What kind of tests can be passed to ensure qualified PTFE membrane material standards

PTFE membrane materials are used in many industries, so what strict testing procedures must a good membrane roll material pass to meet the application standards?
1. Water pressure resistance

The hydrostatic resistance test refers to the resistance encountered when water passes through the membrane. Under the condition of standard atmospheric pressure, the membrane is subjected to continuously rising water pressure until water droplets seep out from the back of the membrane. At this time, the measured water pressure is the hydrostatic pressure. The greater the hydrostatic pressure that the membrane can withstand, the better the water or leak resistance.
2. Moisture permeability

Moisture permeability means passing through moisture, moisture is water vapor, water vapor is the gas form of water, and it is a gas like air. Water vapor transmission rate is generally used to indicate the ability of water vapor to pass through the membrane. Contains two meanings of water vapor transmission rate and water vapor transmission coefficient. The water vapor transmission rate indicates the weight of water vapor passing through the film under certain time, temperature and humidity conditions, which is what we often call moisture permeability. There are two main methods of moisture permeability testing: weighing method and sensor method. The weighing method can be divided into the weight gain method of penetrating into the moisture permeable cup and the weight loss method of penetrating out of the moisture permeable cup: the sensor method includes electrolytic sensor method, infrared test method and humidity sensor method.
3. Ventilation

Air permeability refers to the time required for a certain amount of air to pass through the diaphragm under a certain pressure and measurement area. High air permeability indicates long air permeability time and poor permeability. The air permeability tester detects its air permeability effect. Due to the support body, it is similar to the saying that the waterproof breathable membrane has no deformation and vibration amplitude. If it is a waterproof and breathable membrane used for acoustics, it is necessary to detect the deformation and vibration amplitude, and a deformation tester and an amplitude tester can be used.
4. Weight/Thickness

The measurement of the weight and thickness of the film adopts the traditional ultrasonic method or the latest optical method, which is the most accurate method at present, and uses special optical instruments for thickness testing.
5. Tensile/tear strength
The tensile and tear resistance test of the membrane refers to the application of increasing tensile load on the membrane to deform the filter pores beyond the standard pore size of the membrane. The maximum tensile stress required is the tensile strength of the membrane. The tensile tear strength measurement of films requires a specialized measuring instrument.
6. Water repellency
The degree of dewatering refers to the anti-seepage degree of the membrane. It is evaluated according to the number of water droplets on the coating layer of the membrane by using a fabric wetness tester. It has different equivalent values according to different standards.
7. Dimensional stability.
The ptfe membrane itself has a certain geometric stability. Under certain conditions such as pressure and temperature, its expansion and contraction rate will change, and it is also prone to expansion and contraction under the action of mechanical force or heat during the process of coating, hot pressing and lamination. Deformation and stability are measured by special instruments, and the membrane size, micropore diameter, etc. are measured under extreme conditions.
8. Washing test
The water washing test of the membrane is the performance of the membrane to resist dimensional changes when it is immersed or washed. It is directly related to the accuracy of the film size, the shape and stability of the coating. Mainly manifested as shrinkage and heat shrinkage. After the film is immersed in water at room temperature or washed and dried, the degree of dimensional shrinkage in the length and width directions is called shrinkage, and the degree of dimensional shrinkage that occurs when subjected to higher temperatures is called thermal shrinkage. Thermal shrinkage mainly occurs in synthetic composite films. middle.
In addition to the above routine tests, some other tests are also included, such as dry cleaning test, friction resistance test, antistatic test, flame retardancy test, etc.