What should I do when a water-repellent jacket is worn for a long time and repels water less?
This is a situation where rainwater has started to seep into the jacket, raising concerns about whether it has reached the end of its lifespan. The user is looking for a way to revive the water-repellent function at home through washing and care.
After the garment is completely dried, ironing it at a low temperature with a thin pressing cloth will revive the weakened water repellency on the outer surface.
Jackets from POSTALCO initially bounce water droplets off lightly, but frequent wear or repeated washing gradually weakens the water repellency of the surface[1]. The choice of detergent is important when washing. Fabric softeners or detergents containing softening agents should not be used because they coat the fabric surface and reduce its water-repelling properties[2]. This is because if softening ingredients remain on the fiber surface, water droplets cannot bead up and will seep into the fabric.
Applying heat restores the function. After washing, dry the garment completely, then iron it at a low temperature using a thin pressing cloth[3]. Lowering the iron's temperature and moving slowly over the cloth allows gentle heat to align the treated layer on the outer surface of the fabric, restoring its function of repelling rainwater.
Whether the water repellency can also be restored using the warm air of a clothes dryer instead of ironing has not yet been confirmed.