Shrink-proofing
Shrink-proofing is a process that stabilizes shrinkage in advance to reduce dimensional changes that occur when textile or products are washed or hand-washed.
Definition and Overview
Shrink-proofing is a process used to reduce shrinkage that occurs when a material is exposed to moisture, heat, drying, and similar conditions. It is used for woven fabrics, knits, and also for fabric before sewing and finished products after sewing.
Sanforize is a term used to refer to the mechanical compression process mainly applied to woven fabrics as one type of shrink-proofing. By contrast, shrink-proofing is a broader general term that includes resin finishing, heat treatment, washing processes, and more.
Features and Effects
Fibers with water absorbency such as cotton, linen, and rayon, as well as wool, are materials that are prone to dimensional change during washing or when wet, so they are often candidates for shrink-proofing. The processing method is selected according to the type of fiber, woven or knitted structure, and applications.
Even with shrink-proofing, shrinkage may not be eliminated completely. Product dimensional changes and appearance vary depending on household washing conditions, whether tumble drying is used, and the grain alignment and combination with auxiliary materials during sewing.
- It improves dimensional stability at the fabric stage and makes it easier to control distortion after cutting and sewing.
- It makes it easier to anticipate changes in garment length and width after washing, which is useful for pattern design.
- Processing may change the texture, thickness, stiffness, and stretchability.
Main Applications
Shrink resistance is required for shirts, blouses, cut-and-sew items, pants, denim, uniforms, and other items that are washed frequently. In particular, fabrics containing natural fibers are considered for the purpose of maintaining the product's fit.
Even for coat fabrics, linings, and garment fabrics, it is important to minimize differences in shrinkage between the outer fabric, lining, and auxiliary materials. Confirm the shrinkage rate of each material and take into account the dimensional changes of the materials being combined.
Selection and Handling Notes
When selecting fabric, check not only whether it has been shrink-proofed, but also the shrinkage rate by washing method, care label instructions, and test information for each lot. Before mass production, it is important to make samples and conduct washing tests under the actual sewing specifications and assumed washing conditions.
The need for prewashing before cutting varies depending on the material and finish. Check the fabric care label and the supplier's instructions, and if you apply your own treatment to already processed fabric, confirm changes in texture, dimensions, and color in advance.
In sewing, differences in shrinkage among the outer fabric, interfacing, tape, and lining can cause puckering and drawing after washing. Align the grain before cutting and manage dimensions, including sewing shrinkage.
Differences from Similar Terms
Shrinkage rate is a value that shows how much the dimensions of a fabric or product have changed before and after washing or similar processes. Shrink-proofing refers to a means of reducing that shrinkage rate and stabilizing dimensions.
Shape retention finishing is a process that makes it easier to preserve wrinkles, creases, and appearance after washing. It may also have shrink-resistant properties, but the main purpose and evaluation items are different.
Frequently Asked Questions
If a fabric is shrink-proofed, is prewashing unnecessary?
It cannot be said to be unnecessary in all cases. Even shrink-proofed materials can change dimensions depending on washing conditions and drying methods. Also, prewashing before cutting is a process to check color fading, texture, and grain changes. Prioritize the fabric handling instructions and make a judgment after testing before mass production.
Are Sanforize and shrink-proofing the same?
Sanforize refers to processing that suppresses shrinkage through mechanical compression mainly used for woven fabrics. Shrink-proofing is a general term that includes this and has multiple methods depending on the material and purpose, such as resin finishing, heat treatment, and washing processes.
