What is Space Dyeing / Yarn Printing? Space dyeing is a yarn dyeing process that creates multi-colored effects along the length of a single yarn. Space dyeing produces an effect of unorganised design in subsequent fabric form. There are different methods of space dyeing using package dyeing, knit-de-knit, warp printing, hank dyeing, cheese dyeing, etc.
Space dyeing of yarn has been established for many years; previously, the best-known method was the Texinox (UK) system, in which an impregnation head, comprising 40 nozzles, can be connected to any of the four color distributors. The head is situated over a brattice, on which the yarn hanks are loaded traverse to the brattice movement. The brattice passes the hanks under the jet nozzles in the impregnation head, and a four- or five-colored space-dyed effect is achieved.
Space dyeing is a technique used to give yarn a unique, multi-colored effect. While a typical skein of yarn is the same color throughout, a skein of space dyed yarn is two or more different colors that typically repeat themselves throughout the length of the yarn. Space dyed yarn is sometimes referred to as dip dyed yarn. The secret to space dyeing yarn involves the use of a special chemical called a mordant. The purpose of a mordant is to help permanently fix the dye to the yarn after the space dyeing process. Since different colors of dye require different types of mordants, this makes it possible to dye the same skein of yarn many different colors.
Space dyed yarn can be dyed in either coordinating or contrasting shades. Space dyeing yarn in coordinating colors, such as various neutral tones or assorted shades of blue, provides a subtle yet sophisticated look. Space dyed yarn in contrasting shades, such as yarn that is purple, red and blue, offers a funkier feel. Spaced dyed yarn is most commonly used for knitting and crocheting. When space dyed yarn is made to make a knitted or crocheted item, the resulting project features uneven horizontal stripes that produce a collage- like effect. However, the size of the stripes in the finished piece depends on what size of yarn is used. As you might expect, thicker yarn produces thicker stripes. There are various methods of space dyeing on different forms of yarn.
Fig: Space dyed yarn
Space Dyeing is also known as “Yarn printing”. Although the printing of yarns for true patterned effects proved very difficult tom control, the random space-dyed effects that can be more readily attained by a variety of yarn-printing methods have continued to be popular. The patent literature abounds with systems for producing colored flecked effects on yarns but the two most successful methods entail either warp printing or color application to a tubular knitted ‘sock’. The essential process sequence begins with dye liquor application, followed by steam fixation, washing-off and drying.
The space dyeing of yarn involves the use of a special chemical called a mordant. The purpose of a mordant is to help permanently fix the dye to the yarn after the space dyeing process. Since different colors of dye require different types of mordents, this makes it possible to dye the same skein of yarn many different colors.
Fig: Space dyed fabric
Space dying can be done in either coordinating or contrasting shades. Space dyeing in coordinating colors, such as various neutral tones or assorted shades of blue, provides a subtle yet sophisticated look. Space dyed yarn in contrasting shades, such as purple, red and blue, offers a funkier feel. Space dyeing yarn allows one to create a multi-colored color-way in a single pot.
Purpose of Space Dyeing of Yarn: The purpose of space dyeing is to ensure special effects of dyeing yarn at different spaces are produced on yarns effectively so that the fabrics produced out of it have delighting and decent fancy effects. Space dyeing should produce yarn with differently dyed with either different colors or with varying shade, which can give a pleasant look to the fabrics may be woven or knitted.
Different Methods of Space Dyeing: Space dyeing can be achieved through various methods, each offering unique outcomes based on how color is applied to the yarn. Here are the most common methods:
Space dyeing in hank or skein form
Space dyeing in package form
Continuous or warp yarn printing
Knit–de-knit process
Space dyeing of cheeses
1. Space dyeing in hank or skein form: Space dyeing can be done on hanks using either single or multi-color spaces along a given length in either a repeat or random pattern. When woven together, patterns can emerge depending on the length and variation of each color block. This type of space dyed yarn is sometimes referred to as dip dyed yarn.
The ready to dye yarn in hank or skein form is mounted on a stand or laid on a suitable surface and then different colors are applied either by brush or by spraying at fixed places to achieve the desired multicolor effect. Depending on the type of substrate and the dyestuffs used, the hanks are then processed for suitable dye fixation followed by finishing. Though this method imparts controlled yarn coloration at specified points and desired length, the process is cumbersome and time consuming and is mainly suitable for short length fabric.
The space dyeing of hanks can be performed in one of two ways:
Multiple strands of yarn sprayed with color at set intervals
Multiple strands of yarn continuously printed using rollers as set intervals
After the color is applied, the dye is fixed in a steam oven and washed off before drying. This technique is used to create design effects in knits. Further processing can include doubling of the yarn. Space dyeing is also carried out when the fiber is in the form of a top or sliver and the effect of the different colors is then spun into the yarn. Similar techniques are also possible on packages of yarns. Other techniques to get the same result are available, such as the knit–de‐knit process.
2. Space dyeing in package form: Depending on the machinery available and the effect desired, the yarn printing in package form is done by two methods
a) Manual operation: Colors are injected by hand at different places in the package using a syringe filled with the dye solution. The skill set developed by the technicians enable them to insert the needle in the package horizontally, vertically or at various angles and release the color while taking the needle out so that the required amount of dye is applied at the specified place in the package. Another variant of this method is dip-stick process. In this case, different places of the yarn package are dipped in different dye solution so that multiple colors get applied at various places and with varying intensity which after unwinding of yarn provides a unique fancy dyed effect.
b) Machine processing: The ready for dyeing yarn is pre-treated as per the standard application process for the specified substrate and dyed in a single package form in a machine which can dye up to eight colors. Each color has a different feed tank as well as injector pump. The color is injected at a fixed place at high pressure and the excess color is collected through vacuum. This creates beautiful patterns of dyed patches on package with good sharpness. Subsequently the colored yarn package is given adequate dye fixation treatment followed by washing off of unfixed superficial dye and finishing with a yarn lubricant/softener.
3. Continuous or warp yarn printing: In warp printing method, a warp sheet passes between pairs of printing rollers. Afterwards, the color is fixed in a dye fixation unit. This operation is a continuous operation just like roller printing. This gives repeat effects. In this process, multiple strands of yarn are continuously printed at spaced intervals with different colors. These yarns usually have long spaces of each color spaced at about 3–7 inches. The yarn is dyed as singles or piled form and the color is applied either by air jets or by dye troughs. Given below are few methods of continuous yarn printing for achieving space dyeing effect based on the information gleaned from various patented processes.
Fig: Schematic diagram of warp printing
Various warp-printing methods have been used over the years. In most present-day systems several ends of carpet yarn are taken from wound packages on a creel and color is applied, either by lick rollers or by some form of spray or spinning disc applicator, to the yarns. The yarns are carried past the print heads in warp form or lying on a brattice on which they have been laid down in a continuous circular or elliptical coil. Warp printing tends to give the so-called ‘long spacing’ designs in the tufted carpet produced from them.
4. Knit–de-knit process: This process involves first knitting the yarn on a circular or flat-bed knitting machine into a tubular fabric followed by printing using engraved rollers and then unravelling the knit to produce a space dyed yarn. As the printed color does not readily penetrate the areas of the yarn where it crosses itself, alternately dyed and undyed spaces appear. In another method, the pre-dyed knitted material is overprinted with different colors and subsequently deknitted to produce contrast effect of overprinted and base dyed areas.
This imparts a unique ‘micro-spaced’ design, owing to the limited dye diffusion during the printing stage. The unravelled printed yarn is rewound onto cones and used for subsequent knitting or carpet weaving. Since this process achieves limited dye penetration into the yarn, as the pressure exerted by the printing rollers is insufficient to insure adequate dye diffusion, incomplete and non-uniform coloration may result. Also, there is a characteristic curl to the unravelled yarn due to pre-knitting which affects cut pile of carpets.
5. Space dyeing of cheeses: Space dyeing of cheeses is a process used in the textile industry to apply multiple colors to yarn wound on a cone, creating a multicolored effect. The yarn is first prepared by winding it uniformly onto a cheese and undergoing pre-treatments like scouring or bleaching to ensure better dye absorption. Space dyeing of cheeses is done by using a machine fitted with multiple color tanks and color pipes that are programmable to inject the required color to the cheese.
Space Dyeing Process of Yarn Step by Step: The activities in space dyeing (Cheese dyeing) are as follows:
(i) Selecting the yarns to be dyed depending on the customer needs and/or design needs. Getting them wound on soft packages as per requirement. The diameter of the soft package is very important; the package should be tightly held by the package holder. Hence, there is no tolerance for diameter in the negative side.
(ii) Selecting the dyes and the blank bath recipe to be used for dyeing. Following is an example of blank recipe for Polyester filament dyeing:
(iii) Preparing the blank recipe: Take one mug of water of around 2 liters. Put 8 Kg of printing paste while stirring. After completing the printing paste, add PBI, HTS, Acetic Acid, PESI and WS in the same sequence. Keep stirring for minimum 10 minutes.
(iv) Deciding whether coordinating or contrasting shades are to be developed.
(v) Deciding the color recipe by referring to shades that are to be developed along with the proportion of blank bath to be used.
(vi) Prepare dye recipe as per the recommendation of dye stuff manufacturers depending on the class of dye being used. Alternately, if the same combination has worked earlier, take the reference from that.
(vii) Select the sequence of colors and put the liquor in respective tanks.
(viii) Set the parameters on the machine:
51 seconds per package for operation,
Vacuum at 700 mm,
Quantity of dye to be fed per injection pick up.
Timing for vacuum 1st – 25 to 29sec and 2nd – 45 to 55 sec.
Pick up 65% for warp 46% for bright tolerance ± 2%.
(ix) Mounting the dye package in the machine and closing the lid.
(x) After mounting the package on the spindle, put the switch ON. The upper die (Cap) shall close first and then the outer die shall close and hold the package. The process shall start. After the set time, the package holder will open out followed by the cap. Remove the dyed cheese and feed the next one.
(xi) After the operation in the space dyeing machine, do the curing.
(xii) Load dyed yarn packages in the Ageing machine. Do the activities as follows (example):
Loading 10 minutes approximate.
While loading the cheeses, put brown craft paper on the top of each layer of cheeses.
Heat and maintain 125˚C
20 min for light shades,
30 min for medium shades,
35 min for dark shades.
Cooling 20 minutes approximate.
Reverse the package. Put fresh brown paper, Approximately 10 minutes.
Heat at 135˚C for
65 minutes for light shades,
70 Minutes for medium shades,
80 Minutes for dark shades.
Cooling for 20 minutes approximate.
Remove the cones – 10 minutes approximate.
Keep steam pressure of 2 Kg/sq. cm. (35lbs/sq.in)
(xiii) After ageing is over, close the steam valve and wait till the machine becomes cool.
(xiv) Remove the top lid and allow the steam to go out.
(xv) After all steam has gone out, remove the cheeses.
(xvi) Give the cheeses for hydro extraction.
(xvii) After hydro extraction, send the cheeses for final hard winding.
Advantages of Space Dyeing: Space dyeing offers numerous advantages, particularly in its ability to create visually appealing, multicolored effects that add depth and texture to yarns. The advantage of the space dyeing process over conventional solid dyeing lies not only in achieving unique multicolor effects but also in its environmental and economic benefits. It significantly reduces the consumption of dyestuffs and chemicals, eliminates the need for printing thickeners, and minimizes effluent generation, contributing to a more sustainable production process. It eliminates the need for additional printing on finished fabrics, saving time and reducing costs.
Disadvantages of Space Dyeing: While space dyeing offers numerous advantages, it also has some disadvantages and challenges that must be addressed. The process is complex, requiring precise control to prevent color mixing or overlapping, which can result in visible streaks on the fabric surface, thereby affecting its appearance.
Another issue with space dyeing is the tendency for dye migration during subsequent heat-setting operations, which can cause blurring of adjacent color bands and negatively affect the appearance of the final product. Additionally, dye dripping or contact marking between different yarn layers can result in unwanted patches that compromise fabric quality.
Despite these disadvantages, advancements in technology and process control have helped mitigate many of these challenges, allowing space dyeing to remain a valuable technique in textile manufacturing.
Conclusion: Space dyeing is a versatile and creative textile dyeing process that offers unique multi-colored effects, customization, and environmental benefits compared to conventional dyeing techniques. When woven or knitted together for apparel, home furnishing and carpet making, beautiful patterns can emerge depending on the length and variation of each color block. By utilizing adequate dyes, auxiliary chemicals, and advanced machinery, space-dyed products can achieve exceptional quality and design. Although the space dyeing segment currently holds a small share (<1%) in the textile coloration industry, its potential for producing unique and customizable designs positions it for significant growth in the future as demand for innovative textile solutions increases.
References:
[1] Mahapatra, N. N. (2018). Textile dyeing. Woodhead Publishing.
[2] Miles, L. W. C. (2003b). Textile printing. Amer Assn of Textile.
[3] Purushothama, B. (2016b). Handbook on fabric Manufacturing: Grey Fabrics: Preparation, Weaving to Marketing. Woodhead Publishing India in T.
[4] Lewis, D. M., & Rippon, J. A. (2013). The coloration of wool and other keratin fibres. John Wiley & Sons.
[5] Wardman, R. H. (2017). An introduction to textile coloration: Principles and Practice. John Wiley & Sons.
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
