The silk fiber derived from the silk worm is still popular with consumers even with the introduction of polyester look alike. Consumers enjoy the feel and look of silk compared to synthetics. Silk has been woven into at least 200 fabrics with different names and look. The look differs from the type of filament produced by the silk worm, the weave and blend with other fibers. Most of the silk produced is made to withstand a professional wetcleaning process. Some of the names associated with silk weave are shantung, pongee, tussah, jacquard and crepe de chine.
SILKS THAT CANNOT BE WETCLEANED
There are a few silks that cannot be wetcleaned. These are:
- those with a fugitive dye, A poor dye can easily be tested by pacing a towel under the silk and flushing with the steam gun. Note how easily the dye transfers to the towel.
- silk velvet-the pile easily distorts with water and cannot be restored.
- Bias cut silk chiffon -this fabric contains a sizing that dissolves in water, causing shrinkage and distortion.
WETCLEANING PROCEDURE
The new state of the art wetcleaning equipment, new detergent and finishing equipment makes wetcleaning silk easy and with a very good result. It is important to know how to pre-spot silk as the different chemicals may not be compatible with different detergent and softening agents used.
CATIONIC DETERGENTS
These detergents are the best for wetcleaning silk fabrics. It carries a positive ionic surfactant. It tends to remain with the silk fabric, even after rinsing, giving the silk a soft feel and hand. It is also compatible with cationic softening agent which I use in the rinse cycle. When using this detergent it is also important to use compatible spotting and pre-spotting products. Some spotting agents such as neutral lubricant, spray spotter, tannin and protein formulas may not be compatible with this detergent. These spotting agents may break down, causing rings and swales. The detergent is chemically neutral or slightly acid. They contain enzymes and brightening agents.
FABRICS THAT MAY POSE PROBLEMS WITH CATIONIC DETERGENTS
- Glued on beading and trimming-the glue will soften, causing separation of the trimming.
- Pigment or surface print-the adhesive binder can soften causing loss of the print.
- Plastic trimming-the plastic can soften, peel and pucker.
ANIONIC DETERGENTS
This detergent has a negative ionic surfactant charge. These detergents clean and rinse well but do not give the silk as softer feel as cationic detergent. They are also not compatible with cationic softening agents. They are used in many wetcleaning systems for processing silk but the cationic systems work far better.
NONIONIC DETERGENTS
These detergents do not carry an ionic charge. They are compatible with all detergents and softening agents. They do tend to give the silk a soft feel when used in wetcleaning. Their primary purpose is to remove greasy soil, oils. Wax and grease.
SOFTENING AGENTS
There are many different softening agents ranging from cationic, silicone, anionic and nonionic. The best softening agent for silk is the cationic type with a positive ionic charge. They are compatible with cationic and nonionic detergents but cannot be used with anionic detergents. The positive ionic charge neutralizes static electricity and gives the fiber more hand and feel.
WETCLEANING FORMULATION FOR A CATIONIC DETERGENT SYSTEM
- Fill the washer wheel with warm water, 90~100°F.
- Stop the wheel and inject cationic detergent. Do not inject directly on the garments and if possible inject from the bottom.
- Agitate slowly.15 seconds on, 45 seconds off for 8 minutes.
- Drain
- Extract at low speed
- Fill again, gentle agitation, same speed, same temperature.
- Add softener 1~2 ounces per 10 pounds
- Agitate 4 minutes. 15 seconds on, 45 seconds off.
- Drain
- Extract to desired water retention.
It must be remembered that all spotting and pre-spotting must be done with cationic detergent or nonionic detergent and these formulations can be effectively made up into tannin or protein formulas.
ADDING CHEMICALS TO THE CATIONIC FORMULATION
If the silk load is heavily soiled nonionic detergent can be added which would increase the removal of greasy soil. For removing soil and oxidation a hydrogen peroxide and nonionic surfactant can be added to the wash load.
SPECIAL PRECAUTIONS WHEN SPOTTING SILK FABRICS
- Use a padded spotting brush or wrap a towel around a bristle brush.
- Keep steam gun a safe distance from fabric. High heat and pressure set stains and chaffed the fabric.
- Try to spot silk satin on the reserve side. The delicate floating yarns shift and damage easily.
- Ribbed silk fabrics such as silk faille should be brushed against the ribs.
CHEMICALS TO USE IN A CATIONIC WETCLEANING SYSTEM
The following chemicals are used to prevent rings caused by a breakdown of cationic detergents mixed with anionic detergents.
- Use glycerin or a nonionic lubricant for general spotting.
- Use a nonionic tannin formula or glycerin with acetic acid.
- Use a nonionic protein formula with enzymes.
- Use hydrogen peroxide without ammonia for oxidized stains.
