U.S. patent application number 13/226226 was filed with the patent office on 2011-12-29 for plant treatment material.
This patent application is currently assigned to EXTENDAY IP LIMITED. Invention is credited to Jonathan Dallas Toye.
Application Number | 20110314731 13/226226 |
Document ID | / |
Family ID | 35785498 |
Filed Date | 2011-12-29 |
United States Patent
Application |
20110314731 |
Kind Code |
A1 |
Toye; Jonathan Dallas |
December 29, 2011 |
PLANT TREATMENT MATERIAL
Abstract
Described is a reflective ground cover sheet material (1) in
which longitudinally extending opposite side margins (A) of the
sheet material are stronger than a longitudinally extending centre
section between the side margins of the material. Also described is
a reflective ground cover sheet material (1) having longitudinally
extending opposite side margins (A) of the sheet material of lower
porosity than a longitudinally extending centre section between the
side margins of the material.
Inventors: |
Toye; Jonathan Dallas;
(Auckland, NZ) |
Assignee: |
EXTENDAY IP LIMITED
Auckland
NZ
|
Family ID: |
35785498 |
Appl. No.: |
13/226226 |
Filed: |
September 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11572485 |
May 8, 2007 |
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PCT/NZ2005/000182 |
Jul 22, 2005 |
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13226226 |
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Current U.S.
Class: |
47/31 |
Current CPC
Class: |
A01G 13/0268
20130101 |
Class at
Publication: |
47/31 |
International
Class: |
A01G 13/02 20060101
A01G013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 22, 2004 |
NZ |
534251 |
Claims
1. A reflective woven which is longer than it is wide and which is
woven from warp and weft tapes at least some of which are spaced
apart from each other so that at least a longitudinally extending
center section of the material has a porosity comprising holes or
apertures through the material between spaced apart warp and weft
tapes of at least 2%, and wherein at least said longitudinally
extending center section of the material is reflective of at least
50% of visible solar light on at least one side of the sheet
material.
2. A reflective woven ground cover sheet material as claimed in
claim 1 having a porosity comprising holes or apertures through the
material between spaced apart warp and weft tapes of 2 to 15%.
3. A reflective woven ground cover sheet material as claimed in
claim 1 having a porosity comprising holes or apertures through the
material between spaced apart warp and weft tapes of 4 to 12%.
4. A reflective woven ground cover sheet material as claimed in
claim 1 having a porosity comprising holes or apertures through the
material between spaced apart warp and weft tapes of 5 to 10%.
5. A reflective woven ground cover sheet material as claimed in
claim 1 having a porosity comprising holes or apertures through the
material between spaced apart warp and weft tapes of 6 to 8%.
6. A reflective woven ground cover sheet material according to
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending section of the material, said longitudinally extending
side margins being stronger than said longitudinally extending
center section of the material, and wherein said longitudinally
extending center section of the material is wider transversely
across the sheet material than said side margins of the
material.
7. A reflective woven ground cover sheet material according to
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending section of the material, said longitudinally extending
side margins being of lower porosity comprising holes or apertures
through the material between spaced apart warp and weft tapes, than
said longitudinally extending center section of the material, and
wherein said longitudinally extending center section of the
material is wider transversely across the sheet material than said
side margins of the material.
8. A reflective woven ground cover sheet material according to
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending section of the material, said longitudinally extending
side margins being woven with a tighter or denser weave than said
longitudinally extending center section of the material, and
wherein said longitudinally extending center section of the
material is wider transversely across the sheet material than said
side margins of the material.
9. A reflective woven ground cover sheet material woven according
to claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending center section of the material and in which a width of
warp tapes is reduced in said side margins of the material relative
to the width of the warp tapes in said longitudinally extending
center section of the material, and wherein said longitudinally
extending center section of the material is wider transversely
across the sheet material than said margins of the material.
10. A reflective woven ground cover sheet material according to
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending section of the material and in which a thickness of the
warp tapes is greater in said longitudinally extending side margins
of the material relative to a thickness of the warp tapes in said
longitudinally extending center section of the material, and
wherein said longitudinally extending center section of the
material is wider transversely across the sheet material than said
margins of the material.
11. A reflective woven ground cover sheet material as claimed in
claim 6 in which said side margins extend up to about 300 mm in
from either side edge of the material.
12. A reflective woven ground cover sheet material as claimed in
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending section of the material and in which the warp tapes in
the side margins have a width between about 1 and about 3 mm and
the warp tapes in said longitudinally extending center section of
the material have a width between about 3 and about 5 mm.
13. A reflective woven ground cover sheet material as claimed in
claim 1 in which at least in said longitudinally extending center
section of the material the warp and weft tapes have not been
folded or twisted during weaving or have been folded or twisted
minimally, so that there is not more than one fold or twist per 10
m.sup.2 surface area of said longitudinally extending center
section of the material.
14. A reflective woven ground cover sheet material as claimed in
claim 1 wherein the warp and weft tapes are substantially flat.
15. A reflective woven ground cover sheet material as claimed in
claim 1 woven from warp tapes and weft tapes of a plastics
material.
16. A reflective woven ground cover sheet material as claimed in
claim 1 having longitudinally extending opposite side margins one
on either side of said longitudinally extending center section of
the material and in which a transition between an inner edge of
each said side margin and said center section of the material is
marked by a line or other marking of contrasting color.
17. A reflective woven ground cover sheet material as claimed in
claim 1 having longitudinally extending opposite side margins one
each on either side of said longitudinally extending center section
of the material between the side margins and woven from warp tapes
and weft tapes and in which the color of all the warp tapes in the
side margins contrasts to that of the balance of the sheet
material.
18. A reflective woven ground cover sheet material according to
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally center
section of the material and in which the chemical composition of
warp tapes in said side margins of the material is different than
that of warp tapes in said longitudinally extending center section
of the material to strengthen said side margins of the material or
to increase the resistance of said side margins of the material to
strength degradation from exposure to the external environment or
aging, relative to said center section of the material.
19. A reflective woven ground cover sheet material according to
claim 1 having longitudinally extending opposite side margins of
the sheet material one on either side of said longitudinally
extending center section of the material and in which said
longitudinally extending opposite side margins of the material have
had applied thereto one or more agents to strengthen said side
margins of the material or to increase the resistance of said side
margins of the material to strength degradation from exposure to
the external environment or aging, relative to said center section
of the material.
20. A reflective woven ground cover sheet material as claimed in
claim 19 in which said one or more agents has been sprayed or
otherwise overcoated onto said warp and weft tapes in said side
margins of the material.
21. A reflective woven ground cover sheet material as claimed in
claim 20 wherein said one or more agents comprises one or more of
polyproylene, polyester, polyethylene, a polyvinyl
acrylonitrile-butadiene-styrene, styrene-acrylonitrile,
polyethylene terephthalate, polymethylmethacrylate, polycarbonate,
and ethylene alpha-olefin.
22. A reflective woven ground cover sheet material as claimed in
claim 20 wherein said one or more agents include at least one light
or heat stabilizer.
23. A reflective woven ground cover sheet material according to
claim 1 wherein at least said longitudinally center section of the
material is colored white.
24. A reflective woven ground cover sheet material as claimed in
claim 7 in which said side margins extend up to about 300 mm in
from either side edge of the material.
25. A reflective woven ground cover sheet material as claimed in
claim 8 in which said side margins extend up to about 300 mm in
from either side edge of the material.
26. A reflective woven ground cover sheet material as claimed in
claim 9 in which said side margins extend up to about 300 mm in
from either side edge of the material.
27. A reflective woven ground cover sheet material as claimed in
claim 10 in which said side margins extend up to about 300 mm in
from either side edge of the material.
Description
RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/572,485, filed May 8, 2007, which is the
National Stage of International Application No. PCT/NZ2005/000182
filed Jul. 22, 2005 claiming the benefit of New Zealand Patent
Application No. 534251 filed Jul. 22, 2004, the entire disclosures
of each of which are hereby incorporated by reference herein.
FIELD OF INVENTION
[0002] The invention relates to woven materials and particularly
but not exclusively to woven materials for use as ground covers or
other agricultural applications.
BACKGROUND
[0003] Ground cover materials have been used in agriculture for a
number of purposes. These include moisture retention, water
conservation, weed or sward suppression, soil warmth retention and
for light reflecting.
[0004] 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 the 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.
[0005] 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. During the
period in which the material is in place fixed to the ground wind
may apply substantial loading to the fastening system by which the
material is fixed to the ground.
SUMMARY OF INVENTION
[0006] In broad terms in one aspect the invention comprises a
reflective ground cover sheet material in which longitudinally
extending opposite side margins of the sheet material are stronger
than a longitudinally extending centre section between the side
margins of the material.
[0007] Preferably the sheet material is formed from warp and weft
tapes of a plastics material.
[0008] Preferably the width of the warp tapes is reduced so that
the material has a higher density of warp tapes, or the thickness
of the warp tapes is increased, in the side margins between the
outer edge of the material generally parallel to the warp tapes to
about 150-200 mm in from either side edge of the material towards
the centre of the material.
[0009] Preferably the transition between the reduced width or
increased thickness warp tapes at the side margins of the material
and the greater width or lower thickness warp tapes is marked by a
line or other marking of contrasting colour. Alternatively the
colour of all of the reduced width or increased thickness warp
tapes may contrast slightly to that of the balance of the sheet
material.
[0010] Optionally the warp tapes in side margins of the material
may be of both greater width and increased thickness than the warp
tapes between the side margins of the material.
[0011] In broad terms in a further aspect the invention comprises a
woven ground cover sheet material woven in which the width of warp
tapes is reduced in longitudinally extending opposite side margins
of the material relative to the width of warp tapes in a
longitudinally extending centre section between the side margins of
the material.
[0012] In broad terms in a further aspect the invention comprises a
woven ground cover sheet material in which the thickness of warp
tapes is increased in longitudinally extending side margins of the
material relative to the thickness of warp tapes in a
longitudinally extending centre section between the side margins of
the material. In the material of the invention the side margins of
the material, in which the warp tapes are of reduced width and
higher density, or are of increased thickness, are stronger than
the balance of the material. When the sheet is fixed in place and
using a fixing system including prong fastening components or
claws, or similar, which pierce through the side margins of the
sheeting material, the increased strength of the side margins
provides more secure fixing of the material, with reduced risk of
tearing or enlargement of the holes formed when the prongs pierce
through the material which increases risk of dislodgement of the
fastening components. At the same time the major part of the sheet
material may be woven with warp tapes, and weft tapes, having a
width greater than that of the warp tapes in the side margins, as
may be desirable to optimise the tape width for the particular
property desired from the ground cover. For example wider tapes may
provide higher porosity or ease of movement through the material
(see below) to wind, air, dirt, soil and water.
[0013] In broad terms in a further aspect the invention comprises a
woven ground cover sheet material woven with a tighter weave in
longitudinally extending opposite side margins of the material than
in a longitudinally extending centre section between the side
margins of the material. That is, the width & thickness of the
tapes in the side margins of the material may be the same as in the
centre section of the material but the weave of the material in the
side margins may be tighter to give the side margins increased
strength as referred to above.
[0014] In broad terms in a further aspect the invention comprises a
woven ground cover sheet material in which the chemical composition
of warp tapes in longitudinally extending opposite side margins of
the material is different to that of warp tapes in a longitudinally
extending centre section between the side margins of the material
to strengthen the side margins of the material relative to the
longitudinally extending centre section of the material, or to
increase the resistance of the side margins of the material to
strength degradation from exposure to the external environment
and/or aging, relative to said longitudinal centre section of the
material. In broad terms in another aspect the invention comprises
a reflective ground cover sheet material in which longitudinally
extending opposite side margins of the material have had applied
thereto one or more agents to strengthen the side margins of the
material relative to a longitudinally extending centre section of
the material, or to increase the resistance of the side margins of
the material to strength degradation from exposure to the external
environment and/or aging, relative to said longitudinal centre
section of the material.
[0015] In one form said one or more agents are incorporated in a
resin from which warp tapes of a plastics material of the side
margins of the material are formed. An increase in resistance of
the side margins to strength degradation can come from the type or
concentration of light or heat stabilisers used, or by the type of
polymer resins or additives to the main polymer resin, for these
side margin tapes in the warp direction. Alternatively for example
said one or more agents may be sprayed or otherwise overcoated onto
the side margins of the material after manufacture of the
material.
[0016] Preferably said one or more agents includes at least one
light or heat stabiliser or processing aids which will increase the
resistance of the side margins of the material to degradation
through exposure from solar radiation or heat or chemical or
environmental degradation in an external environment. Additionally
or alternatively said one or more agents include at least one agent
which increases the strength of a plastic material from which the
side margins are formed. Another agent to increase the strength of
the side margin could be the use of different polymers from the
main body of the fabric. These polymers could be either on their
own or in combination polypropylene, polyester, polyethylene,
polyvinyl acetates, low density polyethylene, linear low density
polyethylene, ethylene butyl acrylate, ethylene methyl acrylate,
polystyrene, styrene-butadiene, acrylonitrile-butadiene-styrene,
styrene-acrylonitrile, polyethylene terephthalate,
polymethylmethacrylate, polycarbonate, and ethylene
alpha-olefin.
[0017] In the material of this aspect of the invention the side
margins of the material are stronger than the balance of the
material, so that when the sheet is fixed in place as referred to
previously, the increased strength of the side margins provides
more secure fixing of the material with reduced risk of tearing or
enlargement, especially when under load, of the holes formed when
the prongs pierce through the material. The approach here is to
increase the strength of the weakest link of the material that
affects its longevity, to give an overall material with a longer
life in order to give users a useful choice to extend the life of
the material. Alternatively the side margins of the material may
have equivalent strength to that of the centre section of the
material initially, but the side margins are more slowly degraded
from exposure to the external environment such as solar radiation,
or from aging generally, and maintain their strength for longer, so
that the material will remain securely fixed with reduced risk of
tearing or enlargement of the holes formed in the side margins of
the material when the prongs pierce through the material, then the
material is subjected to wind loading for example. It may also be
possible to reuse the material for more subsequent seasons than
would otherwise be the case and thus achieve a longer useful life
from the material.
[0018] In broad terms in a further aspect the invention comprises a
reflective ground cover sheet material having longitudinally
extending opposite side margins of the sheet material of lower
porosity (as herein defined) than a longitudinally extending centre
section between the side margins of the material.
[0019] In broad terms in a further aspect the invention comprises a
ground cover sheet material in which longitudinally extending
opposite side margins of the sheet material have a lower porosity
(as herein defined) than a longitudinally extending centre section
between the side margins of the material.
[0020] In broad terms in a further aspect the invention comprises a
reflective ground cover sheet material in which longitudinally
extending opposite side margins of the sheet material are stronger
and have a lower porosity (as herein defined) than a longitudinally
extending centre section between the side margins of the
material.
[0021] In broad terms in a further aspect the invention comprises a
woven ground cover sheet material woven in which the width of warp
tapes is reduced and the thickness of the warp tapes is increased
in longitudinally extending opposite side margins of the material
relative to the width of and thickness of warp tapes in a
longitudinally extending centre section between the side margins of
the material.
[0022] In broad terms in a further aspect the invention comprises a
reflective ground cover sheet material woven from warp tapes and
weft tapes in which the warp and weft tapes have not been folded or
twisted during weaving or have been folded or twisted minimally, so
that there is not more than one fold or twist per 10 m.sup.2
surface area of the material at least in the centre section of the
material.
[0023] In broad terms in a further aspect the invention comprises a
reflective ground cover sheet material in which the transition
between an inner edge of each side margins and the centre section
of the material is marked by a line or other marking of contrasting
colour.
[0024] In broad terms in a further aspect the invention comprises a
reflective ground cover sheet material woven from warp tapes and
weft tapes and in which the colour of all of the warp tapes in the
side margins contrasts to that of the balance of the sheet
material.
[0025] In broad terms in a further aspect the invention comprises a
reflective ground cover sheet material having a porosity (as herein
defined) of at least 2%.
[0026] Preferably, the material has a porosity of at least 2%.
[0027] Preferably the material has a porosity up to 15%, more
preferably 4-12%, even more preferably 5-10%, and most preferably
6-8%.
[0028] By "porosity" is meant the percentage of the surface area of
the material which is made up of holes or apertures through the
material, between spaced apart warp and weft tapes of the material
for example, relative to the overall surface area of the material.
For example a material having warp and well tapes spaced apart from
each other so that the air space between the warp and well tapes
constitutes 8% per square metre surface area of the material will
have a porosity of 8%. The porosity is made up of small evenly
spaced apertures rather than large holes. Thus the porosity is
generated by weaving the tapes so that there is some tree space
between the tapes, such that they are not butted up hard against
each other as is the current practice.
[0029] By having a low porosity with the tapes butted up hard
against each other, this leads to twisting during manufacture. This
twisting and folding generates areas for dirt to collect. This
reduces the light reflectivity and/or light transmission of the
material or otherwise reduce the reflectivity or strength or life
of the material.
[0030] By "reflective" in general is meant that the material is
reflective of at least 50% of visible light on at least one side of
the material.
[0031] Generally it is considered essential for ground cover
materials to be either extruded film materials or tightly woven
materials having minimal porosity, to effectively suppress weed
growth and/or maximise light reflection from the upper surface of
the material. The material of the invention may be formed so as to
have acceptable reflectivity while the relatively high porosity of
the material reduces the sail-effect of the material during windy
periods as wind or air may pass through the more porous material,
which reduces the mechanical loading on the fixing system which
fixes the material in place and therefore reduces the likelihood of
the material becoming dislodged and/or damage to the material
and/or the fixing system. Additionally the more porous material
allows more air movement between the ground and the air above the
ground cover. Also with reflective ground covers there can be
occasions where excessive moisture is beneath the material, which
can be a disadvantage particularly when the material is laid
between rows of trees or vines or plants, and tractor movement over
the material occurs. Excessive soil moisture beneath the ground
cover can lead to tractor wheel marking and soil compaction. With
the more porous material of the invention water from irrigation or
rainfall can pass more readily and rapidly through the ground cover
material, so that ponding (or where water from rainfall or
irrigation runs across the material to collect at the lower areas)
of water on the material is reduced, which can result in uneven
water distribution to the soil underneath the material. 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, and the
materials are referred to in the specification as "ground cover
sheet materials". It is possible however that the materials may be
suspended or positioned above the ground in a vertical or angled
position to reflect the solar radiation onto the crop, for example
on either side of the crop row, for example trees, and held in
position by guy ropes or attached to wires that are positioned
along the row direction or poles or a frame, and the expression
"ground cover sheet material" is intended to encompass materials
for such applications also.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The invention is further described by way of example with
reference to the accompanying drawings in which:
[0033] FIG. 1 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;
[0034] FIG. 2 shows a single fastening component;
[0035] FIG. 3 shows a section of woven material according to one
aspect of the invention;
[0036] FIG. 4 shows a construction of the side margin of the
material with a marker tape 40 mm in from the edge marking the
start of the fastener attachment area and another marker tape 160
mm in from the edge marking the end of the fastener attachment
area, and a batch marker tape;
[0037] FIG. 5 shows another construction of the side margin of the
material with a marker tape 40 mm in from the edge marking the
fastener attachment area on either side of the marker tape
depending on the fastener method;
[0038] FIG. 6 shows a section of woven material according to
another aspect of the invention; and
[0039] FIG. 7 shows use of a ground cover material according to
another aspect of the invention between two rows of trees with an
attachment system including fastening components which penetrate
reinforced side margins of the material where there is extra
strength and lower porosity relative to the central area of the
material which has higher porosity.
DETAILED DESCRIPTION OF THE DRAWINGS
[0040] Referring to FIG. 1, agricultural sheeting 1 is anchored
underneath agricultural crops such as rows of orchard trees 4 as a
ground cover, which typically has reflective properties to reflect
solar radiation onto the fruit trees and fruit from below. In FIG.
1 only part of the sheeting is shown. 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. Fastening claws 20 connect to
the sheeting along its edges, and in turn may connect to clips 10
usually by loops or lengths of extensible or optionally
inextensible material 30. The clips 10 may in turn attach to
staples 5 hammered into the spaced trees 4 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.
[0041] By way of example one form of fastening claw 20 is shown in
more detail in FIG. 2 and includes two arms 21 which extend to
prongs 22 on either side, which prongs are in use forced through
and pierce the sheeting 1. The fastening claws or equivalent
fastening components may be of other forms however. The claw 20 and
clip 10 are shown connected by a loop 30 of extensible or
optionally inextensible material.
[0042] FIG. 3 shows the side margin of one form of sheet material
of the invention. The side margin area shown in FIG. 3 is the area
A indicated and bounded by broken lines in FIG. 1. The sheet
material is woven from longitudinally extending warp tapes 25a and
25b and transverse weft tapes 26. The tapes are flat plastic tapes
either or both of which are formed from a polymer containing
pigments which give the ground cover material the desired light
reflective and transmissive properties. Typically the tapes are
formed by extruding a film material from the polymer resin and then
cutting the film into tapes which are in turn used to weave the
woven material. The tapes from which the material is woven may be
formed by any other suitable process however.
[0043] The warp tapes 25a towards the side edge 27 of the sheet
material have a reduced width and higher number of warp tapes per
unit area than the warp tapes 25b making up the balance of the
sheet material. Typically the width of the warp tapes in the side
margins of the material will be 20-80% of the width of the warp
tapes of the balance of the material.
[0044] In a particularly preferred form the warp tapes 25a in the
side margins of the material will be between 1 mm and 9 mm in
width, while the other warp tapes 25b will be between 2 mm and 10
mm width. The weft tapes which extend transversely across the woven
material are woven through both the wider warp tapes and the
reduced width warp tapes at either side margin of the material. In
some cases the reinforced margin may only be required on one side
of the cover.
[0045] Preferably the width of the warp tapes is reduced so that
the material has a higher density of warp tapes, in the side margin
between the outer edge of the material generally parallel to the
warp tapes to about 40 to 200 mm in from either side edge of the
material towards the centre of the material.
[0046] The side margins of the material, in which the warp tapes
are of reduced width and higher density, tend to be stronger than
the balance of the material with the increased number of tape cross
overs. When the sheet is fixed in place and using a fixing system
including fastening components as shown in FIGS. 1 and 2 in which
prongs or similar fastening components pierce through the side
margins of the sheeting material, the increased strength of the
side margins provides more secure fixing of the material, with
reduced risk of tearing or enlargement of the holes formed when the
prongs pierce through the material which increases risk of
dislodgement of the prongs. At the same time the major part of the
sheet material may be woven with warp tapes, and weft tapes, or a
greater width than in these side margins, as may be desirable to
optimise the reflective and transmissive properties of the material
when the material is a reflective ground cover material for
example, and/or to give more desired porosity properties. The wider
tapes are more suited to give a higher porosity and less physical
resistance or less friction to aid in the air, water, dirt and soil
movement through the material.
[0047] In an alternative form the warp tapes 25a towards the side
edge 27 of the sheet material may be of the same or a similar width
to the warp tapes 25b making up the balance of the sheet material,
but may be thicker. Typically the warp tapes in the side margins of
the material will be 10 to 100% and preferably 10 to 50% thicker
than the warp tapes of the balance of the material. Again this will
strengthen the side margins of the material so that when the sheet
is fixed in place using a fixing system including fastening
components in which prongs or similar pierce through the side
margins of the material, the increased strength of the side margins
provides more secure fixing of the material, with reduced risk of
tearing or enlargement of the holes formed when the prongs pierce
through the material.
[0048] In a further alternative form the warp tapes 25a towards the
side edges 27 of the sheet material may have both an increased
thickness, and a reduced width and therefore a higher number of
warp tapes per unit area, than the warp tapes 25b making up the
balance of the sheet material.
[0049] In a further alternative form the warp tapes 25a may have a
similar width as the warp tapes 25b but be woven with a tighter
weave in side margins of the material relative to the weave between
the side margins of the material, so that the material has a lower
porosity in said side margins of the material than between the side
margins of the material. The width & thickness of the tapes in
the side margins of the material may be the same as in the centre
section of the material but the tighter weave of the material in
the side margins will give the side margins increased strength as
referred to above.
[0050] In the preferred form a single warp tape 25c or a small
number of adjacent warp tapes have a contrasting colour to the
balance of the warp tapes 25 a and 25b, to mark one boundary of the
stronger side margin of the material. This defines to a person
installing the material the higher strength side margins of the
material through which the fastening claws 20 should be inserted.
Optionally a second contrasting colour warp tape or tapes 25 d may
be provided closer to the edge 27 of the material, to define the
other side of the strip extending longitudinally of the edge of the
material through which the fastening claws should be inserted. It
is not desirable to insert the fastening claw very close to the
edge of the material or the fastening claw may pull through or
damage the edge of the material. Tape 25d where provided may be
positioned 20-60 mm for example 40 mm, from the edge 27 of the
material, and tape or tapes 25c 150-200 mm and for example 160 mm
from the edge 27 of the material. FIG. 4 is an example of a
construction where marker tape 25d is 40 mm in from the edge 27,
and then the next marker tape 25c is 160 mm from the edge 27 and a
batch marker tape 25e is 5 mm from marker tape 25c (note the
drawings are not to exact scale). Alternative to the warp tapes of
contrasting colour a line or lines may be printed on the woven
material after manufacture or alternatively a strip of a printed
pattern or shading may be printed along the either longitudinal
side margin of the material to again mark the strip through which
it is desirable to insert the fastening components in use.
Alternatively again the reduced width warp tapes in the side
margins of the material may be formed of a contrasting colour to
the balance of the material.
[0051] Where the material has a narrower width, of for example
about 2.0 metres or less, it may be preferable to fix the material
in place with the U-shaped staples which are inserted through the
material in the ground, and in this case the first contrasting
colour warp tape or tapes 25c may be positioned between 30 and 60
mm FIG. 5 is an example of a construction where the marker tape 25c
is 40 mm in from the edge 27. In this case the ground staple is
placed in the area from the edge of the material 27 to the marker
tape 25c, and for the case where a claw is used the prongs pierce
in the area on the other side of marker tape 25c. The transition
from warp tapes 25a to 25b occurs 60 to 160 mm from marker tape 25
c, preferably 60 mm.
[0052] Preferably woven materials of the invention are formed from
tapes which have not been lengthwise folded or twisted during
weaving, or minimally so (for example not more than one fold or
twist per 1 m.sup.2, more preferably 5 m.sup.2, most preferably 10
m.sup.2 and even more preferably 25 m.sup.2 of material). It is
common in the weaving of materials from synthetic tapes for the
tapes to be folded lengthwise and crosswise during weaving.
Increasing the porosity assists in reduction of folds or twists. As
there are no folds for soil and dirt to lodge in and reduce the
light reflectivity and/or light transmission of the material or
otherwise reduce the reflectivity or strength or life of the
material. The resulting reflective ground cover material has a very
flat appearance without the folds.
[0053] Preferably woven materials of the invention are woven from
tapes having a width of 3 mm or more preferably 3.5 mm or greater,
or alternatively 4 mm or greater or more preferably 4.5 mm or
greater, and most preferably between 3.5 mm and 4.5 mm in width
(except that where the warp tapes in the side margins of the
material are of reduced width to increase the side margin strength
of the material, the side margin warp tapes such as the tapes 25a
in FIG. 3 will have a reduced width). Materials formed of such
wider tapes allow easier movement of air, water and soil particles
through the material. Wider tapes tend to slide more easily over
and away from each other than narrower tapes. (With narrower tapes
there are more tape crossovers, this tends to give a tighter
construction and the tapes are less prone to slide over each
other). At the side margins the material may be woven with narrower
warp tapes to give a tighter weave and stronger material at the
side margins, so that when prongs of a fastening claw or similar
device penetrate the material the hole(s) formed will not enlarge
easily, to form a more secure connection. For the tapes in the main
body of the material away from the edges, more movement in the
tapes is acceptable as this movement is associated with more rapid
air and water movement, and soil and dirt is less likely to lodge
between the tapes where this movement occurs to maintain the
reflective and transmission properties.
[0054] In another form of the invention the longitudinally
extending opposite side margins of the ground cover material
incorporate one or more agents which strengthen the side margins of
the material relative to a longitudinal centre section of the
material, or increase the resistance of said side margins of the
material to strength degradation from exposure to the external
environment and/or aging, relative to said longitudinal centre
section of the material. Preferably said agent(s) include at least
one light or heat stabiliser which will increase the resistance of
the side margins of the material to degradation through exposure to
solar radiation and temperature in an external environment, such as
Irganox 245, Irganox 259, Irganox 565, Irganox 1010, Irganox 1035,
Irganox 1076, Irganox 1098, Irganox 1135, Irganox 1141, Irganox
1330, Irganox 1425, Irganox 1520, Irganox 3052, Irganox 3114,
Irganox 5057, Irganox MD 1024, Irgafos 168, Irgafos DDPP, Irgafos
P-EPQ, Irgafos TNPP, Irgafos TPP, Irganox PS 800, Irganox PS 802,
Irganox B 215, Irganox B 225, Irganox B 551, Irganox B 561, Irganox
B 612, Irganox B 900, Irganox B 921, Irganox B 1171, Irganox B
3557, Irganox B 3596, Irganox HP 3560, Irganox HP 2215, Irganox HP
2225, Irganox HP 2921, Ca 100, Chimassorb 119, Chimassorb 944, Nor
371, Tinuvin 123, Tinuvin 144, Tinuvin 622, Tinuvin 765, Tinuvin
770, Tinuvin 783, Tinuvin 791, Chimassorb 81, Tinuvin 213, Tinuvin
234, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin
329, Tinuvin 350, Tinuvin 360, Tinuvin 492, Tinuvin 494, Tinuvin
571, Tinvin 622, Tinvin 765, Tinuvin 1577, Tinuvin P, Tinuvin B 75,
Tinuvin B 241, MD 1024, Araldite 7072, AO-I, Ni-Quencher, TiO2 and
Calcium Sterate. Additionally or alternatively said one or more
agents include at least one agent which increases the strength of a
plastic material from which the side margins are formed, such as
the addition of strength enhancing polymers such as polyester,
polypropylene, high density polyethylene, or linear low density
polyethylene.
[0055] Said agent(s) may be incorporated in a resin from which the
warp tapes of the side margins of the material are formed.
Alternatively said agent(s) may be applied to the side margins of
the material after forming, for example weaving, of the material.
The agent(s) may for example be sprayed or otherwise overcoated
onto the side margins of the material after manufacture of the
material.
[0056] Optionally the warp tapes in the side margins of the
material may have different reflection or transmission properties
from the warp tapes in the centre and major body of the material.
For example the warp tapes in the side margins of the material may
be more opaque, black, clear or otherwise have different reflection
or transmission properties, without significantly compromising the
overall effect or performance of the material, as the warp tapes in
the side margins represent a relatively small percentage of the
surface area of the material. FIG. 6 shows a further material
according to the invention, which has increased porosity to reduce
wind loading and increase air and water passage through the
material. Again the material is a woven material, comprising warp
tapes 45 and weft tapes 46. The warp and weft tapes are spaced
apart from each other so that multiple air spaces 47 occur between
the warp and weft tapes of the material, to give the material
porosity relative to a conventionally tightly woven material. The
material has a porosity of at least 2%, preferably up to 15%, more
preferably 4-12%, even more preferably 5-10%, and most preferably
6-8%.
[0057] Typically a ground cover needs properties across its width
that vary, thus giving more strength at the edges and higher
porosity at the centre. The invention details a method by which a
material such as this can be created where previous materials have
the same properties across the entire width.
[0058] Alternatively a woven or non-woven or extruded film material
may be perforated, for example by needle punching or a similar
process, after manufacture. Alternatively again the material may be
formed as a non-woven synthetic material having the desired degree
of porosity (whilst having similar properties of a known ground
cover material).
[0059] Referring to FIG. 7, the material of the invention may be
formed so as to have acceptable reflectivity while the relatively
high porosity of the material reduces the sail-effect of the
material under wind loading as wind or air may pass through the
more porous material as indicated by arrows 50 and 51. This reduces
the mechanical loading on the fixing system which fixes the
material in place. It allows air and moisture movement between the
ground and the air above the ground cover. It reduces excessive
moisture beneath the material. Irrigation or rainfall water can
pass more readily and rapidly through the ground cover material, so
that ponding of water on the material is reduced, or water running
across the material to collect in areas, which can result in uneven
water distribution to the soil underneath the material. Also, soil
and dirt can more easily pass through the material with this higher
porosity. The areas indicated by 52 in FIG. 7 have a lower porosity
to give the extra strength required where the material is fastened
but the porosity of area 53 is at a suitably higher level. Ground
cover materials may incorporate any one or more of the above
aspects of the invention in combination. For example a ground cover
material in which the side margins of the material are woven to
have an increased density of warp tapes to strengthen the side
margins of the material may also at least in the longitudinally
extending centre section of the material be woven with a relatively
looser or more open weave so that the material has higher porosity,
or perforated to give the material a high porosity. Optionally also
in the same material the side margins of the material and for
example the warp tapes may be formed from a plastics resin which
incorporates one or more pigments of agents which give the side
margins of the material a higher strength, a higher resistance to
solar radiation or heat degradation, and so forth.
[0060] 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.
* * * * *