Net for aquatic use and method for making the same

Abstract

Nets having low solidity for aquatic uses. The nets include a twine (2) having an outer braid (4) with at least one material having partially oriented filaments, and an inner portion (6) that extends within the outer braid, wherein the twine is arranged to form the net.

Description

LOW SOLIDITY NETS AND METHODS FOR MAKING THEMCROSS-REFERENCE TO RELATED APPLICATION

[0001] The present disclosure is based on and claims priority to Indian Provisional Patent Application No. 202521021939, filed March 23, 2025 and Indian Provisional Patent Application No. 202621012961, filed February 6, 2026, the disclosures of which are incorporated herein by reference.FIELD

[0002] The present disclosure generally relates to nets for aquaculture and fisheries, and specifically to nets having low solidity and methods for making them.BACKGROUND

[0003] Aquaculture and fisheries is a rapidly growing industry that requires efficient and durable netting solutions to contain and protect aquatic Biomass. More specifically, these functions are provided via two separate types of nets known in the art: 1) containment nets designed for retaining the product therein (e.g., fish, seafood, plants, biomass generally), and 2) protective net cage solutions known as anti-predator nets designed to prevent predators from preying on the product (Biomass) residing inside the containment nets. In practice, anti-predator nets (or simply, predator barrier nets) are provided outside the containment nets with at least several feet / meters therebetween. These nets and the areas defined thereby may be referred to as having circular shapes, for example with the predator nets being concentrically aligned with the containment nets, but radially displaced therefrom so as to provide an annular buffer region therebetween. The containment nets and the predicator nets may be connected to each other or have separate mechanisms of support (e.g., fixation in a particular geographic location, floatation, etc.). Generally, performance parameters for predator nets and containment nets are different.

[0004] Some containment cage nets generally known in the art are made of nylon and HDPE and are knotless, which are common in the Mediterranean region, South America , Canada, Australia and New Zealand. These (primary) containment cages of nylon and polyester are typically used in conjunction with predator barrier cages as secondary cages outside the containment cage nets, whereby the predator barrier cages are configured to protect from predators like sea lion, sharks, tuna etc.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Examples are described with reference to the following drawing figures. The same numbers are used throughout to reference like features and components.

[0006] FIG. 1A is a cross-sectional view of one embodiment of twine produced according to the present disclosure for making low solidity nets.

[0007] FIG. 2 A is a flow chart for one embodiment of method for making low solidity nets according to the present disclosure.

[0008] FIG. 3A is a schematic view illustrating one method for measuring a low solidity net according to the present disclosure.

[0009] FIG. 3B is a side view depicting a low solidity net according to the present disclosure.

[0010] FIG. 3C is a side view depicting a low solidity net according to the present disclosure.

[0011] FIG. 4 is a schematic depicting characteristics for describing nets produced according to the present disclosure.

[0012] FIG. 5 is a cross-sectional view of another embodiment of twine produced according to the present disclosure.

[0013] FIG. 6 is a cross-sectional view of another embodiment of twine produced according to the present disclosure.

[0014] FIG. 7 is a cross-sectional view of another embodiment of twine produced according to the present disclosure.

[0015] FIG. 8 is a cross-sectional view of another embodiment of twine produced according to the present disclosure.

[0016] FIG. 9 is a cross-sectional view of another embodiment of twine produced according to the present disclosure.

[0017] FIG. 10 is a chart depicting example components usable within embodiments of twines produced according to the present disclosure, as well as benefits thereof.

[0018] FIG. 11 is a chart depicting experimental test data of mesh breaking strength and solidity as a function of mesh size.

[0019] FIG. 12 is a chart depicting experimental test data showing reduced solidity by runnage for twines produced according to the present disclosure.SUMMARY

[0020] This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0021] One aspect of the present disclosure generally relates to a net having low solidity for aquatic use, the net comprising twine having an outer braid with at least one material having partially oriented filaments, and an inner portion that extends within the outer braid, wherein the twine is arranged to form the net.

[0022] In certain examples, the twine is arranged such that the net has a solidity less than 30%. In further examples, the net has mesh openings spanning at least 5 mm.

[0023] In certain examples, the twine has a thickness of less than 12 mm.

[0024] In certain examples, the twine is knotted to form the net.

[0025] In certain examples, the at least one material comprises at least 45% of a total mass of the twine.

[0026] In certain examples, the at least one material comprises a first material and the outer braid further has a second material braided with the first material, and wherein the first material has a first elongation and the second material has a second elongation that is greater than the first elongation. In further examples, the first elongation is at least 30%, 40%, or 50% of the second elongation.

[0027] In certain examples, the at least one material comprises a first material and the outer braid further has a second material braided with the first material, and wherein the first material and the second material are different materials. In further examples, the outer braid comprises a monofilament and a multifilament.

[0028] In certain examples, the inner portion comprises HDPE, stainless steel, HMPE and / or polyester, and a cord comprising a polymer, and wherein the outer braid comprises HDPE and HMPE.

[0029] In certain examples, the inner portion comprises HDPE without comprising a metal and without comprising PET, and wherein the outer braid comprises HDPE and HMPE.

[0030] In certain examples, the twine is within one of a 96kgf, a 117kgf, a 136kgf, or a 151kgf strength class, and the twine is arranged such that the net has a normalized solidity of less than 3.5 if within the 96kgf MBS strength class, less than 4.5 if within the 117kgf MBS strength class, less than 6 if within the 136kgf MBS strength class, and less than 7.5 if within the 15 Ikgf MBS strength class.

[0031] Another aspect according to the present disclosure generally relates to a method for making a net having low solidity for aquatic use. The method includes producing a twine by elongating a first material to a first elongation that is greater than a second elongation of a second material, and braiding the first material and the second material to form an outer braid around an inner portion comprising a third material. The method further includes knotting the twine to form the net.

[0032] In certain examples, the first material and the second material are braided via a braiding machine, with the method further comprising heating and / or cooling the first material and / or the second material while on the braiding machine.

[0033] In certain examples, the method further includes coating the twine with a resin and / or anti-fouling paint.

[0034] In certain examples, the twine is knotted so as to provide a net with mesh openings spanning between 5 mm and 400 mm.

[0035] In certain examples, the twine is produced so as to have a thickness less than 12 mm. In further examples, the twine is knotted such that the net has a solidity less than 30%.

[0036] Another aspect according to the present disclosure generally relates to a net having low solidity for use as a predatory net and a containment net for aquaculture. This may be any shape, including rectangular, circular, conical, or square, and may be knotted or knotless. The net includes an inner portion comprising HDPE, stainless steel, HMPE, polyester film, polyester tape, and / or a PET hollow tube. A first material and a second material are braided together as a braided outer portion around the inner portion to form a twine, wherein the first material and the second material comprise at least two of HMPE, HDPE, polyester, carbon tape, carbon film, aramid, polyolefin, liquid crystal polymer, polyamide, polyimide, PTFE, or PVC, wherein one of the first material and the second material is elongated more than the other, and wherein one of the firstmaterial and the second material comprises partially oriented polymer chains. The twine is knotted to form the net having a solidity less than 30% such that the net is suitable for use as both a predatory net and a containment net for aquaculture.

[0037] In certain examples, the first material and the second material are different from each other and together comprise HMPE tape and HDPE monofilament, and wherein the inner portion comprises the HDPE as an HDPE monofilament, and the HMPE as an HMPE tape or an HMPE film, wherein the twine has a thickness of less than 12 mm.DETAILED DESCRIPTION

[0038] The present disclosure generally relates to netting for use in aquaculture (which should be understood to include fisheries, etc.), such as fencing, for lifting, and / or for safety. Aquaculture is a rapidly growing industry that requires efficient and durable netting solutions to contain and protect aquatic biomass or other products. It should be recognized that the netting may also be referred to as being part of a cage, which also includes structural elements for supporting and positioning the nets. For brevity, nets may be referred to as cages and vice versa. It should further be recognized that these nets may refer to containment and / or predator nets.

[0039] Netting solidity is a crucial factor in the design and performance of aquaculture containment cages. It refers to the ratio of the solid area of the netting to the total area, which affects water flow, drag forces, and the overall environment within the cage. Lower solidity enables higher cross flow of water thereby sufficient oxygen availability required for targeted growth of biomass. Further discussion of solidity, as well as mechanisms for calculating solidity, are provided below.

[0040] Traditional netting materials often suffer from high solidity. Higher solidity corresponds to increased drag and reduced water flow, which can negatively impact the health of the contained biomass. The present inventors have recognized a need for single solution netting eliminating need for separate containment and predator. Also the disclosed netting here balances strength, durability and cut resistance of predator net with low solidity into single cage solution. This optimizes aquaculture operations and reduces the need for maintenance and capex thereof. Netting solidity impacts aquaculture in multiple ways, some of which are described further below.

[0041] 1. Water Flow and Oxygen Levels: Low solidity netting allows for better water flow through the cage, which helps maintain higher oxygen levels and allows for removal of wasteproducts more efficiently. This results in healthier fish and improved growth rates. In contrast, high solidity netting restricts water flow, resulting in lower oxygen levels and the accumulation of waste. This leads to poorer fish health, slower growth, and thus lower overall product quality and highest production costs. Lower solidity also plays a very important role considering that biofouling of the nets over time would further adversely impact net aggregate solidity and waterflow in cages.

[0042] 2. Drag Forces: High solidity nets have relatively high solid areas as compared to the open spaces through which water may flow, and thus have high drag in the water. The time bound biofouling on to these nets further complicates the available space for cross flow of water through it. This high solidity therefore makes it more challenging for intentional (installation) and unintentional (drag) movement of the nets in water. The time bound biofouling further reduces the prevailing high solidity making the net more susceptible to unintentional movement from waves, currents, and tides in the water broadly known as high drag, (which must be countered to retain the position of the net). The increased drag forces also result in greater structural stress on the net, cage, and all structural elements associated therewith, and thus requires heavier and expensive support structures to accommodate for these additional stresses. In addition to the greater cost and weight of supporting these cages with high solidity nets, there is a greater complexity and higher energy costs for maintaining its position. In contrast, the low solidity nets disclosed herein have substantially less drag, and consequently have reduced requirements for the strength of associated support structures and thereby less cost and weight. Additionally, the low solidity nets are less prone to damage in rough sea conditions and the like, as water can more easily flow therethrough. Furthermore the disclosed low solidity nets provides adequate protection from predators in unknown environment due to its high break and cut resistance.

[0043] 3. Biofouling: Low solidity netting can provide for less biofouling because there is less surface area to catch and accumulate biomatter, and also because the increased water flow helps prevent the accumulation on the netting. This can therefore reduce maintenance costs and improve the longevity of the netting. In contrast, high solidity nets as known in the art are more prone to biofouling. Problems are further compounded as biofouling occurs, which only further increases the net’s solidity and thus further restricts water flow, increasing biofouling and the other problems discussed herein (e.g., further increasing drag forces, stresses on the net and support structures that require accommodation, decreasing fish health from reduced flow, etc.). Regularcleaning and maintenance are required to keep the netting functional, which is substantially reduced with the low solidity netting disclosed herein.

[0044] 4. Structural Integrity: Low solidity netting offers reduced drag, reduced weight, and reduced fouling, each of which reduce the requirements for the structural elements supporting the net. This cannot simply be achieved by making existing nets with thinner twine and / or larger mesh openings, as the net must still meet its intended function of withstanding environmental stresses and either containing the product or preventing predator attacks. The low solidity nets disclosed herein thereby provide at least the same functionality as known nets, but provide greater structural integrity based on the materials, manufacturing process, and lower solidity design.

[0045] 5. Fish (or other product) Welfare and Growth: Low solidity netting help to promotes a healthier environment for the fish and / or other biomass by ensuring better water quality and oxygen levels. This can lead to improved growth rates and overall welfare over known, high solidity netting, which provides a more stressful environment for the fish due to poorer water quality and lower oxygen levels, potentially leading to slower growth and higher cost, as also mentioned above.

[0046] Each of these areas is improved with the designs of low solidity netting described herein. As discussed further below, in certain embodiments low density materials are used for producing the net with a high-strength mesh structure. The low solidity netting is designed to maximize water flow and minimize drag, while maintaining sufficient strength to withstand environmental stresses and predator attacks. The method of making the netting includes selecting appropriate materials, twisting, braiding, weaving and / or knitting the mesh structure, and optionally treating the netting to enhance its resistance to biofouling.

[0047] As will also become apparent, the low solidity nets here also provide further benefits over nets presently known in the art. These include allowing the use of braids that use more compact and thinner twine and lower solidity despite achieving the required net strength and cut resistance Likewise, embodiments of the nets disclosed herein provide abrasion resistance, such as optionally being coated with resin / antifouling paint. By way of example, these coatings may be such commercially available products as Aquanet, Netwax NI3, Notorious, Runner, and others, which provide hydrophobic, biostatic and biocidal effect on the surface of net. This multifunctionality of the paint on the net surface help loosen the bonding of biofouling with net surface that can easily be cleaned. Additionally, the nets disclosed herein can advantageously beused to function as both containment nets and predator nets, further eliminating cost, size, complexity, and the support structures needed for the overall system.

[0048] FIG. 1 illustrates an exemplary of twine 2 for producing a net with low solidity according to the present disclosure. The twine 2 has an outer braid 4 with at least one material having partially oriented filaments. The outer braided 4 may include one or more polymer yams of different type of polymers, such as polyolefins, polyester, polyamide, UHMWPE, HMPE, Aramid, etc. In the example of FIG. 1, the outer braid 4 includes a first material 12 and a different second material 14, either or both of which may be partially oriented. One of the materials in the outer braid 4 may be more elongated than the other during the braiding process in the case in which one of the two material is partially oriented and another is not. In certain embodiments, for example when both materials are partially oriented or neither is partially oriented, the twine may be formed using fibers having differential lengths and / or denier combination to match elongation at break. In certain embodiments in which the materials have different elongations, the material having the lesser elongation may be elongated at least 50% of the other material with the greater elongation (e.g., 40%, 50%, 60%, 75%, 80% ,90%, 95%, 99%, 100%). In certain embodiments, the elongation of one or more fibers (whether the same or different from each other, may be a target elongation of 9 - 16%, 9 - 12%, or nominally about 11%, for example.

[0049] By way of example, the outer braid 4 may comprise at least HMPE and HDPE. The HDPE may further be provided as a monofilament, joint filament (e.g., being extruded together with other filaments) and / or multifilament material. The HMPE may be provided as a tape or a film or monofilament known in the art. In certain embodiments, one of the materials comprising the outer braid 4 is a monofilament / tape / film / multifilament / joint filament and another material comprising the outer braid 4 is a mono / tape / film. However, the present disclosure contemplates all different combinations of the above types of material forms, as well as different types of materials being used within the outer braid 4 (in addition to, or as an alternative to those provided as examples above). The braiding process is further discussed below.

[0050] The materials of the outer braid 4 are braided around an inner portion 6 that extends therein. The inner portion 6, which may sometimes also be referred to as a core, may include-one or all but not limited to following combinations: 1) HDPE mono / film / joint / tape, 2) HMPE or polyester tape / film / mono, 3) SS (metal) wire 4-hallow polymer tube or rigid polymer rod. In certain embodiments, one or more materials within the inner portion 6 are twisted, which may bealone, with others of the same material, and / or with other materials. In certain embodiments, the entire inner portion 6 is twisted together.

[0051] The present inventors have found that the follow materials may be incorporated within the twine to provide these functions, by way of example: HDPE yarn for strength and knot tightness, stainless steel wire for cut resistance and sinking properties, HMPE tape for strength and cut resistance, polyester film / tape for specific gravity and elongation, and / or PET hollow tube or rigid rod for stiffness and sinking properties. The resultant twine 2 can then be used to produce a braided knotted net in a conventional manner, as discussed further below.

[0052] Additional information is now provided regarding methods of making twine and low solidity nets according to the present disclosure. FIG. 2 shows one such method 200 for making a net composed of a lower solidity, net thinner twine structure, in accordance with the present disclosure. Step 202 provides for Yam Extrusion: extruding yarn from polymers such as polyolefins. The extruded yarn may have a denier ranging from 100 to 2500D, and may be mono or flat or joint yarn. In certain embodiments, the extruded yarn (e.g.. HDPE monofilament, joint filament, film, and / or tape) has a tenacity ranging from 3 to 12 grams per denier (gpd) and an elongation of 7-24%.

[0053] With continued reference to FIG. 2, step 204 provides for Twine Making: forming circular or rounded twine using a braiding machine, such as forming a braided cover (e.g., an outer portion 4 as in FIG. 1) around a core (e.g.. an inner portion 6 as in FIG. 1). The braiding machine may comprise 6, 8, 12, 16, 24 strands. The twine is composed of a bundle of yarn made from materials such as polymers, metals, or ceramics, with a diameter ranging from 1 mm to 12 mm, as also discussed above. The braiding machine and braiding process may be as conventionally known.

[0054] Step 206 provides for using the developed twine from step 204 to produce braided knotted netting, referred to as raw net. The knotted netting machine is selected based on the twine diameter, pitch, gear, and type / size of knot. The netting is produced with a predefined mesh size with respect to mesh depth (MD) and mesh length (ML) (see FIG. 4). For brevity, since known processes and calculations may be used for step 206, the processes of knotting and the mesh sizes are not described further herein.

[0055] Step 208 provides for processing the raw net to produce the final low solidity net 100 having low solidity according to the present disclosure. This includes stretching the net in the depth direction (see FIG. 3C) at a temperature more than 60°C for a time period (e.g., >10 min),and stretching the net in the length direction at a temperature more than 60°C for another period (e.g., also >10 min, or other times). The machines and techniques used for stretching and heating (or cooking) the raw net may otherwise be as generally known in the art and thus is not described further herein for brevity.

[0056] In certain examples, the raw net is mounted with metal bars on at least two sides to prevent the net does not get entangled. In an exemplary instance, the bars have rings which can be used to hook the net.

[0057] In an embodiment, the raw net is composed of the combination of UHMWPE / HMPE in the form of tape / film / Mono yarn with other material like metal wire, polymer tube / rod, mono and joint filaments of polyolefins -based twine which has not yet been subjected to a heat treatment.

[0058] In another embodiment, the raw net is stretched along the width of the net in a depth way stretch machine. The depth way stretch module is set based on desired net parameters such as hanging ratio, mesh size, depth mesh and netting weight.

[0059] In another embodiment, the raw net is stretched depth way for a specified period of time at a specified temperature. The desired knot tightness may be achieved by thermal stress on the netting made from disclosed composite twine.

[0060] In another embodiment, the raw net is stretched along the length of the net in a length way stretch machine. The length way stretch module is set based on desired net parameters such as hanging ratio, mesh size, depth mesh and netting weight.

[0061] In another embodiment, the raw net is stretched for a specified period at a specified temperature, the raw net being at a temperature around the melting point of the low melting polyester multifilament (e.g., 80-1100C).

[0062] In an exemplary embodiment, the tension for the length way stretching is the zero stretch ratio (with no load on net. oriented such that the meshes are diamond shaped.

[0063] In another exemplary embodiment, the meshes of the net are further joined to one another using a suitable twine such as braided nylon twine, which in certain examples has a mean diameter of more than 2 mm, in the process known as cage fabrication.

[0064] Other methods according to the present disclosure may be as follows: producing a twine by elongating a first material to a first elongation that is greater than a second elongation ofa second material, and braiding the first material and the second material to form an outer braid around an inner portion comprising a third material; and knotting the twine to form the net.

[0065] In an embodiment, the first material and the second material are braided via a braiding machine, and the method further includes heating and / or cooling the first material and / or the second material while on the braiding machine.

[0066] In certain embodiments, the method further includes coating the twine with a resin and / or anti-fouling paint. The present inventors have recognized that for other twines and nets known in the art having 100% HDPE yarn, the twine cannot be painted as there is no opportunity for covalent bonding. This is enabled by the presently disclosed twines. Additionally, the present inventors have recognized that HMPE film provides larger surface area for binding paint, which is further advantageous for the completed net.

[0067] In certain embodiments, the twine is braided knotted so as to provide a net with mesh openings spanning between 5 mm and 400 mm (discussed further below).

[0068] In certain embodiments, the twine is produced so as to have a thickness of less than 12 mm (discussed further below).

[0069] In certain embodiments, the twine is knotted such that the net has a solidity of less than 30% (discussed further below).

[0070] FIGS. 3A-3C show a net 100 produced with twine 2 according to the present disclosure. FIG. 3A shows one method for measuring a mesh side and solidity of netting as per NS9415, which shows a first measurement 102 (also referred to as the mesh side) in one direction and another measurement 104 in another direction. The twine 2 also has a thickness 106. The knots 108 cause the twine 2 to form meshes 99 having mesh openings 110 that span a distance 112 (which here is the same in both directions as the meshes have square shaped openings. Rectangular or other shaped meshes are also contemplated.

[0071] The mesh side shown in FIG. 3A is shown when the twine 2 in the netting is gently stretched out by hand (using a force of approx. 100 g), specified as a straight-line center-to-center spacing between two consecutive knots / joints

[0072] The mesh side 102 is determined by measuring the length over at least 10 meshes 99 and dividing this measurement by the number of meshes 99 measured. The mesh side 102 shall be measured in three different places on the netting 100 and specified as the mean value of the measurements. The value is rounded to the nearest half millimeter.

[0073] FIG. 3B shows one method for measuring twine 2 thickness, which here is specified in mm and determined based on image processing. In other examples, the twine 2 can also be clamped together using a caliper, for example. The twine 2 can be pulled using a force of up to 100 g on each twine 2 in each direction. The diameter (or thickness 106) is measured by pixel method in at least 10 places in the 5 thickest and 5 thinnest parts. The diameter is determined as the mean of the measurements.

[0074] As discussed above, the present disclosure contemplates different materials for making twine and nets to provide the desired low solidity described herein, as well as providing additional properties like high strength, abrasion resistance, good cut resistance and optionally paintable properties.

[0075] In an embodiment, low solidity netting may be made of HMPE tape / film / mono in the braided twine having a composition less than 50% by weight (e.g., based on denier).

[0076] In an embodiment, the un-cooked composite twine 2 as shown in FIG 3A in the proposed disclosure having tenacity more than 4 gpd resulting in high strength to weight ratio and low GSM for all twine diameters more than 0.8mm.

[0077] In an exemplary embodiment, the HMPE Mono / tape / film have denier ranging from 400 to 6000D with the tenacity ranging from >12 gpd with elongation at break 3 to 14%.

[0078] The netting may have a twine diameter less than 12 mm, in certain cases ranging from 0.5 mm to 12 mm. and Mesh size varies with 15mmkk to 400mmkk.

[0079] The composite fiber rod may have a specific gravity of greater than the salinity of saline water (i.e., 1.025), for example measuring in the range of 1.08 - 1.1.

[0080] As discussed above, the twine and methods described herein provide for low solidity netting, in contrast to those presently known in the art. The present inventors have recognized problems with nets presently known in the art, which relate to weight, functionality in supporting biological products, cost, maintenance, longevity, and other attributes discussed below.

[0081] For example, the present inventors have recognized that drag forces on nets represent the largest contribution to hydrodynamic loads on traditional fish farms, and thus have a large impact on total loads and performance of net walls (or simply, nets). This drag force is inversely proportional to mesh size, or solidity, of the netting. Solidity can be measured as the ratio between the solid netting area (based on the twine diameter) and total area of a net or net panel. As per Aquaculture standard NS9415, solidity can be calculated by formula mentioned in standardas below. In the case of square meshes with knots, solidity shall be calculated using the following formula (see also FIGS. 3A-3C):„ 2 • t - + t24- D2- 2< / 2 ■ I) * tA — ~~~”^^MSWhere:S -solidityMs-mesh sidet-Twine diameterD-Knot diameter

[0082] In certain embodiments, for a given diameter 2.1mm and for the 40mmkk full mesh will give us solidity level 20.53% with associated MBS more than 200 kgf, while for same solidity level nets presently known in the market have MBS of 150kgf. Through experimentation and testing, the present inventors have determined that a net matching the performance of nets known in the market may be produced using a twine diameter of only 1.8mm (by way of example), having an associated solidity 17.5% solidity. This represents a 15% lower reduction in twine diameter, and thus a reduction of the solidity level more than 10% over nets presently known in the art.

[0083] In this manner, the netting according to the present disclosure provides for reduced solidity, which enhances water flow and reduces drag, thereby improving the health and growth rates of aquatic organisms. The method of making the netting involves specific materials and manufacturing processes that ensure durability and resistance to biofouling.

[0084] The present inventors have recognized further unmet needs within the industry, including a need for other improvements in nets and twines for making nets. Among these include nets from twines of other compositions than those described above, as well as twines and nets that can be easily and / or completely recycled for a more sustainable future.

[0085] FIG. 5 depicts another twine 302 according to the present disclosure, which has some similarity to the twine of FIG. 1. For brevity, embodiments of twines that may use similar or the same components as those described above are not repeated, but rather are labeled with similar numbering that is incremented by 100s. For example, the HDPE 312 for the twine 302 of FIG. 5 may be the same or similar to the HDPE 12 from the twine 2 of FIG. 1, noting the incrementingof 300. While descriptions are not repeated for the sake of brevity, it should be recognized that the similarly number components need not be identical to each other.

[0086] One difference in the twine 302 of FIG. 5 is the use of a rigid cord made from a polymer, which is indicated as rigid cord 324. Examples of materials that may be used as the rigid cord 324, and likewise for other components, is provided in FIG. 10. Other examples of materials that may be used as the rigid cord 324 include

[0087] The present inventors have further recognized an unmet need for twines and nets that can be readily recycled, whether in entirely or mostly. This may be particularly advantageous within the aquaculture industry, which is becoming increasingly concerned with sustainability. Moreover, aquaculture nets have the unique quality that they are designed to capture wildlife, and thus may be uniquely harmful to dispose of in a conventional manner due to inadvertent capture of additional wildlife. For example, nets discarded in a landfill may catching birds, turtles, and the like, may be blown away from landfills, or other problems over a long time period after discarding. As such, designing a net that can be recycled not only allows the materials to be reused, but ensures that these nets cannot have these negative side effects when no longer in use.

[0088] Additionally, the presently disclosure demonstrates low solidity performance with extremely low linear density of twines, thereby leading to less plastic being used at sea in the first place. The twines, nets, and methods disclosed herein advantageously enable the use of materials having nearly the same melting point polymers, which as discussed above makes them recyclable post product life cycle. Therefore, this lesser plastic load on the sea and post life recyclability option makes this solution sustainable and paves the path of responsible care. In one such example, the incumbent non-recyclable solution in the market having the weight of 8000kg would be replaced by current invention with the weight range of 4500-5000 kg with option to recycle post life. The disposal after recycled life will leave lesser environmental footprint within options of landfill or incineration.

[0089] FIG. 6 discloses another embodiment of a twine 402 according to the present disclosure. In view of the benefits to recycling as discussed above, the twine 402 has been designed so as to be entirely cyclable. In this embodiment, the inner portion 406 does not include any metals (e.g., stainless steel wire), any PET, or any other component that cannot be recycled. The same is true of the outer braid 404, and thus the entire twine 402 can be recycled via conventional methods when the net has exceeds its useful life.

[0090] The present inventors have recognized that even if recyclable twine exists in the market for a given strength class, no known recyclable twine provides the weight saving and low solidity provided herein. The presently disclosed twines, nets, and methods of making them provide high performance in terms of weight savings and low solidity, while concurrently doing so with materials and engineering arrangements making them recyclable.

[0091] FIG. 7 depicts another twine 502 according to the present disclosure, which is similar to the twine 402 of FIG. 6 but further includes a solid core made from polymer HDPE within the inner portion 506, labeled as stiff core 526. The present inventors have recognized that the addition of the stiff cord 526 (which is other embodiments according to the present disclosure may be hollow) further improves cut resistance and increases stiffness. However, these benefits are achieved while still being recyclable after the net has exceeded its useful life, for recycling scrap, and / or the like (see also, FIG. 10).

[0092] FIG. 8 depicts another twine 602 according to the present disclosure, which is similar to the twine 502 of FIG. 7, including the stiff core 526 (which may be hollow, as discussed above), but also including HMPE 618 that may be similar to the embodiment of FIG. 1 or FIG. 5.

[0093] It should be recognized that the present disclosure also contemplates embodiments that include non-recyclable materials added to examples expressly shown in recyclable configurations. For example, the present disclosure contemplates twines that are similar to those of FIGS. 1 and 2, but further add a polyester tape or film for a non-recyclable version. For brevity, further figures that expressly show these additional materials added to other examples are not provided. However, it should be recognized that materials shown in one figure may be incorporated into an example from another figure, along with other combinations of materials as described herein.

[0094] FIG. 9 depicts another twine 702 according to the present disclosure, which is similar to the twine 602 of FIG. 8, but does not include a stiff core.

[0095] As stated above, FIG. 10 depicts some examples of materials that may be used for the components of the twines described above. FIG. 10 also details some of the benefits of including these example components within these twines. However, it should be recognized that these examples are non-limiting, and further that additional components may be added to those shown in the figures.

[0096] FIG. 11 shows example test data from experimentation using twines produced according to the present disclosure. Breaking strengths are shown for various mesh sizes, which were tested using the methods described above. For the sake of comparison, the solidity % for nets produced at each mesh size according to the present disclosure are also shown with the corresponding measurement for nets known in the art. For example, a twine produced according to the present disclosure with a mesh size of 18mmsq has a solidity percentage of 20.53% compared to 24.88% for conventional nets, and had a breaking strength of 136 Kgf.

[0097] Through experimentation and testing, the present inventors have found that twines produced according to the present disclosure provided multiple benefits over twines known in the art (including comparing nets made therefrom). By way of non-limiting example, these include a twine diameter that is 25-50% smaller than existing products in market, a 25-50% reduction in weight compared to current market offerings, and a 10-20% or 15-20% decrease in solidity relative to existing products in the market. However, these are merely examples, with some twines benefitting to greater than the example data provided above.

[0098] FIG. 12 depicts experimental data comparing, among other things, the solidity for competitive twines in the market versus twines produced according to the present disclosure. Standards exist for twines, for example with Norwegian Standard NS 9415 defining breaking strength classes that include 96kgf, 117 kgf, 136kgf, and 151kgf strength classes, among others. The strength classes vary in twine diameter and the associated weight / meter for that twine. The present inventors have further identified that it is advantageous to compare twines not solely by conventional solidity calculations (e.g., Norwegian STD NS9415 described above), but also by normalizing these solidity calculations as a function of runnage. In particular, solidity calculations performed per NS 9415 can be normalized for a given MBS by dividing solidity calculations by the twine runnage, multiplied by 100. In the example of FIG. 12, normalized solidity calculations are provided as a percentage per meter length for a 100 meter length twine.

[0099] As shown in FIG. 12, twines produced according to the present disclosure resulted in substantially reduced solidity over those known in the art. In certain examples, the twines produced according to the present disclosure resulted in reductions in normalized solidity of at least 25%, at least 30%, at least 35%, and at least 40%. By way of example, 96 kgf MBS class twines produced according to the present disclosure demonstrated a 33% reduction in normalized solidity over known competitor products, whereas 136 kgf MBS class twines had a normalizedsolidity reduction of 40%. These are substantial reductions demonstrated with actual test results, advantageously providing the many benefits over known twines as discussed above.

[0100] In this manner, the twines, nets, and methods of making them disclosed herein provide unique solutions for problems identified by the present inventors, including by providing reduced solidity that is particularly beneficial for aquaculture uses.

[0101] The functional block diagrams, operational sequences, and flow diagrams provided in the Figures are representative of exemplary architectures, environments, and methodologies for performing novel aspects of the disclosure. While, for purposes of simplicity of explanation, the methodologies included herein may be in the form of a functional diagram, operational sequence, or flow diagram, and may be described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and / or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology can alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation.

[0102] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. Certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have features or structural elements that do not differ from the literal language of the claims, or if they include equivalent features or structural elements with insubstantial differences from the literal languages of the claims.

Claims

CLAIMSWhat is claimed is:

1. A net having low solidity for aquatic use, the net comprising twine having an outer braid with at least one material having partially oriented filaments, and an inner portion that extends within the outer braid, wherein the twine is arranged to form the net.

2. The net according to claim 1, wherein the twine is arranged such that the net has a solidity less than 30%.

3. The net according to claim 2, wherein the net has mesh openings spanning at least 5 mm.

4. The net according to claim 1, wherein the twine has a thickness of less than 12 mm.

5. The net according to claim 1, wherein the twine is knotted to form the net.

6. The net according to claim 1, wherein the at least one material comprises at least 45% of a total mass of the twine.

7. The net according to claim 1, wherein the at least one material comprises a first material and the outer braid further has a second material braided with the first material, and wherein the first material has a first elongation and the second material has a second elongation that is greater than the first elongation.

8. The net according to claim 7, wherein the first elongation is at least 50% of the second elongation.

9. The net according to claim 1, wherein the at least one material comprises a first material and the outer braid further has a second material braided with the first material, and wherein the first material and the second material are different materials.

10. The net according to claim 9, wherein the outer braid comprises a monofilament and a multifilament.

11. The net according to claim 1, wherein the inner portion comprises HDPE, stainless steel, HMPE and / or polyester, and a cord comprising a polymer, and wherein the outer braid comprises HDPE and HMPE.

12. The net according to claim 1, wherein the inner portion comprises HDPE without comprising a metal and without comprising PET, and wherein the outer braid comprises HDPE and HMPE.

13. The net according to claim 1, wherein the twine is within one of a96kgf, a 117kgf, a 136kgf, or a 15 Ikgf strength class, and wherein the twine is arranged such that the net has a normalized solidity of less than 3.5 if within the 96kgf MBS strength class, less than 4.5 if within the 117kgf MBS strength class, less than 6 if within the 136kgf MBS strength class, and less than 7.5 if within the 151kgf MBS strength class.

14. A method for making a net having low solidity for aquatic use, the method comprising:producing a twine by elongating a first material to a first elongation that is greater than a second elongation of a second material, and braiding the first material and the second material to form an outer braid around an inner portion comprising a third material; andknotting the twine to form the net.

15. The method according to claim 14, wherein the first material and the second material are braided via a braiding machine, further comprising heating and / or cooling the first material and / or the second material while on the braiding machine.

16. The method according to claim 14, further comprising coating the twine with a resin and / or anti-fouling paint.

17. The method according to claim 14, wherein the twine is knotted so as to provide a net with mesh openings spanning between 5 mm and 400 mm.

18. The method according to claim 14, wherein the twine is produced so as to have a thickness less than 12 mm.

19. The method according to claim 18, wherein the twine is knotted such that the net has a solidity less than 30%.

20. A net having low solidity for use as a predatory net and a containment net for aquaculture, the net comprising:an inner portion comprising HDPE, stainless steel, HMPE, polyester film, polyester tape, and / or a PET hollow tube; anda first material and a second material braided together as a braided outer portion around the inner portion to form a twine, wherein the first material and the second material comprise at least two of HMPE, HDPE, polyester, carbon tape, carbon film, aramid, polyolefin, liquid crystal polymer, polyamide, polyimide, PTFE, or PVC, wherein one of the first material and the second material is elongated more than the other, and wherein one of the first material and the second material comprises partially oriented polymer chains;wherein the twine is knotted to form the net having a solidity less than 30% such that the net is suitable for use as both a predatory net and a containment net for aquaculture.

21. The net according to claim 20, wherein the first material and the second material are different from each other and together comprise HMPE tape and HDPE monofilament, and wherein the inner portion comprises the HDPE as an HDPE monofilament, and the HMPE as an HMPE tape or an HMPE film, wherein the twine has a thickness of less than 12 mm.

Images