browning (sometimes confused with wicking or yellowing) only
occurs when cellulosic fibers are present. Cellulosic
fibers come from plant material and include cotton, jute, and
rayon. Browning occurs on the tips of carpet tufts or on
upholstery fabric. This will be more noticeable on light
is the oxidation of a sugar called lignin. This dissolves
in water or cleaning solutions and wicks to the surface during
drying. Alkalinity will greatly accelerate cellulosic
browning. Over-wetting, slow drying and the age of the
fabric also increase the likelihood and severity of browning.
of the fiber(s) you are dealing with. Jute backed carpets
make up only a small percentage of the carpets you will clean.
Woven carpet and area rugs are likely to have cotton foundation
yarns. Cellulosic fibers are more common in upholstery
uncertain of the fiber content, do a burn test (this is covered
in another Technical Bulletin).
neutral or acid side cleaner if it will provide sufficient
cleaning ability. For example, use
Avenge Fabric Pre-spray, Haitian Powder, or Haitian Shampoo
for upholstery. Rinse with
Avenge Clean Rinse. If you use an alkaline cleaning
agent, neutralize by rinsing with an acid side product such as
This Quick Guide
highlights preventing browning when cleaning natural
upholstery fabrics. The detailed methods covered
in this Technical Bulletin apply to both carpet and
Use a low moisture tool on
Make extra drying strokes to remove
as much moisture as possible.
Leave fibers in an acid condition by
Fab-Set during or after cleaning.
Dry quickly with
air movers or an
Air King. Direct air flow across fabrics,
not into them.
Spray a mist of
Fab-Set over the entire area. Wet only the surface.
Do not saturate. Allow a few minutes dwell time.
Go over the surface with a
Micro Fiber or Cotton Bonnet dampened with
Fab-Set. Use a rotary machine on carpet. There
are powered tools for bonnet cleaning on upholstery or this step
can be done by hand with white cotton terry cloth. The
idea is to clean the browning off the surface without rewetting
the entire fiber and allowing browning to recur.
Dry quickly using
air movers or an
In severe cases of browning it
may be necessary to lightly re-clean the entire area in order to
loosen the oxidized sugars. Then follow the correction
steps listed above. Remember, moisture and alkalinity
caused this problem. Use a neutral cleaner and be careful to
control the moisture.
Using the prevention methods
above for all of your cleaning situations will greatly reduce
your callbacks. These methods help prevent browning,
yellowing, soil wicking, bleeding, etc., in addition to
preparing the carpet for Bridgepoint's Maxim Protector.
Older cellulosic fibers
(cotton, jute) will pose the highest risk and correction will be
the most time consuming. Be sure to identify cellulosic
fibers before you start. It is always easier and less
costly to prevent problems before they occur.
advances in encapsulation chemistry are showing promise in
helping to control and correct cellulosic browning.
Encapsulation cleaning using
Encapuclean with Maxim uses limited moisture and a neutral
pH and thus is less likely to trigger browning. Try
encapsulation on a carpet that has potential to brown.
decide to clean using hot water extraction, a post cleaning
spray application of Encapuguard resists wicking of lignin to
Encapuguard can also be used as a corrective measure.
Apply a light mist after Step 2 above (or in mild cases instead
of Step 2) prevents additional wicking and browning.