Materials used for slash resistance

The fibres that are used extensively for armour products are Kevlar , Spectra , Dyneema , and Zylon . The properties of the main fibre types used for slash resistance are summarised in Table 7.4. All the fibres listed provide excellent strength-to-weight (tenacity) properties and high modulus. 

In para-aramids, the links are formed on the opposite comers of the rings. Para-aramids do not melt, bnt decompose above 430 °C. They absorb a small amount of water due to their low moisture regain. Kevlar, in particular, starts to decompose only above 550 °C.  

2 Uitra-high moiecuiar weight poiyethylene (UHMWPE) 

UHMWPE is a type of polyolefin that is commercially produced in the fibre form as Dyneema by DSM and as Spectra by Honeywell. It is produced by gel spinning. 

The weak van der Waals bonds between the molecules in UHMWPE give it very poor heat resistance. The fibres melt at 150°C and their properties deteriorate as the temperature inaeases above room temperature. Under high stress, the fibres tend to creep extensively and can break after a short time under load. A secondary slow heating, under tension, when approaching the melting point, increases modulus and reduces CTeep. It is extremely resistant to chemical and biological attack and has better abrasion and fatigue resistance than aramid fibres.  

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