Many customers are particularly interested in some of our factory's making processes and quality inspections. So today, let's take a look at our factory's general production process and commonly used quality inspection methods.
Regarding the production process, it usually includes the following steps:
1. Material preparation: Select suitable packaging materials, such as plastic film, aluminum foil, paper, etc., and conduct inspections and screening to ensure that the material quality meets the requirements;
2. Printing: Use printing technology to print product information, patterns, text, etc. on the packaging material. Commonly used printing technologies include letterpress printing, lithography, gravure printing, etc.;
3.Lamination: Multiple material layers are bonded together by heat pressing or adhesives to form a composite film. Lamination can improve the strength, tear resistance and barrier properties of packaging;
4. Cutting: Cut the laminated film or printed film according to certain sizes and shapes to meet different packaging needs;
5. Bag making: According to customer requirements, the cut film is made into various bag types, such as flat bottom bags, three-dimensional bags, zipper bags, etc.;
6. Quality inspection: Quality inspection of the finished soft packaging, including appearance inspection, sealing test, strength test, etc., to ensure that the product meets relevant standards and customer requirements.
Finally, we will package the finished products according to customer requirements and deliver them to customers.
Some tests of packaging quality inspection
Packaging bag sealing test
The sealing performance of a packaging bag is the most basic function of a packaging bag. Therefore, after each bag is made, our colleagues in the quality inspection department will conduct sampling inspections according to the proportion.
The following are some common packaging bag sealing test methods:
Positive pressure method: Fill the packaging bag with a certain pressure of gas, keep it for a period of time, and observe the pressure changes to determine whether there is a leak.
Negative pressure method: Place the packaging bag in a negative pressure environment to see if air is sucked into the bag.
Water decompression method: Immerse the packaging bag in water, evacuate the bag to form a negative pressure, and judge the sealing performance by observing whether bubbles emerge in the water.
Helium mass spectrometry leak detection method: Use helium as a tracer gas to determine the sealing performance of the packaging bag by detecting the leakage of helium.
Sealing performance tester detection: Use a special sealing performance tester to perform detection and evaluation according to the set procedures and standards.
Strength test of packaging bags
Mainly includes the following methods:
Tensile strength test: Use a tensile testing machine to apply tensile force to the packaging bag sample until it breaks, measure the tensile force and elongation at the time of break, and evaluate the strength of the packaging bag in the tensile direction.
Burst strength test: Apply gradually increasing pressure to the packaging bag until the packaging bag breaks, and record the pressure value at the time of break, reflecting the ability of the packaging bag to withstand internal pressure.
Drop strength test: Drop a bag containing a certain weight of goods from different heights onto a rigid plane to observe whether the bag is damaged, to test its ability to resist drop impact.
Puncture strength test: Use a puncture tester to let a sharp object puncture the bag, measure the force required during the puncture process, and measure the bag's resistance to puncture by sharp objects.
Barrier performance test of packaging bags:
Oxygen permeability test: Use a professional oxygen permeability tester to measure the amount of oxygen that passes through the bag per unit time under certain conditions. The lower the value, the better the oxygen barrier performance.
Water vapor permeability test: Similarly, the amount of water vapor that passes through the bag per unit time is tested by a water vapor permeability tester. The smaller the amount, the stronger the water vapor barrier performance.
Odor barrier test: Put an odorous substance into the bag, and test whether the odor can be smelled outside after a certain period of time to judge the odor barrier effect.
Solvent penetration test: For solvents that may be exposed, test their penetration to evaluate the barrier ability to solvents.
Thickness measurement: Thicker packaging bags usually have better barrier properties to a certain extent, but this is not absolute, it is just a reference factor.
Comparative experiment: Compare and test with standard packaging bags with known good barrier properties to observe the differences.
Long-term observation: In actual use, observe the changes in the materials in the packaging after a period of time to indirectly evaluate the durability of the barrier properties.
In addition to testing the relevant properties of packaging bags, the quality inspection department also needs to conduct material analysis. Customers often send samples, so how to judge their material structure and thickness by peeling?
The following methods can be used to analyze the material structure of packaging bags through samples:
Microscope observation: Use an optical microscope or an electron microscope to observe the sample at high magnification to directly distinguish the morphology and thickness of each layer.
Infrared spectroscopy analysis: It can determine the functional groups present in the material and thus infer the type of material.
Thermal analysis: Such as differential thermal analysis, thermogravimetric analysis, etc., can understand the changes of materials at different temperatures, which helps to judge the composition and structural stability of the material.
Solvent dissolution test: Place the sample in different solvents and observe its dissolution to make a preliminary judgment on the material type.
Elemental analysis: Detects the content of specific elements in a sample to help understand the composition of the material.
X-ray diffraction analysis: Used to analyze the crystal structure of a material.
Layer separation technology: Carefully separate the layers of material and then analyze and identify them separately.