Redeposition

Photo: Redeposition can cause rings in stain removal.

Redeposition occurs in drycleaning when soils in the solvent resettle or redeposit on clothing instead of being carried off to the filters. Soil redeposition will be minimized if the filtered solvent flow rate is high enough to flush the soil rapidly from the washer and into the filter.

Classifying items improperly can also cause redeposition. Dark colored garments should not be cleaned with light colored garments for several reasons. Dark colored garments may bleed in the load, allowing the dye to be absorbed by the lighter colored garments. In addition, darker colored garments are usually worn for a longer period of time since they do not readily show soils. The soils that are released in the cleaning cycle may be absorbed by the lighter colored garments.

Garments that are prespotted should be allowed to dry completely before recleaning to prevent localized redeposition. Cellulose fabrics are more prone to this type of staining, although it can occur on other types of fabrics.

Even though there are several other factors that can contribute to redeposition in the drycleaning machine, proper flow rates and the thorough drying of fabrics after stain removal are a few of the ways to prevent it.

For more information see the following bulletins in DLI's Drycleaning Encyclopedia:

• Shirt Laundry Procedures 132 "How White are Your Shirts"
• Technical Operating Information (TOI) 667 "Greying of Fabrics in Drycleaning" 
• TOI 744 "Importance of Adequate Solvent Levels in the Drycleaning Machine"