National Clothesline

here is a great misunderstanding about handling rayon which accounts for the large number of problem garments sent to my analysis laboratory. Many cleaners can not understand why sometimes rayon shrinks when wetcleaned and other times it does not shrink.

Rayon is the oldest of the

man made fibers and is the most widely used. Rayon is a synthetic fiber made from cellulose obtained from wood pulp and cotton linter and has most of the characteristics of cotton. Rayon does not have the heat sensitivity of acetate, polyester, acrylic and nylon. There are several major types of rayon produced today.

Regular rayon. The term viscose is often applied to regular rayon. The distinguishing property of regular rayon is the weakness of the yarn when it is wet. Regular rayon is often sized to stabilize the yarn. Contact with water can weaken the yarn as much as 80 percent and produce shrinkage as high as 10 percent. When rayon dries it regains its strength, but shrinkage may be permanent.

High wet modulus(HWM) is a modified rayon that has the same properties as regular rayon plus high wet strength. HWM rayons usually can be wetcleaned and tumbled dry with a performance similar to cotton. Terms used to describe HWM rayon include polynosic rayon, high performance rayon (HP) or by the trade names Moldel, Zantral and Avril.

Lyocell. This is a fiber similar to rayon and is also composed of solvent spun cellulose. Lyocell is stronger than other forms of rayon and has shrink resistant properties. Tencel is the trademark for Lyocell fiber.

Rayon can be made into fine fibers (micro fibers) from either regular or HWM rayons. Rayon can be made less than the thickness of regular silk. It can be made to look like silk in sheen, color and hand or to look like linen and cotton. Rayon can be used entirely or blended with other fibers in many weaves, knits and fabrics, including velvet, satin, matte jersey and crepe. Rayon is used in coats, jackets, suits, shirts, dresses and gowns. Rayon is also used in household fabrics.

Fabric problems

Rayon is subject to many problems due to the limitations of sizing used and weakness of the yarn. Most fabric problems occur in viscose or regular rayon.

Sizing limitations. Due to the non-permanency of the sizing, rayon fabrics are subject to loss of luster, loss of sheen and rings. The sizing is removed by moisture used in spotting or drycleaning.

Weave and fiber limitations. Because rayon is extremely weak when wet, the yarn can snap and shift easily from abrasion and mechanical action. This can occur in routine spotting or from customer use in normal wear.

Shrinkage and distortion. The sizing used in manufacture is often used to stabilize rayon that is not pre-shrunk. Loss of sizing causes relaxation of the yarns resulting in permanent shrinkage and distortion. Distortion is readily observed on fabrics with a bias cut construction.

Loss of pleats, fluting, embossing or wrinkled effect. Any garment that is pleated, fluted or wrinkled by the manufacturer for special fabric effects can never be permanent. These special effects can be lost in normal wear, spotting or routine drycleaning.

Inspection

Examine rayon for discolorations due to fading, perspiration, spillage of food and beverages. Check the garment for yarn shifting, especially on the seat and arm areas of the garment.

Drycleaning

Printed and dyed rayons should be tested before drycleaning even if the label says “Dryclean.” Use a towel to blot an unexposed seam with volatile dry solvent. Note color loss and transfer to cloth. Dryclean rayons in a moisture-free load with proper soap addition. Assort rayons into a silk load.

Spotting

Test all chemicals including protein formulas, ammonia, tannin formulas and all acids. Rayon is usually more sensitive to acids than alkali. Do not use oily type paint removers without testing for the safety of the dye first.

Do not use the steam gun too close to the fabric as the heat and pressure can affect the dye. Heat can cause some red and purple rayon fabrics to form a black or blue discolored area. Avoid excess mechanical action when spotting a wet area since regular rayon is extremely weak when wet. Use leveling agents to prevent rings. Dryclean fabric only when spotted area has been allowed to dry.

Wetcleaning

The following rayon fabrics should not be wetcleaned: crepe, matte jersey, velvet, satin, taffeta, chenille, viscose, rayon and acetate.

The following rayon fabrics should be wetcleaned: polynosic or HWM rayon, tencel, lyocell, modal, avril and zantral.

Wetclean rayon classified as a silk using a cationic detergent. Dry for a few minutes until 90 percent dry.

Correcting problems

Discoloration due to sizing. The fogging method is a technique used to remove rings or light areas on viscose rayon. Hold steam gun 4 to 5 inches from fabric and steam affected area until light area blends in. Use air to dry. Do not oversteam the fabric during the fogging procedure.

Blue or black discolored areas. Pre-spot with amyl acetate and dryclean.

Acid color change. Neutralize with alkali or ammonia.

Whitening a rayon fabric. Use sodium perborate or sodium percarbonate or a diluted sodium hypochlorite.

Flattened velvet pile. Steam the fabric, spray lightly with a mist from a water gun and use a velvet brush to raise pile. Some manufacturers sell special brushes for raising the pile of velvet fabrics.

Dan Eisen recently retired as chief garment analyst for the Neighborhood Cleaners Association after 33 years with that organization. He is available for seminars, consultations and independent garment analysis. He also has published a book, “The Art of Spotting,” which is an indexed compilation of articles he wrote for National Clothesline and NCA over the past three decades. He can be reached at (772) 340-0909. His address is 274 NW Toscane Trail, Port St. Lucie, FL 34986. His e-mail address is cleandan@adelphia.net.