Wednesday, July 28, 2010

Heat Sensitive Thermochromic dyes on Garments - a special effect!

Thermochromic colors:
Color changing inks were introduced during the 1970s with novelty items such as cups that change color when not liquids such as coffee or tea are poured in to them.
Color changes of thermo chromic pigments are induced by a temperature change. When temperature rises to a specific temperature, the color changes. The color starts fading back to the original color as the pigment is cooled down. 

Application of thermo chromic color on garment:
There are fifteen thermo chromic colors like Americos Red, Magenta, Vermilion, Orange, Yellow, Yellow Green, Charm Green, Sky Blue, Turq Blue, Dark Blue, Violet, and Black. The temperature interval available from 0OC to 70OC. Specific demand can be set up for different temperature intervals from 2OC to 10OC.

By using the above colors another color can be obtained but use different colors of thermo chromic pigments with the same temperature range to create more colors. Regular pigments can also be mixed with thermo chromic pigment so that the color can be changed from one to another. At lower temperature, the color reveals matched shade. When the temperature is increased, the thermo chromic pigments start fading to colorless. It only shows color of the regular pigments. By mixing the thermo chromic pigments with different temperature ranges, the color can be varied for more than two colors like temperature ranges for 3 color variation.
These t-shirts and other garments can change color by wearing or touching them. The heat from your body, hand or the environment makes this clothing change color. Once cooled the fabric changes back to the original color.

Sun Fading dyes and special effect garments

SUN FADING  - Photochrmic dyes on garments

Photo chromic color changes from clear when indoors to color when taken out-doors. The phenomenon produced in Photo chromic materials is called photochromism, where the change in color is due to incident light. Specifically, they exhibit color in response to exposure to sunlight or other source of UV radiation. UV light changes the chemical structure of the photo chromic material and makes it absorb color like a dye. It then reverts to a clear state when the UV source is removed.

However, to date, photochromism is most important for optical switching data and imaging systems, rather than in textile applications.

Application of photo chromic colors on garment:
Now  photo chromic colors are plastisol based ready to use off-white liquid are available in the market. When exposed to UV radiation, color appears. These colors are available in various hues.

Photo chromic colors can be applied on garment by three methods:
•    Spray
•    Brush
•    Screen Print
In all the above methods, photo chromic colors are directly applied on garment and cured at 1500C for 30-90 seconds.

These t-shirts and other garments can change color by wearing or touching them. The heat from your body, hand or the environment makes this clothing change color. Once cooled the fabric changes back to the original color.

The ghost printed  t-shirts have color changing screen prints when exposed to sunlight. The screen print appears as a black and white image with color highlights when indoors but once you go outside into the sun it appears in full color.

Teflon Treated Garments - stain resistant

Denim Treated with Teflon

Cotton is the most highly demanded fiber on the planet and is prized for its absorbent qualities, comfort, ease of wear, and versatility. Although a popular choice for many differing articles of clothing, there is one problem with the versatile fabric, it is extremely prone to soiling. Everything from chocolate to oil to red wine instantly stains the fabrics made from this fiber and are sometimes tricky to remove. This is where Teflon comes in to save the day. Teflon is part of advanced stain repellent technology that provides excellent protection against liquid spills and stains.

Teflon, also known as Polytetrafluoroethyhlene, was discovered in 1938 by the DuPont Company in their Jackson laboratory and is at the forefront of stain resistant innovations. The technology of Teflon is simple. The molecular make-up of chemicals binds around the individual cotton fibers instantly repelling oil and water based stains and releasing ground in dirt and natural stains during the laundering process. The molecules that make up Teflon are hydrophilic or water loving and they attract water and detergent into the fabric, liberating the stains into the wash leaving the fabric looking bright and clean. This new technology for repelling stains uses "nano-whiskers" that are adhered to the individual fibers and cause liquids to bead or roll off of the surface of the fabric. The stain does not adhere with the fibers and therefore soiling is minimal (Kadolph, 369). It is quite remarkable and clearly the best stain repellent out there.

Teflon creates a completely stain-resistant fabric that still has the natural drape, color, or breathability of similar untreated fabrics and that is something that people are willing to pay for. Denim is the perfect fabric for Teflon treatment because of its diverse market of consumers, versatile end uses, and the wide range of environmental factors that it is exposed to every day. It needs to be wearable, functional, and long lasting; all characteristics that are enhanced by Teflon treatments. Denim may be used for a tablecloth, a pair of jeans, or even a backpack and although each of these products requires different things from a fabric; they all need to be stain resistant. Cotton and Teflon are a perfect blend of style and function for daily life due to their combined ease of wear, soft hand, versatility, stain resistance, and breathability.

Sanded Finish of Denim Garment

Sanded Denim - fashion of the day!
A sanded finish for denim is achieved through a combination of pumice stones, enzymes and sand; used to create the illusion of aged denim jeans. Although the purpose of this is generally for aesthetics, this process also loosens the fibers in the denim, making the denim fit more comfortably and move more easily. Sanding jeans creates an uneven, worn look, which is ideal for daily casual wear, and also for pairing with solid colors or denim jackets . However, it is very labor intensive to sand finish denim, therefore a pair of jeans that has been sand finished will usually be slightly more expensive than one that has not . It is a necessity to finish denim in order to get a final soft touch. 

Most denims are enzyme washed or stonewashed for an overall softness, however, it is essential to sand-wash, or sandblast, for a more strategically placed worn and frayed finish . The picture on the next page displays what a sand-finished pair of jeans looks like. 

There are many types of finishes for jeans, and sand finishing is just one of the many ways to make denim more aesthetically pleasing the eye. This type of finish became popular around the 1980's, and is still a huge trend today because of it's ability to make jeans look and feel more versatile. Although there are many ways to go about finishing jeans, sanded finishes continue to prove to be a popular choice among consumers throughout the years

Garment Enzyme Washing Procedure

Stones are not only  abrasive to garments but also to the equipment.
Stones can create sludge in waste treatment systems.

Cellulase enzyme is a particular strain of enzyme derived from microorganisms  selective to cotton form of  cellulose and not to starch.  They attack 1  - 4 beta glucoside linkages resulting in reduced molecular weight and therefore removal of surface fiber.

Main factors  that control enzyme washing:
1  -  pH
2- temperature
3- time
4 -  concentration
5 - mechanical action

Once the reaction takes place, the mechanical action between garments and
equipment as well as between garments femoves weaker fibers resulting a cleaner,
smoother surface.  Stones may be added to enhance the abrasion.


Load garments (addition of  stones optional)
Desize for starch
-  alpha-amalase enzyme or
-  oxidative desize


Adjust pH to 4.5 - 5.0 with
-  acetic acid or  a buffer system

Heat to 50 to 60 C ( 122  - 140  F)

Add cellulase enzyme
Tumble for 30 - 60 minutes

*Deactivation step   -  rinse hot  >  65° C

Rinse cold

Soften and/or optically brighten

Tumble dry

*Deactivation of  the cellulase enzyme to prevent further weight reduction
can be done by temperatures in excess of  60 C (140 F)  and/or at a pH
higher than 5.0.

Cellulase enzymes may be used as an aftertreatment to clean up surfaces of garments which have become fuzzy during garment dyeing.  The shade of  the dyed garments may change which requires preliminary lab work to determine if this will be a problem or not.

Acid Washing of Denim Garments - an over view!

Acid wash is also considered to produce an worn-out effect that is harsher than stone wash. This treatment is mainly being carried out on denim and coarser varieties of garments.

  • Acid wash is also known as  Ice wash, Snow Wash and White wash.
  • In acid wash a complete discharge or removal of  color possible
  • Uses pumice rocks,  bleaching agents and dyestuffs that are sensitive to the bleaching agents.
  • Porous rocks that have a medium to high dusting capability are soaked in solutions of bleaching agents such as sodium hypochlorite or  potassium permanganate.  The chemical is absorbed and is transferred by  the cutting action of the rocks and deposited with the dust onto the garment surfaces.
Some more points a garment washer should take care of during acid wash:

-  Rocks must have ability to
  • absorb chemistry in less  than 2 hours
  • dust easily
  • apply dust evenly on smooth surfaces and on high peaks of garment such
  • around cuffs, waist band, fly, side seams, etc. and not in recessed spaces
  • in those same areas.
-  Load size in pounds of garments should only be 25 -  33% of  rated capacity to allow for free  tumbling of  the garments and stones and for proper drop distance. 
-  Ratio of  the weight of  the stones to the garments should be
                                    0.5 : 1  for a light wash out
                                      3  : 1 for a complete white out

Procedure for Acid Washing:
1) Load  (25 - 33% rated capacity)
2)  Desize for starch with alpha-amalase enzyme or oxidative desize
3)  Rinse
4)  Extract to a certain uniform moisture
                 60 - 70% light frost
                 70 - 90% medium frost
                 90 - 100%  heavy frost (white-out)
5) Add presoaked stones (machine should be dry)  with ratio dependent 
6) Tumble  for 10  - 30 minutes
7)  Remove garments
8) Neutralize
9)  Soften and/or brighten upon desired effect (0.5-3.0 :  1,  stones to garments)
10) Tumble dry 

Some more points about Acid Washing:
  • Stones should be allowed to drip or blotted with waste fabric  to remove
    excess solution to prevent spotting.  Stones can be used up to three times
    in some cases before resoaking is necessary.
  • Neutralization usually takes place in another machine and the exact proced
    ure is dependent on the discharge agent used.
    Potassium permanganate (KMnO  and  purple in  solution )  converts
    to manganese dioxide (MnO  which is orange-brown in color)
    which must be neutralized with sodium bisulfite or  hydroxylamine
    sulfate ((NH  OH)  H SO  ).

Simple Garment Stone Washing Procedure

This is just a process to abrade the surface of the garments randomly with the help of stones to get different worn-out effects, especially used on denim garments. According to the required severity of effect, the size, amount of stones and the duration of process would change.

Stones Type:
  • pumice rock
  • volcanic rock
  • man-made substrates 
Property of Stones:
    • Hardness of stones
    • Size of stones
    • Shape of stones
    • Porosity of stones
    • Dusting ability of stones
    • large, hard stones which last longer for heavy fabrics
    • smaller, softer stones for lightweight and more delicate fabrics
    • ratio of stone weight to fabric weight = 021 up to 3:l
    1- Load garments and stones ( load to 30-50% of normal machine capacity)
    2- Desize if needed with
    - detergent plus enzyme for starch
    - oxidative desize
    3- Rinse
    4- Stone wash (with or without bleaching agent)
    5- Rinse
    6- Soften
    7- Extract
    8- Unload garments, remove stones from garments
    9- Tumbledry
    a- Backstaining or color deposition can be reduced by a- adding dispersantlsuspension agent to wash cycle
    b- intermediate replacement of wash liquor
    c. use of alkaline detergent (sodium perborate with optical brightener
    as an afterwash

    Tuesday, July 27, 2010

    Facinating Rust Dyeing of Garments!

    What Is Rust Dyeing?
    Rust dyeing is an easy, fascinating way to dye fabric. You can dye wonderful imprints on cotton, silk, wool or even synthetic fibers using rusty “stuff.”

    You can dye:                                             
    •    Cotton quilting fabric
    •    Silk scarves and shawls
    •    Flannel fabric for sewing

    What Is Rust and does it rust?
    Rust is the common word for several naturally occurring iron oxides. These iron oxides are formed by the corrosion of iron or steel; this corrosion happens when iron is exposed to oxygen and water.

    Rust will permanently dye a variety of fabrics, and can even dye other materials such as leather and paper. The resulting fabric is completely colorfast, washable and totally unique.

    How Does It Work?
    The rust-dyeing process is extremely simple.  When a rusty object is in contact with fabric, fiber or paper, it leaves an imprint. We place our rusty items on our fabric, wet it with water and vinegar to hasten the oxidization (rusting) process, and leave the fabric and rusty item together until we are satisfied with the color or pattern. Then we remove the item, wash the fabric and use it however we choose! The whole process takes only a few days and requires little effort.

    What do you need?
    Only a few simple items are needed for rust dyeing. To begin dyeing, you should assemble:
    •    Fabric
    •    Plastic kitchen gloves
    •    Spray bottle filled with a mixture of 50 percent water and 50 percent vinegar
    •    Plastic bags or wrap (optional)
    •    Plastic bin, box or tray
    •    Rusty items or steel wool pads (new ones are fine)

    You can found that cotton and silk are the best fabrics for dyeing, but you can experiment with cotton blends. Even some synthetic fibers will dye well; you can experiment to find out which ones. Wool fabric will take dye, but the rust tends to color it a bit harshly; a wool/cotton blend can be a better choice, if that works for your project.

    Find, buy or assemble a collection of rusty items. Wire, nails, bolts, tools, sprockets, pans, cooking items, irons, tractor or car parts, chain, hinges… the list is endless! And once you begin rust dyeing, you’ll be scouting garage sales, thrift stores, antiques shops and auctions for uniquely-shaped or –patterned rusty items. You can also use brand-new or used (but clean) steel wool pads. You can use these items over, and over, and over again.

    You can even rust non-rusty iron items. I found a bike sprocket that was in pristine condition, but I wanted it to rust! I put it outside in a shallow pan with a bit of salt, water, and vinegar, and in a few weeks, it was fabulously rusty and ready for dyeing.

    Some more points to consider:

    You can use white cloth for the purest rust colors and clearest designs, but don’t be afraid to experiment with colored or even patterned fabrics. Scraps of sewing or quilting fabrics in assorted colors are wonderful for rust dyeing; you can achieve batik-like effects and wonderful color shifts by over dyeing colored fabrics.

    Look for neutral-colored natural fiber shirts, t-shirts, skirts, tablecloths, or fabric scraps at garage sales or thrift stores. These can be turned into one-of-a-kind designer works of art with the application of a little rust.

    Follow these steps:
    •    Assemble your items on a workspace.
    •    You may want to cover your table or bench with plastic bags or wrap.
    •    Rust will also dye your clothes, so wear old clothes that you don’t mind staining.
    •    Always wear gloves (kitchen gloves are perfect) when handling rusty items. It’s safer, cleaner, and protects your hands from both discoloration and scrapes or scratches.

    If you want specific imprints from your rusty items:
    •    Lay your fabric flat in a plastic box or tray.
    •    Lightly spray your fabric with the vinegar/water mixture.
    •    Place your rusty items on the fabric in any pattern you like.
    •    Place another piece of fabric on top.

    Keep your fabric slightly moist for the next few days; this will help the rust designs to develop. (Tip: Weight down the fabric with small items such as rocks or bottles if you want to make your imprint clearer.)

    You can lay a plastic bag or sheet lightly over the fabric, but you also want to make sure air can reach the fabric as well. Oxygen is necessary for the rust to develop.

    My favorite way to rust-dye is to leave the items outside, uncovered, for a few rainy or humid days!

    Here are some more dyeing options:
    •    Roll or wrap your fabric around rusty items; if you have a rusty pot or kettle, you can wad the fabric up and stuff it inside the pot or kettle.
    •    If you’re using steel wool, unroll it and wrap or fold it into your fabric, or cut it into strips, pieces or bits, and place or sprinkle them onto your fabric.
    •    you can even bundle rusty chain, wire, nails and other small items willy-nilly into fabric, and put it all in a plastic bucket or bag for fantastic results.

    The important thing is to make sure that the rusty items are in contact with the fabric—that’s how the dyeing occurs. This process can be as planned or as random as you like. And you cannot fail – if you don’t like your results, you can simply dye your fabric again with more rusty items.

    Length of the Dyeing Process
    Check your fabric once a day or so; make sure it’s damp, and see how the color is developing.

    For light colors, you may only want to leave your dyeing project for one day.

    For very dark intense color, you might leave it for 4 or 5 days.

    If left too long, the rust can eventually damage the fabric, especially if it is thin or delicate (I’ve left silk too long and it developed holes). However, if you check your fabric every day or so, you should not have any problems.

    Rust dyeing is most suitable during summer, as the rusting takes place more quickly than at other times.

    Rust dyeing does damage the integrity of fabrics slightly; however, I have found my rust-dyed fabrics perfectly suitable for crafting, wearing, quilting and sewing. Items with very strong or dark rust-dye will be more difficult to sew, simply because your needle will dull quickly.

    Finishing Your Dyeing Process

    When you are satisfied with the color and patterning of your fabric, remove the rusty items and keep them for use in your next project.

    Next, immerse the fabric in a light saline solution; this completely stops the rusting process and neutralizes the fabric. For the solution, I use about one tablespoon of salt in a gallon of water.

    Then wash the fabric as normal – if it’s silk or wool, hand wash with Nunonwet-con 0.5 gpl liquid and rinse thoroughly. If it’s a cotton or synthetic, you may machine wash and dry as normal.

    Fancy effects on garments - some tips on T-Shirt dyeing

    The best method for tie-dye!

    Generally tie-dye is a method of dyeing in which the fabric is tied securely as per the design requirement, to prevent the dye to reach the tied portion. People used to fold, twist, stitch, crumple and knot to inhibit the flow of dye. Presently all folding, twisting, knotting etc., is done starting with a wet garment spread flat on a plastic sheet covered table. The pattern of the folds etc. and where the colors are squirted dictates the resulting design. With experience, the end result can be predicted and controlled to some extent, but surprise is part of what makes tie-dye an exciting and interesting art form - and there will be plenty of surprise.

    1. Fold and/or tie the fabric into the desired patterns. The designs will be more defined if you wet the shirt and squeeze or spin out excess water before folding.
    2. Wear your dust mask and dissolve 250 grams of Soda Ash Fixer per 4 liters of warm water. Soak the tied garments about 5-15 minutes (until saturated). Reuse solution until gone. Squeeze out excess so garment is just damp, not dripping.
    3. Using your dust mask and gloves, combine water with all chemicals except dye. Add liquid to dye gradually, pasting up to avoid lumps. Apply dye with squeeze bottles, paint brushes, sponges, etc., as many colors as you want. Easiest to use a funnel to pour dissolved dye into squeeze bottles.
    4. Put fabric (still tied) in a plastic bag (the idea is to keep it wet and chemically active - any method of keeping it wet is O.K.) and let sit for at least 4 hours but preferably 24 hours to "cure". Shorter times work better in summer, and longer times are needed when it is cold.
    5. Remove from bag and while still tied, rinse off the excess dye under cold running water (faucet, hose or shower), then rinse in warmer water while you untie and after garments are untied, until water runs fairly clear. Have your washing machine pre-filled with hot water with Nunonwet-con and throw in the clothing as soon as it is rinsed, running it through a full cycle.
     Some more tips on tie-dyeing:
    Dye shirt a solid color first using Tub Dyeing Method, then tie-dye using above method.
    • After step 4, untie and re-tie in contrasting pattern.
    • After tie-dyeing item, re-tie and use Discharge paste to bleach out a contrasting pattern.
    • Sprinkle pure Cotfix Vinylsulphone dye powder onto tied and pre-soaked item for different effect (super intense color. Use a salt shaker with lots of salt and some dye for a lighter application)
    • Put a small amount of Sodium Alginate thickener into dye mixture (step 3) to slow down the rate that the dye spreads and to create sharper edges.
    In step 4 any method keeping the fabric wet is OK, needn't be a plastic bag - cover many with plastic drop cloth, wrap in plastic wrap, etc.
    • The warmer the temperature where you lay out your tie-dyes to cure, the quicker the chemical reaction.
    • Use Water Softener if you suspect you have "hard" water.
    • DON’T USE HOT WATER. The dyes work best in warm water (60°C).
    • Urea helps dye to dissolve, so dissolve the Urea in water first. Add this water to the dye powder gradually and paste it up to avoid lumps. Un-dissolved dye makes "explosions" of color or "freckles", so if a color is difficult to dissolve, straining through some light fabric might be necessary. Coffee filters only work if the dye is really liquid. Otherwise, they filter out too much of the dye.
    • If you have trouble making a paste of the colors, a little Calsolene Oil can help because it breaks the surface tension.