March 2014 | SportsTurf 29 www.stma.org
During
installation, in very cold or very hot weather, a good out-
door adhesive should prevent the turf from moving due to wind lift,
edge curl, creep, wrinkling, buoyancy from unexpected rain, expansion
and/or contraction due to surface temperature changes from sunlight,
shadows, passing clouds and so on. Furthermore, selecting an outdoor
adhesive based on indoor laboratory test results after the adhesive has
cured is a waste of time. The first important thing is installation in
variable weather and after cure, then long-term exterior durability.
Q: What different types of adhesives for synthetic turf are used
commercially today?
Legue: They are hot melts, one and two-part liquid solvent-free
urethanes; one-part and two-part solvent-based urethanes; two-part
epoxy and one-part solvent-free silane/silicone based adhesives.
Q: Of those, which type is most often used for synthetic turf?
Legue: It's one-part urethane adhesives by far, but the word
"urethane" is like the word "metal." Just as there is a big difference
between gold, zinc, cobalt, lead, iron, uranium, tin, aluminum, etc.,
there is also a big difference between adhesives that fall under the
word "urethane". For synthetic turf, some give disastrous results and
others, in our opinion, are far superior to other adhesives.
Q:
Can you narrow down the type of urethanes that make it easier
to install synthetic turf and those that are the opposite?
Legue: Relatively speaking, one-part liquid urethanes that are
both solvent-free and with high isocyanates (NCO) contents above
9% have a host of installation problems ranging from crystallizing
(turning solid) at about 50° F and not re-liquefying when warmed;
to foaming in high humidity; to slow cure in low humidity; to
negligible tack and "grab" to prevent turf movement during
installation.
Oppositely, many solvent containing one-part urethanes with
low NCO contents, enable turf installations ranging from freezing
to hot desert temperatures; they do not crystallize on cold days;
do not foam on humid days and do not stop curing in dry
desert-like conditions. Installers don't have to "baby sit" them
during installation.
Q: How do you find a synthetic turf adhesive that is suitable for
an application?
Legue: I suggest contacting adhesive manufacturers and ask for
literature and a MSDS sheet. If the information received is weak,
ask about some of the points I've made here. Don't accept a verbal
sales pitch or buy solely on low price. n
