Touch-Free Dye Application
Fleissner's dye liquor applicator features rapid color change technology.
Manfred J. Aulbach
To meet this requirement - while at the same time reducing water, energy and chemicals costs, as well as the incidence of second-quality goods - innovative machinery design solutions are needed. Quality demands, rapid material and process changes, and a constantly growing number of regulations for environmental protection all must be taken into account.
Germany-based Fleissner GmbH has always decisively contributed to and influenced the development of textile finishing with trend-setting inventions. One of these is a new dye application system for tufted carpets.
The Fleissner dye liquor applicator operates on the pouring principle. The applicator pours the dye liquor over the carpet as an even liquid film without touching the pile.
Uniform dye liquor application over the width without color variations from end to end ensures maximum production speeds irrespective of the pile weight. The applicator controls pouring precisely - from 15 liters to 180 liters per meter of fabric width.
The Fleissner dye liquor application system comprises the following components:
• dye liquor supply;
• predistributor system;
• dye liquor application head; and
• centering control dye liquor head/carpet.
Fleissner’s new dye liquor applicator features a programmable logic controller for automatic control and adjustment of a variety of parameters.
Dye Liquor Supply
The dye liquor is supplied through flow meters to the predistributors without any pulsation from the dye liquor preparation station.
Two predistributors are located centrally above the dye application head. The hose connections are located radially on both sides of each predistributor.
The predistributors are connected by hoses of identical length to a pneumatically controlled multiple-way valve system, and from there to the distribution system of the overflow edge by short hose connections. To adapt the pouring width, valves for the supply hoses to the overflow edge can be opened or closed in the predistributor. This avoids loss of dye liquor and complicated recirculation of edge liquors.
An advanced distribution system considerably reduces color change lengths - whereas with traditional systems, about 2 to 5 running meters are customary in practical operation, depending on pile weight. For example, the length of loss for a pump capacity of about 300 liters per minute and a production speed of 20 meters per minute is reduced to about 30 centimeters, because of the small liquor quantity in the liquor head - approximately 3.5 liters for a working width of 4,600 millimeters (mm).
Figure 1: A schematic of Fleissner’s dye liquor application unit shows the design and basic functions of the machine.
Dye Liquor Head
The dye liquor head with small liquor contents - about 4 liters for a working width of 5,200 mm, or 3.5 liters for a working width of 4,600 mm - is suspended in four linear guiding units.
The dye liquor head consists of the stainless steel overflow edge and the distribution plates made of high-tech synthetic material that is resistant to chemicals.
The hose connections in the dye liquor head are spaced 40 mm apart. A further reduced distance between the exit bores in the distribution plates ensure uniform dye liquor distribution. Each exit bore ends in a diffuser. The diffusers form a distributing comb.
Here the dye liquor flow is spread in such a way that a closed and highly regular dye liquor film is formed over the width of the overflow plate.
For Dye Liquor Head And Carpet
In order to keep the dye liquor head and carpet always exactly aligned with each other, the dye liquor head is traversed with respect to the carpet by a centering control.
The traversing unit consists of a carpet pile detection system with two sensors to the left and right of the carpet length, an electronic signal evaluation unit with software and the positioning motors for the dye liquor head, and two lateral collecting trays for dripping edge liquor.
The sensors provide a control signal to the positioning motor that moves the dye liquor head and to the positioning motors that move the collecting trays.
Mode Of Operation
Figure 1 shows the design and basic functions of the dye liquor applicator. One eccentric screw pump feeds the dye liquor from each liquor tank to a predistributor. Each predistributor is assigned a certain color. Hoses connect the predistributors to the pneumatically controlled multiple-way valve system where the color change is implemented. This computer-controlled valve system opens the pre-selected dye liquor line or switches to the next color. The short hoses between the valve system and the dye liquor head, and the small liquor quantity in the head result in minimum color change lengths. The patented parallel distribution system ensures a constant, uniform and pulsation-free liquor distribution over the entire working width. The dye liquor flows as a regular thin film over the pouring edge onto the carpet.
The dye liquor pouring width is always adapted to the carpet width, controlled by special valves in the predistributor.
Advantages At A Glance
In summary, Fleissner's new dye liquor applicator offers the following advantages:
• uniform application without pole contact to the pouring principle;
• extremely precise application across the entire width and length without dye liquor loss;
• automatic rapid color change without intermediate runners, rinsing and liquor remainders;
• minimum mixing distance for color changes;
• pouring width adjustable in steps of 40 mm each, depending on the tufted width;
• operation with undyed center strip for carpet tiles or automotive goods; and
• automatic adjustment using a programmable logic controller (PLC) to set parameters for color changes.
The PLC allows the dye liquor applicator to be used for the following processes:
• detection and processing of all variables (speed, carpet width, carpet weight per area unit, application quantity and liquor flow);
• automatic control of dye liquor application with digital indication of all entered set points of the current batch;
• automatic rapid color changes; and
• control of valves in the predistributor and digital indication of pouring width.
Editor’s Note: Dipl.-Ing. (FH) Manfred J. Aulbach is a project manager with Fleissner GmbH, Germany.