Sponging
Sponging is a pretreatment in which moisture or steam is applied to textile before cutting to pre-set shrinkage and tension, reducing dimensional changes after cutting and sewing.
Contents6 sections
Definition and Overview
Sponging is a process in which moisture or steam is applied to textile in the roll state and then dried and stabilized. Its purpose is to relax tension generated during weaving, dyeing, finishing, and rolling, and to pre-check and absorb shrinkage that may occur in later processes.
Depending on the material, weave, and finish, textile may be supplied in a particularly tensioned state in the lengthwise direction. For such textile, sponging or sufficient relaxation before cutting helps create dimensionally stable products.
Position in Product Making
In general, sponging is carried out after incoming inspection and necessary testing, and before marking and cutting. By checking the post-treatment textile width, shrinkage rate, grain line, and surface condition before pattern layout, it becomes easier to reduce cutting dimension deviations.
For specifications that include product washing after sewing, the process is designed to account for changes caused by product washing as well. Sponging alone does not guarantee the final dimensional change, so it is important to judge based on tests under conditions close to mass production.
- Receiving inspection and textile inspection
- Advance confirmation of shrinkage rate and hand feel
- Sponging or relaxation
- Grain correction and marking
- Cutting and sewing
Procedure and Practical Points
Methods include wetting and drying the textile, or using steam, and vary depending on the equipment and material. First, confirm the moisture amount, temperature, drying method, and tension on a small sample, then determine the conditions for full-scale production.
After treatment, measure the width and length once the temperature and humidity have been sufficiently balanced. For patterned goods, pay attention to pattern distortion; for brushed goods, to the nap direction; and for coated goods or textile using fusible interlining, also to changes in appearance. Avoid pulling the textile excessively when cutting.
Procurement and Quality Considerations
When ordering, share the material composition, finish, rolling direction, and assumed washing and pressing conditions with the processing partner or sewing factory. If necessary, reflect the effective width and shrinkage rate after sponging in yardage calculations, and arrange the quantity with allowance for loss.
The effect of sponging and the appropriate conditions differ for each textile. Excessive moisture, heat, or pressure can lead to color bleeding, changes in hand feel, wrinkling, and changes in the appearance of coatings, so be sure to conduct prior testing and pre-production approval.
Differences from Similar Terms
Relaxing the roll is the work of spreading out the roll of textile and leaving it for a period of time to naturally relieve the roll set and internal tension. Sponging is a pretreatment that uses moisture or steam to promote change, and is used when you want to more actively confirm shrinkage than with relaxing the roll.
Grain correction is the work of aligning a distorted grain line and selvedge condition to make cutting easier. Since the grain line and width may change after sponging, grain correction is performed as needed. Shrink-resistant finishing is a treatment applied during textile production to suppress shrinkage, and its purpose and timing differ from sponging before cutting.
Frequently Asked Questions
Which should be done, sponging or relaxing the roll?
It is determined by the material, finish, tension condition, and the dimensional change that can be tolerated in the product. Some textile will stabilize with relaxing the roll alone, but if shrinkage is a concern, sponging should be considered. In either case, it is necessary to confirm with tests close to the actual cutting, sewing, and washing conditions before mass production.
Can cutting be done immediately after sponging?
Immediately after treatment, the textile temperature and moisture condition may be unstable, so it is basic to allow the condition to settle before cutting. Check the width, length, grain line, and surface condition, and make sure it is in a state where it can be laid out on the cutting table without being pulled.
