This is the most suitable machine for dyeing delicate yarns (Silk, Bemberg, etc.) since it prevents the material being too tightly packed; in fact other skein dyeing systems frequently produce an excessive packing of the dyed material. The machine is equipped with horizontal arms perforated in the upper part; skeins are stacked and suspended on this rack. The liquor, forced through the arm holes, penetrates the skeins and is then collected in an underlying vat. Standard machines are equipped with a rod which moves the skeins at preset times, changing the bearing point to obtain a more uniform dyeing. During the skein motion, the flow of the liquor is stopped to avoid the formation of tangles in the yarn; since yarns are not fixed to rigid supports, they can thoroughly shrink. This machine does not run under pressure. It is possible to dye at steady temperatures since the liquor is contained in a separate tank.
Skein Dyeing Machine
Modular skein dyeing machine with pullout arms. Pullout arms also allow the loading and unloading of skeins far from the dyeing machine, without manually intervening in the intermediate dyeing, squeezing and drying operations. It can be used for silk, cotton, viscose and Cashmere yarns.
The operating costs of this machine are generally very high because it require a very high liquor ratio (1:15 . 1:25 . 1:30 ). Standby times for loading and unloading operations are also very high and the arms must be often cleaned. This machine can be used also for scouring and finishing processes.
Some machine manufacturers have designed machines with slant covers to avoid unwanted liquor dripping on the skeins; the skein rotation is determined by the perforated arms, and not by the rotation of the skein-lifting device when the arm is stopped; it is therefore possible to eliminate the sliding contact with the skeins and preserve them perfectly.
There are also package dyeing machines with triangle-shape arms, arranged radially on a variable-speed rotor. When the dyeing process has terminated, the material can be centrifuged and dried, by forcing a hot air flow into the arms and through the skeins.
