Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to drapeable decorative sheet
material. There is a large demand for natural-looking drapeable
sheet materials which are used in window dressings and in floral
displays to conceal displaying surfaces, and the holders, foam
plastic blocks and the like, used to support floral itemsr thus
presenting a natural-looking setting. The preferred material for
this purpose is a form of moss known as "sheet moss" which occurs
in nature as a coherent sheet of intertwined leafy shoots. This
has excellent qualities of drapeability and appearance, but is
found in relatively few locations and is expensive. ~p to the
present time there has been, as far as the inventor is aware, no
acceptable substitute for the natural sheet moss material.
The present invention provides drapeable decorative sheet
material comprising a flexible film, a flexible adhesive layer
bonded to the film, and fragments of sphagnum moss adhering to
and substantially covering said adhesive layer, said fragments
comprising relatively large fibrous fragments upstanding from the
adhesive layer and having spacings between them, and relatively
smaller particulate fragments distributed on the adhesive layer
between the relatively large fragments.
This material may be manufactured relatively inexpensively, and
the relatively large fibrous Eragments of moss upstanding from
the surface of the sheet provide the material with an
outstandingly realistic mossy-textured appearanceO The
relatively small particulate fragments distributed on the
adhesive surface between the larger fragments serve to conceal
the adhesive and underlying film, and contribute to the natural
appearance.
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The material and its method of manufacture will now be described
in more detail, by way of example only, with reference to the
accompanying drawings wherein:
Figure 1 illustrates somewhat schematically successive stages in
the manufacturing process; and
Figure 2 shows a view from one edge of the sheet material.
The natural sphagnum moss used as a starting material for the
manufacture of the present sheet material, comprising leafy moss
shoots, has a somewhat unattractive grayish-green appearance, and
has a rather dry, brittle texture~ In order to improve the
appearance and texture of the sphagnum moss material it is
desirably impregnated with dye and with a humectant agent.
The preferred humectant agent is glycerin, preEerably employed in
solution in water in a ratio of about 1 part by volume glycerin
per 20 parts by volume water. Other humectants which will
preserve the moss fragments from drying out and acquiring a
brittle texture during storage may of course be employed.
In order to achieve a desired moss-green coloration, it will
usually be necessary to use a combination of green, yellow and
black dyes. Dye materials suitable for dyeing vegetable tissue
are in themselves well known. The preferred dye materials are
those that, once fixed to the vegetable material, are non-running
and non-staining on exposure to moisture. ~ypically, in order to
be fixed to the vegetable tissue, the dyes need to be applied
from a hot aqueous solution. In the example illustrated, bales
of natural sphagnum moss 1 are broken into manageable clumps, and
are placed in a tank 2 containing water, dissolved dye, and
humectant supplied from tanks 3, 4 and 5, respectively. The
tank 2 is equipped with a heating device 6, to maintain the con-
tents of the tank 2 at the desired elevated temperature. After asuitable period of impregnation, e.g. 10 to 30 minutes, the dyed
moss material is dried in a centrifuge 7, and subsequently in a
current of warm air in a tumble dryer 8, so that it is dry to the
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touch. The dried ma~erial is fed to a shredder or other size
reduction apparatus 9~ and the size-reduced moss material is
screened to separate it into relatively small and relatively
large-size fractions. Suitably, the screening is conducted in a
rotating cylindrical screen having its axis inclined downwardly,
and consisting of a first cylindrical screen section 11, of
relatively fine mesh, and a second cylindrical screen section 12
of relatively coarse mesh. The fine particles passing through
the section 11 are received in a bin 13, and the coarse sections
from the section 12 in a bin 14.
Preferably, the fine mesh section 11 has mesh openings in the
range about 1 to about 2.5 mm square, more preferably about 1 mm
square, and the coarse mesh section 12 has mesh openings about 4
to about 10 mm square, more preferably about 4 to about 8 mm
square.
The fraction recovered in the bin 13 consists predominantly of
small laminar particles, such as individual moss shoot particles
and fragments thereof, and short lengths of stems of the moss
material. Typically, this particulate fraction will comprise at
least about 60~ by weight of fragments having their largest
dimension no greater than about 3 mm. The relatively large
fragments of moss recovered through the screen 12, and obtained
from the bin 14 consist predominantly of short fibrous lengths of
the moss, and contains large amounts of leafy shoots. Typically
the fraction recovered in the bin 14 will comprise at least about
60~ by weight of fibrous fragments having their lengths in the
range about 4 to about 15 mm.
Material which does not pass through the screens, and exits
through the open end 15 of the screen 10, is received in a bin
16, and may be returned to the shredder 9, for further size
reduction. After numerous passes through the shredder 9 and
screen 10, the material may tend to contain an undesirably large
quantity of woody fibrous stems, and thus periodically the
material collected in the container 16 may be discarded, as
indicated by the line 17.
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In the preferred form, the flexible film material which forms the
substrate of the sheet material of the invention is a relatively
thin plastic film. The film need only be sufficien~ly strong to
withstand handling without undue risk of tearing, and is
desirably sufficiently thin that, for conve~ience of use in
floral arrangements, etc., it can readily be perforated by
pressing the ends of flower stems and other floral display items
firmly against it. Preferably, the film is a polyethylene film
with a thickness in the range about 0.001 to about 0.02 mm, more
preferably about 0.01 to about 0.1 mm. Desirably, the film is
one which is treated on the side which is to receive the adhesive
coating so as to be receptive to and to key firmly to coating
materials. Such treated films, which are intended to be
receptive to printing inks, paints, and the like, are in
themselves well knownO
In the example illustrated, the plastic film material 18 is drawn
continuously from a roll 19 thereof e.g. under the traction of a
pairs of driven rollers 20, e.g. at the far end of the production
line, over a guide roll 21, and through a coating box 22 where
the adhesive layer is applied. The box 22 has slots 23 and 24 at
its rear and front sides, through which the film is drawn, and an
opening 25 in its top into which a liquid adhesive composition is
supplied from a reservoir thereof 26. The adhesive employed is
one which, at least in relatively thin layers~ is flexible.
Preferably, the adhesive employed is a pressure sensitive
adhesive compositionl and more preferably is a water based
pressure-sensitive resin emulsion. The adhesive is coated onto
the film to form a layer which has sufficient thickness to firmly
anchor to it the moss fragments which are to be applied, but is
not so thick as to impart undue stiffness to the finished sheet
material. Preferably, the adhesive layer has a thickness of
about 0.05 to about 1 mm, more preferably about 0.1 to about 0.5
mm. Preferably, in order to assist in spreading the liquid
adhesive 27 evenly over the surface of the film 18, a spreader
device is provided within the coating box 22. The spreading de-
vice may be a metal rod 28, having generally circumferentially-
extending grooves in its surface, e.g. a continuous screw thread,
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which rests freely on the upper surface of the film 18, and is
retained loosely against the inner side of the front wall of the
coating box 22 in a position extending transversely of the film
18. The thickness of the film of adhesive applied to the film
may be varied by varying the diameter of the rod 28, and the
depth and the pitch of its grooves.
Screened moss fragments are then applied to the upper side of the
layer of tacky adhesive while this is still wet. ~elatively
large size fragments, obtained from the bin 14 are applied from a
hopper 29, which has downwardly inclining walls 30 terminating at
a lower opening 31 extending transversely across the width of the
film 18. In order to prevent the moss fragments 32 from lodging
within the hopper 29, a driven agitator shaft 33 may be provided
within the hopper. The shaft 33 is provided with transversely
extending agitator elements 34. A similar agitator device 35 may
be provided adjacent the opening 31, to prevent the moss frag-
ments from lodging in and blocking the opening 31. secause of
their fibrous and leafy-shoot-like nature, the relatively large~
fibrous fragments tend to interengage with one another as they
are applied onto the adhesive, do not form a mat completely
covering the adhesive layer, and leave spacings between them, at
which portions of the surface of the adhesive material are
exposed.
After the relatively large fragments have been applied, the
adhesive-coated film is passed under a rotating cylindrical
screen 36 and having a cylindrical surface 37 consisting of a
mesh having a mesh opening slightly larger than the mesh opening
of the first screen 11. The cylindrical screen 36 is driven to
rotate about its axis, which extends transversely of the film
18. The screen 36 is loaded with the relatively small
particulate screened material obtained from the bin 13 and, as it
rotates, it showers the particulate material onto the adhesive-
coated film.
These relatively small particulate fragments fill in the spacings
between the larger fibrous fragments applied from the hopper 29,
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and adhere to the entire exposed upper surface of the adhesive
layer, and thus provide the material with a substantially
complete covering of the moss fragments, so that there are no
areas of the adhesive layer which are left exposed.
Desirably, the moss fragments are applied to the adhesive-coated
film 18 while the film is being vibrated in a direction perpen-
dicular to its general plane. In the example illustrated, this
is achieved by disposing beneath the film 1~, in the region
adjacent the hopper 29 and screen 36 a series of square-section
bars 38, e.g. of wood. The bars 38 extend transversely beneath
the film 18, are driven to rotate about their axes and are
positioned such that the corners of the square bars rub on the
underside of the film 18 as they rotate, as illustrated.
Desirably, thin strips 39, e.g. of wood, are secured on the faces
of the square-section bars 3~, these strips extending longi-
tudinally along the faces of the bars 38 and transversely of the
film, and being of such thickness that, as the bars rotate, the
upper surfaces of the strips 39 also rub on the underside of the
film 18. The corners of the bars 38, and the edges of the
strips 39, as they engage the film 18, tend to displace the film
upwardly and downwardly, thus vibrating it in directions as
indicated by the small arrows in Figure 1 in a direction
perpendicular to its general plane. The vibration assists in the
penetration of the moss fragments within the liquid adhesive
composition 27, so that portions of the fragments contacting the
surface of the adhesive tend to become firmly anchored in the
adhesive layer. Also, the vibration results in the fragments of
moss applied to the adhesive, particularly the larger fibrous
fragments applied from the hopper 29 aligning themselves in
positions upstanding from the general plane of the film 18, thus
providing more realistic mossy-appearing lofty texture to the
fragment-coated material.
After coating the film with the fragments, any non-adhering
fragments are removed from the film by blowing them away with
streams of air directed downwardly from nozzle openings 40 spaced
transversely alonq the lower surface of a cylindrical plenum 41
extending transversely above the film 18, and supplied with air
from a blower 42.
The moss fragment-coated film is then passed through a drying
oven 43 wherein the film is heated for a period sufficient to dry
substantially all free moisture from the coating of water-based
adhesive 27 so that, in storage, free moisture from the adhesive
layer does not tend to be absorbed into the moss fragments, which
would tend to be subject to deterioration, e.g. mold or other
microbi~logical growth, if they remained moist for prolonged
periods. In the preferred form, the sheet material is heated
within the oven 43 by exposure to infrared radiation from infra-
red lamps 44. The infrared radiation is particularly effective
in heating the wet adhesive layer and driving moisture from it.
The dried sheet material, on exiting from the oven 43 is then
preferably severed into separate lengths 45, for example by
cutting it with a guillotine 46 on a board 47.
The resulting sheet material has an outstandingly natural-looking
mossy appearance. As illustrated in Figure 2, the adhesive layer
27 coated on the film layer 18 is substantially completely
covered with particulate relatively fine moss fragments, which
conceal the adhesive material 27. The relatively large sprig-
like fibrous fragments 49 of the moss which extend upwardly from
the surface of the sheet at irregular intervals and at various
attitudes, present a natural mossy-looking appearance and
texture.
An example of a method of making the drapeable mossy sheet
material will now be given.
Example
Using the apparatus illustrated in the drawings, bales of
sphagnum moss were broken into clumps by hand, and were immersed
in the tank 2 containing a solution of 1 volume glycerin ~.S.P.
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in 20 volumes of water. Also dissolved in the liquid in the tank
2 were the following dyes, employed in the parts by weight
indicated per 1 kg of moss:
SA~DOCRYL* Brilliant YellowB- 6GL200 - 100 g
SANDOCRYL* Black B- BLN- 50 g
Malachite Green 20 g
* trade marks
The above dyes were obtained from Sando~ Canada Inc., Dorval,
Quebec, Canada.
The treatment solution in the tank 2 was heated to 75 to 80C,
and the sphagnum moss was maintained in the solution for a period
of about 15 minutes. It was then removed, centrifuged, tumble
dried for 30 minutes, and passed to a Steinmax 1500 (trade mark)
chopper shredder machine, obtained from Steinmax Crones & Co.,
D-8800 Ansback, West Germany. The fragmented material obtained
from the chopper-shredder device was screened through the
cylindrical screen 10 having a fine mesh section 11 with mesh
openings about 1 mm square~ and a coarse mesh section 12 having
openings about 6.5 mm sguare.
The plastic film 18 was a 1 mil (approximately 0.025 mm)
thickness polyethylene film having its surface treated to be
receptive to aqueous-based compositions. The film employed was
that obtained under the designation 25 LT3 PA from DuPont Canada
Inc., Montreal, Quebec, Canada.
The adhesive 27 was a water based pressure-sensitive resin
emulsion available under the designation R1815 from Industrial
Adhesives division of Timminco Limited, Toronto, Ontario,
Canada. The adhesive was applied to the film 18 at a coating
weight of about 14 kg per 42 square metres of the film 18. The
adhesive composition had a density of about 1.13 kg/l, and was
thus applied to the film at a coating thickness of about 0.3 mm.
After application of the coarse fibrous moss fragments and the
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fine moss fragments and removal of excess, non-adhering
fragments, the moss fragment-coated film was passed through the
drying oven 43 and was dried under infrared radiation over a
period oE about 10 minutes.
The resulting film had a natural-looking mossy appearance, and
had excellent qualities of flexibility and drapeability.
