Karl Mayer, Germany’s leading textile machinery manufacturer, has revamped its machine technology for producing packaging sacks, with the introduction of RDS 11 EL machine. With a new level of flexibility, the double-bar raschel machine has been equipped with an EL pattern drive, which enables variable sack lengths and lappings to be worked.
An FTL unit is located at the beginning of the processing chain for producing sacks. This element in the production line has a cutting bar for cutting a double-layered, primary polyolefin film into tape yams and drawing them in a heating zone to produce mono-axial flat film yarns. These yarns are delivered to the Double-bar raschel machine, in depending of the demand. The needs-based delivery of the tape yarns is a decisive factor for online process control, just as is the exact harmonisation of the machine technology as a whole.
An RDS 11 EL is used to knit the tape yarns to produce complete sacks. The machine is supplied with a width of 193”, a gauge of E 6, a threading arrangement of 1 in, 2 out, and a set of warp knitting elements comprising two compound needle bars, two knock-over comb bars, four ground guide bars and seven pattern bars. With this configuration, the RDS 11 EL works a combination of a pillar stitch and weft lapping.
The RDS 11 EL offers a number of options for the efficient production of ready-to-use sacks, including the incorporation of sealing tapes, flaps for automatic filling, an adhesive strip for the subsequent application of labels, and contact yarns for subsequent process control. Above all, the dimensions of the product can be varied.
This electronic system replaces the old, mechanical NNC type. It does not use pattern chains or discs and enables the pattern to be changed easily. The repeat lengths can also be changed easily to adjust the size of the sacks. The RDS 11 EL has also been newly equipped with the tried-and-tested KAMCOS-system, so that its extensive potential can be easily exploited.
Thanks to online process control and the high efficiency of the RDS 11 EL, Karl Mayer’s line for producing sacks operates at an extremely high production rate. At a speed of 900 courses/min, an average of about 900 sacks per hour can be produced – depending on the dimensions selected and the stitch density.