Reports and Surveys 71 © Copyright Hohenstein Institute, Boennigheim, Germany. All rights reserved. Don't give micro-organisms a chance Development of workwear that is antimicrobial, comfortable and suitable for leasing In many areas, but especially in food-processing companies and catering facilities, hospitals and care homes, hygienic workwear is extremely important. As part of a research project (IGF No. 16039 BG), scientists at the Hohenstein Institute, in cooperation with the Thüringen Institute forTextile and Plastics Research and the SaxonyTex- tile Research Institute at the Technical University of Chemnitz, have developed a fabric for making antimicrobial workwear suitable for leasing that is based on regenerated cellulose fi- bres, and they have examined it with regard to its properties when it is used and cleaned. The aim of the research project was to combine properties such as, on the one hand, a protective function, high mechani- cal strength, a long service life and ease of care with, on the other, good physiological functionality and a high level of com- fort, in one garment.This would result in workwear made from regenerated cellulose fibres that is pure white, antimicrobial, suitable for leasing and comfortable as well. Textiles are an important transmission route for micro-orga- nisms and so there is a high risk of microbial contamination from unhygienic workwear. Along with the requirement for the workwear to meet high hygiene standards, it is also very im- portant for it to be comfortable to wear , as this affects the well-being of the wearer. Many users still prefer cotton be- cause it is so comfortable to wear. Regenerated cellulose fibres show some of the same characte- ristics as cotton, but, because they are synthetic in origin, they can be given an antimicrobial treatment.This characteristic was used in the manufacture of the new material. Very often, the effectiveness of the antimicrobial workwear that is available on the market is based on silver which is incor- porated into the fibres. Silver has been known to have bacteri- cidal qualities for about 3000 years. One of the disadvantages of it is that, depending on the form in which the silver is applied on or in the fibres, it can cause darkening or colour changes when the fabric is washed, or as a result of other external influences. However, because of the association with cleanliness, in hygienically sensitive areas pure white workwear is preferred. Three versions of the fibre: zinc, zinc oxide and silver nitrate In developing the new materials, three versions of the fibre were first produced, to which zinc, zinc oxide and silver nitrate were added. Using zinc to produce an antimicrobial effect in textiles is an innovative approach, because zinc has hitherto barely been used at all in textiles. Zinc proved to have the same advantages as silver when used as an active ingredient, and is a safe, well-researched substance which, unlike silver, does not cause any change of colour during processing and care treatments. The results show that the new, carefully dosed fibre variants, subject to certain specific requirements, can be used to make workwear containing a high proportion of cellulose fibres, so- mething which is often requested by wearers.The version with silver nitrate also had titanium oxide added, so as to avoid sub- sequent discolouring of the thread even at the manufacturing stage. However, adding titanium oxide to the fibres containing silver nitrate did not result in any improvement.The changes in colour which occurred were lighter, but still visible. The quality of the new fibres was tested in practical use. Com- pliance with the minimum technical standards for textiles, such as garment manufacturing requirements, comfort and suitability for leasing, was tested using the terms of DIN 10524, and the antimicrobial effectiveness was tested after 100 washing and drying cycles. The positive results of these tests show that the research pro- ject can form the basis for a new, innovative approach to ma- king antimicrobial textiles using zinc and regenerated cellulose fibres.These newly developed fibres and the woven and knit- ted fabrics made from them provide effective hygienic protec- tion, are comfortable to wear and very suitable for leasing, and so will help improve hygiene and reduce the transmission of infectious diseases, especially through food.This should considerably reduce infection rates in the general population, leading to financial savings in the healthcare system and so, ultimately, to benefits for members of health insurance schemes. The results are being made available for general use by all interested parties such as the textile industry, the chemical industry and the clothing industry. JOBWEAR 59 4o TRIMESTRE 2011