This is another feature in conjunction with the Aachen-Dresden-Denkendorf Internatinal Textile Conference taking place at the end of November 2017
Shock waves and liquid detergents
A Revolution for industrial laundry looms on the horizon: cleaning with shock waves at washing temperatures at 20 °C with low energy consumption.
A stain of red wine at the suit or pullover, a sweaty jacket or a coat with a spot of dirt: superior business wear and outerwear from old age homes and nursing homes have a lot in common – at least from the view of textile service companies. Currently, both types of wear have to be frequently cleaned in organic solvents or alternatively washed by wetclean processes at washing temperatures of up to 40 °C. But these treatments show disadvantages: germs and dirt residuals as well as sweat spots are partly not removed; consequences are often negative textile changes and accordingly cost extensive finishing treatments.
The novel cleaning process of wfk-Cleaning Technology Institute was recently introduced the first time at the Innovation Day 2017, organized by the Federal Ministry for Economic Affairs and Energy in Berlin. Special feature of the innovation from Krefeld: high quality outerwear is cleaned by high pressure generated impulses if applicable in combination with liquid detergents and completely without organic solvents. This is the way to clean more efficient.
Hygienic, gentle, effective
The radial shock wave technology – based on compressed air application – gives the researchers of Prof. Dr.-Ing. Hans Günter Hloch’s team the possibility for hygienic and at the same time gentle processing of sensitive outerwear. Innovative quintessence of the approach, which was developed within pre-competitive collaborative industrial research, is a washing machine with adapted shock wave generators and slanted moving drum. According to wfk-institute, technology and process design arouse interest by washing machine manufacturers also outside of Europe. Cleaning with shock waves could be also interesting for the metal industry, stated Prof. Hloch.
Washing tests show: The shock wave treatment with up to 125000 shot per minute causes no changes or damage of the textile surface which was proven by microscopic evaluation; in addition, colour, brightness and gloss of the textiles maintain. Concerning cleaning efficiency, the new process outreached the values of common wetcleaning procedures, even by omitting detergents. Wfk project leader Prof. Hloch assumes that the new energy saving process will be adapted by industry and that the necessary washing technology will be available within few years.
The specific energy consumption values (kWh/kg laundry) of the developed cleaning device are about 18 % lower compared to a typical cleaning process for sensitive textiles in the professional area (wetclean-process at 30 °C). Reason is in particular the reduced wash temperature. The program duration is for both processes in the same range.
Currently, treatment of sensitive outerwear in industrial laundries is in the range of about one tenth of the personal wear with increasing percentage.