Crush Resistance of Wool Carpets

The crush resistance of a carpet has many different aspects:

• Pile fiber resilience or springiness
• Resistance to compression or flattening
• Recover from compression
• Texture retention
• Color change due to flattening

Wool carpets have excellent resistance to compression due to the physical nature of the fiber -- its natural crimp comes from millions of coiled molecules, as opposed to the artificially induced sinoidal waves in man-made fibers. The right balance between compressibility and resilience equals optimum comfort underfoot.

Wool's unique ability to absorb moisture means that pressure marks from furniture disappear completely when the fiber is gently moistened and allowed to recover naturally.

Wool's molecular nature, which features intermolecular chemical bonds, allows the fiber to be hot water, steam or chemically set into a predetermined configuration (e.g. a twisted yarn), which is then retained with great tenacity.

Wool is a naturally opaque fiber with a matte surface, so the effect of flattening wool pile on the color of a carpet is much less obvious than it would be with many other pile fiber types.

Insect-Resist Treatment

To prevent insect pest damage to wool carpets and rugs, wool pile yarns are given a durable insect-resist treatment during manufacture. When wall-to-wall wool carpets are not treated, they are subject to infestations of wool-eating insects in the home, which can lead to damage. Moths do not eat carpet; they lay eggs (larvae) that eat the carpet, which causes the damage

Insect-resist treated wool is harmless to humans and pets because only small amounts of the agents, with low mammalian toxicity, are applied by manufacturing processes. This not only enables complete penetration of the agent into the wool fibers, but also ensures that the treatment is resistant to carpet cleaning -- both vacuuming and wet cleaning.

Wool carpet manufacturers ensure the correct amount of agent is applied -- too much is unnecessary and wasteful, and too little would not adequately protect the carpet.

Even wool-eating insects cannot be harmed by mere contact with treated fiber -- they must eat and digest it before the agent takes effect.

Insect-resist treated wool carpets that comply with Wools of New Zealand standards do not constitute a risk to human health.

Wool Carpets and Fire

Wool carpets:

• Are naturally flame retardant due to the high nitrogen content
• Are difficult to ignite, due to a higher ignition temperature
• Have a low flame spread
• Have low heat release properties and low heat of combustion
• Do not melt or drip
• Form an insulating cool char and self-extinguish
• Contribute less to smoke or toxic gas formation than other carpet pile fibers

Wool carpets are specified for those installations with the most stringent flammability regulations, such as on passenger aircraft and ships, casinos and hotels.

Wool Carpets and the Indoor Environment

Many materials used to furnish or decorate the inside of buildings emit small amounts of volatile products. The volatile organic compound (VOC) emissions from carpets are only a fraction of those emitted by other materials used in buildings.

With paints rated 100, relative emissions are:

• Paints 100.0
• Adhesives 72.5
• Wallcoverings 8.3
• Plywood 1.0
• Carpeting 0.5

So-called new carpet odor is usually caused by minute but very odorous quantities of a by-product of the latex used in the back, 4-PCH, which is not harmful and will dissipate with good ventilation within days.

Moth resist agents used on wool carpets are increasingly applied using low (or zero) effluent techniques and, once applied, are totally safe to humans and pets.

Because wool carpets soil less rapidly than man-made fibers, the reduced use of cleaning chemicals makes a positive contribution to the environment.

Sick Building Syndrome is not related to the type of pile fiber used in carpets.

Carpets are not implicated in Legionnaire's Disease.

Did you know...Wool actually assists in stabilizing the relative humidity in buildings by absorbing or releasing moisture during periods of high or low atmospheric humidity?

There are several gases produced by the burning of fossil fuels and by emissions from certain building components that pollute the indoor air. Among these gases are nitrous oxides, sulphur dioxide and formaldehyde. Scientific studies have shown that wool fibers absorb these gases, thereby purifying the indoor air and improving the health and well-being of building occupants. Wool chemically reacts with these gases, neutralizing and binding them irreversibly in structure.

Natural fiber backings, as in those made from jute or cotton, have a similar beneficial effect.

Nylon fibers have a much more limited ability to absorb these gases, having a much slower rate of absorption and being unable to reduce the final concentrations to the very low levels achieved by wool.

Heating of wool carpets -- as in by underfloor central heating -- does not cause significant quantities of the gases to be reemitted into the atmosphere.

Carpets and Allergic Reactions

Allergies are widespread in the developed world, and the incidence is increasing for two main reasons: a greatly increased number of synthetic substances produced and the improved diagnoses of allergic conditions.

Wool is a non-allergenic fiber that does not promote the growth of bacteria or dust mites, or give off harmful emissions.

Though carpets are often blamed for the incidence of allergic reactions, cumulative evidence now strongly suggests that carpets actually have a beneficial effect on people's health, provided of course that they are maintained regularly and appropriately.

Wool fibers are too long and too coarse to be inhaled and therefore do not affect asthma sufferers.