Why Waterproof Acoustic vents can be used in high temperature environment

Waterproof Acoustic ventsPTFE is a highly crystalline polymer, and its raw material crystallinity can reach up to 92%~98%. However, after processing or sintering-cooling, the crystallinity is reduced to no more than 70% of the raw crystallinity. When PTFE is at 19°C, it exhibits a space helical conformation in which every 13 links rotate 180°C. Above 19°C, the number of chain units required for the same rotation of 180°C increases to 15, because the distance between each chain The rise is 0.195nm. This change means that the hardness of the powdery particles differs significantly below and above 19°C. When the temperature is above 19°C, the bond has a certain degree of angular displacement, and this displacement will increase with the increase of temperature; when the temperature is above 30°C, the tendency of this energy displacement will continue to increase until it reaches 327°C. This means that the particles are softer and more easily deformed above 19°C. This has very important guiding significance for the selection of post-treatment process of PTFE resin, the movement mode of materials on the assembly line and the design of equipment, the determination of packaging method and storage temperature. The stretching method used to make the film also plays a key role in the selection of temperature.

When the temperature is below 19°C, the crystalline state of PTFE is a triclinic crystal lattice. At 19°C, the crystal form changes, the rotation of the chain segment becomes slightly smaller, and the unit lattice transforms into a hexagonal crystal system. At 30°C, PTFE crystals undergo crystallization relaxation, and the orderly rotation of bonds becomes random winding. These two temperature points are usually referred to as phase transition points.

The high crystallinity and high molecular weight of Waterproof Acoustic vents PTFE resin lead to PTFE has extremely high melt viscosity. The kinematic viscosity measured at 380°C is 1010~1011Pa.s, and it does not have fluidity at the melting point temperature. Therefore, ordinary PTFE resin cannot be processed by the processing method usually suitable for melt-processable plastics. Suspended PTFE resin can only be processed by a method similar to powder metallurgy, that is, the suspended PTFE resin powder is placed in a mold and preformed by compression to disperse the PTFE resin. It is necessary to add a booster (lubricant) to form a paste to push the preform, and they must be sintered to become a product.