#Knitting & Hosiery
E 50 – a new standard for gauging the fineness of warp-knitted fabrics
Principles for operating at a gauge of E 50 on the HKS 2-3 E. There is currently a high demand in the clothing and lingerie sectors for delicate, sheer, elastic knitted fabrics. These exceptionally pliable fabrics enable completely new designs to be created, offer haptic characteristics that have never been achieved before, and promise continuing lucrative business – a trend that has encouraged warp and weft knitters to develop fabrics in extremely fine gauges. The basis for this exceptional achievement is the clever way in which tried-and-tested components for processing elastane have been combined with specific new innovations. The knitting elements in particular were completely redesigned for operating at this particular needle gauge to enable them to process extremely fine yarns. Elastic fabric batcher no. 29 B
The HKS 2-3 E provides controlled relaxation and handles the fabric so that felting and tension variations are eliminated. To do this, the machine was equipped with the elastic fabric batcher no. 29 B. The standard fabric batcher no. 34 A or AE, which is also suitable for taking-up stretch fabrics, was not used because its friction-driven ascending batch winder cannot handle the textile gently enough. When producing very fine articles, the increasing roll weights may often cause felting and stitch distortion. On the other hand, type no. 29 B operates with a central winder equipped with an active drive. The speed of the shaft is adapted to suit the increasing roll diameter by means of an automatic, fabric-tension-controlled speed regulator – an expensive but reliable solution, especially when taking-up very fine fabrics, which also guarantees a uniform roll build-up. Another device for improving the quality of batching is the integrated spreading device. The three shafts just in front of the central winder smooth out any edges that have rolled over by means of spiral springs, thus ensuring that the roll build-up is straight in the horizontal direction. In addition to the central winder, the 29 B batcher also has a relaxation zone. This zone, which is located immediately after the fabric take-down point, reduces any inherent tension and consists of several smoothly rotating rollers for transporting the fabric. Seamless quality control Protechna can supply the Procam camera monitoring system for use in fabric quality control. This optical inspection system was premiered at ITMA 2003, and is mainly used in the production of high-quality stretch articles and automotive fabrics. KARL MAYER has equipped its E 50-gauge HKS 2-3 E with the Procam system for this year’s ITMA trade fair.
Unlike conventional systems using a scanner, which moves continuously from left to right and back again along the fabric web to detect faults, the new Procam camera monitoring system provides a complete overall picture of the entire fabric piece between the knitting elements and the take-down point. The fabric is therefore inspected in the lengthwise and crosswise directions across the entire width. Any faults are detected reliably, objectively and reproducibly - and this system reduces the reaction time considerably when dealing with yarn breakages. The machine is stopped instantly and reliably right at the position where the fault has occurred, which guarantees the shortest possible fault lengths, even at high operating speeds. Minimal time and effort are required to make adjustments when the fabric has to be changed, which increases the efficiency of the Procam system even more. The maintenance and upkeep costs are also low, since this contactless monitoring system operates without any wearing parts.
The finest fabrics for maximum efficiency The HKS 2-3 E was largely developed to process elastane yarns only. It can reach speeds of more than 3,000 min-1and can thus achieve a rate of productivity that puts it far above comparable technologies, especially when compared to established circular weft knitting machines. The HKS 2-3 is also available with a gauge of E 50, and is an all-round machine for producing non-stretch articles as well. Both machines are also available in gauges of E 36 and E 40 and with a working width of 130". This high-speed, two-bar tricot machine in a gauge of E 50 can produce a lightweight, opaque stretch fabric from microfibre yarns, whereby the construction of the knitted surface can hardly be detected by the naked eye. This is due to the exceptionally large number of stitches per square centimetre. Despite having the look of a woven fabric, these pliable fabrics have the typical stretch characteristics of warp-knitted textiles. The fine fabrics can even be used to produce bodyshaping effects. At ITMA 2011, the HKS 2-3 E in a gauge of E 50 was producing a sample that fully meets the requirements of INVISTA’s Lycra® beauty fabric concept. The bodyshaping and comfort characteristics of the fabric were successfully tested in accordance with the standards laid down by this producer of polymers and fibres. It now carries the Lycra® beauty label in the “Sculpt” category. This classification applies to lighter-weight fabrics with high-tech functions and more subtle shaping. The fabrics weigh less than 200 g/m2. “Sculpt” comes after the categories of “Smoothing” and “Sensual Curves” and before “Control” in the sequence of shaping effects, and describes a fabric where the main emphasis is on compression and the bodyshaping effects. The high yarn density in the E 50-gauge fabric also produces a silky shimmer, a soft, uniform handle and a drape that can adapt easily to different shapes and forms. These characteristics open up completely new possibilities when designing products. The specific physical and textile characteristics of these extremely fine warp-knitted stretch fabrics are currently being evaluated by KARL MAYER’s product developers, who are carrying out the relevant tests and investigations.
