Karl Mayer, Brückner Team Up To Develop Seamless Finishing Method

Warp knitting and technical textiles equipment supplier Karl Mayer Textilmaschinenfabrik GmbH and
textile finishing machinery supplier Brückner Textile Technologies GmbH & Co. KG, both based in
Germany, report they have developed a method for continuous finishing of seamless, warp-knitted
fabric in open-width form.

Using Karl Mayer’s RDPJ and DJ machines, seamless goods can be knitted with a built-in
selvage. This selvage can then be used to hold the open-width fabric in place during heat-setting
in the tenter. Karl Mayer reports the two-bar raschel RDPJ and DJ machines can produce
variable-diameter tubular goods; goods with functional zones knit into specific areas and knit-in
seams; and decorative effects with different patterns on the front and back of the fabric or
open-work jacquard designs.

During recent trials, a Karl Mayer RDPJ 4/2 machine produced three long-sleeved shirts in a
fabric panel featuring two knit-in selvages. The fabric was comprised of 81-percent nylon and
19-percent elastane.

The new processing method offers a pre-heat-setting stage directly linked to the
warp-knitting process. According to the companies, this pre-heat-setting reduces tears, creases or
snags in the fabric; and also reduces color and elasticity variations, and fluctuating widths.

In typical relaxing and heat-setting of seamless goods, the separate tubes or stockings are
attached to a special frame prior to processsing. Brückner’s Power-Frame VNB tenter features a
perforated belt carrier that supports and transports the fabric vertically through the machine with
a gentle vibrating effect to relax the fabric and promote shrinkage in the steamer zone. According
to Karl Mayer, the VNB tenter also features: an intensive steamer with fabric relaxation on the
belt before the drying section for low residual shrinkage values; a precisely adjustable dryer with
uniform air and temperature distribution over the length and width of the fabric; short fabric
paths to reduce stitch distortion and fabric stretching; pyrometric fabric temperature control for
accurate monitoring and future reproducibility of heat-setting time and temperature; and a cooling
zone at the machine’s exit to instantly cool and condition the fabric.

The companies report the trials performed on the long-sleeved shirts showed minimal
differences between the inner and outer fabric panels with maximum variations of +/- 1 centimeter.
Maximum residual shrinkage after washing at 60°C was between 0 and 5 percent.

According to Karl Mayer, this new knitting and finishing technique offers cost savings, and
is particularly well-suited to fishnet stockings, lingerie, outerwear, sportswear and medical

November 15, 2011