There are several commercially important types of polyurethanes, which can be conveniently classified as follows: flexible foams, rigid foams, elastomers, fibres and moulding compositions, surface coatings and adhesives. Because of their versatility, light weight, durability, ease of processing, and cost efficiency, polyurethane foams are now used in a wide range of applications. The sport and leisure market are one that makes use of the inherent qualities of polyurethane foams.
PU Foam For Helmets and Safety Mats
Motorcycle and cycling helmets meant to protect the rider’s head during a collision are made up of two primary parts: a strong outer protective shell and an inside energy-absorbent layer. The hard shell spreads the initial impact, while the energy-absorbing layer, which is often polyurethane foam, cushions and absorbs energy, transferring less impact energy to the rider’s skull and hence the brain.
In contact sports like American football, lacrosse, hockey, and cricket, rigid protective helmets constructed of thermoplastic polymers like polycarbonate are frequently layered with shock-absorbing foams like polyurethane or synthetic rubber foams. Flexible polyurethane foam’s cushioning and energy absorption capabilities may be easily varied by modifying the formulation used to create the foam, making it useful as a personal protection material for many types of sports headgear and other body parts.
Polyurethane foam is also commonly used as a cushioning material in gymnastic mats, martial arts mats, judo mats, wrestling mats, and agility mats for usage in schools, sports halls, leisure centres, and climbing centres, among other places. The most common type of foam used is combustion modified rebond foam (recycled foam), which is made from scrap foam generated during block foam production and conversion processes and chipped and bonded together with a polyurethane binder. For impact protection, high jumping and pole vaulting mats are filled with top-quality low-density polyurethane foam. The European Standard BS 12503-1:2001 (Parts 1-7) classifies all types of sports mats based on their application and safety standards such as shock absorption.
Bouldering is a sort of rock climbing which takes place on boulders or small rock formations where no ropes are used to aid the climber. Boulder mats composed of polyurethane foam blends are used to safeguard against falls. To provide varied amounts of support and impact cushioning, the mats are often composed of two or three layers of polyurethane foam. The top layer is made of higher-density combustion modified rebond foam (130-160 kg/m3), while the lower layers are made of lower-density combustion-modified polyurethane foam.
Polyurethane foam logs are used in dismount pits in gymnastics centres and huge trampoline parks, which are becoming popular in the United Kingdom. Different kinds of polyurethane foam might be utilised depending on how often the pits are used. Higher-density foams with improved rip and abrasion resistance extend the longevity of the foam before it needs to be replaced in areas where the pits are heavily used, such as trampoline parks.
The foam core in rugby post protectors, as well as tackle and rucking shields, is made of low to medium-density high-load-bearing polyurethane packing foams that are meant to provide mechanical dampening of unexpected impacts. High-resilience foam is used for tackle bags, which allow players to practise tackling.
Shoes and Trainers
Nowadays, sports shoes must be as light as feasible, as comfortable as possible, and feature a durable sole with good abrasion resistance. These requirements can be met using polyurethane-integrated foams. Nowadays, running shoes often have a thin running surface of solid or microcellular polyurethane with a 400 kg/m3 softer foam centre/midsole. To provide cushioning for the insole, viscoelastic/memory foam or high load-bearing polyurethane foams are used; the foams can also contain antibacterial chemicals to avoid foot infections.
The properties of flexible polyurethane foams are primarily determined by the starting materials and formulations used in their production, as well as additives that can modify the polymer chemistry and other properties such as flammability, antibacterial, antistatic, and acoustic properties, among others. As a result, it is not surprising that polyurethane foam is used in a wide range of sports applications, from personal protection equipment to athletic footwear and as a sound absorbent material in sports venues.