According to warp knitting machinery manufacturer Karl Mayer, warp-knitted spacer fabrics produced on the RD 6/1-12 and RD 7/2-12 (EL) are absolutely indispensable nowadays for use as upholstery fabrics and shoe textiles.

The German company reports that the breathable 3D textiles with their high compressive elasticity have become firm favourites on the market – as have the efficient, two-bar raschel machines used to produce them.

The technical features of these RD machines are continuously being improved and revamped in order to enhance the performance of this successful machine series and to adapt them to the constantly changing demands of the market.

The latest upgrade covers a whole package of specific improvements and at the request of many of its customers, Karl Mayer now offers the RD 6/1-12 and RD 7/2-12 (EL) with individual needle mounting. Replacing the needle leads with this optional feature makes it easier to change the needles on the machine itself.

Another improvement concerns the service life of the machine components. In order to protect the yarn sleys from being worn by the high loads that occur when processing monofilaments in the pile bars, these guide elements are now chromium-plated as standard.

In addition to the modifications made to both machines, some of the changes are specific to each machine individually.

Modifications to the RD 7/2-12 (EL)

One instantly visible change that has been made to the RD 7/2-12 (EL) concerns the warp beam frame. Only one, more compact version is now available for this double-bar raschel machine. The warp beams for ground guide bars GB 1 and GB 2 are positioned at the front support, for GB 3 to GB 6 they are fitted to the girder, and for GB 7 they are positioned at the rear support.

The warp beams are handled via a new arrangement of access points. A service platform now runs along each of the left and right front sides, i.e. along the warp beam rolls. Another footbridge runs lengthwise between the warp beams at beam positions GB 4 and GB 5.

Another modification relates to changing the pattern over when working with pattern chains. In order to facilitate this process, a pattern drum having a new divided arrangement is now available for the RD 7/2-12 (EL). The pattern drum is made up of two separate parts. The four tracks for the pattern chains for controlling guide bars GB 1 to GB 4 are located on the front part. The movements of pile bar GB 5 and ground guide bars GB 6 and GB 7 are controlled by the pattern chains on the three tracks on the rear part of the pattern drum. A chain path having a length of 1.5 m is also available.

Modifications to the RD 6/1-12

The RD 6/1-12 is now available with a new optional feature for processing multifilament yarns in the pile bars. This package of features, which extends the applications of this machine, includes special guide needles – 1 in/1 out – for pile bars GB 3 and GB 4.

The yarn sleys for the pile bars, which are needed for processing monofilament yarns, are supplied as an accessories kit, since they are often not used when producing plush. This new accessories kit enables multifilament yarns to be processed without any problems, Karl Mayer says, as long as certain restrictions relating to the type of yarns used and the stitch density are taken into account. The following conditions should be met for a machine gauge of E 22:

• the yarn count in ground guide bars GB 2, GB 5 and GB 6 should be a maximum of 167 dtex per latch needle head
• the yarn count in pile bars GB 3 and GB 4 should be a maximum of 350 dtex per latch needle head
• the individual filaments should have a count greater than 1 dtex
• the maximum number of filaments in pile bars GB 3 and GB 4 is 150
• the stitch density should be a maximum of 20-22 stitch courses per cm.

The machines with these new modifications are available as of immediate effect.

www.karlmayer.de