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Performance Characteristics Kevlar & Fiberglass Reinforce Helmet Generic Plastic Molded Hart Hat Comments
Strength-to-weight ratio (strength as in tensile strength measured in MPa and weight in terms of density, i.e. g/cm3).

• Ratio for Kevlar = (3,620/1.44) =2,514.

• Ratio for fiberglass = (3,400/2.60) =1,308.

• Ratio for polypropylene = (80 / 0.90) = 89. Strength-to-weight ratio for reinforced helmet is anything between 15~28 times higher than plastic hat. In weight for weight term, the reinforced helmet is much more stronger.
Penetration resistance to sharp object. The Kevlar is in the form of a woven sock, Kevlar strands wrap around the helmet from crown to brim. It is then embedded in the composite resin. No reinforcement of any kind. Made of thermoplastic only. By virtue of the Kevlar high tensile strength, it does not break easily and hence provides high resistance to penetration.
Resistance to shattering upon impact. Fiberglass mat is embedded in the composite resin to form a matrix. This holds the resin together very much like what the iron rebar does in concrete by holding the cement together. Resistance to shattering is dependent on the purity of the plastic and the process control during injection molding.
Resistance to lateral crushing. Reinforced composite has higher compressive strength. Generally low compressive strength. This prevents the reinforced helmet from crushing when pressed laterally from side to side.
Resistance to UV degradation. Both Kevlar and fiberglass have strong resistance to the damaging effect of UV radiation. Thermoplastic does not have resistance to UV radiation, unless special stabilizing additive is added. No need to include additive in the composite resin, thus not compromising the polymer structural integrity that follows most additive inclusion.
Performance Characteristics Kevlar & Fiberglass Reinforce Helmet
Other features of Kevlar and fiberglass reinforced helmet.

• Non-magnetic.

• Corrosion resistant – suitable for use in chemical and petro-chemical industries. • Thermally non-conductive – suitable for use under extreme temperature like the foundry or other smelting plants.

• Electrically non-conductive – suitable for use in explosive work environment like mining or other subterranean activities like underground sewage/utility maintenance works, or for electrician doing live work.

• Virtually maintenance free.