Note: Descriptions are shown in the official language in which they were submitted.
1 17(::96~3
.
Back~round and Summary of the Invention
By definition a retroreflective material is
a material which when engaged by a beam of light will
reflect the li~ht directly back to the location of the light
source. Such a material is commonly used in roadways and
aircraft runways to define the outer edges and/or center
line of the roadway so that when engaged by headlights
of a vehicle at night, the operator of the vehicle will
be able to visually perceive and determine the roadway
edges and/or center line.
Retroreflective material is also marketed in the
form of a thin film, usually with an adhesive backing on
one surface thereof, whereby the retroreflective film may
be adhered to a person's clothing for safety purposes, i.e.
to make that person more readily discernible at night by
the headlights of approaching vehicles, or for securing
to any other surface where retroreflective characteristics
are desired, such as roadsigns, etc. U. S. Patent
No. 3,849,804 dated November 26, 1974; No. 3,276,416 dated
October 4, 1966,and No. 3,499,416 dated March 10, 1970, are
representative of prior art patents that suggest the
attachment of light reflecting material to clothing,
automobiles, safety belts, etc., although it is not
clear whether the reflective material used in these
-2- ~ '
117V~6~3
.:
patents is actually retroreflective material.
In any event, there are numerous disadvantages
. to having to secure a light reflecting film to fabric
material, and specifically, a problem exists in effecting
a secure attachment of the film to the fabric because of
the flexibility of the latter, there is always the danger
that the film will inadvertently become detached, and
additionally one must necessarily suffer the expense and
inconvenience of spearately purchasing the light reflective
film, and then going through the steps of cutting the
reflective film to the desired size or configuration and
then attaching it to the fabric or garment, etc.
It therefore would be highly desirable to provide
a yarn which includes as a part thereof retroreflective
fibers so that when said yarn is woven, knit~ed or spun
to provide a finished fabric and/or garment, the latter
will inherently have retroreflective characteristics. Such
garments would have obvious utility for persons who jog
in the nightti~e, policemen on traffic duty in heavily
congested areas at nighttine, etc. The problem, however,
is that the retroreflective film presently being marketed
does not have sufficicnt body or strength so as to be effect-
ively handled if cut or slit into the form of elongated strands
of fibers. Specifically, the elasticity of the material
~17(~96~
as well as the inherent weakness thereof preclude effective
use of such strands, even as part of a composite yar-n, for
conventional weaving, knitting, spinning, etc.
It is therefore the primary object of the present
invention to provide a method of making a continuous thread-
like fiber of retroreflective material which nevertheless
has sufficient strength and body so that it may be
effectively combined with other fibers to provide a composite
yarn which has retroreflective characteristics, which composite
yarn may then be conventionally woven, knitted or spun to
provide a fabric or garment having retroreflective
characteristics.
The present invention, therefore, may be considered as
providing a retroreflective thread-like fiber comprising a
first elongated strand of a thin film of retroreflective
material consisting of a plurality of exposed minute glass
beads bonded in a flexible elastomeric material and a second
elongated strand of a thin flexible support.ing film adhered.
to the retroreflective material so as to provide a laminate
defined by the retroreflective material on one surface and
the supporting film on the opposite surface.
Furthermore, the present invention may be considered as
providing a method of making a thread-like continuous fiber
having retroreflective characteristics and having sufficient
structural strength to permit it to be effectively used during
knitting, weaving or spinnlng of a composite yarn or fabric
consisting of the following steps: (A) providing a thin film
of retroreflective material consisting of a plurality of
sd/~ -4-
117~9~
exposed minute glass beads bonded in a flexible elastomeric
material; (B) la~,inating thereto a thin flexible supporting
film so as to provide a laminate defined by the retro-
reflective material on one surface and the supporting film
on the opposite surface; and (C) slitting the laminate into
elongated thread-like fibers.
Other objects, features and advantages of the
invention shall become apparent as the description thereof
proceeds when considered in connection with the accompanying
~l~lustrative drawings.
sd/~ -4A-
117V968
Description of the Drawing
In the drawing which illustrates the best mode
presently contemplated for carrying out the present
invention:
Fig. 1 is a schematic perspective view illustrating
the process for forming the thread-like retroreflective
fiber of the present invention;
Fig. 2 is a fragmentary perspective view,
on a greatly enlarged scale, showing the retroreflective
fiber per se;
Fig. 3 is a schematic view of apparatus for
combining a retroreflectivefiber of the presen. invention
with another fiber for providing a composite yarn having
retroreflective characteristics; and
Fig. 4 is a fragmentary enlarged view of the
yarn per se produced by the apparatus of Fig. 3.
117~968
Description of the Invention
Referring now to the drawing, and more
particularly to Fig. 1, a first roller 10 carries and
feeds a supply of a thin retroreflective film 12, such as
the retroreflective film presently being marketed by the
r,~
3M Company and identified as ~t8710 Scotch Lite brand transfer film.
The retroreflective film 12 preferably has a thickness of
approximately 5 mils and is provided with an adhesive, either
of the pressure or heat sensitive type, on surface 14
thereof. A similar roller 16 carries and feeds a thin
polyester film 18, such as Mylar (Dupont trademark), the
thickness of which is preferably in the range of 1/2 mil.
As will be noted, the film 18, which is of the same width
as the film 12 and is aligned therewith, is brought into intimate
contact with adhesive surface 14 of the retroreflective film
12 by rollers 22 and then the two layers of film are passed
between pressure rollers 24, 26 which firmly adhere the
supporting film 18 to the retroreflective film 12. It will
be understood that if heat is required to effect the desired
securement of film 18 to the film 12, then the rollers 24, 26
may be heated rollers. The now laminated film 28 then passes
to any conventional slitting or cutting apparatus 30 which
apparatus slits or cuts the laminated film 28 into thin
strands or fibers 32 which are then received and stored on
1~7~396~3
spools 34. The width of the strands or fibers 32
may vary but will normally be somewhere in the range 1/16
of an inch to 1/100 of an inch.
In order to enhance the reflective characteristics
of the strand or fiber 32, as well as the aesthetics thereof,
the supporting film 18 may be metallized on one or both
of its surfaces. If metallized on only one surface, then
obviously the non-metallized surface is the surface that
would be adhered to surface 14 of retroreflective film 12.
It will be understood that the retroreflective
film 12 is frequently marketed with carrier and/or
release films on opposite sides thereof. In this connection
the apparatus shown in Fig. 1 may also comprise means
(not shown) for automatically separating and removing the
carrier and/or release films from the retroreflective material
12 prior to the lamination of such material to the supporting
polyester film 18.
It will be understood that the supporting
polyester film 18 provides sufficient body and strength to
the laminated strand or fiber 32 so that the latter may
effectively be used in the weaving, knitting, or spinning
of fabrics. Although it is conceivable that a fabric could
be made entirely of the retroreflective strands 32, the
preferable procedure is to combine the retroreflective s~rand
117~6 !3
.:
~ith any other textile strand, either synthetic or non-
synthetic, in order to provide a composite yarn having
retroreflective characteristics. Fig. 3 illustrates the
continuous retroreflective fiber 32 being twisted or
otherwise combined with another nonreflective fiber 36
to provide a composite yarn 38 shown in detail in ~ig. 4.
It should also be noted that the retroreflective strand
or fiber 32 constructed in accordance with the present
invention may be utilized in the same apparatus and method
disclosed and discribed in my patent No. 3,382,655 dated
May 14, 1968. Specifically, the exact same apparatus and
method would be employed, except that instead of utilizing
the metallic yarn 17 ln my aforesaid patent, the retroreflective
yarn 32 would be substituted in place thereof. In either
I5 case, the resultant yarn would have sufficient retroreflective
fibers therein so as to acheive the desired retroreflective
characteristics. The composite yarn would then be used to
produce any desired fabric or article of apparel, such as
by conventional weaving, knitting or spinning techniques,
and the end product would likewise possess,as an integral
and inherent part thereof, the desired retroreflective
characteristics.
~ lile there is shown and described herein certain
specific structure embodying the invention, it will be
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117~96~3
manifest to those skilled in the art that various modifications
and rearrangements of the parts may be made without departing
from the spirit and scope of the underlying inventive
concept and that the same is not limited to the particular
forms herein shown and described except insofar as indicated
~y the scope of the appended claims,
