Thursday, 20 March 2014

Splittable Bico Fibres in Decorative Nonwovens

The final summaries from Roubaix...

Ralf Taubner of STFI (Germany) promoted STFI’s facilities mentioning their Reicofil spunbond, Hergerth carding, Fleissner hydroentanglement, Danweb air-laying and Küsters calendering.  He provided a wealth of data on nonwovens which could be made from the kit before concentrating on a current project for Duni (Sweden) intended to improve the lustre and colour intensity of their majority-pulp tableware range.  All composites where the pulp was sandwiched between spunbond and/or carded webs looked and felt better than those with a pulp surface, and surfaces of splittable PLA/PE fibres which had been hydroentangled were best of all.

Modelling Nonwoven Compression Behaviour

Amit Rawal of the Indian Institute of Technology, Delhi (India) has developed a two-step model to describe the uniaxial compression behaviour of thermally bonded nonwovens.  The results from this model have been compared with experimental data on the thickness under various pressures of parallel and random laid structures.  Good agreement was obtained.  It was concluded that fibre modulus, fibre volume fraction, Poissons ratio and the alignment of fibres are the key determinants of compression behaviour. The model could be applied to other porous networks such as those made from multiwalled carbon nanotubes.

Modelling the Spun-laid Nonwoven Process

Christian Leithäuser of the Fraunhofer Institute of Industrial Mathematics (Germany) described the modelling of melt-flow in the spin pack, of extrusion and drawdown, of turbulence in the drawing air and of fibre laydown.   By combining these models developed within 8 different doctoral theses undertaken between 2009 and 2013 the Fraunhofer ITWM has, in essence, created a virtual spunbond line.  The models are now being used to optimise or even completely redesign the spinning process and to evaluate and compare virtual nonwovens prior to their production.

A Viscose/Bico Air Laying Expert System

Tobias Maschler of DITF Denkenorf (Germany) presented an expert system for the development of air-laid nonwovens which is being constructed with funding from the Allianz Industrie Forschung programme.  It is a Web 2.0 client server application which can be accessed via a browser.  It contains all the important facts about the process, and how they relate to the Oerlikon Neumag air-layer and the Fleissner through-air bonder at STFI.  It also contains data on the fibres which might be used, allows input of the desired nonwoven properties (e.g basis weight, density, thickness, absorbency) and calculates the fibre blend and process parameters to obtain those properties.  It also calculates an initial estimate of the likely nonwoven production costs.

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