1) reduce the cable size, (2) reduce the cost of the cable, (3) to obtain low attenuation (high bandwidth, wiring extension), (4) high transmission speed.
Foam insulation can be through the chemical foaming and physical foaming two f foaming,
Chemical foaming method with foam mixing uneven, foam instability and other issues.
The physical foaming has the advantages of high foaming degree, low dielectric constant and low dielectric loss angle, and reduces the attenuation of the cable insulation.
Physical foam insulation has a look, uniformity is good, the cell is fine, sealed. The production efficiency is becoming extraordinarily high, requiring the bandwidth of the transmission cable to become wider and wider
Physical foam insulation has sufficient mechanical strength to ensure that the insulation structure is stable and reliable, therefore, the physical foam insulation in the CATV, digital transmission system, requiring low attenuation transmission test and other cables, widely used.
The main application of physical foaming with PE is also used with PP, FEP (Fluoroplastics).