34—THE CONTROL OF THE SHAPE AND DIMENSIONS OF KNITTED WOOL FABRICS

Abstract

An account is given of an investigation of the use of steam treatments as a means of controlling the shape and dimensions of plain-knitted wool fabrics, firstly by allowing the fabric to relax towards its dimensionally stable state during steaming and secondly by steam-setting the fabric while it is held at a predetermined width. This steam-setting procedure is compared with two permanent-setting treatments for wool—a chemical-setting treatment and setting in boiling water.

Of the two methods of producing a dimensionally stable fabric, namely, by relaxation and by setting, the relaxation method is by far the more effective. The most important result of this work is that knitted wool fabrics—whether unset, steam-set, or permanently set—will always approach their completely relaxed shape and dimensions after only a couple of minutes' gentle agitation in water. It is concluded that conventional methods of shaping knitted wool fabrics and garments, which rely principally on steam-setting the fabric or garment to a size and shape different from its relaxed size and shape, are not likely to produce garments that have good dimensional stability and good shape-retention properties.

The ineffectiveness of permanent-setting agents in producing dimensionally stable knitted garments is contrasted with the relative effectiveness of these agents in producing pleats and permanent creases in wool cloths. This difference in behaviour is explained in terms of the different levels of individual fibre strains involved.

KEY WORDS (SPECIFIC TERMS):

• SHAPE
• DIMENSIONS
• KNITTED FABRICS
• WOOL
• COURSES PER INCH
• WALES PER INCH
• STITCH LENGTH
• COVER FACTOR
• KNITTING
• PLAIN-KNITTED FABRICS
• WORSTED-SPUN YARNS
• DIMENSIONAL STABILITY
• RECOVERY (SELF-RESTORATION TO ORIGINAL CONDITION)
• STEAMING
• DURABLEPRESS TREATMENTS
• RELAXATION
• DRY RELAXATION
• WET RELAXATION
• CHEMICAL SETTING
• BOILING-WATER SETTING
• LAUNDERING
• TEMPERATURE
• REGAIN
• PLEATS

KEY WORDS (BROADER TERMS):

• FABRICS
• STRUCTURAL PROPERTIES
• FABRIC PROPERTIES (STRUCTURAL)
• WET FINISHING