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Classify Stains to Ease Removal

There it is, all right. It’s a stain. The garment would look better without it. That’s why the customer brought it to you, the drycleaner. The vision the customer sees in their mind’s eye is of a pristine, like-new garment.
What results you can deliver depend on your effort and expertise. Knowing where and how to start is the problem. Many stains need more than processing — more than a quick tumble in the wheel with some liquid. Many stains need individual attention — either before (prespotting) or after (postspotting) the garment has been drycleaned.
Thinking about what you’re doing can make spotting much more effective. There is no reason to routinely return garments with stains. In many plants, “Sorry” tags have become the rule rather than the exception. But with a little thought and direction, stain removal can be improved.
You need to ask questions and get answers in quick succession and in order. What is the stain? Was it wet when it contacted the garment? What will it take to break it down and flush it away?
One way of approaching the job of stain removal is to focus on the stain. Stains are divided into four groups.  Once stains are grouped, it will become easier to deal with the very similar characteristics each group carries.
The first is the solvent-soluble group. The solvent inside your drycleaning machine will break down the light oils and greases in this group easily. Depending on your solvent’s aggressiveness, many of these stains can go straight into the machine.
The traditional way to gauge the aggressiveness of a solvent against oils and greases is the Kauri butanol (Kb) scale. In round numbers, perc is about 95, petroleums and hydrocarbons are about 30, and cyclic siloxanes are about 20. Therefore, we can expect better oil and grease removal in perc.
Some of the other solvents may need help with heavier oils and greases, while perc will be tougher on paints and trims. If all we cleaned was salad oil on khaki pants, we’d be home free. (By the way, if you ever get a phone call about paint or nail polish on a garment, tell the customer to smear the area with petroleum jelly — it will keep the stain from setting, and the petroleum jelly will come out easily in drycleaning.)
The second group of stains is the water-soluble group. These stains usually come into contact with the garment when it gets wet in some way, or result from agents that are moist in their natural state. They are usually completely dry by the time they get to the drycleaning plant, and must be remoistened to achieve complete removal.
Water-soluble stains are things like coffee, soft drinks, wine, blood, urine and perspiration. Staining substances that start out moist but dry quickly are things such as mustard, ketchup and pollen. They will require a certain amount of moisture to be removed and are best treated on the wet side.
Wet-side stains are prime candidates for prespotting on the steam spotting board, or with some type of water-based spray spotter or a semi-wet prespotter. Semi-wet prespotters are a mixture of two parts spray-spotter and one part volatile dry solvent (VDS); they can be bought premixed or made at the board in a spare spotting bottle.
Start with a Flush-NSD-Flush protocol to increase your chances of achieving complete removal. The first flush of steam will rehydrate the stain, break its surface tension and expand the fibers slightly, “breaking up” the stain. NSD will penetrate the stain and continue the breakdown process. The second flush with steam will remove any of the stain loosened by the NSD and heat the area. Heat will accelerate the action of any tannin or protein spotters used later.
The third group of stains is the chemical-soluble group. This group is characterized by ink, paint, nail polish and glue. These stains tend to be water-resistant and are best treated on the dry side.
The dry-side protocol is only slightly different from the wet-side protocol, but uses different chemicals: It’s Flush-POG-Flush. Flushing is done with VDS followed by a paint, oil & grease (POG) remover, followed by a second flush with VDS. In addition to these two chemicals, you’ll want to have amyl acetate or a premixed “glue remover” to use on the spotting board. Flush all dry-side spotters with VDS before drycleaning to reduce or eliminate their contribution to non-volatile residues (NVRs) in the system.
The fourth group of stains are insoluble stains, which can’t be broken down. The group includes stains like carbon (routinely found in car exhaust) and graphite (used as a dry lubricant). Insoluble stains are difficult to remove completely. They require lubrication and mechanical action.  You will have to judge how much mechanical action the fiber, weave and dyes of a garment will withstand.
Common lubricants are any oily-type paint remover, mineral oil or even petroleum jelly, all of which will flush out with VDS or in the drycleaning machine. Just remember to remove the stain at the board, since very little of an insoluble stain can be removed in the wheel.
By categorizing stains like this, you will be able to choose your first course of action quickly and confidently. This strategy also reduces the chance of doing harm to the garment or “setting” the stain significantly.
Once stains are categorized, you will have a predetermined starting point and a fairly constant sequence of procedures to follow. The variety of stains is greatly reduced, making any additional steps required for complete removal easier and safer.
Proper stain removal is neither difficult nor risky. It is a function of the knowledge you possess and the effort you are willing to apply to the job at hand.
 

Have a question or comment? E-mail our editor Dave Davis at [email protected].