The common feature of all nonwovens is that they are produced from fibers that are not woven, knitted or stitch bonded. That is why they are called “nonwovens”. A wide variety of raw materials, such as glass fibers, chemical fibers, wool or silk, cotton or cellulose, are used to produce nonwovens. During manufacture the fibers are wet-laid or dry-laid to form a web and then bonded using mechanical, chemical or thermal means. Only after the bonding process are they referred to as nonwovens. Wet tissues, called flushable wipes, consist of cellulose fibers. They are made using a process similar to that for papermaking.

Voith and nonwoven experts Trützschler have been collaborating since 2013 and offer a complete product range for the manufacture of wet-laid and hydro-entangled (spunlaced) nonwovens. The aim of the cooperation is to jointly develop and market innovative and cost-efficient production systems for nonwovens.

Sheet formation in Voith HydroFormer. In the wet-laid process, a suspension of fibers and water is passed over a wire on which a homogeneous fiber mat forms. As the stock consistency of the suspension for nonwoven manufacture is extremely low, sheet formation is performed using the inclined wire technology of the Voith HydroFormer. This technology has been constantly optimized through many years of development work. It is offered for single-ply and multi-ply nonwovens. When producing multi-ply nonwovens, an intelligent baffle system in the HydroFomer corrects the flow parameters and prevents swirling and mixing of the suspension flows.

Bonding in the Trützschler Nonwovens AquaJet. Following sheet formation, the hydro-entanglement process takes place in the Trützschler Nonwovens AquaJet system. The bonding occurs through the momentum of the water jets and is therefore a purely mechanical process. As no binding agents or bi-component fibers are used, the wipes disintegrate easily in water and are completely biodegradable.

Wet-laid spunlacing. Voith and Trützschler Nonwovens have jointly developed the wet-laid spunlacing process for manufacturing wet-laid and hydro-entangled nonwovens.They have managed to produce nonwovens for wet wipes that have high strength when wet but can still be disposed of via the sewage system. In various tests by the two international associations INDA and EDANA, nonwovens produced using the wet-laid spunlacing process met the requirements for flushable wipes.

Nonwoven production with Voith automation technology. Voith also provides the automation technology used in nonwoven manufacturing. Since 2013, construction material and nonwoven manufacturer Johns Manville has been using Voith technology in the production of glass fiber nonwovens at its plant in Wertheim, Germany. This includes the complete automation package with quality control system and scanner for the quality parameters color and thickness, the control system and the OnView information system, which archives and visualizes all relevant data. Johns Manville also uses the Voith HydroFormer for sheet formation. Volker Krallmann, Production Manager in Wertheim, confirms the excellent performance of the entire package: “We are highly satisfied with the new quality control system and HydroFormer from Voith. From the first day of commissioning they have been operating stably and reliably and guarantee a consistently high nonwoven quality.”//