test simulates the degree of firmness of the bag when the bag is subjected to a sharp object. Labthink's XLW series intelligent electronic tensile testing machine can accurately measure the puncture force of pet food packaging. The test principle is to penetrate the pointed needle at a certain speed through the test sample, and evaluate the puncture resistance ability of the packaging bag through the measured maximum force value.
The SLY-S1 tear tester uses the Elemendorf method. The test principle and method are to lift the pendulum to a certain height to make it have a certain potential energy. The sample is clamped and an incision is made in the tear direction. When the pendulum falls, the sample is torn with its own stored potential energy, and the energy consumed to tear the sample is calculated to obtain the force required to tear the sample and determine the tear resistance of the package.
In summary, the integrity of the package will directly affect the shelf life of pet food. Therefore, in order to ensure the pet food quality and prolong the shelf life of pet food, it is very necessary to inspect the integrity of the packaging. Through the detection of the integrity of the package, pet food manufacturers can monitor the quality of the package and adjust the packaging materials or packaging process in a timely manner based on the test results. This can also avoid pet food quality problems caused by package quality.
to sum up
In summary, manufacturers of pet foods should combine the selection of packaging materials and integrity testing of packaging to achieve complete control of pet food packaging, thereby avoiding adverse effects on shelf life of foods caused by packaging problems.
Copyright Notice: The article is copyrighted by Jinan Languang Electromechanical Technology Co., Ltd.
