Jeans Beneficiation

Laundries have evolved significantly in recent times, adopting new processes, methodologies, recipes and chemical products used. However, it is essential to analyze the oxidizing effects that these chemical products can cause on metal zippers, whether during the preparation of the garments, washing or drying.

Excessive or inappropriate use of chemical products can compromise the components of the jeans (fabrics, threads, trims). This reaction is common with the use of peroxides, depending on the weight of the fabrics, the concentration of the chemicals and the time and temperature of the processes.

It is important to correctly observe the rinsing levels of the pieces to neutralize the action of the chemicals between processes. If neutralization is insufficient, the deposition of chemicals may occur between the teeth and/or cavities of the zipper sliders, concentrating the action of the reagents and potentially damaging the fabric in contact with them.

The guidance of a chemical professional is crucial when formulating recipes, ensuring the correct amount of chemicals and avoiding their excessive use. It is also essential to monitor the processing times, as the chemicals are constantly reacting.

Strategically positioned wear (on the legs, pockets, “whiskers”, etc.), which are common in denim garments, should be carefully observed when using “floats” to inflate the garments, as illustrated in the attached photos. These floats can exert enough pressure to compromise the zippers, exceeding their resistance and causing the teeth to be removed or dislodged, in addition to affecting the sewability.

This excessive effort must be controlled by regulating the pressure applied to each piece or by the sensitivity of each operator, to avoid using excessive pressure that could damage the piece.

It is important to remember that the pieces still do not have buttons and, if too much pressure is applied, all the effort will fall on the zipper teeth, which may result in the detachment and/or removal of some teeth.

In wet processes, shrinkage is common, especially in fabrics, resulting in wrinkling in the seam areas. This is often caused by irregular stitches made by unregulated sewing machines.