Established in 1999, Beijing Tongyizhong Specialty Fiber Technology & Development Co Ltd (TYZ) is a high-tech enterprise which specialises in research and development, as well as the production and distribution of ultra-high molecular weight polyethylene (UHMWPE) fibre and fibre composites.
TYZ’s Doyentrontex UHMWPE polymer is processed to disentangle the polymeric chain, with the fibre reconstituted in a unidirectional matrix, where each fibre layer is arranged in a 90 degree alignment to adjacent layers and then bonded together using special aqueous dispersion adhesive and proprietary techniques. The company said this enables each sheet of Doyentrontex fibre to be more flexible and thinner than traditional Aramid-based sheets despite retaining comparable performance.
The Doyentrontex protection range includes the WB-422B Bulletproof UD sheet which features an area density of 130±8g/m2 with each sheet just 0.16±0.02 mm thin. TYZ says that 36 layers of WB-422B sheets can defeat 9mm parabellum rounds fired by an Uzi submachinegun, while 54 layers can stop 7.62x54mm lead-core ammunition.
TYZ has also developed the multi-layered SF-102 bulletproof & stab-resistant sheet with a total area density of 10.8 kg/m2, which meets FDC-2 performance requirements set by China’s Public Security Ministry.
Doyentrontex ZF series ceramic composite plates and helmets, which are constructed from UHMWPE fibre are also marketed by the company. These are combined with silicon carbide or aluminium ceramic special gels via thermal pressing moulding techniques, and offer high levels of resistance against water, moisture, ageing, and physical impact, ensuring that its ballistic protection properties are maintained consistently over time.