Finishing Silk Fabrics

Like all other fabrics, silk fabrics can also be given a variety of finishes. The one and the most common type of finish that is unique to silk is weighting.

Various finishing in silk fabrics include:

• Weighting: Manufacturers mostly buy silk by weight and thus the amount of weight that silk loses in the degumming process is an important factor in manufacturing costs. The weighting of silk fabrics with metallic substances to compensate the weight lost by degumming is the most common practice in the silk industry.
  
  
• Weighted silk is generally less compactly woven than unweighted silk and less silk is used in the manufacture of the cloth. Weighting is usually done during the dyeing process. In order to weight coloured silks, stannic chloride is used followed by treatment with sodium phosphate. Black silks are weighted with metallic mordants like iron salt and logwood.
  
  
• Taffeta is the most commonly used fabric that is generally heavily weighted.
  
  
• Pure-Dye Silk: Silk is usually weighted during the dyeing process and hence, the term "pure-dye silk" indicates that weighting was not added that time. As per FTC rulings, pure-dyed silk is a fabric, exclusively made of silk fibers not possessing any metallic weighting whatsoever.

Additional Finishing Processes

Apart from the above, a wide variety of other finishes are also applied to silk fabrics to beautify their performance and look. Some of the common finishes are:

• Calendering: This technique is applied for enhancing luster.
• Bleaching: This is required very little for silk that is totally degummed.
• Embossing: It is applied if patterns as moire are desired.
• Steaming: Used for raising pile weaves.
• Cireing: Applied for body and luster of silk.
• Singeing: Used for obtaining smoothness.
• Stiffening: Applied for smoothness.
• Pressing & Lustering: The technique is applied for removing wrinkles from finished fabric by means of heated rollers, soaking in dilute acid to improve luster.
• Wringing & Stretching: Applied for softening the fiber and increasing the luster.