• The chief distinguishing characteristic of Type S-7 is its high modulus.
• Available in 125 - 2920 denier.
• Lightweight.
• Withstands heat and abrasion.
• Compatible with wide variety of dyes, including acid, premetalized, direct and disperse.
• Optimized uniformity along the length and from end-to-end.
• Silk-soft hand.
• Resistant to harmful effect of bleaches and dry cleaning solvents.

Competitive Advantages

• Will provide strong but sheer support stockings.
• Low set - very small percentage of stress decay.
• Heat settable - can be heat set at temperatures ranging 375 to 400° F (191 to 205° C) for 30 to 60 seconds, depending on fabric construction.
• Durable - maintains physicals in chlorine and ultraviolet light.
• High performance in covering with a very low breakage rate.

In addition to tubes, cones and beams, it is also available in multiple end knit tape in 840 to 2920 denier on request.

Suitable Applications

• Applications where greater modulus is required than Type S-5 can produce.
• Ergonomic support fabrics where extra support is needed.
• Medical end uses like prescription hose.

End uses

• Sheer Support Pantyhose and Hosiery.
• Comfort Hosiery and Pantyhose.
• Narrow, wide woven and knit elastic fabrics, where combination of power and shorter stretch are required.
• Heavy duty support belts.
• High power narrow fabrics.
• Covered yarns.
• Nonwovens such as baby and adult incontinent diapers.

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 THERMAL PROPERTIES

Recommendations for Molding Fabrics Containing Type S-7

The molding operation is used on knitted fabrics where a sewn seam is undesirable, such as a bra cup application. One must have enough fabric stretch in the wale and course (warp and weft) direction in order to prevent the non-elastic fibers (i.e., nylon or polyester) from cutting and rupturing the spandex fibers as the fabric is stretched during molding.

Ideal Fabric Properties for Molding

Wale stretch 210%, plus or minus 10%

Total fabric stretch 300 to 320% with 95 to 100% minimum.

Molding Temperatures

Commercial molding is normally performed on 8 layers of fabric.

390° F (199° C) - 30 to 45 Sec.

Finishing Chemicals

In preparing fabrics for molding, chemicals which show minimum shade change on exposure to heat should only be used. Soft Acrylic or Polyvinyl acetate thermoplastic resins can be used satisfactorily for hand builders.

Silicone dispersions can be used as softeners or hand modifiers with the resins.

Thermosetting resins based on Melamine or Triazine Formaldehyde condensate discolor and are therefore not recommended.

Dyed fabric to be molded should be dyed with acid type dyes for minimum shade change. Disperse type dyes are not recommended.

Fluorescent whitening agents of the acid-type (Stilbene derivatives) are recommended. Disperse type opticals are more susceptible to shade change.

White fabrics should be finished on the acidic side (pH 5.0) with citric acid for maximum whiteness retention.

Maximum molding depth is 5.0 inches (127 mm).

Recommendations for Heat Setting Fabrics

Heat setting fabrics containing Type S-7 spandex is necessary in order to stress-relax the fabric, set the final fabric width and final fabric weight. If heat setting were not performed, the fabric would shrink to an unacceptable degree during dyeing, and fabric weight would be too heavy. The net effect of heat setting is to re-denier the spandex to a lower denier and produce a more stable fabric.

Type 6'6 Nylon/ Type S-7 spandex 375 to 400° F (191  to 204° C) 15 to 60 Sec.

Type 6 Nylon/Type S-7 spandex 355 to 365° F (179 to 185° C) 15 to 60 Sec.

Temperatures and time depend on fabric weight and construction. Sample trials are recommended.

Recommendations for Steam Autoclaving

Do not use temperatures above 240° F (115° C) or significant tensile loss of Type S-7 spandex will occur. Use steaming cycles of 2 to 4 minutes. Sample trials are recommended.

The process is usually performed on circular knit fabric that is intended for tubular put-up, or for those mills that do not have tenter frame capability. It is performed in an autoclave with steam in a batch operation.

HEAT SETTING ELASTIC FABRICS GUIDELINES

The following is recommended for developing new styles of fabrics.

• Fabrics showing excessive shrinkage as determined in a preliminary test in boiling water. Take a one yard cut and boil it 10 minutes in 0.5% (of fabric weight, O.W.G.) synthetic detergent and rinse, then air dry flat at 180°F (82° C). Measure the maximum hand stretch. Use a greige fabric.
• Knit structures containing a high percentage of RadiciSpandex.
• Woven structures in which the desired finish width is close to the reed width.
• Fabrics with a high stretch potential that require low stretch in the finished state, such as ski pants.
• When the desired finished width is greater than the greige or jammed width or when a greater fabric yield is desired. When the off-loom width is greater than the finished width, use a hot wet pretreatment to reduce the width to manageable dimensions for heat setting.
• Heat setting is designed to be less than 100% efficient.

or for example:

52 Inches, Divided By 57 Inches, x 100 = 91% Heat setting Efficiency

If the desired finished width is 55 inches, the width at which the fabric should be heat-set can be adjusted accordingly.  For example:

100, Divided By % Heat setting Efficiency, x (Desired finished width) = Heat setting width

or for example:

100 Divided By 91 x 55 inches = 60 inches

CHEMICAL RESISTANCE PROPERTIES

Type S-7 spandex fibers are resistant to:

• Mineral Oil
• Fatty Acids
• Waxes
• Dry Cleaning Solvents
• Suntan Oils
• Cosmetic Lotions
• Body Oils and Perspiration
• Coning, Needle Oil and Lubricants, except those having Glycols or Glycerine as main ingredients Household Detergents and Bleaches

Type S-7 Spandex Fibers Are Affected By:

• Oils, based on Glycols and Glycerols
• Sodium Chlorite Bleaches
• Peracetic Acid, Formic Acid, Oxalic Acid
• Caustic Soda
• Wet processing pH limits lower than 4.0 (acidic) and higher than 10.0 (alkaline). pH limits should be kept between 4.0 and 10.0, especially at elevated dyeing temperatures.
• Dye carriers based on phenol
• Damp/wet storage and high humidity storage

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Hydrolysis of Spandex Fiber

Hydrolysis can be defined as the chemical breaking of the polymer backbone of the spandex fiber. There are three caused of hydrolysis:

• Strong acids of alkalis will cause hydrolysis damage of spandex.
• Strong caustic conditions will cause hydrolysis.
• Prolonged exposure of spandex fiber to high humidity and high temperatures.

Four our Type S5 and S7 spandex, we recommend processing fabrics containing these fibers at no lower a pH and at no higher pH of 10. Also, we would recommend that damp fabric be dried completely as soon as possible after dyeing and finishing or wet processing operations and preferably within 24 hours of being damp or wet.

Also greige goods and finished goods should be stored in moisture proof plastic bags that do not contain BHT type anti-oxidants if the goods are to be stored in high humidity conditions for any length of time. These procedures should significantly reduce or eliminate the hydrolysis damage of spandex.

RADICISPANDEX Corporation’s Technical Customer Service staff will evaluate any product for its effect on RadiciSpandex fibers at customer’s request. Inquiries are most welcome.

DYEING CHARACTERISTICS AND

Type S-7 spandex has excellent dyeability with acid type dyes. When used with nylon fibers, fabrics will have little, if any, "grin-through" of the spandex when the fabric is stretched. This unique feature of Type S-7 yields fabrics of good union shades.

Type S-7 spandex has affinity for the following classes of dyestuffs:

• Acid
• Neutral Acid
• Pre-metallized
• Chrome
• Disperse

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Type S-7 exhibits poor affinity for dyes substantive to cellulosic fibers. Direct, Fiber Reactive, Vat and Sulfur dyes should be first screened for dye or staining effects depending on fabric construction.

Tensions must be kept at a minimum in dyeing and finishing to preserve the inherent elastic fabric properties of spandex, Processing temperatures should also be kept as low as possible consistent with producing quality elastic fabrics.

Disperse Dyeing Polyester/Type S-7 Spandex Fabrics

Recommended dyeing temperature is no higher than 225° F (107° C) for lengthy dye cycles. Temperatures above this may lead to a loss in fabric modulus or power. The customer should run production trials if temperatures above 225° F (107° C) are being used. RADICISPANDEX Corporation will not be held responsible for damaged fabric if dyeing temperatures above 225° F (107° C) are being used.

GAS FADE INHIBITORS

Type S-7 spandex has excellent resistance to gas fading.  This resistance is achieved by means of an additive introduced in the polymer spinning solution.  This is a permanent part of the spandex and will not be extracted by yarn and fabric processing.  In addition to the built in gas fade resistance, available are gas fade inhibitors P-116 for lace fabrics and Inhibitor 100 for narrow fabrics.  These have been developed for white and pastel shades.

P-116 INHIBITOR FOR RASCHEL - LACE FABRICS

P-116 Inhibitor is a textile chemical developed by RADICISPANDEX Corporation for use on fabrics containing Type S-7 spandex fibers.

P-116 Inhibitor is a white powder and is compatible with other textile chemicals such as optical whiteners, wetting agents, surfactants and reducing agents. P-116 Inhibitor is applied from an exhaust bath with the optical whitener. No changes in exhaust procedures are required. P-116 is wetted out and made into a paste with normal wetting agents or surfactants and added to the optical whitening bath. Bath temperature is raised to normal operating temperature and run for 30 - 60 minutes, letting P-116 absorb into Type S-7 spandex.

P-116 Inhibitor is specifically designed for use on elastic fabrics to be finished in white and pastel shades such as pinks, blues, and orchids. It is not recommended for use on dark colors.

Recommended Concentrations:

O.W.G. - On Weight of Goods

0.7% O.W.G. - For fabrics containing 26% Type S-7 spandex and higher.

0.3% O.W.G. - For fabrics containing 25% Type S-7 spandex and less.

All white fabrics should be treated in the last rinse with citric acid to achieve a finished fabric pH of 5.0 to 5.5. Oxalic Acid should never be used on fabrics containing Type S-7 spandex because oxalic acid will cause Type S-7 to turn an orange yellow cast.

P-116 Inhibitor when applied correctly, will improve resistance, and minimize or eliminate the reaction of, spandex fibers to shade change or discoloration on exposure to atmospheric gases, oxides of nitrogen or products of combustion.

INHIBITOR 100 - FOR NARROW FABRICS

Inhibitor 100 is a textile finishing chemical developed by CNC International in partnership with RADICISPANDEX Corporation for use on narrow (2 inch - 6 inches) fabrics containing Type S-7 spandex fibers.

Inhibitor 100 is a nonionic or neutral product and is compatible with other finishing chemicals such as optical whiteners, acrylic or thermoplastic resins, hand builders etc. The Inhibitor 100 should be added at room temperature ((70° F (21° C)) to the finishing bath. It should never be heated with live steam, as this will cause the product emulsion to break/separate.

Inhibitor 100 is designed for use on elastics to be finished in white and pastel shades such as pink, blue, orchid etc. It is NOT recommended for use on shades such as beige, yellow or dark colors.

Recommended Concentrations

• Dry Pick up - 25 Grams / Liter or 2.5% on weight of bath, for dry fabrics entering the bath.
• Wet Pick up - 40 Grams/Liter or 4.0% on weight of bath, for wet fabrics entering the bath.

Inhibitor 100 - The product should be stirred in the drum before each use. When not in use, the drum should be sealed.

All narrow elastic fabrics should be finished on the ACIDIC side pH 5.0 to 5.5. Citric acid is recommended. Oxalic acid is never be used on Type S-7 spandex fabrics as Oxalic Acid will cause the spandex to turn a yellow orange cast.

Note - The product should be stirred in the drum before each use. When not in use, the drum should be sealed.

Care must be exercised not to damage the thread with any sharp instrument that may be used to cut open the carton. Once opened - pull the plastic bag liner over the sides of the case to prevent contact of the spandex with the liner, which could disturb the wind and affect the performance in knitting.

• Remove the returnable black separator tray by grasping the handle holds and pulling straight up to prevent contact with the layer of spandex packages below.
• Grasp the spandex package by positioning the thumb (not thumb nail) in the top center of the package with one or more of the remaining fingers placed inside the tube, again avoid contact with the edges or shoulders of the package.
• Handle only one package at a time. Stacking, cradling or otherwise transporting more than one tube or cone at a time dramatically increases the likelihood that the package may be bumped and the wind may be disturbed causing running tension variation and breaks.
• The use of a tray, pin truck or other suitable carrier is recommended for handling multiple packages by one operator.

Inspection

• Remove empty spandex packages from the let-off rolls and place them aside leaving the threaded spandex end in machine.
• Place the new full package on the let-off rolls. Tie the threaded end to the loose end on the new package. A square knot is commonly used but other knots are adequate.
• Once positioned and tied, adjust the tension on the spandex to prevent it spandex from back winding on the let-off rolls, but not an "excessive" amount that would result in breaks due to exceeding the ultimate elongation of the spandex. A good spandex stretch ratio starting point is 3 to 1 (200%), however higher stretch ratios are likely and will be dictated by fabric requirements (stretch, density, % components etc.).
• When practical, jog knots slowly through before increasing to full speed.

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Additional Information

Certain circular knit applications (e.g. sheer fabrics) require that all spandex packages be the same size as to prevent the occurrences of a particular type of banding barre´.

Note: RadiciSpandex packages are metered to ensure even run out.

Over time, all spandex will generate tack (spandex to spandex bonding) and the level of tack developed could affect the performance of the spandex. Therefore, the practice of "First In, First Out" is essential. Although RadiciSpandex has good shelf life, we recommend maintaining a maximum of one month’s spandex requirements.

RECOMMENDED KNITTING TENSIONS

These are recommendations only, and trials should be performed to determine optimum running conditions.

In general, spandex knitting tensions can be calculated by using the formula:

Covering Drafts

These drafts are good starting points, however, trials are recommended to optimize machine setup.

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RECOMMENDED STORAGE CONDITIONS

FOR PACKAGES AND FABRICS

Storage of Type S-7 Fibers

Radicispandex fibers are packaged in heavy corrugated cardboard containers, lined with a sealed polyethylene bag, to protect the fiber from most degrading outside influences.

Storage of Fabrics Containing Type S-7 Fibers

Type S-7 spandex fibers are designed to withstand virtually an unlimited number of commercial dry cleaning and pressings, launderings, and tumble dryings.