Structural Shrinkage
The tendency of a woven fabric to change its physical dimensions during subsequent washing or finishing processes is a major quality concern for garment manufacturers. In flax-based products, dimensional instability arises from the release of internal stresses locked into the linen fibers during spinning and weaving. This phenomenon causes either shrinkage or elongation when the fabric is exposed to moisture and heat.
Quality control laboratories test for this behavior by measuring fabric samples before and after standard washing cycles.
Structural Relaxation
Washing relaxes the tight yarn crimps and causes the fibers to swell, which forces the fabric to contract in both warp and weft directions. High dimensional instability in linen is often the result of excessive tension applied to the warp yarns on the loom. When the fabric is wetted out, the stretched fibers return to their natural state, leading to severe shrinkage.
Mill finishers must apply controlled pre-shirking processes like sanforizing to stabilize the fabric before it is packed for export, documenting the final shrinkage percentages on the batch release certificate to satisfy the buyer’s criteria.
Quality Criteria
Garment makers specify strict limits for warp and weft shrinkage to ensure that finished linen clothes do not lose their shape. A fabric that fails these limits requires re-processing or is downgraded to secondary status. The mill’s testing laboratory records these results in the export batch report.
