Understanding chemical action
If you understand true chemical action,
the procedures you undertake for stain removal will be easier
and more proficient.
Chemical action is the changing of the
properties of the stain to make it either invisible or
water-soluble. Before we start understanding chemical action,
why don’t we take a little quiz to test our knowledge of
chemicals.
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Answer:
No. You are only changing the physical state of the sugar, but
chemically it still remains the same sugar. This is an example
of wetside solvent action.
2. Is the
strongest acid battery acid or the acid found in the human
digestive system?
Answer:
The digestive system contains a stronger acid, which is
hydrochloric acid while battery acid, which is sulfuric, is
slightly weaker.
3. Which
is stronger — acids used in tannin formulas for removal
of citrus stains or acids found in citrus stains?
Answer: About
the same.
4. Which
is more likely to cause color loss on a rayon and acetate
fabric — acetic acid (33%) or hydrofluoric (rust
remover)?
Answer: Acetic
acid
Let’s start.
In order to be a chemical it must be
soluble in water and acid or an alkali. This means that
drycleaning solvents, amyl acetate and volatile dry solvents
which are not soluble in water cannot be termed chemicals. You
may argue this, but we need this definition to explain how
chemicals work in spotting.
Acid facts
Acids are defined as chemicals that
release hydrogen ions in the presence of water. The PH, or
potential of hydrogen, measures the strengths of the acids. Any
number under seven means that the substance is acid in nature.
Acids are used for tannin stains, inks,
dyes and medicines. Acids neutralize alkali.
Alkali are capable of causing color change
on fabrics. Acids neutralize the alkali, which in most cases
can restore the color.
Heat accelerates all chemicals, which
means a relatively safe acid can become much stronger and
dangerous when heated.
Acids used for spotting
Tannin formulas are prepared formulas
consisting of a mild acid mixed with a wetside lubricant.
Tannin formulas are usually safe to fabrics and are not as
strong as most acids used in its pure chemical state.
Acetic acid has a strong relationship to
vinegar. Vinegar is produced through the action of bacteria on
yeast fermented brews.
Vinegar can be made of any plant that can
be fermented to form alcohol, which is subsequently converted
to acetic acid.
Acetic acid is more effective than tannin
formulas on some tannin stains such as wine and liquor.
Some people do not like using acetic acid
because of its odor. Add a little neutral lubricant to the
acetic acid and the odor problem is solved. When using acetic
acid, remember to order it at 28%. It is also advisable to
dilute this down with a little water to bring the concentration
to about 20%.
Acetic acid may be safe and used as a
general spotting agent but when it is heated it may affect
acetate fabrics. Besides using tannin formulas, learn to add
acetic acid as an additional spotting agent.
Oxalic acid is a useful acid in removing
many types of tannin stains, especially berry, cherry and wine.
It is also effective on rust and metallic stains. It is also a
mild reducing agent which makes it effective on dye stains. It
is considered a more aggressive chemical and should be tested
for the safety of dyes on fabrics.
You can order oxalic acid from your jobber
in crystal form and mix with 20 parts water. Laidlaw Chemical
Co. sells oxalic acid as a rust remover. The product is called
Rustaid and is already mixed so it makes it easier to use.
General formula is a mixture of a
lubricant, alcohol, and a mild acid. It is very effective on
ink stains and dye but not generally very effective on other
tannin stains.
Be careful using it because the alcohol
content may be dangerous to the dye on some fabrics.
General Formula should not be used if the
stain is protein or albuminous in nature. The alcohol will set
these type of stains.
Rust remover is hydrofluoric acid. This is
effective not only on rust stains but on many types of tannin
stains. Rinsing is difficult and I have found that the best way
to flush and neutralize rust remover is to use a neutral
lubricant or a protein formula. This will not only aid in
removing it from the fabric but it also will neutralize any
trace of the rust remover.
Keep rust remover away from metallic
fabrics, metallic ornaments and glass. It is also advisable to
test the safety of this acid before using on the fabric.
Alkali facts
Alkalis release hydroxyl in the presence
of water. Alkalis are effective on protein and albuminous
stains. It is also an aid in removing ground in soil. It will
neutralize color change caused by an acid. The PH of alkalis is
measured in numbers higher than seven.
Alkalis used for spotting
Ready-made protein formulas are mixed with
a mild alkali and a lubricant. It is relatively safe and
effective, but should be tested on wools and silks.
Ammonia (26) is used for spotting protein
and albuminous stains. It is stronger and more aggressive than
ready made protein formulas. The dyes on silks and wools must
be carefully tested.
Spotting procedures: Tannin stains
Tannin stains are vegetable or are
obtained from a plant source. Examples of tannin stains are
coffee, tea, liquor, wine and soft drinks. Tannin stains
respond best to acids. Never use alkalis or protein formula on
tannin stains because the stain will become set and often
impossible to remove.
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2. Neutral lubricant.
3. Mechanical action.
4. Flush.
5. Tannin formula.
6. Mechanical action.
7. Flush.
8. Acetic acid plus neutral lubricant.
9. Mechanical action.
10. Flush.
11. Oxalic acid: test fabric.
12. Heat.
13. Flush.
14. General formula: test fabric.
15. Mechanical action.
16. Flush.
17. Rust remover: test fabric.
18. Heat.
19. Flush.
20. Protein formula, to neutralize rust
remover.
21. Flush.
22. Peroxide (3%) plus Ammonia: Test
fabric.
23. Heat.
24. Flush.
25. Acid.
26. Flush.
27. Feather.
At any stage that the stain is removed you
would then stop the procedure.
Protein procedure:
1. Flush.
2. Neutral lubricant.
3. Mechanical action.
4. Flush.
5. Protein formula.
6. Mechanical action.
7. Flush.
8. Ammonia plus neutral lubricant.
9. Mechanical action.
10. Flush.
11. Digest, if stain is stiff.
12. Flush.
13. Peroxide (3%) plus Ammonia. Test
fabric
14. Heat.
15. Flush.
16. Acid.
17. Flush.
18. Feather.
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 (561) 340-0909. His address is 274 NW Toscane Trail,
Port St. Lucie, FL 34986. His e-mail address is cleandan@adelphia.net.
