Degradable extrusion netting prepared from a polymer blend composition

Abstract

The present disclosure relates to a degradable extrusion netting comprising a plurality of interconnected strands, wherein at least a portion of the strands are prepared from a polymer blend comprising a polylactic acid polymer composition, polybutylene succinate, and a degradation additive, wherein the degradation additive comprises a degradation agent in a carrier resin. The present disclosure also relates to a turf sod using such degradable extrusion netting and a method for manufacturing the turf sod.

Description

Background Technology

[0001] Cross-reference with related applications

[0002] This application claims the benefit of U.S. provisional application serial number 62 / 860,931 filed on June 13, 2019, the entire disclosure of said provisional application incorporated herein by reference for all purposes.

[0003] background

[0004] The field of the present disclosure is to extruded plastic netting, more particularly to biodegradable extruded netting comprising a plurality of interconnected strands for use in turf sod.

[0005] In the conventional method of growing sod, grass seeds are planted in the soil. After the grass crop is grown until its roots are sufficiently intertwined so that it clumps together like a cohesive carpet-like mat when cut, the sod can be peeled or rolled up and separated from the underlying soil. Often, the soil layer contains a synthetic structure, such as netting, that helps keep the sod intact and cohesive after harvesting.

[0006] Extruded plastic netting is used for numerous commercial applications, such as erosion control, netting for supporting climbing plants, barrier fences, tree guards, and turf netting. Currently, a typical extrusion process for manufacturing plastic netting involves extruding individual plastic strands into an interconnected network to provide a net-like structure. Conventional plastic netting and methods for manufacturing the same are disclosed in U.S. Patent No. 3,700,521; U.S. Patent No. 3,767,353; U.S. Patent No. 3,723,218; U.S. Patent No. 4,123,491; U.S. Patent No. 4,152,479 and U.S. Patent No. 4,190,692, the full disclosures of which are incorporated herein by reference in their entirety.

[0007] Conventional plastic netting is typically manufactured from various base resins, such as metals, polyethylene, polypropylene, nylon, polyester, etc., that are non-corrosive and / or abrasion-resistant and / or chemical-resistant and / or durable. Pigments and additives may be introduced during the extrusion process to provide unique colors or properties, such as stabilization against UV light degradation.

[0008] One of the drawbacks of conventional plastic netting is that the materials used to manufacture it are generally not biodegradable or renewable. Consequently, it occupies more landfill space and causes more harm to the environment than is desired.

[0009] Therefore, it would be desirable to provide an improved extrusion netting having acceptable mechanical strength, manufactured using easily processable and degradable materials derived from renewable resources.

[0010] To provide a basic understanding of some aspects of the claimed subject matter, a simplified summary of the claimed subject matter is presented below. This summary is not a comprehensive overview of the claimed subject matter. It is not intended to identify the core or decisive elements of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Its sole purpose is to present some concepts of the claimed subject matter in a simplified form as an introduction to the more detailed description to be presented later.

[0011] The present disclosure relates to a degradable extrusion netting comprising a plurality of interconnected strands. At least some of the strands of the netting are prepared from a polymer blend comprising a polylactic acid composition; and a polybutylene succinate composition. In certain embodiments, the polymer blend further comprises a degradation additive. At least some of the strands of the netting are prepared from a polymer blend comprising a polylactic acid composition; a polybutyrate composition; a polylactic acid-polybutyrate compatibilizer composition; and a degradation additive. The degradation additive may comprise a degradation agent in a carrier resin.

[0012] In certain embodiments, the polymer blend contains an amount of polylactic acid composition in the range of about 40 weight% to about 60 weight%, and an amount of polybutylene succinate (PBS) in the range of about 40 weight% to about 60 weight%. The polymer blend further contains an amount of a degradation additive in the range of about 0.1 weight% to about 5 weight%.

[0013] The polylactic acid composition may comprise at least one polymer derived at least partially from lactide or lactic acid, and such polymers are collectively referred to herein as polylactic acid or PLA. In certain embodiments, the polylactic acid composition comprises one or more polylactic acid polymers derived from plant starch, such as linear aliphatic thermoplastic polyesters derived from renewable resources such as corn.

[0014] The PBS composition may comprise one or more polymers, including an aliphatic polyester prepared by the polycondensation of succinic acid or any derivative thereof and 1,4-butanediol.

[0015] The degradation additive preferably comprises a degradation agent in the carrier resin. In one or more embodiments, the carrier resin constitutes about 90% to about 99% by weight of the degradation additive, and the remainder is the degradation agent. In an embodiment, the carrier resin is biodegradable, transparent, and derived from renewable resources.

[0016] The degradation additive may include a number of suitable degradation additives that cause degradation of plastic materials primarily based on heat exposure. In certain embodiments, the degradation additive includes iron stearate, manganese stearate, metal carboxylate, or any suitable combination thereof.

[0017] In another aspect of the disclosure, a polymer blend composition for producing a degradable extrusion netting comprises an amount of polylactic acid (PLA) composition in the range of about 55 weight% to about 60 weight%, an amount of polybutyrate composition in the range of about 35 weight% to about 40 weight%, an amount of compatibilizer composition in the range of about 0.5 weight% to 3 weight%, and an amount of degradation additive in the range of about 2 weight% to about 7 weight%.

[0018] The polybutyrate composition may comprise one or more polybutyrate adipate terephthalate (PBAT) polymers. The compatibilizer composition may comprise any composition that helps ensure a substantially homogeneous mixture of PLA and PBAT is obtained. In certain embodiments, the PLA-PBAT compatibilizer composition comprises a mixture of a PLA carrier resin and a compatibilizer, such as polypropylene glycol diglycidyl ether, epoxidized cottonseed oil (ECSO), or maleated (MCSO) cottonseed oil.

[0019] The degradation additive may include a number of suitable degradation additives that cause degradation of plastic materials primarily based on heat exposure. In certain embodiments, the degradation additive includes iron stearate, manganese stearate, metal carboxylate, or any suitable combination thereof.

[0020] In another aspect of the present invention, the present disclosure relates to turf grown in soil and soil-degradable extruded netting. The netting comprises a plurality of interconnected strands, at least some of the strands are prepared from a polymer blend comprising a polylactic acid composition in an amount ranging from about 40 weight% to about 60 weight% and a polybutylene succinate composition in an amount ranging from about 40 weight% to about 60 weight%. The polymer blend may further comprise a degradation additive in an amount ranging from about 0.1 weight% to about 5 weight%.

[0021] In another additional aspect of the present invention, the present disclosure relates to a method for growing turf sod, comprising the following steps: providing a netting material in soil, wherein the netting material comprises a plurality of interconnected strands, at least some of the strands being prepared from a polymer blend comprising an amount of polylactic acid composition in the range of about 40% by weight to about 60% by weight; an amount of polybutylene succinate (PBS) composition in the range of about 40% by weight to about 60% by weight; and an amount of a degradation additive in the range of about 0.1% by weight to about 5% by weight; and growing a turf crop in soil.

[0022] It should be understood that both the general description above and the detailed description below are illustrative and descriptive only and do not limit the present disclosure. Additional features of the present disclosure may be partially presented in the subsequent description or learned through the practice of the disclosure. Brief explanation of the drawing

[0023] The attached drawings included in and constituting part of this specification illustrate various embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure. FIG. 1 is a perspective view of netting according to an exemplary embodiment of the present disclosure; FIG. 2 illustrates QUV test data collected from extruded films prepared from the compositions according to Examples 1-5 of the present disclosure as well as comparative compositions, showing the percentage of strength loss in the machine direction over time; FIG. 3 illustrates QUV test data involving condensation collected from extruded films prepared from the compositions according to Examples 1-5 of the present disclosure as well as comparative compositions, showing the percentage of strength loss in the machine direction over time; FIG. 4 illustrates QUV test data collected from extrusion netting prepared from the compositions according to Examples 3 and 5-7 of the present disclosure as well as comparative compositions, showing the percentage of strength loss in the machine direction over time; FIG. 5 illustrates modulus data of blends prepared from compositions according to Examples 7-10 as well as the present disclosure; FIG. 6 illustrates tensile strength data of blends prepared from compositions according to Examples 7-10 as well as the present disclosure; FIG. 7 illustrates QUV test data collected from extrusion netting prepared from the compositions according to Examples 8 and 10-12 of the present disclosure as well as comparative compositions, showing the percentage of strength preserved over time. Specific details for implementing the invention

[0024] This description and the accompanying drawings illustrate exemplary embodiments and should not be construed as limiting, and the claims, including equivalents, limit the scope of this disclosure. Various mechanical, compositional, structural, and operational variations, including equivalents, may be made without departing from the scope of this description and claims. In some cases, widely known structures and technologies have not been described in detail to avoid obscuring this disclosure. Identical numbers in two or more drawings indicate identical or similar elements. Furthermore, elements and related aspects described in detail in relation to one embodiment may be incorporated into other embodiments in which they are not specifically described or explained, whenever practiced. For example, if an element is described in detail in relation to one embodiment but not in relation to a second embodiment, that element may nevertheless be claimed to be incorporated into the second embodiment. Furthermore, the descriptions herein are for illustrative purposes only and do not necessarily reflect the actual shape, size, or dimensions of the system or the illustrated components.

[0025] As used in this specification and the appended claims, it should be noted that the use of any singular form of any word includes multiple referents unless explicitly and clearly limited to a single referent. Since the term "include" and its grammatical variations as used herein are intended to be non-restrictive, the reference to an item included in the list does not exclude other similar items that may replace or be added to the listed item.

[0026] Although the following disclosure is presented in relation to biodegradable extruded netting for use in connection with turf sod, it should be understood that the biodegradable extruded netting can be readily adapted for use in a variety of other applications, e.g., packaging netting, e.g., onion and turkey bags; agricultural netting, e.g., sod netting, sod wrap, hay bales, etc.; and erosion control applications; and as netting for industrial, filtration, and household furniture applications. Additionally, the biodegradable extruded netting can also be adapted for use in composite fabrics and other similar products, e.g., in building and construction composites, for disposable diapers, incontinence pants, potty training pants, bandages, dressings, diaper holders and liners and feminine hygiene clothing, medical gowns, medical drapes, mattress pads, blankets, sheets, clothing, and consumer wipes.

[0027] As seen in FIG. 1, the netting (10) comprises a strand (12) extending in one direction and a strand (14) extending generally in a cross or transverse direction. The strands (12 and 14) are elongated extruded polymer members that cross and transverse during extrusion to form a net-like structure. The strands (12 and 14) may also be formed as extruded strands that are knitted together rather than crossing during extrusion. In certain embodiments, the strands (12 and 14) are made of the same material. In alternative embodiments, the strand (12) is made of a different material from the strand (14). For example, the netting (10) may comprise 10 to 90 wt.% of the material of the strand (12) and 10 to 90 wt.% of the material of the strand (14). In another embodiment, the netting (10) may comprise 45 to 55 wt.% of the material of the strand (12) and 45 to 55 wt.% of the material of the strand (14). In an embodiment where the strands (12 and 14) are made of the same material, the material used to make the strands (12 and 14) is a biodegradable composition according to the present disclosure. Where a material other than the biodegradable composition is used to make one of the set of strands (12 or 14), such material may comprise a non-biodegradable composition.

[0028] Accordingly, the degradable extrusion netting may be manufactured entirely from degradable materials or from a combination of degradable and non-degradable materials. In certain embodiments, the degradable material used to manufacture the extrusion netting may comprise a combination of materials including one or more polylactic acid (PLA) polymer compositions, one or more polybutylene succinate (PBS) polymer compositions, and a degradation additive. In other embodiments, the degradable material used to manufacture the extrusion netting may comprise a combination of materials including one or more polylactic acid (PLA) polymer compositions, one or more polybutyrate adipate terephthalate (PBAT) polymer compositions, a PLA-PBAT compatibilizer, and a degradation additive.

[0029] PLA composition

[0030] Generally, a polylactic acid composition may comprise one or more polymers derived at least partially from lactide or lactic acid, and such polymers are collectively referred to herein as polylactic acid or PLA.

[0031] Generally, in polymer nomenclature, polymers are sometimes referred to based on the monomers used to manufacture them, and in other cases, they are characterized based on the smallest repeating unit found in the polymer. For example, the smallest repeating unit in polylactide is lactic acid (actually, a residue of lactic acid). However, in typical cases, commercial polylactide will be produced by the polymerization of lactide monomers rather than lactic acid. Of course, lactide monomers are dimers of lactic acid. In this document, the terms "polylactic acid," "polylactide," and "PLA" are intended to include both polylactic acid-based polymers and polylactide-based polymers within their categories, and the terms are used interchangeably. That is, the terms "polylactic acid," "polylactide," and "PLA" are not intended to be restrictive with respect to the manner in which the polymer is formed.

[0032] The term "polylactide-based" polymer or "polylactic acid-based" polymer refers to a polymer of polylactic acid or polylactide as well as a copolymer of lactic acid or lactide, wherein the polymer produced comprises at least 50 weight percent of a lactic acid residue repeating unit or a lactide residue repeating unit. In this context, the term "lactic acid residue repeating unit" refers to the following unit:

[0033]

[0034] In light of the above definition, it is clear that polylactide can be referred to as both lactic acid residue-containing polymers and lactide residue-containing polymers. In this document, the term "lactide residue repeating unit" refers to the following repeating units:

[0035]

[0036] It should be noted that lactide residue repeating units can be obtained from L-lactide, D-lactide, and meso-lactide. L-lactide is composed of two S-lactic acid residues; D-lactide is composed of two R-lactic acid residues; and meso-lactide is composed of both S-lactic acid residues and R-lactic acid residues.

[0037] In an embodiment, PLA may be a linear aliphatic thermoplastic polyester derived from renewable resources such as corn and may be compostable in various environments. In recent years, PLA has been increasingly utilized in fiber applications, such as netting, because it provides raw materials derived from sustainable and renewable resources.

[0038] Plant-based PLA derived from corn is widely known. Traditionally, corn is immersed in a mixture that loosens its molecular bonds, after which the mixture is ground and centrifuged to separate corn oil from the starch. Subsequently, dextrose is extracted from the starch using hydrolysis. Ultimately, the dextrose is fermented to form lactic acid. Lactic acid is converted to lactide using electrodialysis and then polymerized to form long lactide chains, thereby producing complete plant-based PLA.

[0039] In an embodiment, the PLA composition comprises a mixture of PLA polymers, at least some of which are derived from sustainable and renewable resources such as plant starch.

[0040] In an embodiment, the PLA composition comprises at least 50 weight percent of a PLA polymer having a nominal average molecular weight of about 200,000 daltons.

[0041] PBS composition

[0042] Generally, the PBS composition may comprise one or more polymers, including an aliphatic polyester prepared by the polycondensation of succinic acid or any derivative thereof with 1,4-butanediol. These biodegradable polymers naturally decompose into carbon dioxide, water, and biomass. In the embodiments, the PBS used may be synthesized via chain extension using a diisocyanate following melt condensation polymerization. While bio-based succinic acid is suitable for the production of these biodegradable polymers, polyalkylene succinates may be synthesized from petrochemical precursors. In the embodiments, the PBS composition may be the commercially available FZ91 / FD92 sold under the trade name BioPBS® from PTT MCC Biochem Company, Ltd.

[0043] PBAT composition

[0044] Generally, the PBAT composition may comprise one or more polymers comprising a diol-dicarboxylic acid condensation type polyester having an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and an aliphatic diol as its constituents. In an embodiment, the PBAT composition may comprise any biodegradable, statistical, aliphatic-aromatic copolyester. In an embodiment, the PBAT composition comprises at least one aliphatic-aromatic copolyester based on monomers 1,4-butanediol, adipic acid, and terephthalic acid in the polymer chain. When metabolized in soil or compost under standard conditions, such biodegradable polymers eventually decompose into carbon dioxide, water, and biomass. In an embodiment, the PBAT composition may be the commercially available F Blend C1200 sold under the trade name ecoflex® from BASF SE.

[0045] In an embodiment, the PBAT composition comprises at least 50 weight percent of a PBAT polymer. If the PBAT comprises a polymer having a lower molecular weight than the polymer included in the PLA composition, the PTAB composition can enhance the flexibility of the PLA when mixed with the PLA composition.

[0046] PLA-PBAT Compatibilizer Composition

[0047] Generally, a PLA-PBAT compatibilizer composition is any composition that helps ensure a substantially homogeneous mixture of PLA and PBAT is obtained. In an embodiment, the PLA-PBAT compatibilizer composition comprises a mixture of a PLA carrier resin and a compatibilizer. In an embodiment, the PLA carrier resin constitutes about 90% to about 99% by weight of the PLA-PBAT compatibilizer composition, and the remainder is the compatibilizer. The PLA carrier resin may be any extrusion-grade thermoplastic resin that is easily processable. In an embodiment, the PLA carrier resin is transparent and derived from renewable resources. In an embodiment, the PLA carrier resin may be Biopolymer 2003D, sold under the trade name Ingeo™ available from NatureWorks, and may constitute 95% by weight of the PLA-PBAT compatibilizer composition. In an embodiment, the compatibilizer may be polypropylene glycol diglycidyl ether (EJ400) or an epoxy-based compound, such as epoxidized cottonseed oil (ECSO) or maleated (MCSO) cottonseed oil.Other suitable compatibilizers that can be used in PLA-PBAT compatibilizer compositions include 4,4'-diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, 3,3'-tolidine-4,4'-diisocyanate, toluene diisocyanate, methylcyclohexane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, secondary methylphenylene diisocyanate, hydrogenated secondary-toluylenebismaleimide diisocyanate, tetramethylxylylene diisocyanate, tetramethylxylylene diisocyanate, methylene diphenyl diisocyanate, and 4,4'-diisopropyl It includes isocyanate compounds including, but not limited to, diphenyl diisocyanate, polymethylene polyphenyl diisocyanate, phenylene diisocyanate, 1,8-4-isocyanate methyl octane diisocyanate, 1,5-naphthalene diisocyanate, dianisidine diisocyanate, diphenyl ether diisocyanate, lysine methyl ester diisocyanate, lysine ester triisocyanate, triphenyl methane triisocyanate, triisocyanate phenyl phosphorothioate, 1,6,11-undecane triisocyanate, bicycloheptane triisocyanate, trimethyl hexamethylene triisocyanate, polymethylene polyphenyl isocyanate, or combinations thereof. In an embodiment, the compatibilizer may also be Joncryl ADR sold by BASF, Lotader AX8900 sold by Arkema, or Biomax Strong 120 sold by DuPont.

[0048] Decomposition additives

[0049] In certain embodiments, the degradation additive comprises a degradation agent in the carrier resin. In one or more preferred embodiments, the carrier resin constitutes about 90% to about 99% by weight of the degradation additive, and the remainder is the degradation agent. In the embodiments, the carrier resin is biodegradable, transparent, and derived from renewable resources. In the embodiments, the carrier resin may be Biopolymer 2003D, sold under the trade name Ingeo™ available from NatureWorks, and may constitute 95% of the degradation additive. In the embodiments, the degradation agent comprises iron stearate, but any suitable degradation agent may be used. A suitable degradation additive is an additive that causes the degradation of the plastic material primarily based on heat exposure. Metal carboxylates are relatively widely known degradation additives, and examples of other degradation additives include, but are not limited to, auto-oxidizable unsaturated organic compounds, such as ethers, acetals, ketals, amines, aldehydes, natural oils, unsaturated fatty acids, and other compounds that help generate free radicals and peroxides involved in oxidation reactions.

[0050] Other additives

[0051] In an embodiment, conventional additional additives may be included in the composition used to manufacture the extrusion netting.

[0052] In the embodiments, a suitable photodegradable additive may be used. A suitable photodegradable additive is an additive that causes the degradation of a plastic material primarily based on light exposure. Examples of photodegradable additives include, but are not limited to, photosensitive polymers such as aromatic ketones, aromatic amines, peroxides, quinones, and azo compounds.

[0053] In an embodiment, a coloring agent may be included. The coloring agent can affect the degradation rate because it can reduce the intensity of UV light by reflecting, diffusing, absorbing, or diffracting UV light. One suitable coloring agent includes the green coloring agent 29025 GN PE Masterbatch available from PolyOne Corporation in Acess, Belgium, which is a green coloring agent in the carrier for imparting green to the resulting extrusion netting.

[0054] In an embodiment, a stabilizer is included. The stabilizer can help protect netting from excessive degradation caused by UV light exposure. In at least certain embodiments, the stabilizer includes a hindered amine compound, such as an oligomeric hindered amine photostabilizer or a hindered amine photostabilizer (HALS).

[0055] Exemplary composition

[0056] In an embodiment, the polymer composition blend used to manufacture the degradable extrusion netting may comprise an amount of PLA composition in the range of about 40 wt% to about 60 wt% and an amount of PBS composition in the range of about 40 wt% to about 60 wt%. In an embodiment, the polymer composition blend used to manufacture the degradable extrusion netting may further comprise an amount of degrading agent additive in the range of about 0.1 wt% to 5 wt%. In a preferred embodiment, the polymer blend may comprise an amount of PLA composition in the range of about 48 wt% to about 52 wt% and an amount of PBS composition in the range of about 48 wt% to about 52 wt%.

[0057] In another embodiment, a polymer blend composition for producing degradable extrusion netting comprises an amount of polylactic acid (PLA) composition in the range of about 55 wt% to about 60 wt%, an amount of polybutyrate composition in the range of about 35 wt% to about 40 wt%, an amount of compatibilizer composition in the range of about 0.5 wt% to 3 wt%, and an amount of degradation additive in the range of about 2 wt% to about 7 wt%. In an alternative embodiment, the polymer blend composition comprises an amount of polylactic acid (PLA) composition in the range of about 52 wt% to about 58 wt%, an amount of polybutyrate composition in the range of about 38 wt%, an amount of compatibilizer composition in the range of about 2 wt%, and an amount of degradation additive in the range of about 2 wt% to about 8 wt%.

[0058] Preparation of extrudable compositions

[0059] Extrudable compositions can be prepared by any conventional process for forming polymer compositions. Such processes include, but are not necessarily limited to, blending. Generally, methods suitable for preparing polymer blend compositions include blending as a separate operation using a twin-screw extruder, or in-line blending using a single-screw extruder equipped with a screw characterized by excellent distribution and dispersion mixing properties.

[0060] Non-degradable fiber composition

[0061] As described above, in the embodiments, some of the strands (12, 14) may be made from a non-degradable fiber composition. In the embodiments, the non-degradable fiber composition may include non-elastomer materials, such as nylon, polyester, polylactic acid, polypropylene, polyethylene including HDPE, and copolymers of these resins. In the embodiments, the non-degradable fiber is made from a polyolefin. In the embodiments, the non-degradable fiber is made from polypropylene.

[0062] Net manufacturing

[0063] The degradable extruded netting may be manufactured by any suitable extrusion process. Generally, a suitable method for manufacturing extruded netting comprises extruding a polymer blend composition as described above through a die having a reciprocating or rotating part to form a netting shape. This creates a continuously connected machine-direction strand and an intersecting machine-direction strand. Of course, it should be understood that the degradable polymer blend composition may be used to form both the intersecting machine-direction strand and the machine-direction strand, or to form one or part of said strands, and in such cases, another material, such as a different biodegradable or non-degradable material, may be used to form the other strand. Subsequently, after extrusion, the netting is stretched in the machine direction, typically using the difference between two sets of nip rollers. Then, the material is subsequently stretched in the intersecting direction using a tenter frame, typically in any suitable manner, such as as described in U.S. Patent No. 4,152,479 incorporated herein by reference. It should be understood that the method described above is only one of several suitable methods that can be used to manufacture extrusion netting according to the present invention.

[0064] Examples

[0065] The subject matter of the present disclosure is further illustrated by the following non-limiting embodiments:

[0066] Example 1

[0067] A degradable extruded film according to the present disclosure is prepared using a mixture comprising, as a PLA composition, 57 wt% biopolymer 2003D sold under the trade name Ingeo™ available from NatureWorks; as a PBAT composition, 38 wt% F blend C1200 sold under the trade name Ecoflex® available from BASF SE; 2 wt% TECHMER PLAM111474 compatibilizer; and 3 wt% degradation additive, wherein the degradation additive comprises 5% iron stearate and 95% PLA carrier resin. The film is prepared by a widely known extrusion method, wherein the composition is extruded through a desired die at a temperature of about 355 to about 380 degrees Fahrenheit. After extrusion, the film is moved to a nip roller and finally to a roll stack.

[0068] Example 2

[0069] A degradable extruded film according to the present disclosure is prepared using a mixture comprising 55 wt% biopolymer 2003D as a PLA composition, 38 wt% F blend C1200 as a PBAT composition, 2 wt% Techmer PLAM111474 compatibilizer, and 5 wt% degradation additive, wherein the degradation additive comprises 5% iron stearate and 95% PLA carrier resin. A film of the composition of Example 2 was extruded using the same method as in Example 1.

[0070] Example 3

[0071] A biodegradable extruded film according to the present disclosure is prepared using a mixture comprising 60 wt% biopolymer 2003D as a PLA composition, 38 wt% F blend C1200 as a PBAT composition, and 2 wt% Techmer PLAM111474 compatibilizer, and not containing a biodegradable additive. The film of Example 3 was extruded using the same method as in Example 1.

[0072] Example 4

[0073] A degradable extruded film according to the present disclosure is prepared using a mixture comprising 55 wt% biopolymer 2003D as a PLA composition, 38 wt% F blend C1200 as a PBAT composition, 2 wt% Techmer PLAM111474 compatibilizer, 2.5% degradation additive having iron stearate, and 2.5 wt% degradation additive having manganese stearate. The degradation additive comprises 2.5% iron stearate, 2.5% manganese stearate, and 95% PLA carrier resin. A film of the composition of Example 4 was extruded using the same method as in Example 1.

[0074] Example 5

[0075] A degradable extruded film according to the present disclosure is prepared using a polypropylene composition. No degrading agent additives were used. A film of the composition of Example 5 was extruded using the same method as in Example 1.

[0076] Example 6

[0077] A degradable extruded netting according to the present disclosure is prepared using a mixture comprising, as a PLA composition, 57 wt% biopolymer 2003D sold under the trade name Ingeo™ available from NatureWorks; as a PBAT composition, 38 wt% F blend C1200 sold under the trade name Ecoflex® available from BASF SE; 2 wt% Techmer PLAM111474 compatibilizer; and 3 wt% degradation additive, wherein the degradation additive comprises 5% iron stearate and 95% PLA carrier resin. The netting is prepared by extruding the composition through a die having a reciprocating or rotating part to form a netting shape. The extruded netting is then stretched mechanically and crosswise at a temperature of 100°F to 250°F.

[0078] Example 7

[0079] A degradable extrusion netting according to the present disclosure was prepared using a mixture comprising 55 wt% biopolymer 2003D as a PLA composition, 38 wt% F blend C1200 as a PBAT composition, 2 wt% tecmer PLAM111474, and 5 wt% degradation additive, wherein the degradation additive comprises 5% iron stearate and 95% PLA carrier resin. The netting was prepared using the same procedure as in Example 6.

[0080] Example 8

[0081] A degradable extruded film according to the present disclosure is prepared using a mixture comprising 50 wt% biopolymer 2003D, sold under the trade name Ingeo™ available from NatureWorks, as a PLA composition, and 50 wt% FD92, sold under the trade name BioPBS™ available from PTT MCC Biochem Company Limited, as a PBS composition. No degrading agent additives were used. A film of the composition of Example 8 was extruded using the same method as in Example 1.

[0082] Example 9

[0083] A degradable extruded film according to the present disclosure is prepared using a mixture comprising 50 wt% biopolymer 2003D, sold under the trade name Ingeo™ available from NatureWorks, as a PLA composition, and 50 wt% FZ91, sold under the trade name BioPBS™ available from PTT MCC Biochem Company Limited, as a PBS composition. No degrading agent additives were used. A film of the composition of Example 9 was extruded using the same method as in Example 1.

[0084] Example 10

[0085] A biodegradable extruded film according to the present disclosure is prepared using a composition of 3 wt% Envirocare Ag 1000C and 97 wt% polypropylene, commercially available from Ciba Specialty Chemicals, UK, which is believed to contain 50% to 80% polyethylene, 7.5% to 22.5% cobalt stearate, and 7.5% to 22.5% citric acid. The film of Example 10 is sold under the trade name Oxygrid™, available from Conwed. The film of the composition of Example 10 was extruded using the same method as in Example 1.

[0086] Example 11

[0087] A degradable extruded film according to the present disclosure is prepared using a mixture comprising 58 wt% biopolymer 2003D as a PLA composition, 40 wt% F blend C1200 as a PBAT composition, and 2 wt% degradation additive, wherein the degradation additive comprises 5% iron stearate and 95% PLA carrier resin. A film of the composition of Example 11 was extruded using the same method as in Example 1.

[0088] Example 12

[0089] A biodegradable extruded film according to the present disclosure is prepared using a mixture comprising 70 wt% biopolymer 2003D as a PLA composition, 15 wt% F blend C1200 as a PBAT composition, and 15 wt% polyhydroxybutyrate (PHBH). A film of the composition of Example 12 was extruded using the same method as in Example 1.

[0090] Tests for strength loss in the machine direction (MD strength loss) were performed on the films of Examples 1, 2, and 4, a PLA / PBAT control film (Example 3), and a polypropylene film without degradation additives (Example 5). The MD strength loss of each sample was collected via QUV-accelerated weathering tests following a slightly modified version of the procedure outlined in ASTM D4329-13. Samples were exposed to 50°C conditions with or without condensation using Q-Panel, QUV-Basic, and QUV-EM. A UVA-340 lamp was used for 240 hours to attempt to reproduce conditions similar to those of a typical outdoor environment over an extended period. The data collected from these strength loss tests are presented in Figures 2-3.

[0091] Tests for machine direction strength loss (MD strength loss) of degradable extrusion netting according to the present disclosure were performed on nettings prepared from the compositions of Examples 6 and 7, as well as on the PLA / BPAT control of Example 3 and the netting prepared from polypropylene of Example 5. Data collected from these strength loss tests are presented in FIG. 4.

[0092] Thermal stability tests were performed on films prepared from the compositions of Examples 1, 2, and 4, and the PLA / PBAT control (Example 3). The given formulations did not contain heat stabilizers. To test the materials, film samples were moved along a cast film line at 365 degrees Fahrenheit to determine which compositions might exhibit signs of thermal decomposition due to the composition's thermal profile within the extrusion device during processing. Decomposition during processing results in lower pound-per-inch force measurements because the polymer breaks down through hydrolysis, depolymerization, oxidation, etc. Data collected from the thermal stability tests are presented in Table 1 below. The PLA / PBAT control (Example 3) had a force value of 5061 lb / square inch. Examples 1 and 2 had higher values, whereas Example 4 exhibited signs of decomposition and therefore had a lower value.

[0093] Table 1

[0094]

[0095] In embodiments where the biodegradable netting described herein is used in the manufacture of turf sod, it is desirable to provide biodegradable netting that is substantially bio-based without sacrificing economics or manufacturability. Modulus and tensile strength tests were performed on blends of varying amounts of PLA and PBS. The PLA composition was Biopolymer 2003D. The PBS compositions tested were BioPBS FZ91 and BioPBS FD92. Blends containing 0% PBS, 25% PBS, 50% PBS, 75% PBS, and 100% PBS were tested and compared with a PLA / PBAT / Techmer blend containing 60%, 38% PBAT, and 2% Techmer™ PLAM111474 compatibilizer, and with the composition prepared according to Example 10 above, which is sold under the trade name Oxigrid™ available from Conward. Data collected from these tests are presented in Figures 5 and 6.

[0096] As shown in FIG. 5, the film prepared from the blend comprising 50% PLA 2003D and 50% BioPBS FD92, which is the composition of Example 8, has a lower modulus value than the film prepared from the blend comprising PLA / PBAT / Techmer (Example 7), and thus provides enhanced manufacturability.

[0097] As shown in FIG. 6, the film prepared from a mixture comprising 50% PLA 2003D and 50% BioPBS FD92, which is the composition of Example 8, maintains suitable tensile strength compared to the PLA / PBAT / Techmer control film, while also achieving enhanced manufacturability.

[0098] Tests for strength loss in the mechanical direction (MD strength loss) were performed on the films of Examples 8 and 10-12 via accelerated weathering tests. The percentage of preserved strength for each sample was collected via QUV-accelerated weathering tests following a modified version of the procedure outlined in ASTM D4329-13. Using Q-Panel, QUV-Basic, and QUV-EM, the samples were exposed to two different cycles designed to mimic conditions similar to those of a typical outdoor environment for an extended period. The first cycle was 4 hours long and provided UV light at 50°C. The second cycle was 4 hours long and provided no light at 40°C. UVA-340 lamps were used. After performing the two cycles alternately for 100 hours, the samples were exposed to outdoor temperature and moisture levels of approximately 45°C and approximately 80% humidity. Data collected from the strength loss tests are presented in Figure 7. As shown in FIG. 7, the film prepared from the composition of Example 8 performs similarly to the control film (Example 10) under an accelerated weathering test.

[0099] The degradable netting can also be used to form other types of composites, wherein the netting is fixed to at least one layer of material. Examples of such composites include consumer wet wipes, reinforced tissue towels, and erosion-controlling composites. Depending on the desired function of the netting, a person skilled in the art can control the degradation rate by determining which composition to use to manufacture each layer.

[0100] By way of this, all published patents, disclosed patent applications, and non-patent publications mentioned in this specification are incorporated herein by reference in the same degree for all purposes, as if each individual published patent, disclosed patent application, or non-patent publication were specifically and individually incorporated by reference.

[0101] Although various embodiments of the present disclosure are presented in the drawings, the disclosure is not intended to be limited thereto, because the disclosure is as broad as the relevant art allows, and the specification is intended to be read in a similar manner. Therefore, the above description should not be interpreted as restrictive, but merely as an example of the embodiments disclosed herein. Accordingly, the scope of the embodiments should be determined by the appended claims and their legal equivalents rather than by the given examples.

[0102] A person skilled in the art will understand that the apparatus and method described herein and depicted in the accompanying drawings are non-limiting and exemplary embodiments. Features shown or described in connection with one exemplary embodiment may be combined with features of other embodiments. A person skilled in the art may devise various alternatives and modifications without departing from the disclosure. Accordingly, the present disclosure is intended to include all such alternatives, modifications, and changes. Furthermore, a person skilled in the art will know of additional features and benefits of the present disclosure based on the embodiments described above. Accordingly, the present disclosure should not be limited by what is specifically presented and described, except as indicated by the appended claims.

Claims

Claim 1 A degradable extrusion netting comprising a plurality of interconnected strands, wherein at least some of the strands are manufactured from a polymer blend comprising: a polylactic acid composition in an amount ranging from 40% to 58% by weight; a polybutylene succinate composition in an amount ranging from 40% to 58% by weight; and a degradable additive comprising iron stearate and manganese stearate in a carrier resin in an amount ranging from 2% to 7% by weight. Claim 2 delete Claim 3 The degradable extrusion netting of claim 1, wherein the polymer blend comprises: a polylactic acid composition of 46.5% to 51.5% by weight; and a polybutylene succinate composition of 46.5% to 51.5% by weight. Claim 4 In paragraph 3, the degradable extrusion netting in which the degrading additive is present in an amount ranging from 2% to 5% by weight. Claim 5 delete Claim 6 delete Claim 7 Degradable extrusion netting according to claim 1, wherein the polylactic acid composition comprises one or more polylactic acid polymers derived from plant starch. Claim 8 Degradable extrusion netting according to claim 1, wherein a degradable additive is present in an amount of 5 weight%, a polylactic acid composition is in an amount ranging from 40 weight% to 55 weight%, and a polybutylene succinate composition is in an amount ranging from 40 weight% to 55 weight%. Claim 9 Degradable extrusion netting according to claim 1, wherein the degrading additive is present in an amount of 3 weight%, the polylactic acid composition is in an amount ranging from 40 weight% to 57 weight%, and the polybutylene succinate composition is in an amount ranging from 40 weight% to 57 weight%. Claim 10 Degradable extrusion netting according to claim 1, wherein the polybutylene succinate composition comprises an aliphatic polyester. Claim 11 A composite material comprising: a degradable extrusion netting of claim 1, the netting having a first surface and a second surface opposite to the first surface; and a first material layer fixed to the first surface of the netting. Claim 12 A polymer blend composition suitable for manufacturing degradable extrusion netting, comprising: a polylactic acid composition in an amount ranging from 55% to 60% by weight; a polybutyrate composition in an amount ranging from 35% to 40% by weight; a compatibilizer composition in an amount ranging from 0.5% to 3% by weight; and a degrading additive in an amount ranging from 2% to 7% by weight, comprising iron stearate and manganese stearate in a carrier resin. Claim 13 A polymer blend composition suitable for manufacturing degradable extrusion netting, comprising: 52% to 58% by weight of a polylactic acid composition; 38% by weight of a polybutyrate composition; 2% by weight of a polylactic acid-polybutyrate compatibilizer; and 2% to 8% by weight of a degrading additive comprising iron stearate and manganese stearate in a carrier resin. Claim 14 In claim 13, a polymer blend composition comprising: 55% to 57% by weight of a polylactic acid composition; and 3% to 5% by weight of a decomposition additive. Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 A polymer blend composition according to claim 12, wherein the compatibilizer composition comprises a compatibilizer selected from polypropylene glycol diglycidyl ether, epoxidized cottonseed oil (ECSO), or maleated (MCSO) cottonseed oil. Claim 20 delete Claim 21 A polymer blend composition according to claim 12, comprising a polylactic acid composition in an amount ranging from 55% to 59.5% by weight, a polybutyrate composition in an amount ranging from 35% to 39.5% by weight, and a decomposition additive comprising 2.5% by weight of iron stearate and 2.5% by weight of manganese stearate. Claim 22 A polymer blend composition suitable for manufacturing degradable extrusion netting, comprising: a polylactic acid composition in an amount ranging from 55% to 60% by weight; a polybutyrate composition in an amount ranging from 35% to 43% by weight; and a degrading additive in an amount ranging from 2% to 7% by weight, comprising iron stearate and manganese stearate in a carrier resin. Claim 23 In claim 22, a polymer blend composition comprising: 58 weight% of a polylactic acid composition; 40 weight% of a polybutyrate composition; and 2 weight% of a decomposition additive. Claim 24 delete Claim 25 delete Claim 26 A polymer blend composition according to any one of claims 12, 13 and 22, wherein the polybutyrate composition comprises one or more polybutyrate adipate terephthalate (PBAT) polymers. Claim 27 A polymer blend composition according to any one of claims 12, 13 and 22, wherein the polylactic acid composition comprises one or more polylactic acid polymers derived from plant starch. Claim 28 A turf sod comprising: turf grown in soil; and a soil-degradable extruded netting comprising: a plurality of interconnected strands in which at least a portion of the strands are manufactured from a polymer blend, and the polymer blend comprises: a polylactic acid composition in an amount ranging from 40% to 58% by weight; a polybutylene succinate (PBS) composition in an amount ranging from 40% to 58% by weight; and a degradation additive comprising iron stearate and manganese stearate in an amount ranging from 2% to 7% by weight. Claim 29 In claim 28, turf sod containing a decomposition additive in an amount ranging from 2% to 5% by weight. Claim 30 delete Claim 31 A method for growing turf sod comprising the following steps: providing a netting material in soil, wherein the netting material comprises: a plurality of interconnected strands, wherein at least a portion of the strands are manufactured from a polymer blend, and the polymer blend comprises: a polylactic acid composition in an amount ranging from 40% by weight to 59.9% by weight; a polybutylene succinate (PBS) composition in an amount ranging from 40% by weight to 59.9% by weight; and a degradation additive comprising iron stearate and manganese stearate in a carrier resin as a degradation additive in an amount ranging from 0.1% by weight to 5% by weight; and growing a turf crop in soil. Claim 32 delete

Images