Using digestion for difficult stains
igestion is a
process that uses enzymes to convert insoluble stains to
soluble substances. The advantage of using and understanding
digestion is that the process removes stains safely by
eliminating mechanical action, lubrication and chemical action
that can affect the safety of many fabrics.
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Many cleaners shy away from using this
process, claiming it does not work or it takes too long. The
fact of the matter is that most cleaners do not fully
understand the digestion process and those who do use it are
not using it properly.
Digestion can be used alone as a stain
remover or in combination with other methods, thus increasing
the range of stain removal. Enzymes associated with stain
removal in digestion are proteins that act as a catalyst in a
biochemical reaction. A catalyst affects chemical change but
they themselves are not used up and do not appear in the final
product.
This differs from using acid, alkali or
bleach, which undergo chemical changes themselves.
In general enzymes accelerate reaction by
lowering the free energy necessary to initiate the reaction,
which may be compared to lubricating oil in an engine.
An enzyme can be identified by its name
typically ending in the suffix “-ase.” Today over
2,000 enzymes have been identified. Each enzyme will react with
a different type of staining.
The first portion of the name of the
enzyme is the substance upon which the enzyme works. This is
called the substrate.
Enzyme
Staining
Diastase
Starch
Lactase
Lactose
Lipase
Fats
Protease
Protein
Urease
Urea
The digesters that are manufactured for
stain removal contain a mixture of enzymes so they can be used
in a wide variety of stains.
In general enzymes are used for stains
originating from a living body. This includes albumin, milk,
blood, urine, perspiration, animal glue, some fats, etc.
Remember, enzymes do not remove stains but
convert them to a soluble substance that can be removed by
simply flushing with water.
The classic riddle that I use in my
spotting classes that explains enzymes is as follows:
Question: How
do they get the liquid center inside the liquid filled
chocolate covered cherry?
Answer: The
cherries are put in a solid mold which contain an enzyme. The
cherries are then dipped in chocolate. They are then put in
storage for controlled time and heat. The enzymes then convert
the solid substance on the cherries to a liquid sugar.
Low temperature enzymes
These enzymes are found in a powdered
form. Laidlaw manufactures a product called RSR and the enzymes
have a specific use. They are very useful for spotting delicate
wools, silks and rayons with color problems.
These enzymes are also useful for staining
on Indian and South American blankets that have
old crusty stains.
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These enzymes require specific conditions
to make them work:
Moisture. Water
is needed to activate the enzymes.
Heat at
100 to 120°F. If the temperature goes above 120°F, the
enzymes are destroyed. Under 100°F only slows the enzyme
process, but it will still work.
No chemicals. Acid,
alkali or bleach will destroy the enzymes.
Time. Over
20 minutes.
After making up these enzymes, they can
only be used for one day. I like making up the enzyme formula
and putting it in a coffee thermos bottle. This will keep the
enzymes at a proper temperature for several hours.
I then transfer it to a spotting bottle
for application. The formula for the spotting board is one pint
of water, one-half teaspoon of enzymes and one teaspoon of
glycerin. The glycerin is added so the area will stay wet
longer.
Remember, you do not have to add large
amounts of an enzyme to make it work effectively. The quantity
of enzyme compared to the staining is very small. It is claimed
that the enzyme sucrase will digest 200,000 times its own
weight.
After applying the enzymes to the stain
simply hang the garment for one-half hour and then flush area.
You do not have to roll it up to keep it warm or hang it in a
boiler room.
Bath method. Use
a clean bucket free of chemicals. Add one teaspoon of enzymes
to warm water and one teaspoon of salt as a dye setter. (Except
on silk).
High temperature enzymes
Streets makes a product called
“Devour” that works up until 158°F. The enzymes
are very useful for stain removal, but heating the enzymes with
the steam gun held too close to the fabric will destroy them.
These enzymes also can not be used with other chemicals.
These enzymes are not as safe as the
low-temperature enzymes and some color sensitive fabrics should
be tested. On heavy white wools ,rinsing the enzymes might be
difficult.
These enzymes can also be used in a bath
solution. The manufacturer recommends 1 tablespoon of
“Devour” per gallon of water in a clean container.
High temperature enzymes and bleach
Some companies make enzymes that have a
protective shell and are mixed with bleach. Metro Chem
manufactures a product called “Recover” that
contains enzymes mixed with an oxygen bleach. (sodium
percarbonate).
This has the advantage of not only
digesting the staining but oxidizing the remaining residue and
whitening the fabric. These enzymes can be used for spot
bleaching but will be destroyed if temperatures exceed
150°F. Use in a bath solution according to manufacturers
directions.
Dan Eisen recently retired as chief
garment analyst for the Neighborhood Cleaners Association after
33 years with that organization. He is available for seminars,
consultations and independent garment analysis. He also has
published a book, “The Art of Spotting,” which is
an indexed compilation of articles he wrote for National
Clothesline and NCA over the past three decades. He can be
reached at (772) 340-0909. His address is 274 NW Toscane Trail,
Port St. Lucie, FL 34986. His e-mail address is cleandan@adelphia.net.
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