Friday, 30 April 2010

Moisture Management Garments

Moisture management is one of the key performance factors in today’s garment industry, particularly in the past in the performance market; it is also becoming very important in the workwear market as well.

Moisture Management is defined as the ability of a garment to transport moisture away from the skin to the garment’s outer surface, where it can be dissipated by evaporation. This action prevents perspiration from remaining next to the skin. In hot conditions, trapped moisture may heat up and lead to fatigue or diminished performance. In cold conditions, trapped moisture will drop in temperature and cause chilling and hypothermia. Excess moisture may also cause the garment to become heavy, as well as cause damage to the skin from chafing.

In some areas of workwear, particularly where utility vests or bullet proof vests are being worn i.e. armed forces or police, the use of wicking garments under the vests reduces the fatigue and stress that operating in high temperatures or high activity can cause. This also applies to firefighters who benefit from wearing high wicking shirts under their protective equipment.

Moisture is transported in fabrics by capillary action and is commonly known as wicking. In fabrics, the spaces between the fibres effectively form tubes, which act as capillaries, and transport the liquid away from the skin. As a rule, the narrower the spaces between the fibres in a fabric, the more effectively they will draw up moisture. For this reason, fabrics with many narrow capillaries, such as microfibre, are ideal for moisture transport. Cotton has the ability to wick moisture away but also has a relatively high absorbency level that leads to the perspiration being trapped in the fabric.

Cotton can be treated with chemicals in the finishing process to reduce the level of absorbency, but this treatment may not withstand repeated laundry processes. However cotton exhibits very similar drying times as that of many of the fabrics produced from artificial fibre of which the most common in moisture management garments is polyester. The drying rate of one of the leading branded fabrics is 0.028 grams of water per minute and cotton is 0.026 grams of water per minute.

Thickness of the fabric is a key and controlling variable when it comes to moisture management; the thicker the fabric, the more moisture it holds, Most of the synthetic fabrics, like those made from microfibre polyester, were considerably thinner than cotton fabrics. However if the cotton fabrics are knitted using fine yarns then the thickness is greatly reduced.

In terms of feel a polyester fabric can in fact feel damp and clammy after drying for 90 minutes, a cotton fabric feels dry after 60 minutes, this is due to the low moisture regain of polyester of about 0.5%; cotton has a moisture regain of 8%.

Bi-component fabrics composed of a non-absorbent fibre on the inside and an absorbent fibre on the outside, have proved to be an extremely efficient construction for moisture management fabrics. This is because the absorbent material on the outside draws the moisture away from the skin while the non-absorbent material keeps the skin dry.

With this in mind Granite Workwear feature a high wicking Polo shirt and a T shirt that was developed by Texline Ltd to incorporate the best properties of microfibre and cotton.

The shirts use an inner face of Tactel that is used as a moisture transport to remove the perspiration quickly into the outer layer of cotton where it evaporates. The fabric has a very soft feel next to the skin, looks appealing on the outside as it is cotton and therefore looks natural. It also holds its shape well and has a maximum shrinkage of 2% and a 0% spirality. These garments are used as standard issue in a number of Fire Brigades and Police Forces throughout the UK. They are also extremely cost effective compared to many of the garments made using branded fabrics.

1 comment:

safetysupervisor said...

moister management and protective clothing is very essential for every safety manager while they are working under some hazardous places.