Test method for packaging bag made of composite material

Test method for packaging bags made of composite materials:
1 Appearance visual inspection: Visual inspection of the surface of the composite bag for signs of scratches and pinholes. Focus on checking whether there is any contamination in the seals. If one of the above conditions is a nonconforming product.
2 sealing adhesion inspection: Sealing some small seams, can not be immediately determined by visual inspection, a slight negligence is the cause of leakage and corruption in the future. Check that the seal can be sprayed on the seal with a dye-added surface active agent to determine whether the seal is tight or not.
3 Sealing strength test: The sealed composite bag shall be sealed and cut into strips with a width of 15 mm. The sealing strength shall be measured with a universal material analyzer at a speed of 300±20 mm/min. The general composite bag sealing strength shall be 23–34 N/. 15mm.
Various types of bag seal strength standards can be found in the following table.

Use purpose sealing strength, N15mm (kgf/15mm)
Large packing: 34.3/(3.5)
Composite bag: 22.6-34.3/(2.3-3.5)
General packaging, large volume of content: 14.7-22.6/(1.5-2.3)
General packing, content is small: 5.9-14.7/(0.6-1.5)
General light packaging: 2.9-5.9/(0.3-0.6)

4 Leak test: Saturation solution; usually used to test leaks or pinholes in composite bags with minimal air content. The method is to add the surfactant into the bag, seal the bag and lay it on the filter paper, and after 5 minutes see if there is color liquid on the filter paper, then reverse the bag and test again.
The decompression method in water was used to test whether the air bag with more air content leaked. The method is to put the composite bag to be tested into a device, turn on the vacuum pump, depressurize the glass bottle to 1333 Pa (10 mmHg) within 30 seconds to 1 minute, and maintain it for 30 seconds. Bubble overflows.
5 Compressive strength test: Place the composite bag horizontally on the platform, add a heavy weight on it, hold it for one minute, remove and inspect the seal, and see if there is any leakage in the appearance. The flat mouth compound bag and the box compound bag have slightly different pressurization methods. The pressurization time is 1 minute. The pressurization weight differs depending on the weight of the product (standards are shown in the table below).
Various weight pressure standards

Total weight (g) Compression load N (kgf)
<100 196(20)
>100-400 392(40)
>400—2000 588(60)
>2000 785(80)

6 burst strength test: In a gap between two parallel plates 1.27cm (0.51n), place the composite bag to be tested, install a holder and rubber tube on the bag, in 10 to 30 seconds through the tube Slowly pass the compressed air into the bag and allow the internal pressure to reach the predetermined standard for another 30 seconds. The breaking strength of general commercial bags should reach 0.1 MPa or more.
7 Drop test: Composite bagged products are dropped horizontally and vertically on a rough concrete floor, one at a time. After dropping, check whether the compound bag has caused bag leakage or perforation. The drop height is based on the size of the composite bagged product. The weight varies (see the table below).
Drop height standard

Total weight (g) Drop height (cm)
<100 80
>100-400 50
>400-2000 30
>2000 20

8 bags of air inventory test: Destructive test: Using the principle of drainage and steam collection method, under the surface of the water will be a composite bag cut a notch, the funnel is inverted above it to collect the gas floating up from this gap, then add a funnel The amount of water that is filled is simple, and the amount of gas that is filled in the measuring cylinder can finally be used to know the amount of air remaining in the bag (this method is not easy for the gas to be completely discharged, which may cause errors for certain products with high viscosity).
Non-destructive inspection: It is determined by using the principle that a buoyancy force of a composite bag containing air is exactly equal to its weight under a liquid surface pressure and is suspended. The samples tested were not destroyed and could be used again.
The method is as follows: Put the test composite bag into a transparent container full of water and slowly pull the vacuum. The vacuum degree when the bag is suspended is called the neutralization point.