The FLOOR COVERING DICTIONARY gives
LATEX - A water emulsion of synthetic rubber, natural rubber, or other
polymer. In carpet, latex is used for laminating secondary backings to tufted
carpet, backcoating carpet and rugs, and for manufacturing formed cushion.
Almost all carpet latex consists of styrene-butadiene synthetic rubber (SBR)
compounded with large quantities of powder fillers. The latter are most often
whiting, which is calcium carbonate. Latex is the raw material from which rubber
If the carpet is Tufted and the latex is made with
excessive amounts of non-elastic materials, it can effect faceyarns slipping
and/or pulling, buckling, and delamination. There are four popular laboratory
tests to be familiar with.
- For Tuft bind the test is
Standards from UM44d is 6.25 pound for loop-pile and 3.0 pounds for cut-pile
average. However, this test often does not give a clear picture of the
problem. Often after a carpet is stretch, the latex cracks releasing its hold
on the yarns. Another test is without a ASTM protocol is called
AVERAGE LATEX BUNDLE WRAP and AVERAGE LATEX PENETRATION testing.
The FLOOR COVERING DICTIONARY gives this definition which can act as a
LATEX PENETRATION - Yarn is removed from the primary and secondary backings
and inspected under a micro-scope to determine how much latex penetrated the
yarn bundle that exist beneath the primary backing. The results are stated as a
percentage of latex penetration. A generally acceptable level is about 85% Latex
penetration determines the tuft bind of the carpet.
- The test for
Delamination is ASTM 39361
and the standard is 2.5 pound average.
Some experts consider this a low standard and
it will often tell if the latex is defective.
- The last recommendation
for testing is DIMENSIONAL STABILITY and
it does not have an ASTM number. However in this test, weights are attached to
the carpet to make it stretch and measurements are taken afterwards to see how
much it recoils and/or how much unrecovered extension there is. The standard
for this test is the installation standards, either CRI104 or CRI105. If the
carpet goes over 1.5 percent in either direction, then it can not remain
tight after its installation. Click here
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