How to judge the quality of vents?

1. Appearance inspection:
1. Material observation: High-quality vents are usually made of polymer materials, with bright colors, uniform texture and no odor. If the material is rough, dull or has a pungent smell, it may be a low-quality product. For example, some counterfeit vents may be made of ordinary plastic materials, and their performance and quality are far inferior to those of polymer materials.
2. Composite process inspection: Genuine vents are generally made by hot pressing composite technology to composite multiple layers of materials together. There will be obvious pressing points on the film, and the layers are tightly fitted without bubbles or stratification. Counterfeit products may be glued together, which may easily cause three layers to separate, or the pressing points are not obvious and uneven.
3. Surface flatness: The surface of a good quality vent should be flat and smooth, without wrinkles, scratches, holes and other defects. These defects may cause the film to leak and ventilate poorly during use.
2. Waterproof performance test:
1. Hydrostatic pressure test: This is one of the important indicators to measure the waterproof performance of vents. Place the vents sample on a professional hydrostatic pressure tester, gradually increase the water pressure, and observe whether the membrane leaks under different water pressures. Generally speaking, the hydrostatic pressure of thin vents should be at least 1.5 meters, and the hydrostatic pressure of thick vents should be at least 2 meters to meet the standard. For example, in building waterproofing projects, if the hydrostatic pressure of the vents does not meet the standard, rainwater may penetrate the membrane into the building, causing problems such as dampness and mold on the wall.
2. Soaking test: Take a small piece of vents, tie it to a small beaker with a rubber band, and then put some water on the membrane. After a period of rest, observe whether the amount of water on the upper layer of the membrane decreases, whether there are water droplets on the lower layer of the membrane, and whether there are water droplets in the beaker. If the amount of water on the upper layer of the membrane decreases, water droplets are precipitated on the lower layer of the membrane, or there are water droplets in the beaker, it means that the waterproof performance of the waterproof breathable membrane is poor.
3. Simulated use environment test: According to the actual application scenario of the waterproof breathable membrane, simulated use environment test is carried out. For example, the waterproof breathable membrane used in electronic products can be installed on mobile phones, tablets and other devices, and then the device can be soaked in water for a period of time to observe whether the device has water ingress and whether the waterproof breathable membrane can breathe normally.
3. Breathability test:
1. Water vapor permeability test: Use a professional water vapor permeability tester for testing. The water vapor permeability of the membrane is obtained by measuring the water vapor partial pressure difference on both sides of the membrane. The higher the water vapor permeability, the better the breathability. Generally speaking, the water vapor permeability of a high-quality waterproof breathable membrane should be above 1500g/square/24 hours. For example, in the field of clothing, if the breathability of the waterproof breathable membrane is not good, the wearer will feel stuffy and uncomfortable, affecting the use experience of the clothing.
2. Air permeability test: The air permeability of the waterproof breathable membrane can be tested through a simple experiment. Take a small beaker, fill it with some water, and then seal the mouth of the small beaker with a rubber band and a small piece of waterproof breathable membrane. Then place the beaker on the alcohol stove to heat it, and observe whether the water vapor can be released smoothly through the membrane to the outside of the cup. If the water vapor can be quickly released through the membrane to the outside of the cup, it means that the air permeability is large; conversely, if the water vapor is difficult to release through the membrane to the outside of the cup, it means that the air permeability is small.
4. Physical performance test:
1. Tensile strength test: Use a tensile testing machine to test the tensile strength of the waterproof breathable membrane sample, and measure the maximum tensile force and elongation at break of the membrane during the stretching process. The higher the tensile strength and elongation at break, the better the strength and toughness of the membrane, and the greater the external force that can withstand without breaking. For example, in a building waterproof project, if the tensile strength of the waterproof breathable membrane is insufficient, it may be torn during construction or use, resulting in failure of the waterproof performance.
2. Tear strength test: Use a tear tester to test the tear strength of the waterproof breathable membrane sample, and measure the maximum tear force of the membrane during the tearing process. The higher the tear strength, the better the tear resistance of the membrane, and it can resist puncture and tearing by external objects.
3. Puncture strength test: Use a puncture tester to test the puncture strength of the waterproof breathable membrane sample and measure the maximum puncture force of the membrane during the puncture process. The higher the puncture strength, the better the puncture resistance of the membrane, which can prevent sharp objects from penetrating the membrane and causing water leakage.
V. Chemical performance test:
1. Chemical corrosion resistance test: Soak the waterproof breathable membrane sample in different chemical solutions (such as acid, alkali, salt solution, etc.), and observe the changes of the membrane in the chemical solution, such as whether deformation, dissolution, discoloration, etc. occur. The waterproof breathable membrane with good chemical corrosion resistance can maintain stable performance in various harsh chemical environments and will not be damaged by contact with chemicals.
.2 Aging resistance test: Accelerated aging test is performed on the waterproof breathable membrane sample by simulating the light, temperature, humidity and other conditions in the natural environment. Observe the performance changes of the membrane during the aging process, such as whether the waterproof performance, breathable performance, physical properties, etc. decrease. The waterproof breathable membrane with good aging resistance can maintain stable performance during long-term use and will not prematurely age and fail due to environmental factors.
VI. Check product certification and test reports:
1. Product certification: Choose waterproof and breathable membrane products that have passed relevant international or national standard certifications, such as the EU CE certification, the US ASTM standard certification, etc. These certifications are a recognition of product quality and performance, and can ensure that the product meets certain quality standards.
2. Test report: Check the product test report to understand the test results of the product on various performance indicators. The test report should be issued by a professional testing agency and have a certain degree of authority and credibility. By checking the test report, you can intuitively understand the quality of the product and whether it meets the relevant standard requirements.