U.S. patent application number 17/826919 was filed with the patent office on 2022-09-08 for flexible rope net gabion.
The applicant listed for this patent is GARWARE TECHNICAL FIBRES LTD.. Invention is credited to Vayu Garware, Thirumalai Purushottam KULKARNI, Gaurav Pathare, Vijay RAMAKRISHNAN, Sanjay Vasudeo RAUT.
Application Number | 20220282441 17/826919 |
Document ID | / |
Family ID | 1000006409267 |
Filed Date | 2022-09-08 |
United States Patent
Application |
20220282441 |
Kind Code |
A1 |
RAUT; Sanjay Vasudeo ; et
al. |
September 8, 2022 |
FLEXIBLE ROPE NET GABION
Abstract
A transportable, flexible rope net gabion useful for scour
protection includes a lifting ring, a plurality of polymer ropes
connected to the lifting ring, a polymer net connected to the
polymer ropes, and a plurality of stones or boulders. Up to 45% of
the volume of the polymer net is packed with the stones or
boulders, so that the rope net gabion can be evenly positioned
around a structure to be supported. The polymer ropes, the polymer
net, or both the polymer ropes and the polymer net are made using
virgin high density polyethylene (HDPE).
Inventors: |
RAUT; Sanjay Vasudeo; (Pune,
IN) ; KULKARNI; Thirumalai Purushottam; (Pune,
IN) ; RAMAKRISHNAN; Vijay; (Mumbai, IN) ;
Garware; Vayu; (Pune, IN) ; Pathare; Gaurav;
(Pune, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GARWARE TECHNICAL FIBRES LTD. |
Pune |
|
IN |
|
|
Family ID: |
1000006409267 |
Appl. No.: |
17/826919 |
Filed: |
May 27, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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17051061 |
Oct 27, 2020 |
|
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|
PCT/IN2019/050522 |
Jul 13, 2019 |
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17826919 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02D 29/0208 20130101;
E02B 17/0017 20130101; E02B 3/123 20130101 |
International
Class: |
E02B 3/12 20060101
E02B003/12; E02B 17/00 20060101 E02B017/00; E02D 29/02 20060101
E02D029/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 2018 |
IN |
201821030314 |
Claims
1. A transportable, flexible rope net gabion for scour protection
comprising: a. a lifting ring; b. a plurality of polymer ropes
connected to the lifting ring; c. a polymer net connected to the
polymer ropes, the polymer net having a volume; and d. a plurality
of stones or boulders, wherein up to 45% of the volume of the
polymer net is packed with the plurality of stones or boulders,
such that the rope net gabion could be evenly positioned around a
structure to be supported; wherein the polymer ropes, the polymer
net, or both the polymer ropes and the polymer net are made from
20% to 100% by weight of high density polyethylene (HDPE).
2. The rope net gabion as claimed in claim 1, wherein the HDPE is
virgin HDPE of ethylene or bioethylene.
3. The rope net gabion as claimed in claim 1, wherein the HDPE is a
polymer of bioethylene produced by dehydration of ethanol.
4. The rope net gabion as claimed in claim 2, wherein the HDPE is a
polymer of bioethylene produced by dehydration of ethanol.
5. The rope net gabion as claimed in claim 1, wherein the polymer
ropes, the polymer net, or both the polymer ropes and the polymer
net are made from 20% to 100% by weight of virgin HDPE and 0% to
80% of virgin polyester.
6. The rope net gabion as claimed in claim 5, wherein the virgin
polyester is virgin polyethylene terephthalate.
7. The rope net gabion as claimed in claim 1, wherein the polymer
ropes, the polymer net, or both the polymer ropes and the polymer
net are made from 20% to 90% by weight of virgin HDPE and 10% to
80% of virgin polyester.
8. The rope net gabion as claimed in claim 1, wherein the polymer
ropes, the polymer net, or both the polymer ropes and the polymer
net are made from 50% to 100% by weight of virgin HDPE and 0% to
50% of virgin polyester.
9. The rope net gabion as claimed in claim 1, wherein the polymer
net is a knotted net.
10. The rope net gabion as claimed in claim 1, wherein the polymer
net is a knotless net.
11. The rope net gabion as claimed in claim 1, wherein the polymer
net is monolithically connected to the plurality of polymer
ropes.
12. The rope net gabion as claimed in claim 1, wherein: the polymer
net is made from 50% to 100% of virgin HDPE and 0% to 50% of a
virgin polyester; and the polymer ropes are made from the virgin
polyester.
13. The rope net gabion as claimed in claim 1, wherein: the polymer
ropes are made from 50% to 100% of virgin HDPE and 0% to 50% of a
virgin polyester; and the polymer net is made from the virgin
polyester.
14. The rope net gabion as claimed in claim 1, wherein: both the
polymer ropes and the polymer net are made from 50% to 100% of
virgin HDPE and 0% to 50% of a virgin polyester.
15. The rope net gabion as claimed in claim 1, wherein: the polymer
net is made from 50% to 100% of virgin HDPE and 0% to 50% of a
virgin polyester; and the polymer ropes are made from the virgin
HDPE.
16. The rope net gabion as claimed in claim 1, wherein: the polymer
ropes are made from 50% to 100% of virgin HDPE and 0% to 50% of a
virgin polyester; and the polymer net is made from the virgin
HDPE.
17. The rope net gabion as claimed in claim 1, wherein: both the
polymer ropes and the polymer net are made from virgin HDPE.
18. A method of making a rope net gabion comprising a lifting ring,
a plurality of polymer ropes, and a polymer net having a volume,
the method comprising: making the plurality of polymer ropes from
20% to 100% by weight of HDPE and 0% to 80% by weight of virgin
polyester; connecting the plurality of polymer ropes to the lifting
ring; connecting the polymer net to the plurality of polymer ropes;
and filling up to 45% of the volume of the polymer net with a
plurality of stones or boulders.
19. The method of claim 18, further comprising making the polymer
net from 20% to 100% by weight of the HDPE and 0% to 80% by weight
of the virgin polyester.
20. A method of making a rope net gabion comprising a lifting ring,
a plurality of polymer ropes, and a polymer net having a volume,
the method comprising: obtaining HDPE manufactured from bioethylene
produced by dehydration of ethanol; making the polymer net from 20%
to 100% by weight of the HDPE and 0% to 80% by weight of virgin
polyester; connecting the plurality of polymer ropes to the lifting
ring; connecting the polymer net to the plurality of polymer ropes;
and filling up to 45% of the volume of the polymer net with a
plurality of stones or boulders.
Description
FIELD OF INVENTION
[0001] The invention is in the field of providing scour protection.
More particularly, the current invention relates to flexible rope
net gabion for scour protection.
BACKGROUND OF THE INVENTION
[0002] Scouring is a phenomenon whereby the top loose material of
the upper soil in body of water viz., river bed, river banks,
stream bed, stream bunds, sea bed or coastal area is eroded as a
result of tidal activity or bed-bank movement. This phenomenon
occurs due to disturbance created in the tidal flow pattern due to
an embedded structure or overall seabed movement or "sand
waves".
[0003] The phenomenon is more proclaimed in case of scouring action
on natural river or stream beds and also on the side slopes of the
river banks, bridge piles, offshore structures, wind turbines etc.
whereby a structure is embedded in the water body. Accordingly,
when an underwater structure is embedded in the water body, the
structure acts as a resistor of the tidal current, a vortex flow
occurs, the surrounding ground is scooped around the structure,
so-called washing in which the structures foundation weakens and
may lead to collapse.
[0004] The gradual wearing of the water body bed poses a
significant economic problem. As, once a significant amount of soil
is eroded from water body bed, an embedded structure may lose its
stability and the loose footing may lead to tumbling of the
structure or cause a significant damage to the structure, in case
the structure is supported by plurality embedded structures.
[0005] A similar scouring phenomenon, as described above, could
also be witnessed on river banks, river bed, stream bank and stream
bed.
[0006] One solution to overcome said problem is to place gabions
along the water body bed or river bed or stream bed or packed close
to the bottom of the embedded structure. One such solution was
proposed in EP2341592 filed by Kyowa Co., Ltd. In accordance with
this Patent, a plurality of bags containing block objects, such as
rocks having sufficient porosity are disposed along the water body
bed. The bags acts to reduce the drag force generated by the water,
and consequently reduce scouring of the water body bed. The
construction material used for the bags is a polyester
material.
[0007] However, in view of an article titled "Effect of Seawater on
Ageing of Polyester Composites and Study of Aged Composite Polymer"
by KUUK, Kerem and another article titled "Degradation Effects in
Polyester and Vinyl Ester Resins Induced by Accelerated Aging in
Seawater" by VISCO, A M et al., it is clear that the polyester bags
as used in EP2341592 are not very durable and might lose their
usefulness over a period of time.
[0008] Further, the polyester sack gabions as described in
EP2341592 pose another environmental problem relating to micro
plastic generation. These plastic particles which are less than 5
mm lead to bio-magnification through food chain.
[0009] Indian Patent No. IN195352 granted to Garware Wall Ropes
describes a prefabricated collapsible gabion product made from
ropes, for protection of river bank and/or coastal areas of
sea.
[0010] The rope gabions of IN195352 are relatively inflexible and
cannot be transported easily. These gabions have limitations in
flexibility, durability, transportability and also not useful in
multiple applications and utilities.
[0011] Hence, there is a need to develop such gabions which are
durable in operating conditions and are eco-friendly. Therefore,
the current inventors have developed Flexible Rope Net Gabions
which are durable and eco-friendly, easy-to-transport and use in
wider range of applications.
SUMMARY OF INVENTION
[0012] In an aspect, the present invention provides Flexible Rope
Net Gabions which are durable and eco-friendly, flexible and
easy-to-transport. The Flexible Rope Net Gabions of the current
invention may be made from polymers such as Polyolefins and
Polyesters or mixtures thereof, which is highly resistant to
degradation in corrosive environment.
[0013] Various embodiments disclosed herein relate to a
transportable, flexible rope net gabion for scour protection
including :a lifting ring; a plurality of polymer ropes connected
to the lifting ring; a polymer net connected to the polymer ropes,
the polymer net having a volume; and a plurality of stones or
boulders. Up to 45% of the volume of the polymer net is packed with
the stones or boulders, so that the rope net gabion could be evenly
positioned around a structure to be supported. The polymer ropes,
the polymer net, or both the polymer ropes and the polymer net are
made from 20% to 100% by weight of high density polyethylene
(HDPE). In various embodiments, the HDPE is virgin HDPE. The HDPE
may be a polymer of bioethylene produced by dehydration of ethanol.
The HDPE may be a virgin polyethylene made from bioethylene
produced by dehydration of ethanol.
[0014] In various embodiments, the rope net gabion includes polymer
ropes, a polymer net, or both polymer ropes and a polymer net made
from 20% to 100% by weight of virgin HDPE and 0% to 80% of virgin
polyester, which may be virgin polyethylene terephthalate. The
polymer ropes, the polymer net, or both the polymer ropes and the
polymer net may be made from 20% to 90% by weight of virgin HDPE
and 10% to 80% of virgin polyester, from 50% to 100% by weight of
virgin HDPE and 0% to 50% of virgin polyester, or from 75% to 100%
by weight of virgin HDPE and 0% to 25% of virgin polyester.
[0015] The rope net gabion includes a polymer net, where the
polymer net is a knotted net or a knotless net. The polymer net may
be monolithically connected to the polymer ropes in the rope net
gabion.
[0016] In various embodiments, the rope net gabion includes a
polymer net made from 50% to 100% of virgin HDPE and 0% to 50% of a
virgin polyester; and polymer ropes made from virgin polyester.
[0017] The rope net gabion may include polymer ropes made from 50%
to 100% of virgin HDPE and 0% to 50% of a virgin polyester; and a
polymer net made from virgin polyester.
[0018] The rope net gabion may include both polymer ropes and a
polymer net made from 50% to 100% of virgin HDPE and 0% to 50% of a
virgin polyester.
[0019] The rope net gabion may include a polymer net made from 50%
to 100% of virgin HDPE and 0% to 50% of a virgin polyester; and
polymer ropes made from virgin HDPE.
[0020] The rope net gabion may include polymer ropes made from 50%
to 100% of virgin HDPE and 0% to 50% of a virgin polyester; and a
polymer net made from virgin HDPE.
[0021] The rope net gabion may include polymer ropes and a polymer
net which are each made from virgin HDPE.
[0022] Various embodiments disclosed herein relate to a method of
making a rope net gabion comprising a lifting ring, a plurality of
polymer ropes, and a polymer net having a volume, including steps
of:
obtaining HDPE manufactured from bioethylene produced by
dehydration of ethanol; making the plurality of polymer ropes from
20% to 100% by weight of the HDPE and 0% to 80% by weight of virgin
polyester; connecting the plurality of polymer ropes to the lifting
ring; connecting the polymer net to the plurality of polymer ropes;
and filling up to 45% of the volume of the polymer net with a
plurality of stones or boulders. The method may also include a step
of making the polymer net from 20% to 100% by weight of the HDPE
and 0% to 80% by weight of the virgin polyester.
[0023] Various embodiments disclosed herein relate to a method of
making a rope net gabion comprising a lifting ring, a plurality of
polymer ropes, and a polymer net having a volume, including steps
of:
obtaining HDPE manufactured from bioethylene produced by
dehydration of ethanol; making the polymer net from 20% to 100% by
weight of the HDPE and 0% to 80% by weight of virgin polyester;
connecting the plurality of polymer ropes to the lifting ring;
connecting the polymer net to the plurality of polymer ropes; and
filling up to 45% of the volume of the polymer net with a plurality
of stones or boulders.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 illustrates the flexible rope net gabion in
accordance with one of the embodiments of the invention.
[0025] FIG. 2 illustrates the open state of the polymer net 3.
[0026] FIG. 3 illustrates one embodiment of using the flexible rope
net gabion 3 of the invention for anchoring the structure.
[0027] FIGS. 4A and 4B illustrate turbidity from immersing
polymeric ropes suitable for making the rope net gabion of FIG. 1
in water.
[0028] FIGS. 5A and 5B illustrate turbidity from immersing
polyester ropes suitable for making the rope net gabion of FIG. 1
in water.
DETAILED DESCRIPTION OF THE INVENTION
[0029] As used herein, the term "polyethylene" refers to a polymer
including ethylene monomers. The terms "high density polyethylene"
and " HDPE" refer to a polyethylene with a density of 930 to 970
kg/m.sup.3, and little branching. High density polyethylene may be
a iomopolymer of ethylene, or may contain a limited amount of
another olefin as a comonomer.
[0030] As used herein, the term "ethylene" refers to an olefin
monomer with the formula CH.sub.2.dbd.CH.sub.2. Unless otherwise
specified, ethylene may be obtained by any method known in the art,
including:
Thermal cracking of hydrocarbons found in petroleum; Oxidative
coupling of methane found in natural gas; Fischer-Tropsch synthesis
from carbon dioxide; and Catalytic dehydrogenation of alcohol.
[0031] As used herein, the term "bioethylene" refers to:
ethylene produced by dehydrogenation of ethanol obtained from a
renewable source; or ethylene produced enzymatically from
S-adenosyl-L-methionine. Polymerization of bioethylene produces
HDPE which is structurally and functionally similar to HDPE
produced by polymerization of conventionally sourced ethylene,
while avoiding environmental issues caused by processes such as
thermal cracking of hydrocarbons.
[0032] As applied to polymers herein, the term "virgin" means that
the polymer has never been processed into any product before, i.e.,
the polymer is new. As applied to polymers herein, the term
"recycled" means that the polymer has been previously processed
into a product; the recycled polymer may have been contaminated
with other polymers or other materials.
[0033] The flexible rope net gabion 5 comprises of a lifting ring
1, a plurality of polymer ropes 2, a polymer net 3 and stones or
boulders 4.
[0034] The lifting ring 1 functions as a lifting element to
facilitate easy lifting of the flexible rope net gabion 5 for
positioning, as required. The lifting ring 1 can be hung to a
crane. The material used for construction of the lifting ring 1 is
a polymer or stainless steel or the like.
[0035] The plurality of polymer ropes 2 which are connected to the
ring 1 function as lifting ropes for suspending the flexible rope
net gabion 5 from the crane.
[0036] The polymer net 3 is monolithically connected to the
plurality of polymer ropes 2. The net is manufactured from a
polymer yarn made from a mix of polymer netting and polymer
ropes.
[0037] The boulders or stones 4 are held in the polymer net 3. The
stones or boulders 4 act as porous structure which provide scour
protection to the embedded structure. The size of the boulders is
immaterial for efficient implementation of the current
invention.
[0038] FIG. 2 details the open state of the polymer net 3 of the
flexible rope net gabion 5, having a conical top end and open
bottom end. The polymer net 3 comprises of two lacing twines 31A
and 31B. The twines 31A and 31B are configured for facilitating
tying of the open end after filling the polymer net 3 with stones
of boulders 4.
[0039] The polymer net 3 is further adorned with a bottom 10 mm
twisted polyester rope 34, disposed close to the top open end,
which functions as a load-bearing portion for hanging to hook 1.
The polymer net 3 further comprises of multitude of structural
ropes 33, which are 6 mm polyester twisted ropes. The structural
ropes 33 extend from the top 10 mm twisted polyester ring 32 till a
top 10 mm twisted polyester rope ring 34. In accordance with this
embodiment the 34 has a diameter which is substantially larger than
the diameter of top 10 mm twisted polyester rope ring 34, such that
the structural ropes 33 along with the rings 32 and 34 form a
substantially conical structure.
[0040] As illustrated in FIG. 3, the flexible rope net gabion 3
packed with rock to an extent of 45% allows the flexible rope
gabion 3 to be evenly positioned around the structure 100 to be
supported thereby ensuring that it is anchored in a balanced
fashion.
[0041] The flexible rope net gabion is used to provide scour
protection for bridges, piles, offshore structures, wind turbines,
river training, channel lining, erosion control, etc.
[0042] In an embodiment, the material used for construction of the
lifting ring 1 is a polymer or stainless steel or the like.
[0043] The polymer ropes 2 and/or polymer net 3 of the flexible
rope net gabion 5 is made from a polymer yarn constructed from a
mix of polymer netting and polymer ropes. Further, in accordance
with current embodiment, said polymer net 3 can be a knotted net or
knotless net.
[0044] The net 3 and/or the rope 2 can be made of twisted/braided
yarn. The polymer net 3 could be either knotless net or knotted
net.
[0045] The polymer net 3 and/or ropes 2 could be made of yarn
containing polyolefin with a polyester content varying from 0% to
less than 100%, e.g., 10-80% polyester, 0-50% polyester, or 0-25%
polyester.
[0046] The polymer net 3 and/or ropes 2 could be made of yarn
containing 20-90% polyolefin and 10-80% polyester, 50-100%
polyolefin and 0-50% polyester, or 75-100% polyolefin and 0-25%
polyester.
[0047] The polyolefin may be high density polyethylene (HDPE)
produced using conventionally sourced ethylene or bioethylene. The
polyolefin may be virgin HDPE.
[0048] Recycled HDPE is frequently used for preparation of ropes or
nets. However, recycled HDPE frequently contains polypropylene or
branched polyethylene copolymers as contaminants. Due to their
increased levels of tertiary carbon atoms in the polymer backbone,
polypropylene and branched polyethylene copolymers are more
susceptible to oxidative reactions. These oxidation reactions can
lead to chain scission, to produce shorter polymer chains.
Additionally, intermediate radicals produced during oxidation of
polypropylene or polyethylene copolymers may attack C--H bonds in
HDPE, shortening these polymer chains as well. Such degradation may
produce microplastics, which are damaging to the environment.
[0049] Similarly, recycled polyethylene terephthalate is also used
for preparation of ropes or nets. However, recycled polyethylene
terephthalate is also susceptible to oxidative reactions. These
oxidation reactions lead to chain scission, leading to shorter
polymer chains and production of microplastics.
[0050] The present disclosure shows that ropes or nets made from
virgin HDPE or virgin polyethylene terephthalate produce very low
levels of microplastics, compared to recycled HDPE or recycled
polyethylene terephthalate.
[0051] Similarly, ropes or nets made using threads or yarns
containing combinations of virgin HDPE and virgin polyethylene
terephthalate produce very low levels of microplastics, compared to
ropes or nets made using recycled HDPE, recycled polyethylene
terephthalate, or a mixture thereof. Additionally, such
combinations of virgin HDPE and virgin polyethylene terephthalate
offer advantages not found in either polymer alone. As virgin
polyethylene terephthalate has higher tensile strength than virgin
HDPE, the presence of virgin polyethylene terephthalate may
increase the overall strength of the ropes or nets. Also, virgin
HDPE is less prone to chain scission or microparticle formation
than virgin polyethylene terephthalate. Thus, if virgin PET and
virgin HDPE are used in combination, the virgin polyester increases
the strength of the resulting rope or net while the virgin HDPE
reduces the susceptibility of the resulting rope or net to chain
scission and/or microparticle formation.
[0052] The present disclosure shows that ropes or nets made from
virgin HDPE produced using conventionally sourced ethylene or
bioethylene produce very low levels of microplastics, compared to
recycled HDPE, recycled polyethylene terephthalate, or virgin
polyethylene terephthalate.
[0053] The present disclosure shows that ropes or nets made from
virgin HDPE produced from polymerization of bioethylene, i.e.,
ethylene produced from dehydration of ethanol, produce very low
levels of microplastics, compared to recycled HDPE, recycled
polyethylene terephthalate, or virgin polyethylene
terephthalate.
[0054] The yarn used for production of the polymer net 3 and/or
ropes 2 is a bio-based yarn.
[0055] The polymer net 3 is packed with rocks to the extent of 45%
of the volume of the Net 3. Packing the rock to an extent of 45% of
the total volume of polymer net 3 which allows the flexible rope
net gabion 5 to be evenly positioned around the structure 100 to be
supported thereby, ensuring that the structure is anchored in a
balanced manner.
[0056] In an embodiment, the polymer net 3 is monolithically
connected to plurality of polymer ropes 2.
[0057] The flexible rope net gabion 5 forms a porous and flexible
structure containing stones or boulders 4. Said stones or boulders
4 provide excellent protection from scouring. In accordance with
this embodiment, it is possible to achieve effective implementation
of the current invention irrespective of the size of the boulders.
Further, in accordance with this embodiment, the flexible rope net
gabion 5 of the invention could be evenly positioned around the
structure to be supported thereby ensuring that it is anchored in a
balanced manner.
[0058] In accordance with one of the embodiments, the polymer net 3
of the flexible rope net gabion 5 has a conical top end and open
bottom end. The polymer net 3 is equipped of two lacing twines 21A
and 21B. The twines 21A and 21B are designed for facilitating tying
of the open end after filling the polymer net 3 with stones of
boulders 4.
[0059] The plurality of polymer ropes 2 comprises of a bottom 10 mm
twisted polyester rope 24, disposed close to the open end of the
polymer net 3, which functions as a load-bearing portion for
hanging to hook 1. The polymer rope 2 further comprises of
multitude of structural ropes 23, which are 6 mm polyester twisted
ropes. The structural ropes 23 extend from the top 10 mm twisted
polyester ring 22 till a top 10 mm twisted polyester rope ring 24.
In accordance with this embodiment the 24 has a diameter which is
substantially larger than the diameter of top 10 mm twisted
polyester rope ring 22, such that the structural ropes 23 along
with the rings 22 and 24 form a substantially conical
structure.
[0060] In accordance with one of the embodiments of the invention,
the flexible rope net gabion 5 packed with rock to an extent of
45%. The 45% packing allows the flexible rope gabion 5 to be evenly
positioned around the structure 100 to be supported, thereby
ensuring that the structure 100 is anchored in a balanced
fashion.
[0061] In an advantageous embodiment, the flexible rope net gabion
of the invention also ensures lower micro-plastic release and lower
harm to environment.
[0062] In an advantageous embodiment, the flexible rope net gabion
of the invention is eco-friendly.
[0063] In another advantageous embodiment, the specific gravity of
the yarn is increased so as to achieve efficient submersion of the
flexible net gabions of the invention.
[0064] In another advantageous embodiment, the flexible rope net
gabion of the invention provides a porous flexible structure that
provides excellent scour protection and is durable.
[0065] In an embodiment of the invention, the flexible rope net
gabion of the current invention could be effectively used for
preventing scouring or soil erosion from on the water body bed or
sea-shore or river bank or riverbed or streambed or stream
bank.
[0066] The invention has the following novel features: [0067] The
flexible rope net gabion of current invention is flexible and
easy-to-transport. [0068] The flexible rope net gabion of current
invention is eco-friendly. [0069] The flexible rope net gabion of
current invention ensures lower micro-plastic release and lower
harm to environment, owing to the composition of the yarns used for
construction of the polymer ropes and the polymer net. [0070] The
flexible rope net gabion of current invention is durable. [0071]
The flexible rope net gabion of current invention could be
manufactured using synthetic yarn or a bio-based yarn. [0072] The
polymer net 3 of the flexible rope net gabion of current invention
could be either knotless net or knotted net. [0073] The polymer net
is monolithically connected to plurality of polymer ropes. The
effective implementation of the flexible rope net gabions of
current invention can be achieved irrespective of the size and
shape of the boulders. [0074] The flexible rope net gabion of the
current invention could be effectively used for preventing scouring
or soil erosion from the water body bed or sea-shore or river bank
or riverbed or streambed or stream bank.
[0075] In the examples below, all HDPE ropes are manufactured from
virgin high density polyethylene, using bioethylene produced by
dehydration of ethanol.
EXAMPLES
[0076] The following examples describe tests carried out on net
materials containing polyester and/or HDPE. Studies of turbidity
were carried out by placing a sample of a net (10 gm) to be tested
and sea water in a steel vessel together, and sealing the vessel.
The vessel was tumbled at 75 RPM, for a time period ranging from 0
hours to 6 hours, while maintaining a desired temperature. At the
end of the test period, residual water was removed from the sealed
vessel and analyzed for turbidity.
Example 1. Resistance of HDPE Net Products to Oxidation
[0077] Test specimens of HDPE net were stored in water at
80.degree. C. for a period of 28 days, with the water changed at
least every seven days and moved at least once per day. Test
specimens were exposed, freely hanging, in a regulated laboratory
oven at an elevated temperature of 100.degree. C. for a period of
112 days. After completion of this oxidation process the test
specimens were subjected to a tensile strength test. For the
machine direction test, the test specimens incorporated 12 yarn
connection points, i.e., 22 complete yarns, and for the cross
direction test, the test specimens incorporated 4 yarn connection
points, i.e., 18 complete yarns
[0078] Control specimens of HDPE were nominally identical to the
test specimens. The control specimens were stored in water at
80.degree. C. for a period of 28 days, with the water changed at
least every seven days and moved at least once per day. The control
specimens were not subjected to oxidation in a laboratory oven. A
tensile strength test was conducted on the test and control
specimens. The results are shown in Table 1.
[0079] Based on the data in Table 1, the retained strength values
for the above test specimens can be calculated relative to the
control specimens. Retained strength of the test specimens is 98%
of the strength of the control specimens in the machine direction.
Retained strength of the test specimens is 95% of the strength of
the control specimens in the cross direction. Thus, the HDPE net do
not undergo significant degradation from oxidation.
TABLE-US-00001 TABLE 1 Results of tensile strength test on control
and test (exposed) specimens. CONTROL EXPOSED SPECIMENS SPECIMENS
Length/ Width Length/ Width machine cross machine cross Direction
of specimens direction direction direction direction Mean force at
peak (kN) 16.3 3.9 16.0 3.7 Mean force at peak 81.6 15.2 80.0 14.3
(kN/m) Time to peak (secs) 138.3 151.1 143.6 141.1 Elongation at
peak (%) 33.1 137.6 34.7 129.3
[0080] Example 2. Percentage weight loss of HDPE net products in
water. Test specimens of virgin HDPE net were immersed in water for
a period of six hours, at a temperature of 10.degree. C. or
26.degree. C. Test specimens were then removed from the water,
completely dried, and weighed. The weight after immersion was
compared to the weight before immersion. The test was repeated with
virgin PET polyester nets. The virgin HDPE nets and virgin PET
polyester nets are 36 ply nets, suitable for preparation of an 8
Ton (lifting capacity) flexible rope net. As seen in Table 2, at
both 10.degree. C. and 26.degree. C., the weight loss from virgin
polyester was higher than the weight loss from virgin HDPE by a
factor of .about.2. Higher weight loss from polyester correlates
with increased release of particles of microplastics.
TABLE-US-00002 TABLE 2 Results of HDPE weight loss test on virgin
HDPE and virgin PET specimens. Polymer Temperature (.degree. C)
Weight Loss (%) Virgin HDPE 10 0.87 Virgin PET 10 1.63 Virgin HDPE
26 0.32 Virgin PET 26 0.69
Example 3. Turbidity of HDPE Net Products in Water
[0081] Test specimens of 36 ply virgin HDPE net were immersed in
water for a period of six hours, at a temperature of 10.degree. C.
or 26.degree. C. Turbidity of the water was measured hourly in NTU
(Nephelometric Turbidity Units; 3 NTU=1 mg/l). The test was
repeated with virgin PET polyester nets. Higher turbidity from
polyester correlates with increased release of particles of
microplastics. As shown in Table 3, and also in FIGS. 4A and 4B,
turbidity from virgin polyester after 6 h exceeds turbidity from
virgin HDPE by a factor of about 6 to about 8.25, depending on
temperature.
TABLE-US-00003 TABLE 3 Turbidity of HDPE and polyester in water.
Turbidity (NTU) Time (hr) HDPE, 10.degree. C. HDPE, 26.degree. C.
PET, 10.degree. C. PET, 26.degree. C. 0 10.6 10.7 97.1 36.6 1 16.4
13.7 139 101 2 24.6 19.3 200 130 3 27.7 20.4 234 140 4 29.2 26.6
262 197 5 32.5 33.3 280 212 6 34.9 36.6 287 221
Example 4. Turbidity of Polyester Net Products in Water
[0082] Test specimens of 18 ply virgin polyethylene terephthalate
net were immersed in water for a period of six hours, at a
temperature of 10.degree. C. or 20.degree. C. Turbidity of the
water was measured hourly in NTU (Nephelometric Turbidity Units; 3
NTU=1 mg/l). The test was repeated with recycled polyethylene
terephthalate nets. As seen in Table 4 at both 10.degree. C. and
20.degree. C., turbidity of water exposed to recycled polyethylene
terephthalate was higher than the turbidity of water exposed to
virgin polyethylene terephthalate. Higher turbidity from polyester
correlates with increased release of particles of microplastics. As
shown in Table 4, and also in FIGS. 5A and 5B, turbidity from
recycled polyester after 6 h exceeds turbidity from virgin
polyester by a factor of about 2 to about 3, depending on
temperature.
TABLE-US-00004 TABLE 4 Turbidity of polyester in water. Turbidity
(NTU) Virgin PET, Virgin PET, Recycled PET, Recycled PET, Time (hr)
10.degree. C. 20.degree. C. 10.degree. C. 20.degree. C. 0 10.2 10.5
12.2 12.7 1 28.4 35.4 67.2 81.7 2 27.6 37.8 68.2 109 3 28.1 39.5
82.2 125 4 34.4 39.8 81.9 135 5 35.7 53.6 76.4 156 6 58.4 63.7 119
174
[0083] It is to be understood that the above description is
intended to be illustrative and not restrictive. Many embodiments
will be apparent to a person skilled in the art upon reviewing the
description. The scope of the invention should therefore, be
determined not with reference to the above description, but instead
should be determined with reference to the appended claims, along
with the full scope of equivalents to which such claims are
entitled.
* * * * *