Wool the Miracle fiber.
Wool Is The Miracle Fiber
Comfort, Coolness, Resilience, Wrinkle Recovery, Absorption, Drape, Elasticity, Style, Texture, Tenacity, Warmth WOOL has it all...naturally!
Try as they may, scientists have not been able to produce a single fiber to match the properties of wool. There is a common misconception that wool is best suited for warmth in cool conditions. Scientific tests however negate this concept and consistently show that wool is ideal for bedding in hot, humid, dry, cold or wet conditions.
Wool has unique attributes, which give it superior performance to other fibers in a number of ways. Our bodies continually produce heat at a rate dependent on our activity level; this heat must be dissipated to the surroundings in the form of perspiration, at the same rate at which it is produced, to keep the body temperature constant 1. When used in bedding wool creates a micro-climate that assists in regulating body temperature and humidity. The degree to which body temperature and humidity is regulated is known as "thermophysical" comfort, that is, a state in which the individual is free from thermal stress.
Freedom from thermal stress is directly related to degree of rest. There are number of "thermophysical" responses that can be measured to indicate how well rested a person is at any given time. Several studies examining and comparing the performance of wool blankets have consistently shown that in hot and cold conditions wool provides comfort and a more restful sleep than any other fiber type.
Umbach from the Holstein Institute in Germany, designed and undertook a series of studies to determine the measured responses which are the most indicative of a rested night's sleep 2. He found that first and foremost that the heart rate is the most accurate indicator. A person with a slow and regular heartbeat is far more relaxed than a person with a fast pace and/or irregular heartbeat. Two factors, which will be reflected in the heart rate, are temperature and humidity of the bed micro-climate. It is a well-known fact that in order for the major organs of the human body to function efficiently, the core temperature must be maintained at or near 37 degrees C (98.6 degrees F).
Using the "thermophysical" responses related to sleep behavior, Umbach monitored several body and climate functions to compare the performance of wool versus acrylic blankets 3. Subjects were monitored in environment controlled (temperature, humidity and airflow) rooms. It was found that the pulse rate of sleepers under the wool blanket was normal at 60 beats per minute, where as it rose erratically up to 80 beats per minute under the acrylic blankets, indicating greater stress on the sleeping person. This was easily explained by Umbach's other observations: the wool blanket absorbed 50% more perspiration than the acrylic blanket, and cotton pajamas worn by the participant remained drier while they were under wool blankets. The micro-climate under the acrylic blanket was too hot and humid for comfort.
The Ergonomics Unit at the Polytechnic of Wales compared comfort properties and sleep patterns of subjects sleeping under duvets rather than blankets 4, again in an environment controlled room. When the bedroom as at 16 degrees C, (60.8 degrees F) all sleepers were comfortable although the humidity under the wool duvet was lower. Interestingly, pulse rate under the wool filled duvets were again found to be lower than under the polyester filled duvets.
However, a 22 degrees C (71.6 degrees F) the results were statistically discounted because the subjects under the polyester bedding exposed their limbs for period of time in an effort to cool down. This response was poor substitute for the thermophysically controlled micro-climate as found under the wool duvet.
A third trial designed by P.R. Dickson used the subject's own room and bed as control. Time-lapse photography monitored movement during the night to determine the sleep quality 5. Dickson found statistically significant differences in the number of immobile periods, immobile sequences, and the percentage of the total time spent sleeping with the wool blanket compared with the acrylic surface. Again the wool blanket was proven to be the most restful surface to sleep upon.
The positive health effect of sleeping with wool is best illustrated by a study by Scott et al 6 of low birth weight babies. His study found that babies nursed while wrapped in lamb's wool consistently showed a significant improvement in weight gain over and above those nursed by conventional methods using cotton.
Wool's comfort advantages have traditionally been attributed to the capacity of the fiber to absorb a significant proportion of its own mass as water* 7 . *Wool can absorb 33.9%of its weight in water compared to synthetics at .4% and cotton 8%. Researchers agree that more than simply absorb, wool fibers have the ability to buffer by reacting to the humidity level within the particular environment. As the humidity rises, wool will absorb and store moisture as required. When the level decreases, the fibers release the moisture thus regulating the micro-climate. This property ensures that a damp, clammy feeling will never be experienced with wool. In this way, instead of the body regulating the micro-climate, the wool bedding acclimatizes the body, ensuring a healthier rest with an even heart rate and blood pressure.
Another advantage of wool over other fibers is its outstanding insulating properties especially when compared with synthetic fibers 8. The unique three-dimensional form of wool allows it to trap small packets of air, thus giving it an insulating property. This property ensures that temperature changes are slow and gradual so that the bed's micro-climate has time to equilibrate. Rapid changes in heat loss or gain would hinder temperature and humidity regulation.
Wool's natural resilience is another property which aids in comfort. The pile of an underlay (or mattress cover) will reduce pressure points and cushion the body. Tests using wool underlays with the elderly and bedridden patients in hospitals have shown dramatic differences between the performance of wool and polyester bed pads.
Patients on wool had significantly fewer skin problems than those of polyester pads. 775 of those on wool had no problems compared to 38% of polyester. Of those with decubitus (skin break down), only 8% had any problems at all for more than one month. Those that slept on polyester had 38% more issues and problems for a period of more than one month. In addition, no patients on wool had renewal of skin irritation once the initial problem cleared up, while 14% had repetitive periods of irritation on polyester** 9. The health aspects of sleeping on wool continually outrank similar synthetic products.
An additional benefit of wool bedding is the peace of mind in knowing that wool is naturally resistant to ignition and is self-extinguishing. Perhaps the most dramatic demonstration of this was a trial developed to evaluate wool and polyester overlays to the British Standard B.S.7175. the ignition sources were, from one to six; a cigarette, 3 butane flames (the smallest of which represents a burning match) and 4 wooden cribs of various weights. Results showed that the mattress assembly containing the wool underlay was capable of resisting ignition source 5, (wooden crib 16g) with no evidence of progressing smoldering. The polyester overlay however, when tested with a simulated match (ignition source #2) was found to act as a secondary source of ignition requiring extinguishing after eight minutes 10. The ignition sources are numbered relative to their propensity to ignite the test material.
Wool with its unique physical properties is the ideal fiber for bedding applications. It has been subjectively and scientifically proven from a number of perspectives that wool has the advantages over other fibers. Irrespective of whether wool is used for protection or comfort, its applications are suitable for conditions ranging from hot and humid temperatures to the harsh and freezing Antarctic.
**Sample of 26 on wool underlays and 21 on polyester.
1 “Wool-Why is it so comfortable?”, B. Holcombe, Proceedings of the 8th International Textile Research Conference, Vol V., Fibre assemblies ad product Properties, ed G.H. Cranshaw (WRONZ) 1990, 205-214
2 “ Comparative Thermophysical Tests on Blankets Made From Wool and Acrylic-Fibre-Cotton Blends”, K.H. Umbach, J. Text. Inst.,1986, No.3.
3“ Comparative Thermophysical Tests on Blankets Made From Wool and Acrylic-Fibre-Cotton Blends”, K.H. Umbach, J. Text. Inst.,1986, No.3.
4 “An Ergonomic Comparison of Wool and Polyester Filled Quilts”, Polytechnic of Wales, Ergonomics Unit, published in IWS Technical Letter Number 26.
5”Effects of a fleecy woolen underlay on sleep”, P.R. Dickson, the Medical Journal of Australia, January 21, 1984, p87-89.
6 “Weight gain and Movement Patterns of Very Low Birthweight Babies Nursed on Lambswool”, S. Scott , P. Lucas, T. Cole and M. Richards, Child Care and Development Group University of Cambridge and the MRC Dunn Nutrition Unit Cambridge, Oct 1980-Sept 1981.
7 W.E. Morton and J.W.S. Hearle, Physical Properties of Fiber, the Textile Institute Manchester, 1986 Edition.
8 W.E. Morton and J.W.S. Hearle, Physical Properties of Fiber, the Textile Institute Manchester, 1986 Edition .
9”Wool Pile Sliver Knit Bedpan Evaluation at Franklin Park Nursing Home”, L.R. Mizell, W.H. Marsden and V. Butler, Summary report by New Market Outlet Section, IWS November 1974.
10CPB-99”The Flammability Performance of Wool and Polyester Mattress Overlays”, R. Woolin, J.L. Webb, IWS Technical Information Bulletin, 29 June 1987.