U.S. patent application number 14/397451 was filed with the patent office on 2015-03-26 for ground cover material.
The applicant listed for this patent is Extenday IP Limited. Invention is credited to Jonathan Dallas Toye.
Application Number | 20150083267 14/397451 |
Document ID | / |
Family ID | 49483561 |
Filed Date | 2015-03-26 |
United States Patent
Application |
20150083267 |
Kind Code |
A1 |
Toye; Jonathan Dallas |
March 26, 2015 |
GROUND COVER MATERIAL
Abstract
A woven ground cover sheet material woven from warp and weft
tapes and in which the thickness of warp tapes is reduced in
longitudinally extending opposite side margins of the material and
in one or more centre regions relative to the width of warp tapes
making up the balance of the material.
Inventors: |
Toye; Jonathan Dallas;
(Auckland, NZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Extenday IP Limited |
Auckland |
|
NZ |
|
|
Family ID: |
49483561 |
Appl. No.: |
14/397451 |
Filed: |
April 24, 2013 |
PCT Filed: |
April 24, 2013 |
PCT NO: |
PCT/NZ2013/000074 |
371 Date: |
October 27, 2014 |
Current U.S.
Class: |
139/384R |
Current CPC
Class: |
D03D 1/0035 20130101;
E02D 17/20 20130101; A01G 13/0268 20130101 |
Class at
Publication: |
139/384.R |
International
Class: |
D03D 1/00 20060101
D03D001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 26, 2012 |
NZ |
599591 |
Claims
1. A ground cover sheet material woven from warp and weft tapes,
wherein the material comprises regions of relatively thicker
(hereinafter: thicker regions) warp tapes and regions of relatively
thinner (hereinafter: thinner regions) warp tapes, the thicker
regions being at or adjacent one or both longitudinally extending
opposite side margins of the material, and one or more
longitudinally extending centre regions near or adjacent a notional
centre or fold line of the material, and the thinner regions making
up the balance of the sheet material.
2. A ground cover sheet material according to claim 1 wherein the
thicker regions are at both longitudinally extending opposite side
margins on either side of the material.
3. A ground cover sheet material according to claim 2 and
comprising two centre regions of thicker warp tapes spaced apart on
either side of the notional centre or fold line of the
material.
4. A ground cover sheet material according to any one of the
preceding claims wherein the warp tapes have a uniform thickness in
the thicker regions and a uniform thickness in the thinner
regions.
5. A ground cover sheet material according to any one of the
preceding claims wherein the warp tapes in the thicker regions are
between about 5 and about 300% thicker than the warp tapes in the
thinner regions.
6. A ground cover sheet material according to any one of the
preceding claims wherein the warp tapes in the thicker regions are
between about 10 and about 200% thicker than the warp tapes in the
thinner regions.
7. A ground cover sheet material according to claim 6 wherein the
warp tapes in the thicker regions are between about 20 and about
100% thicker than the warp tapes in the thinner regions.
8. A ground cover sheet material according to any one of the
preceding claims wherein each of the thicker regions is up to about
500 mm wide
9. A ground cover sheet material according to any one of the
preceding claims wherein each of the thicker regions is up to about
300 mm wide.
10. A ground cover sheet material according to any one of the
preceding claims wherein each of the thicker regions is between
about 20 and about 300 mm wide.
11. A ground cover sheet material according to any one of the
preceding claims wherein each of the thicker regions is up to about
200 mm wide.
12. A ground cover sheet material according to any one of the
preceding claims wherein each of the thicker regions is about 100
mm wide.
13. A ground cover sheet material according any one of claim 1 to
claim 11 wherein each of the thicker regions is, for the side
margins between about 140 and about 180 mm wide, and for the centre
regions between about 40 and about 60 mm wide.
14. A ground cover sheet material according to any one of the
preceding claims wherein the width of warp tapes is decreased in
the thicker regions relative to the width of warp tapes in the
thinner regions.
15. A ground cover sheet material as claimed in claim 14 in which
the warp tapes in the thicker regions have a width between about 1
and about 3 mm and the warp tapes in the thinner regions have a
width between about 3 and about 5 mm.
16. A ground cover sheet material according to any one of the
preceding claims wherein the transition between an inner edge of
each side margin and a thinner region warp tapes of the material is
marked by a line or other marking of contrasting colour.
17. A ground cover sheet material according to any one of the
preceding claims wherein the colour of the warp tapes in the
thicker regions contrasts to that of the balance of the sheet
material.
18. A ground cover sheet material according to any one of the
preceding claims wherein the warp and weft tapes are of a plastics
material.
19. A ground cover sheet material according to any one of the
preceding claims wherein the warp and weft tapes are substantially
flat.
20. A ground cover sheet material as claimed in any one of the
preceding claims wherein the material is reflective of at least
about 50% of visible light on at least one side of the
material.
21. A ground cover sheet material as claimed in any one of the
preceding claims wherein the material is reflective of at least 50%
of visible light and about 40% of the UV in the 280 to 400 nm
wavelength range on at least one side of the material.
22. A ground cover sheet material as claimed in any one of the
preceding claims wherein some or all tapes of a reflective material
are formed from a resin comprising a white pigment, which resin has
been formed by mixing a masterbatch consisting essentially of
between about 5 and about 90% by weight of a white pigment or
combination of pigments, and a first polymer, with a second polymer
such that the resin (masterbatch) comprising the white pigment
comprises between about 0.5 and about 50% by weight of the total
mixture.
23. A ground cover sheet material as claimed in claim 22 wherein
the white pigment is selected from zirconium, dioxide, magnesium,
zirconate, calcium zirconate, strontium zirconate, barium
zirconate, zirconium silicate, zinc sulphide, zinc oxide, calcium
carbonate, barium sulphate, magnesium oxide, strontium carbonate,
barium carbonate, titanium dioxide and potassium titantae.
24. A ground cover sheet material as claimed in either one of claim
22 or claim 23 wherein the material incorporates a compound or
compounds added to cause or increase the extent to which the
material reflects and/or absorption of radiation from the earth
(terrestrial (long wave or infrared) radiation).
25. A ground cover sheet material as claimed in either one of claim
22 or claim 23 wherein the material incorporates a compound or
compounds added to cause or increase the extent to which the
material allows transmission and/or absorption of radiation from
the earth (terrestrial (long wave or infrared) radiation).
26. A ground cover sheet material as claimed in either one of claim
22 or claim 23 wherein the material incorporates a compound or
compounds added to cause or increase the extent to which the
material reflects and/or absorbs solar radiation.
27. A ground cover sheet material as claimed in either one of claim
22 or claim 23 wherein the material incorporates a compound or
compounds added to cause or increase the extent to which the
material allows transmission and/or absorption of solar
radiation.
28. A ground cover sheet material as claimed in claim 18 wherein
the warp and weft tapes are formed from polyolefin, or an ethylene
alpha-olefin, or polyester, or a biopolymer, or a blend of any of
the foregoing.
29. A ground cover sheet material from warp and weft tapes of a
plastics material in which the thickness of warp tapes is increased
in: longitudinally extending opposite side margins of the material,
and one or more longitudinally extending centre regions near or
adjacent a notional longitudinal centre or fold line of the
material, relative to the thickness of warp tapes making up the
balance of the material.
30. A ground cover sheet material from warp and weft tapes of a
plastics material in which the thickness of warp tapes is increased
in: one or more longitudinally extending centre regions near or
adjacent a notional longitudinal centre or fold line of the
material relative to the thickness of warp tapes making up the
balance of the material.
Description
FIELD OF THE INVENTION
[0001] The invention relates to woven materials and particularly
but not exclusively to woven materials for use as ground covers or
other agricultural applications.
BACKGROUND OF THE INVENTION
[0002] Ground cover materials are used in agriculture for purposes
including moisture retention, water conservation, weed or sward
suppression, soil warmth retention, and for light reflecting.
[0003] Typically where the material is used primarily as a
reflective ground cover for light enhancement, the material is
rolled out in lengths onto the ground between rows of trees in an
orchard, rows of vines in a vineyard, or rows of berry fruit plants
for example, to increase the amount of light to which the plants
and in particular fruit are exposed, by reflection of light from
the material towards the fruit above. Each length of the material
needs to be suitably secured in place such that it will not be
dislodged during wind or movement of traffic over the materials. A
fastening system including a multiple number of prong fastening
components or "claws" may be fixed to thicker edges or side margins
of the sheet material by pushing the prongs of the fastening
components into the material so that prongs pierce and pass through
the material. In turn the prongs are fixed to adjacent trees, or
alternatively stakes or pegs inserted for that purpose, typically
but not necessarily by a length of elastic cord. The sheet material
will typically remain in place for some months, before being
removed and reused in a subsequent growing season or on another
crop in the same growing season.
[0004] Referring to FIG. 3a a roll of woven fabric material wound
around a core/spool/cylinder 4 and ready for dispatch is shown. The
fabric is made woven on a loom from warp and weft tapes. If a
circular loom is used, the fabric is first made into a tube, then
slit at one side along the length of the tube to form a sheet,
which is subsequently folded longitudinally in half and wound into
a roll about the core 4. If a flat loom is used, the fabric is
woven directly into a sheet, and subsequently folded longitudinally
in half and wound into a roll on the core 4. The sheet is
lengthwise folded before rolling onto the core 4 to reduce the size
of the roll for shipping and dispatch.
[0005] The warp tapes are the same thickness across the entire
material, but are narrower at the side margins (which are both at
region 3.1 after folding the material) than the remaining tapes in
the warp direction. The roll thickness is hence even as there is no
variation in the tape thickness across the warp tapes. The evenness
of the warp tapes allows the warp tension to be controlled across
the width of the fabric to assist in creating an even fabric.
[0006] Referring now to FIG. 3b, a roll of improved material is
shown having side margins 3.2 of increased thickness. In particular
the warp tapes are thicker in the side margins, which allows the
point of fastening to have greater strength than the other portions
of the fabric. The manufacturing process for this material is
similar to that described above. However thicker warp tapes at the
side margins (which lay adjacent one another once the material is
folded) creates a roll as in FIG. 3b that is difficult to stack.
Also the use of thicker warp tapes for the side margins during
weaving creates uneven tension on the warp tapes in the weaving
machine which in turn generates difficulty in maintaining the
overall evenness of the weaving process. Finally, the thicker
edges/side margins 3.2, when folded onto each other make it
difficult to roll up the length of material evenly (with a constant
axis of rotation) which places undesirable stress on the material
at the fold line after it has been rolled up.
[0007] In FIG. 3b the tapes at the opposite end to the open end 3.2
are exposed to additional winding pressure as this is where the
fold is. This pressure is experienced especially by the weft tapes
which are exposed to added winding tension as they are folded over
themselves to change direction 180 degrees.
[0008] It is an object of the present invention to provide a sheet
material that at least partially alleviates the abovementioned
difficulty, or to at least provide the public with a useful
choice.
SUMMARY OF THE INVENTION
[0009] In a first aspect the invention may broadly be said to
consist of a ground cover sheet material woven from warp and weft
tapes, wherein the material comprises regions of relatively thicker
(hereinafter: thicker regions) warp tapes and regions of relatively
thinner (hereinafter: thinner regions) warp tapes, the thicker
regions being at or adjacent one or both longitudinally extending
opposite side margins of the material, and at two or more
longitudinally extending centre regions spaced apart on either side
of a notional centre or fold line of the material and nearer to the
notional centre or fold line of the material than to the
longitudinally extending opposite side margins of the material, and
the thinner regions making up the balance of the sheet
material.
[0010] Preferably the two or more longitudinally extending centre
regions spaced apart on either side of a notional centre or fold
line of the material are between 20 to 100 mm away from the
notional centre or fold line.
[0011] Preferably the sheet material comprises two side margins on
either side of the material of thicker warp tapes and two centre
regions of thicker warp tapes spaced apart on either side of the
notional centre or fold line of the material. Alternatively the
sheet material comprises a single centre region of thicker warp
tapes adjacent the notional centre or fold line.
[0012] Preferably the warp tapes have a uniform thickness in the
thicker regions and a uniform thickness in the thinner regions.
[0013] Preferably the warp tapes in the thicker regions are between
about 5-300% thicker or more preferably between about 10 and about
200% thicker than the warp tapes in the thinner regions, and even
more preferably between about 200 and about 100% thicker.
[0014] Preferably the width of each of the thicker regions is up to
about 500 mm or more preferably up to about 300 mm. Even more
preferably each of the thicker regions is between about 20 and
about 300 mm wide and most preferably between about 40 and about
200 mm wide. The width of the side margin may be different from the
width of the centre regions on each side of the centre fold line.
The centre regions may be between about 20 and about 200 mm, or
more preferably between about 30 and about 100 mm, and most
preferably between about 40 and about 80 mm in width. While the
side margins may be between about 20 and about 300 mm, more
preferably between about 40 and about 200 mm, and most preferable
between about 60 and about 180 mm in width.
[0015] Preferably the width of warp tapes is also decreased in the
thicker regions relative to the width of warp tapes in the thinner
regions.
[0016] In some embodiments the warp tapes in the thicker regions
have a width between about 1 and about 4 mm, more preferably
between about 2 and about 3 mm and the warp tapes in the thinner
regions have a width between about 2 and about 6 mm, more
preferably between about 3 and about 5 mm.
[0017] In some embodiments the thicker regions have a lower
porosity than the thinner regions.
[0018] In some embodiments the transition between an inner edge or
the inner portion of each side margin and a thinner region of the
material is marked by a line or other marking of contrasting
colour.
[0019] In some embodiments the colour of at least some of the warp
tapes in the thicker regions contrasts to that of the balance of
the sheet material.
[0020] Preferably the warp and weft tapes are of a plastics
material.
[0021] Preferably the ground cover material is woven from warp
tapes and weft tapes which are substantially flat.
[0022] Preferably the tapes that the material is woven from are not
folded on themselves, so they are placed or inserted into the
fabric so there is no placement density to cause folding of the
tapes.
[0023] In some embodiments the material is made of coloured
materials to give a coloured fabric including white, green, black
and other colours and even clear with no apparent colour.
[0024] In some embodiments the material is reflective of at least
about 50% of visible light on at least one side of the
material.
[0025] In some embodiments some or all tapes of a reflective
material are formed from a resin comprising a white pigment, which
resin has been formed by mixing a masterbatch consisting
essentially of between about 5 and about 90% by weight of a white
pigment or combination of pigments, and a first polymer, with a
second polymer such that the resin (masterbatch) comprising the
white pigment comprises between about 0.5 and about 50% by weight
of the total mixture.
[0026] Preferably the white pigment is selected from zirconium,
dioxide, magnesium, zirconate, calcium zirconate, strontium
zirconate, barium zirconate, zirconium silicate, zinc oxide, zinc
sulphide, calcium carbonate, barium sulphate, magnesium oxide,
titanium dioxide, strontium carbonate, barium carbonate, and
potassium titantae.
[0027] In some embodiments the material incorporates a compound or
compounds added to cause or increase the extent to which the
material reflects and/or absorption of radiation from the earth
(terrestrial (long wave or infrared) radiation).
[0028] In some embodiments the material incorporates a compound or
compounds added to cause or increase the extent to which the
material allows transmission and/or absorption of radiation from
the earth (terrestrial (long wave or infrared) radiation).
[0029] In some embodiments the material incorporates a compound or
compounds added to cause or increase the extent to which the
material reflects and/or absorbs solar radiation.
[0030] In some embodiments the material incorporates a compound or
compounds added to cause or increase the extent to which the
material allows transmission and/or absorption of solar
radiation.
[0031] Preferably the warp and weft tapes are formed from
polyolefin, or an ethylene alpha-olefin, or a polyester, or a
biopolymer, or a blend of any of the foregoing.
[0032] Typically sheet materials of the invention will be laid out
in lengths on the ground between rows of the crop being grown,
which may be trees, vines, bushes etc, to increase the amount of
light to which the plants and in particular the fruit are exposed,
by reflection of the light from the material back up towards the
crop above. At the end of a growing season, each length of material
is rolled up for storage. The thicker warp tape regions as defined
above enable the length of material to roll evenly after use. The
particular weight distribution achieved by employing the thicker
regions allows the material to maintain alignment as it is
rolled-up for storage.
[0033] At the time of manufacturing the combination of thicker side
margin warp tapes and the thicker warp tapes at the centre
region(s) in the even winding up of the roll by ensuring (or
supporting) the wind up tension to be more even across all warp
tapes. In addition the thicker warp tapes at the centre region(s)
reduce(s) the roll up tension on the tapes around the fold line.
The latter being especially the case for the weft tapes that are
folded at the centre line during manufacture.
[0034] The terms "thicker" and "thinner" as used in this
specification and claims are relative terms and not intended to be
limited to an absolute value or range of thicknesses unless
otherwise specified.
[0035] The term "comprising" as used in this specification and
claims means "consisting at least in part of". When interpreting
each statement in this specification and claims that includes the
term "comprising", features other than that or those prefaced by
the term may also be present. Related terms such as "comprise" and
"comprises" are to be interpreted in the same manner.
[0036] It is intended that reference to a range of numbers
disclosed herein (for example, 1 to 10) also incorporates reference
to all rational numbers within that range (for example, 1, 1.1, 2,
3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of
rational numbers within that range (for example, 2 to 8, 1.5 to 5.5
and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges
expressly disclosed herein are hereby expressly disclosed. These
are only examples of what is specifically intended and all possible
combinations of numerical values between the lowest value and the
highest value enumerated are to be considered to be expressly
stated in this application in a similar manner.
[0037] The invention consists in the foregoing and also envisages
constructions of which the following gives examples only.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The invention is further described by way of example with
reference to the accompanying drawings in which:
[0039] FIG. 1 shows use of a ground cover material of the invention
between two rows of orchard trees;
[0040] FIG. 2 shows use of a ground cover material and fixing of
the ground cover material in place by the use of a claw and cord
system, including a fastening component that penetrates the side
margins of the material;
[0041] FIG. 3a shows a possible completed roll of fabric after
being rolled but with no thicker side margin or warp tapes on
either side of the fold or centre line.
[0042] FIG. 3b shows a possible completed roll of another version
of a woven ground cover material with thicker side margin tapes
during manufacture;
[0043] FIG. 3c shows a possible complete roll of a woven ground
cover material during manufacture in accordance with a preferred
embodiment of the invention with thicker side margin and centre
region warp tapes;
[0044] FIG. 4a is an enlarged view of a warp tape at the thinner
regions of the preferred form ground cover material;
[0045] FIG. 4b is an enlarged view of a warp tape at the thicker
regions of the preferred form ground cover material;
[0046] FIG. 5 shows a close up view of a section of the woven
material of FIG. 1 at a centre region;
[0047] FIG. 6 shows a close up view of two centre regions of the
woven material of FIG. 1; and
[0048] FIG. 7 shows a close up view at a side margin of the woven
material of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0049] Referring to FIG. 1, agricultural sheeting 1 is shown in use
anchored underneath agricultural crops such as rows of orchard
trees 12 as a ground cover, which typically has reflective
properties to reflect solar radiation onto the fruit trees and
fruit from below. Typically long sections of the sheet material are
anchored along both edges between rows of orchard trees or vines.
The material is woven from flat warp and weft tapes of a plastics
material. Referring also to FIG. 2, in use fastening claws 13
connect to the sheeting along its edges, and in turn may connect to
clips usually by loops or lengths of extensible or optionally
inextensible material. The clips may in turn attach to staples
hammered into the spaced trees 12 as shown, or alternatively to
stakes or pegs hammered into the ground, or to a wire extending
along the row of the trees or vines, or to twine tied around the
tree trunk or vine, for example.
[0050] The sheet material comprises regions of relatively thicker
warp tapes 11 and regions of relatively thinner warp tapes (balance
of material). The regions of thicker warp tapes 11 (thicker
regions) are at one or both side margins and at least one centre
region adjacent to a notional centre or fold line 30 of the
material. The regions of thinner warp tapes (thinner regions) make
up the balance of the sheet material. In the preferred embodiment,
there are thicker warp tapes at both side margins and there are two
spaced centre regions of thicker warp tapes as shown in FIG. 1,
however, the invention is not intended to be limited to this
embodiment. In alternative embodiments there may be more than two
or only one centre region of thicker warp tapes and/or only one or
two side margin(s) with thicker tapes. The line 30 is preferably
along the centre of the material but it will be appreciated that in
alternative embodiments, the fold line 30 may not necessarily be
exactly at the centre of the material.
[0051] Referring to FIG. 3c, during manufacture, a length of
material 3 is woven, then folded and rolled about a spool 4 to form
a sheet of material 1 ready for dispatch. As discussed, a flat
sheet of material may be first formed directly from a flat loom, or
from a circular loom then slit on one side, before being
flattened/folded and rolled about the spool 4. The material 3 is
woven with thicker warp regions at at least one side margin 28 and
at least one centre region 29. The fabric or material in FIG. 3c is
folded (or flattened/closed in the case of a slit tube made from a
circular loom) in half prior to being rolled so that the two side
margins are on one end of the roll 28 and the other end 29 has the
folded section with the one or more centre regions of thicker warp
tapes. Only half of the width of the material 3 is visible in FIG.
3c as the other is folded underneath the first layer, so region 29
is near or adjacent the centre of the material 3. In the preferred
embodiment, the other half of the material 3 (not visible as it is
folded underneath) is a mirror image of the half shown in FIG. 3c.
Once woven (and cut on one side of the tube into a folded sheet in
the case of a circular loom), the sheet can be folded
longitudinally at its centre and then rolled up about a spool 4 for
efficient dispatch of the material to an end user. By employing one
or more thicker warp tape regions 29 at the centre of the sheet 1,
the material can be rolled up more evenly to maintain a more even
tension across the entire warp during the manufacturing process
than if the thicker warp tapes were only on the side margin(s). It
will be appreciated, that during manufacture, the material 3 may be
rolled about the core or spool 4 any number of times depending on
the desired length of the material, but in the preferred embodiment
the material is woven around the spool 4 to form a cylinder or roll
and then when unwound it can be cut along the length of the roll or
cylinder to then form one or more sheets 1 (one of which is shown
in FIG. 1) as desired by the end user.
[0052] Referring to FIG. 7, a side portion of a sheet of material 1
woven from warp (25a-c) and weft (25d) tapes is shown. The warp
tapes 25a towards the side edge 27a (the cut and seal edge on one
side of the fabric) of the sheet material have an increased
thickness compared to the warp tapes 25b at the thinner regions.
FIG. 7 shows one side margin 28a of thicker warp tapes 25a. The
thickness of the warp tapes is mirrored in the opposite side margin
(not shown) of the sheet material. The two opposing side margins
make up two of the thicker regions of the sheet material that when
folded and rolled are on the same side of the fabric in the
roll.
[0053] Referring now also to FIGS. 5 and 6, the warp tapes 25a in
two centre regions 29a/b are also thicker than warp tapes 25b at
the thinner regions making up the balance of the sheet material.
The two longitudinally extending opposed centre regions 29a/b are
spaced apart and located on either side of a notional longitudinal
centre or fold line 30 of the sheet material. The regions 29a and
29b are preferably equally separated from either side of the centre
line 30. They are placed between 20 to 100 mm away from the centre
or fold line. Weft tapes 25d are common/similar for the entire
material or fabric.
[0054] Referring now also to FIGS. 4a and 4b, typically the warp
tapes 25a in the thicker regions 28/29 of the material have a
thickness, T2, that is 5 to 300% or more preferably 10 to 200% or
most preferably 20 to 100% more than the thickness, T1, of the warp
tapes 25b at the thinner regions. Most preferably the thicker
regions 28a, 28b and 29a, 29b comprise warp tapes 25a that are 30
to 50% thicker than the warp tapes 25b of the thinner regions.
Preferably the warp tapes have a uniform thickness, T2, in the
thicker regions and a uniform thickness, T1, in the thinner
regions.
[0055] In one embodiment, the width `w` as in FIG. 7 of each of the
thicker regions across the longitudinal axis of the region may be
anywhere up to 500 mm wide or more preferably 300 mm. The width `w`
may be anywhere between 20 to 300 mm wide or more preferably
between 40 to 200 mm wide. The width of the side margin may be
different from the width of the centre regions on each side of the
centre fold line. The centre regions may be 20 to 200 mm, or more
preferably 30 to 100 mm, and most preferably 40 to 80 mm in width.
While the side margins may be 20 to 300 mm, more preferably 40 to
200 mm, and most preferable 60 to 180 mm in width. In the most
preferred embodiment, each of the thicker regions is 160 mm wide
for the side margins 28a/b and 50 mm wide for the centre regions
29a/b. The width `w`, in the preferred embodiment is larger at the
side margins 28a/b than at the centre regions 29a/b, however in
alternative embodiments, the width `w` may be uniform across all
thicker regions 28/29 or different for each region or even wider at
the centre region than the side margins.
[0056] The thickness, T2, of the side margins 28a/b (28b is not
shown but is the other side margin of the fabric of FIG. 7)
strengthen the side margins of the material, due to the thicker
side warp tapes, so that when the sheet is fixed in place using a
fixing system 13 (including fastening components in which prongs or
similar pierce through the side margins of the material), the
increased strength of the material provides more a secure coupling,
with reduced risk of tearing or enlargement of the holes formed
from prongs piercing through the material. In the preferred
embodiment, an indication means is provided to enable a user to
easily identify the stronger region 28a/b of the material. In the
preferred embodiment shown, each side margin 28a/b may be marked
with a pair of contrasting coloured warp tapes 25c that identify a
region for inserting a fixing component. In this case 25c is away
from the very edge 27a of the material or fabric as placement of
the fastening device so close to the edge is not recommended. In
another embodiment, a single contrasting coloured warp tape is used
at the junction between a side margin 28a/b and an adjacent thinner
warp tape region to identify the strengthened area. In yet another
alternative, the colour of all thicker warp tapes in the side
margins 28a/b may contrast to those in the adjacent thinner
regions. This marker or coloured lines guide the user the best
place to attach the fastening device.
[0057] Thicker regions 29a/b along the centre of the sheet are
provided to allow the material to roll up evenly after it has been
sealed and cut on the edge, 27a, then flattened or folded during
the manufacturing process. This adds convenience and also helps
alleviate the stresses on the material at the fold line 30 by
allowing the thicker raised tapes to alleviate the winding pressure
on the folded centre line of the material or fabric. When the
material is folded along its longitudinal centre line 30, the
centre region(s) 29a/b become opposed sides/edges to the thicker
side margins 28a/b. By creating a balance between the thickness of
the side margins and the thickness of the material at the fold
(i.e. at the centre region(s)), the material is caused to maintain
a more constant axis of rotation as it is rolled up to form the
balanced roll, ready for efficient stacking and dispatch. The
thicker warp tapes at the centre region(s) give a raised area 29 as
shown in FIG. 3c which helps balance the tension created by raised
area 28. The thicker warp tapes at the centre therefore assist in
roll evenness for stacking and transportation and also evens the
tension across the warp tapes during the weaving process.
[0058] It will be appreciated that the invention not intended to be
limited to the number of centre regions described for the preferred
embodiment, but rather is more concerned with providing a balanced
thickness/density between the edges of a folded material. In other
words, any number of centre regions of thicker warp tapes can be
employed adjacent or proximate to (but preferably not at) the
centre/fold lines to substantially balance out the thickness of the
side margins and allow the material to roll up substantially evenly
after it has been folded at the centre/fold line during
manufacture. In the preferred embodiment, the thickness of the warp
tapes at the centre region(s) and side margins are substantially
similar or equal to create this balance. It will be appreciated,
that the width of the thicker regions, the relative thicknesses of
the warp tapes at the thicker regions, as well as the
spacing/distribution of the centre regions are dependent on
particular desired properties of the material and can be altered
accordingly to provide the above described benefits without
departing from the scope of the invention. Preferably the centre
regions are closer to the centre or fold line than the side margins
of the material.
[0059] In the preferred embodiment shown, the warp tapes 25a in the
thicker regions 28/29 of the sheet material respectively have a
reduced width, w2, and a higher number of warp tapes per unit area
than the thinner regions making up the balance of the sheet
material. This allows the advantage of the narrower tapes 25a to be
in the side margins 28a and 28b and centre regions 29a/b and the
advantages of wider tapes 25b to be captured in the remaining parts
of the material. The side margins and centre region warp tapes do
not have to be narrower than the tapes in 25b but would be thicker
to capture the benefits as already discussed. Typically the width
of the warp tapes 25a in the thicker regions, w2, will be 20-80% of
the width, w1, of the warp tapes 25b of the thinner regions in the
balance of the material.
[0060] In a particularly preferred form the warp tapes 25a in
thicker regions of the material will be between 1 mm and 4 mm or
more preferably between 2 mm and 3 mm in width, while the other
warp tapes 25b will be between 2 mm and 6 mm or more preferably
between 3 mm to 5 mm in width. The weft tapes 25d which extend
transversely across the woven material are woven through both the
wider warp tapes 25b and the reduced width warp tapes 25a at either
side margin and at the centre regions of the material. In an
alternative embodiment, only the warp tapes 25a at the side margins
28a/b may have the reduced width and higher number of warp tapes
per unit area but are thicker.
[0061] Alternatively the centre region 29a/b warp tapes 25a are
narrower and the side margin 28a/b warp tapes 25a are of the same
width as the warp tapes 25b making up the balance of the material.
In another embodiment the tapes are all the same width and
difference is only in the tape thickness.
[0062] Preferably the ground cover material is woven from warp
tapes and weft tapes and wherein the warp and weft tapes are
substantially flat. If the tapes are folded then this would
generate thicker tapes where they occur but also areas of extra
pressure and possible weaknesses of the tapes at the folded
areas.
[0063] In an alternative embodiment, the thicker warp tape regions
are only at the one or more centre regions, and preferably at two
centre regions on either side of the fold line 30. In this
embodiment, the resulting roll would not be balanced from a winding
perspective but the fold line 30 would be protected from high
levels of winding pressure or tension.
[0064] Preferably the material is reflective of at least 50% or
alternatively at least 55% or alternatively at least 60% of visible
light on at least one side of the material. In one embodiment of a
reflective material the material may reflect at least 40% solar
radiation on average across the UV (wavelength about 280-400 nm),
visible (wavelength about 400-700 nm) and very near infrared
(wavelength about 700-800 nm) ranges, and which transmits at least
10% or 5% on average of solar radiation across the wavelength range
about 800-2500 nm. The material may reflect more solar radiation
than it transmits and absorbs in the UV, visible, and very near
infrared ranges. The material may transmit at least 15% or at least
20% of solar radiation on average in the wavelength range about
800-2500 nm. In another embodiment the material may reflect no UV
in the 280 to 300 nm or less than 40% or only 5% of the UV. Some or
all tapes of a reflective material may be formed from a resin
comprising a white pigment, which resin has been formed by mixing a
masterbatch consisting essentially of 5 to 90% by weight of a white
pigment or combination of pigments chosen from zirconium,
strontium, barium, magnesium, zinc, calcium and titanium pigments,
and a first polymer, with a second polymer such that the resin
(masterbatch) comprising the white pigment comprises between about
0.5 to 50% by weight of the total mixture. The material could also
be made from a premixed formula or compound so there is no polymer
to be added and the mixture is then extruded as a compound without
a masterbatch. In certain embodiments the white pigment may be
selected from zirconium, dioxide, magnesium, zirconate, calcium
zirconate, strontium zirconate, barium zirconate, zirconium
silicate, zinc sulphide, zinc oxide, calcium carbonate, barium
sulphate, magnesium oxide, strontium carbonate, barium carbonate,
titanium dioxide and potassium titantae.
[0065] In some embodiments the material may incorporate a compound
or compounds added to cause or increase the extent to which the
material reflects and/or absorption of radiation from the earth
(terrestrial (long wave or infrared) radiation). Thus when the
material is placed over or adjunct to plants it will assist in
retaining heat beneath the material, which may be desirable for
some plants or applications.
[0066] In some embodiments the material may incorporate a compound
or compounds added to cause or increase the extent to which the
material allows transmission and/or absorption of radiation from
the earth (terrestrial (long wave or infrared) radiation). Thus
when the material is placed over or adjacent to plants it will
assist in releasing the heat beneath the material, which may be
desirable for some plants or applications.
[0067] In other embodiments the material may incorporate a compound
or compounds added to cause or increase the extent to which the
material reflects and/or absorbs solar radiation. Thus when the
material is placed over or adjunct to plants it will assist in
cooling beneath the material, which may be desirable for some
plants or applications.
[0068] In other embodiments the material may incorporate a compound
or compounds added to cause or increase the extent to which the
material allows transmission and/or absorption of solar radiation.
Thus when the material is placed over or adjunct to plants it will
assist in increasing the heat beneath the material, which may be
desirable for some plants or applications.
[0069] The tapes may be formed from any suitable polyolefin such as
polyethylene or polypropylene, for example, or a mixture thereof,
or an ethylene alpha-olefin, or a polyester, or a biopolymer, or a
blend of any of the foregoing. Certain plastics are particularly
useful when present as minor or major components. Ethylene vinyl
acetate (EVA), ethylene butyl acrylate (EBA) and ethylene methyl
acrylate (EMA) are useful for imparting elasticity and other
properties. Polyesters and polystyrene, styrene-butdienie (SB),
acrylonitrile-butadienie-styrene (ABS), styrene-aciylonitrile
(SAN), polyethylenie terephithialate (PET), polymethylmethacrylate
(PMMA) and polycarbonate are useful as dye carriers and also for
influencing radiation (reflecting, absorbing and transmission)
properties and also other properties on the materials. Starch and
other plant polymers are useful to increase biodegradability.
Alternatively the tapes may comprise in part or whole of paper,
wood or cellulose fibre, starch based polymers, casein, latex or in
any combination of the above and/or with petroleum derived plastic
polymers. The polymer or polymer blend may incorporate agents such
as one or more pigments, UV stabilisers, or processing aids.
[0070] The foregoing describes the invention including a preferred
form thereof, alterations and modifications as will be obvious to
those skilled in the art are intended to be incorporated in the
scope hereof as defined in the accompanying claims.
[0071] While the preferred embodiment of the invention has been
illustrated and described, as noted above, many changes can be made
without departing from the spirit and scope of the invention.
Accordingly, the scope of the invention is not limited by the
disclosure of the preferred embodiment. Instead, the invention
should be determined entirely by reference to the claims that
follow.
* * * * *