Note: Descriptions are shown in the official language in which they were submitted.
CA 02351262 2001-06-22
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TITLE: COMPOSITION P'OR MOLDED ~'r~ S'fO>?
FTELD OF THE INVENTION
The present invention relates to a composition which can
be molded into a coupling for PVC and other plastic pipe
to function as a Pire stop for preventing the spread of
fire through openings or penetrations in the walls and
floors of buildings.
HACKCROUND OF THE INVENTION
Fire stop devices are used to prevent fire from spreading
from one room to another through openings or apertures in
a partition such as a wall, floor or ceiling through
which a pipe passes. The purpose of the fire stop device
is to close off the opening in the partition in the event
of a fire. The fire stop device generally c4ra,tains ari
intumescent material which expands when the temperature
reaches a certain level. The expansion of the
intumesCAnt ItLatBri81 is directed inwardly toward the pipe
and crushes the pipe which is generally softened by the
Gemperatuxes encountered in a fire and closes off the
opening in the wall with a hard char.
A numbdr of such fire stop devices have been proposed
requiring field installation whereby for example foil
lined strips Qf intumoscen,t material are wrapped around a
plate and then a restraining collar is wrapped around the
intumescent material and secured riy screws or straps.
Examples of many such fire stops are provided in amongst
others U.S. pat~nt 5,498 466, 5,953,872, 5,634,304,
5,390,465, and 5,076,309. The installation of such fire
stop devices can be labor-intensive and requires that
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they bo ~7roperly sealed in the opening to fulfill their
function.
S[~ARY OF THE INVEN'I:'I4N
The present ir~vention is directed to a composition which
can be molded into a coupling for PVG and other plastic
pipe to function as a fire stop. ~rhe composition
comprises 100 parts by weight of a PVC resin and 20 to
100 parts by weight of an intumescent material,
preferably exfoliated graphite. The composition may
optionally Contain other typical components utilized in
molding operations for PVC resins such as lubricants,
foaming agents, plasticizexs, modifier and processing
aids.
DETAILED DESCRIPTION dF THE PREFERRED E1~ODIME~TTS
~'he present invention is directed to a composition which
may be used to mold couplings for use with PVC snd other
plastic pipe to bridge an opening in a wall and function
a.s a fire stop for the opening. The composition
comprises 100 parts by we~.ght of a suitable pvG resin and
20 to 100 parts by weight of an l.ntumescent material such
as exfoliated graphite. Depending upon the nature of the
object to be molded, other optional ingredients may be
added such as lubricants, foaming agents, plasticize:rsl.
modifiers, and a~racessing aids.
In a particularly preferred embodiment the composition is
utilized to ~.njection mold fire stop couplings and
compr~.ees 100 parts by weigh of PVC resin, 1 _ 5 to 3 . 0
parts by weight of one or more stabilizers, 0 to 5.0
parts by weight of one ox' more lubricants, 0 to 10 pares
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by weight of acrylic modifiers, 0 to 5.0 parts by weight
of an acrylic processing aid and up to 1.5 parts by
weight of a foaming agent. A particularly preferred
composition for infection molding contains 100 parts by
weight of PVC resins, 2.5 parts by weight of one or more
stabilizers, 4.9 parts bx weight of one or more
lubricants, 8.0 parts by weight of an acrylic modifier,
3.0 parts by weight of acrylic processing aid, 25 parts
by weight of exfoliated graphitA end 1.2 parts by weight
of a foaming agent.
other preferred embodiments of compositions according to
present inventipn contain 100 parts by weight of PVC
resins 2 to 3 parts by weight of one or more stabilisers,
25 to 1D0 parts by weight Qf exfoliated graphite, up to
1.2 parts by weight of foaming agent and up to 100 parts
by weight of one or more plasticizers- Particularly
preferred embodimerxts of these compositions contain 100
parts by weight of PVC xesin, 2 parts by weight of one or
more stabilizer, 25 to 85 parts by weight of exfoliated
graphite 0.6 to 1.2 parts by weight of foaming agent and
87 parts by weight of plastici~er.
the compositions according the present invention are
prepared in a conventional manner by mixing the
components of the compositions together and then molded
in a suitable opex'ation to form the fixe stop couplings
of the present invCntion. The fire Stop Couplings are
utilized to bridge apenings ~-n partitions such that when
the coupling is exposed to the high heat of a fire, the
intumescent material such as the exfoliated graphite
expands to close off the opening in the partition to
prevent the spread of fire through the opening. The
amount of foaming ageri't and intumescent mater~.al in the
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compositions can be adjusted to give the proper amount of
expansion to close off the openir~g upon exposure to the
heat of the fire. Ey providing the coupling as a fire
stop it is nat nec~asary to install additional fire stop
material when a P'tlC pipe bridges an opening. Rather, the
~ire stop coupling is used to join two pieties o~ PVC pipe
to~ethar through the opening. This makes the
installation of the piping systems much easier and
reduces costs associated with pip9 iristallatl.ons.
Although various preferred embodiments of the present
invention have been described herein in detail, it will
be appreciated by those skilled iri the art that
variations may be made thereto without departing from the
spirit of the invention.
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