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GKD: From Polymer Filtration To Nonwovens Forming

Over 80% of such nonwovens are used for hygiene sector products like nappies or cosmetic tissues and for disposable products in the medical sector. And this means high standards for the production of spunlaid nonwovens in ever thinner, lighter and more efficient forms. The internationally leading technical weaver Gkd – Gebr. Kufferath AG has a well-established worldwide reputation as an expert when it comes to the spunlaid process. With its all-round competence in consulting, design, production and service, this owner-managed SME is a sought-after partner and solutions provider for the nonwovens sector.

3The market for technical textiles is growing rapidly all over the world. And the strongest growth in this sector is to be found in the nonwovens sector, where the most important areas of application are in hygiene and medical products. Here, there is a particularly high demand for spunlaid products. The driving factor behind this trend is demographic development. On the one hand, increasing life expectancy leads to increasing demand for products tailored to the needs of older people, for example regarding incontinence, wound healing and infection control. On the other hand, the growing world population and rising standards of living in many regions are reflected in an increasing demand for baby-care and cosmetic products. In order to prevail in this highly competitive global market, manufacturers must consistently optimise the efficiency and productivity of the single-stage spunlaid process. Whether for filter media for central filters and spin beams, quench screens and laydown belts, GKD’s mesh constructions and selection of materials – custom-configured to meet the individual requirements of specific equipment and products – make an important contribution towards the integrated adaptation of spunlaid processes to the ever-increasing demands of the converting industry. In the polymer filtration stage, this contribution is primarily through optimised plain dutch weave meshes (ODW) made of stainless steel. Thanks to their special construction, these meshes combine precise filtration with low differential pressure and long service life. The slot-shaped pores on the mesh surface are smaller than the pores inside the mesh. Particles above the cut point are retained directly on the mesh surface. In this way, ODWs also reliably filter out poorly dispersed additives and solid particles. Gel-like impurities in the melt are crushed by the shearing forces that arise. Their precise separation rates, high dirt-holding capacity and low clogging tendency make ODWs eminently suitable for deployment in several aggregates in the spunlaid process. In screen changers, for example, this mesh type is deployed as a multi-layer construction in process-specifically assembled filter discs or cartridges. When designing the mesh configuration, GKD makes use – if required – of its own in-house further development, the integrated simulation environment Weavegeo®. This enables GKD to modulate the mesh configuration precisely to the requirements of the individual application and to simulate the specific process of polymer filtration. The knowledge and insights acquired through the simulation in the laboratory are then implemented on GKD’s ultra-modern technical looms to produce perfectly customised products, cut to size and ready for use. In the central filter, screens consisting of five to six filter layers with separation rates of 10 to 40μm are used, covered with a protective mesh if the particular application requires this. In the spin beam, several layers of made-to-measure, perfectly phased meshes filter the flow of the melt and thus improved the service life of the spinneret. Manufacturing these frame-mounted long filters or filter discs, which can be up to 6 metres in size, calls for a maximum of engineering expertise and precise selection of media to match the specific application so that the filter packet construction ensures that the required level of process success is achieved. Here, too, thanks to comprehensive quality control and automated cleaning of the mesh before cutting to size, GKD guarantees the production reliability that the high-quality spunlaid products demand. Preconditions that are equally beneficial for rectifiers. These screens – arranged on one or both sides of the fibre flow, harden the still-hot continuous filaments by quenching them with cold air before the laydown section. For the construction of such quench screens, large-format honeycomb carrier plates are covered on both sides with specially pre-treated mesh and mounted in a frame. Whether as original equipment or as repair – thanks to its high-precision meshes and coverings, GKD can guarantee the flow homogeneity essential for trouble-free fibre flow. With its electrostatically conductive laydown belts made of meshes from the Conducto® and Conductive® range, GKD is also the partner of choice for the fourth and final stage of the spunlaid process. Due to the bronze wires or graphite filaments woven into their warp, and to their non-marking pin seams, these endless polyester belts substantially increase the safety of the integrated process flow, constantly conducting away – through their contact with the metallic rollers – any electrostatic charge caused by the process itself. In addition to the production reliability the belts provide throught this feature, their efficiency is further underlined by their low fibre penetration, uniform card web formation, customised air permeability, excellent nonwoven discharge and reliable adhesion in the laydown section. Its winning combination of integrated competence in engineering and consultancy and expertise in manufacturing has made GKD an internationally sought-after problem solver for the challenges of spunlaid processes. And comprehensive service from a single source ensures that collaboration with this technological leader is guaranteed to be an enduringly successful experience.