Story of the birth of a new device: the TSA (Tissue Softness Analyser)

For a long time, softness measurement in tissue making – notably handkerchieves – has been a concern addressed to us by clients who were looking for a dedicated reliable device. Surface or stiffness measurements were never related to softness. We had the feeling that many parameters could interfere with the sensation of softness, which is a highly subjective element. Logically, the “handy panel” has been commonly used to assess smoothness, a very personal feeling indeed, implying the modeling of this measure very difficult. It happens that, in 1972, an American citizen, Mr Taylor, had filed a patent to protect one of his discoveries: when rubbed, tissue paper produces a different noise according to its softness degree. In 2005, European funds have financed projects meant to enable companies from Western and Eastern Europe to join forces in order to go further on that research. In that specific context, Noviprofibre from Eybens (France) and Emtec from Leipzig (Germany), agreed on a cooperation contract. Because the European funding was supposed to support companies from former East-Germany, only Emtec has been granted subsidies, provided for three years. The cooperation agreement clearly stated the tasks and duties of both parties: Emtec would develop and produce, when Noviprofibre would develop and distribute the device if successfully developed and manufactured. This device is now on the market. It is named TSA for Tissue Softness Analyzer. It measures the sound produced by a tissue sample held under a certain tension. The software operating the device and analyzing the results incorporates other relevant parameters from the laboratory. This way, a value of the softness, fully related to the one measured by hand, can be obtained (correlation between 95% and 98% depending on characteristics). To date, according to the country, the product is distributed by Emtec or Noviprofibre. For more than 30 years, softness has been measured by hand, several times a week. Some staff members of the plant organize a meeting to touch and classify every sample of the previous days production. This approach leads regularly to the declassification of a part of the production to secondary quality if the softness is not at the level expected. This downgrading has a direct effect on earnings for the mill and cause significant shortfalls. The softness measurement device can avoid this. It also helps optimizing the use of the pulp, pulp quality being a crucial element in the final sense of touch. With the TSA, every tissue maker can choose the best pulp for the quality required. In addition, on-line measurement avoids the overconsumption of chemicals thanks to a possible instant adjustment. The TSA is a good example of a successful international cooperation leading to innovation in paper making.