HK1251848A1 - A recycling material - Google Patents

Description

Recycled material

Technical Field

The invention relates to a recycled material, the product of which can enhance biodegradation in an environment containing microorganisms. Another advantage of these blends is the extended shelf life in clean environments, where films, containers for solids and liquids, rigid or flexible packaging, woven, knitted and non-woven fabrics of filaments and staple fibers, and composite products of fabrics, films and other materials can be produced by thermoforming, injection molding or melt spinning blends of PHAs and PLA.

Background

In the past 20 years, polylactic acid has become a major biodegradable/compostable polymer that can be used to make plastics and fibers. This is because although polylactic acid is derived from natural renewable materials, it has thermoplastic properties and can be melt extruded to produce plastic articles, fibers, or fabric products. These products have good mechanical strength and flexibility comparable to petroleum-based compositions such as polyolefins (polyethylene and polypropylene) and polyesters (polyethylene terephthalate and polyethylene terephthalate). Polylactic acid is made from lactic acid, which is a by-product from the fermentation of corn (e.g., Zea mays), wheat (e.g., Triticum spp.), rice (e.g., Oryza sativa), or sugar beet (e.g., Beta vulgaris). Lactic acid, when polymerized, forms a dimer repeat unit having the structure:

unlike other synthetic fibrous materials derived from plant sources, such as cellulose, PLA is more suitable for melt spinning (melt spinning) into fibers. Compared with a solvent spinning (solvent spinning) process necessary for synthesizing cellulose fiber, the preparation of PLA fiber by melt spinning can reduce economic cost and environmental cost, and the prepared PLA has wider performance. Like polyethylene terephthalate (PET), PLA polymers need to be dried before melting to avoid hydrolysis during melt extrusion, and both can achieve better tensile strength by drawing (drawing) fibers from the polymer. PLA molecules tend to assume a helical structure which makes them more susceptible to crystallization. Meanwhile, the lactic acid dimer has three isomers: a left-handed type which deflects polarized light in a clockwise direction; a right-handed type deflecting polarized light in a counterclockwise direction; and racemic forms, which are optically inactive. The relative proportions of these types can be controlled during the polymerization process, thereby more broadly controlling the important polymer properties. Control of thermoplastic "natural" fiber polymers, unique polymer morphology and isomer content in the polymer allows manufacturers to design a wider range of properties in the fiber (Dugan, 2001 and Khan et al, 1995).

PLA is not naturally decomposable in the extruded state. Instead, it must first be hydrolyzed before becoming biodegradable. In order to allow a greater degree of hydrolysis of PLA, it is necessary to simultaneously maintain a relative humidity equal to or higher than 98% and a temperature equal to or higher than 60 ℃. Once these conditions are met, degradation occurs rapidly (Dugan, 2001 and Lunt, 2000). However, the composition and arrangement of the three isomers can be controlled by controlling the melting temperature between 120 ℃ and 175 ℃, whereas if the melting temperature is lower, the polymer will be completely amorphous. Adding enzymes and microorganisms to the melt will result in more amorphous polymer. Polylactic acid has been used to make many different products, and factors controlling its stability and degradation rate have also been documented in many documents. Both L-lactic acid and D-lactic acid produced during fermentation can be used to produce PLA (Hartmann, 1998). One advantage of PLA is that its degradation rate can be controlled by varying factors such as the ratio of dextrorotatory to levorotatory forms, molecular weight, or crystallinity (Drumright et al, 2000). For example, Hartmann discovered in 1998 that unstructured polylactic acid samples rapidly degraded to lactic acid within weeks, but high crystallinity materials can take months to years to completely degrade. This flexibility and control makes PLA a very useful raw material for the production of agricultural mulch (mulch) fabrics, where the material degrades in the ground after a certain time has elapsed (Drumright et al, 2000).

Polylactic acid is decomposed into small molecules by different mechanisms, and the final decomposition product is CO₂And H₂And O. The degradation process is influenced by temperature, humidity, pH and enzymes and microbial activity, but not by UV light (Drumright et al, 2000; Lunt, 2000). In some early works evaluating PLA degradation for biomedical applications, Williams discovered in 1981 that bromelain, pronase, and proteinase K can accelerate the rate of PLA degradation. Recently, Hakkarainen et al, in 2000, incubated a 1.8 mm thick sample of PLA in a mixed culture of microorganisms extracted from humic substances at 86 ℃ F. After 5 weeks incubation, the humus-treated films degraded to a fine powder, while the untreated control remained intact. It is noted that the present study only used the levorotatory form, and the degradation rate will vary with the ratio of the levorotatory to dextrorotatory forms. In any event, work in 2000 by Hakkarainen et al showed that decomposition could be accelerated by the use of a large array of microorganisms readily available from humic substances. Current PLA degradation studies have been performed both in liquid culture in vitro and in active humic substances manipulation at temperatures above 140 ℃ F. (Drumright et al, 2000; Hakkarainen et al, 2000; Lunt, 2000; Williams, 1981). PLA degrades rapidly when made into humus at 140 ° F, reaching almost 100% biodegradation within 40 days (Drumright et al, 2000), but below 140 ° F, stability is still being determined when the fabric is in contact with soil organics. Larry Wadsworth (Khan et al, 1995) at the university of Tennessee, USA, first started to study Spunbonded (SB) and Meltblown (MB) nonwoven fabrics (Smith, B.R., L.C. Wadsworth (lecturer), M.G. Kamath, A.Wszelaki, and C.E.Sams) made using PLA, and developed the next generation of biodegradable root-protecting nonwoven fabrics to replace polyethylene plastics ("Development of N.ext Generation Biogradable Mulch Nonwovens to Replace Polyethylene plastics, "), sustainable textile International conference for textile (ICST 08) in 2008, No. Sn in China, 21-24 months in 2008, conference disks).

Biodegradable polymers are required to be resistant to many environmental factors during the useful period, but are required to be biodegradable in the event of being discarded. Biodegradation of PLA was studied at various elevated temperatures, both aerobically and anaerobically, in water and in solid state. The study found that PLA biodegrades very slowly at room temperature but more rapidly at elevated temperatures when exposed to an aerobic aqueous environment. This finding is also supported by the fact that PLA must be hydrolysed before the microorganisms can use it as a nutrient source. At the same elevated temperature, PLA biodegrades much faster under anaerobic solid state conditions than under aerobic conditions. During natural humification, PLA behaves like degradation upon exposure to water, with biodegradation only beginning after it is heated. These results reinforce a widely held view: PLA is compostable and stable at moderate temperatures, but degrades rapidly during waste treatment in composting or anaerobic treatment facilities (Itavaara, Merja, Sari karjoma and Johan-Fredrik Selin, "" Biodegradation of polylactic acid under Aerobic and anaerobic high temperature Conditions "(" biodegration of polylactic acid in Aerobic and anaerobic thermophilic Conditions ")" eischen scientific press (Elsevier Science Ltd.), 2002). In another study, the level of biodegradation of anaerobically digested sludge on various plastics was determined and compared to simulated landfill conditions. Bacterial poly-93-hydroxyvalerate (PHB/PHV), a natural aliphatic polyester produced by bacteria, degrades completely in almost 20 days in anaerobically digested sludge; however, aliphatic polyester PLA, synthesized from natural materials, and two other aliphatic polyesters evaluated: polybutylene succinate and polybutylene succinate-polyethylene succinate copolymer, did not undergo any degradation after 100 days. A cellulose control material, cellophane, degraded similarly to PHB/HV over 20 days. Furthermore, PHB/HV degrades well under Simulated Landfill Conditions for 6 months (Shin, pyrong Kyun, Myung HeeKim and Jong Min Kim, Biodegradability of Degradable Plastics Exposed to anaerobically digested sludge and Simulated Landfill Conditions ("Biodegradability of Degradable Plastics Exposed to Anaerobic digestion sludge and Simulated Landfilm Conditions"), polymer and Journal of the Environment (Journal of polymers and the Environment), vol.5, pp.1, 1566-2543, 1997).

In the search for truly biodegradable polymers, Polyhydroxyalkanoates (PHAs) have been found to be naturally synthesized by many bacteria as intracellular carbon and energy storage substances. As early as the 20 th 19 th century, poly-R-3-hydroxyfatty acid esters (poly [ (R) -3-hydroxybutyrate, P (3HB)) have been isolated from Bacillus megaterium and subsequently identified as a stock polyester of bacteria. However, P (3HB) has not shown significant commercial value because it has been found to become brittle and hard over a long period of time and therefore cannot be used to replace the mainstream synthetic polymers, Polyethylene (PE) and Polystyrene (PS). Finally, other hydroxy fatty acid ester (HA) units than 3HB have been found in microbial polyesters to improve the mechanical and thermal properties when included in P (3HB), which HAs a significant impact on the research and commercial interest of bacterial polyesters. Biodegradability in the natural environment is one of the unique properties of PHA materials. The microbial polyester is biodegradable in soil, sludge or seawater. Because PHA is a solid polymer with a high molecular weight, it is not well transported across cell walls as a nutrient. Thus, microorganisms like fungi and bacteria secrete enzymes that degrade PHA extracellularly, called PHA-degrading enzymes, which hydrolyze solid PHA to water-soluble oligomers and monomers, which can be transported into cells and subsequently metabolized as a source of carbon and energy (Numata, Keiji, Hideki Abe and Tadahisa Iwata, Biodegradability of polyhydroxyalkanoate Materials ("Biodegradability of polyhydroxylkonate Materials"), Materials (2009, p 2 1104-1126). A random copolyester of [ R ] -3-hydroxybutyrate and [ R ] -3-hydroxyvalerate, P (3HB-co-3HV), is commercially produced by the International chemical industries, ICI, of the United kingdom. Studies have shown that Alcaligenes eutrophus uses propionic acid and glucose as carbon sources to produce an optically active copolyester of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) (Holmes, PA, (1985), PHB application: a bacterially Produced Biodegradable Thermoplastic ("Applications of PHB: a Microbioalld Biodegradable Thermoplastic,") Physics (Phys Technol)16:32-36, a Biodegradable copolyester from Kunioka, Masao, Yasushi Kawaguchi and Yoshiharu Doi, Alcaligenes eutrophus producing 3-hydroxybutyrate and4-hydroxybutyrate ("Production of Biodegradable and 4-hydroxybutyrate") application of Biotechnology (569). The chemical structure of P (3HB-co-3HV) is as follows:

in addition, 3-hydroxypropionate, 4-hydroxybutyrate and 4-hydroxyvalerate have been found to be novel components of bacterial Polyhydroxyalkanoates (PHAs), and have gained much attention in a wide range of fields such as marine, agricultural and medical applications. Recently, [ R ] has been carried out by eutrophicating Alcaligenes, Comamonas and Alcaligenes]Microbial Synthesis of 3-hydroxybutyrate and4-hydroxybutyrate copolyester P (3HB-co-4HB)

When 4-hydroxybutyric acid is used as the sole carbon source for Alcaligenes eutrophus, P (3 HB-co-34% 4HB) containing 34% 4HB will be produced; when 4-hydroxybutyric acid containing some additives is used as a carbon source for Alcaligenes eutrophus, P (3HB-co-4HB) copolyesters containing a large amount of 4HB (60-100 mol%) are produced. It was also found that Alcaligenes eutrophus efficiently produced P (3HB-co-4HB) random copolymers in a nitrogen-free environment using sucrose and 1, 4-butyrolactone as carbon sources during one-step fermentation. As the 4HB content increased, the tensile strength of the P (3HB-co-4HB) film decreased from 43MPa to 26MPa, while the elongation increased from 4% to 444%. On the other hand, as the 4HB content increased from 64% to 100%, the tensile strength of the film increased from 17MPa to 104MPa with increasing 4HB (Saito, Yuji, Shigeo Nakamura, Masaya Hiramitsu and Yoshihihara Doi, "Poly-3-hydroxybutyrate-4-hydroxybutyrate copolymer," Microbial Synthesis and Properties ("3-Hydroxybutyrate-co-4-hydroxybutyrate") which, by study, "International Polymer International (Polymer International)1996, at stage 39-174. it was found that as the 4HB content increased from 0 to 49 mol%, the crystallinity of P (3HB-co-4HB) decreased from 55% to 14%, indicating that the 4HB unit could not crystallize in the 3HB unit sequence and would become a defect in the P (3HB) lattice, this is likely to be a negative responsibility for P (3-HB-co-4 HB) and for increasing toughness relative to P (3HB) and for the toughness, as the 4HB content increased from 0 to 18 mol%, the melting point decreased from 178 ℃ to 150 ℃ (Kunioka, Masao, Akira Tamaki and Yoshiharu Doi, the crystallization and Thermal Properties of Bacterial copolyesters, Poly-3-hydroxybutyrate-3-hydroxyvalerate copolymer and Poly-3-hydroxybutyrate-4-hydroxybutyrate copolymer ("Crystalline and Thermal Properties of Bacterial polyesters: Poly (3-hydroxybutyric-co-3-hydroxyvalerate) and Poly (3-hydroxybutyric-co-4-hydroxybutyrate)") Macromolecules (Macromolecules) at No. 22 694-697, 1988). It was also found that when 4HB units are present in P (3HB-co-4HB), the rate of biodegradation increases (Kunioka, Masao, Yasushi Kawaguchi and Yoshiharu Doi, Biodegradable copolyesters for the Production of 3-hydroxybutyrate and4-hydroxybutyrate by Alcaligenes eutrophus ("Production of Biodegradable polyesters of 3-hydroxybutyrate and4-hydroxybutyrate by Alcaligenes eutrophus,") applied microbiology (applied. Microbiolotechnol) at 30.569-573 1989). In another study, enzymatic degradation of P (3HB-co-4HB) membranes was performed in 0.1M extracellular depolymerase (purified from Alcaligenes faecalis) phosphate buffer at 37 ℃ and as a result, it was found that the rate of enzymatic degradation increased significantly with increasing 4HB content, with the highest rate being 28 mol% 4HB (Nakamura, Shigeo and Yoshiharu Doi, microbial synthesis and Characterization of Poly-3-hydroxybutyrate-4-hydroxybutyrate copolymers ("MicrobialSynthesis and Characterization of Poly (3-hydrobutyrate-co-4-hydrobutyrate)") Macromolecules, Vol.85, 1992, pp.17-4237-4241).

This may be due to a decrease in crystallinity of the synthesized product; however, the presence of 4HB in copolyesters above 85 mol% inhibits enzymatic degradation (Kumaai, Y. Kanesawa and Y. Doi, high molecular chemistry (Makromol. chem), microbiological synthesis and characterization of poly-3-hydroxybutyrate-4-hydroxybutyrate copolymers, macromolecules, 1992, Vol.85, pp.17-4237-4241, 1992, 193, pp.53, through Nakamura, Shigeo and Yoshiharu Doi, 1992). In a comparison of the degradation rates of the P (3 HB-co-9% 4HB), P (3HB) and (HB-co-50% 3HV) films, it was found that P (3 HB-co-9% 4HB) was completely degraded in activated sludge within 2 weeks, the degradation rate of the biopolyester was much faster than the other two. The degradation rate of P (3HB) is faster than that of P (HB-co-50% 3HV) films (Kunioka, Masao, Yasushi Kawaguchi and Yoshiharu Doi, biodegradable copolyesters for the production of 3-and 4-hydroxybutyrate esters by Alcaligenes eutrophus applied microbiology technology at 30.569-573 in 1989).

Disclosure of Invention

The invention aims to solve the technical problem of providing a biodegradable material which can prolong the shelf life in a clean environment and accelerate the degradation in a dirty environment aiming at the defect of slow degradation rate of the existing biodegradable material.

The technical scheme adopted by the invention for solving the technical problems is as follows: constructing a recycling regeneration material, which comprises PHAs and PLA, wherein the PHAs are PHBs, the PHBs are P (3HB-co-4HB) polymerized by 3HB and 4HB, and the mole percentage of the 4HB is 28%; the PLA is 85% in mass percentage, the PHB is 15% in mass percentage, and the PLA is prepared by mixingThe blend with PHB was melt mixed and extruded into pellets which were melt spun to produce a meltblown fabric having a basis weight of 50g/m²The average diameter of the fiber in the melt-blown fabric is 2-8um, the melt spinning comprises the non-woven treatment of spun bonding and melt-blown, the melt-blown fabric is a film or a fabric formed by laminating and combining the spinning deposition treatment, the needle punching treatment, the airflow deposition treatment or the water punching treatment of pulp or fiber, the laminating comprises the hot spun bonding-melt-blown-spun bonding or the ultrasonic bonding non-woven treatment, the melt-blown fabric comprises melt-blown filter media with spun bonding as the inner surface and the outer surface, the melt-blown filter media are sewn or thermally bonded or ultrasonically bonded at the edge of a product, the melt-blown fabric is used for preparing a biodegradable covering film or a woven or knitted or non-woven fabric, and the biodegradable covering film or the woven or knitted or non-woven fabric can prolong the quality guarantee period in a clean environment and accelerate the degradation in a microbial environment.

In the recycled regeneration material, the clean environment is wet tissue cleaning solution, and the microbial environment is river water or river mud.

In the recycled materials of the present invention, the recycled materials further comprise cellulose fibers.

In the recycled material of the present invention, the meltblown fabric is obtained by a needle punching process, a spunlacing process, thermal calendering, hot gas flow deposition or the following heat treatment: microwave, ultrasonic, welding, far infrared and near infrared heating.

In the recycled regrind of the present invention, the meltblown fabric is bonded by wet or dry bonding.

In the recycled materials of the present invention, the nonwoven fabric comprises a thermal spunbond-meltblown-spunbond, or ultrasonic bonded nonwoven fabric used as a sling, a seat pocket, or a stretcher for a patient.

The biodegradable material has the following beneficial effects: the present invention relates to a novel polymer blend of PHAs and PLA for making blended products of PHAs and PLA that are capable of accelerated biodegradation in a microorganism-containing environment. The novel products can be thermoformed, injection molded or melt spun to produce films, containers for solids and liquids, rigid or flexible packaging, woven, knitted and nonwoven fabrics of filaments and staple fibers, and composite products of fabrics, films and other materials. These blends also provide extended shelf life in clean environments.

Detailed Description

Although poly-3-hydroxybutyrate and poly-4-hydroxybutyrate polyester (P (3HB-co-4HB)) products are easily degraded in soil, sludge and seawater, the degradation rate is very slow in water lacking microorganisms (Saito, Yuji, ShigeoNakamura, Masaya Hiramitsu and Yoshiharu Doi), "microbial synthesis and performance of poly (3-hydroxybutyrate-4-hydroxybutyrate)," International Polymer 39(1996), 169-174). Therefore, the P (3HB-co-4HB) product has a very long shelf life in a clean environment, such as dry storage in a sealed package or storage in a wet tissue cleaning solution, and the like. However, the P (28.56-co-hydroxybutyrate) treated fabrics, films and packaging materials of discarded P (3HB-co-4HB) are very susceptible to degradation when exposed to microbiological containing foul environments such as soil, river water, river mud, manure sand humus, sludge and sea water. It should be noted that polylactic acid (PLA) is not readily degraded in the above mentioned dirty environment, but is easily degraded. The heat and moisture in the humus first breaks down the PLA polymer into shorter polymer chains and eventually degrades to lactic acid. The humus and soil microorganisms then consume the small polymer fragments and lactic acid as nutrients.

Thus, mixing hydroxybutyrate with PLA will accelerate the degradation rate of PHAs-PLA blended products, such as P (3HB-co-4 HB). Furthermore, by mixing PHAs and PLA, the shelf life of the product in a clean environment will be extended. Although the price of PLA has dropped significantly over the last 10 years, only slightly above synthetic polymers (such as polypropylene and PET polyester), the price of PHAs remains as high as 2 to 3 times the price of PLA. This is because PLA can be made by large-scale synthesis of lactic acid, whereas PHAs are produced by bacteria in combination with specific carbon sources and must be extracted from the bacteria by solvents. Therefore, melt-extruded products (such as woven and knitted fibers, non-woven fabrics, films, food packaging containers, and the like) if more than 25% PHA is mixed in PLA would not be suitable for commercial use.

The formulations of the four groups of sample solutions are shown in tables 1, 2, 3 and4, respectively. These samples were 400Kg, respectively: the wet towel cleaning solution (usually the liquid in the wet towel package for babies), water collected from Dongjiang of Dongguan of China with some river mud, river mud collected from Dongjiang of China and mixed humus produced by sludge/sand/and cow dung are mixed and diluted with distilled water, and the pH value is adjusted to be more than 7 by potassium hydroxide. Wherein each treatment process used two sample solutions of the same formulation, and each treatment chamber containing the treated sample was capped and tested for PH and percent solids every 2 weeks. The average results of the samples treated in the first 4 weeks are shown in table 5.

In one embodiment of the invention, 25Kg of a blend of 85% PLA (2002D manufactured by NatureWorks Corp.) and 15% PHB (3HB-co-4HB), and 25Kg of a blend of 75% PLA (2002D manufactured by NatureWorks Corp.) and 25% PHB (3HB-co-4HB) are melt mixed together and extruded into pellets and shipped to Biax-Fiberflilm of Greenville, Wisconsin, USA and then melt spun to produce Melt Blown (MB) fabrics having a basis weight of 50g/m². For comparative testing, 100% PLA (2002D manufactured by NatureWorks) MB fabric was also made. During the melt-blowing of these polymers, it is increasingly evident that the temperature of the melting and hot gases used to make MB fabrics is too high, because the 2002D PLA polymer has a very low melt index (indicating that PLA has a very high molecular weight), and very high temperatures are required to increase the flowability of MN PLA so that it can be smoothly extruded from the melt-blowing die orifice. 100% 2002D PLA has a melting temperature of 274 ℃ and a hot gas stream temperature of 576 ℃, compared to a melt spun spunbond grade PLA having a melt factor of 70-80 that is commonly usedThe temperature was 266 ℃ and the hot gas stream temperature was 260 ℃ (Wadsworth, Larry and Doug Brown, "High Strength, High Quality Meltblown Insulation, Filters and bristles with LessEnergy," published in the Guangdong nonwovens Association conference, Guangdong, China, 11 months and 26-27 days 2009). Thus, with the two mixtures described above, the contained PHB component is significantly subject to thermal degradation, as evidenced by the high smoke emission in the extruded MB fibres and the low strength of the produced MB PLA/PHB fabrics. Subsequent trials have expected that a PLA polymer (PLA 6251D from NatureWorks, inc.) with a higher melt index (MI 70-85, which would require much lower MB treatment temperatures) would be used to blend with PHB in the same ratio. Furthermore, it is expected that the use of 6251D PLA in the same composition is produced in-line in a 1 meter spunbond nonwoven test, typically operating at a temperature slightly above the melting point of the PLA and the mixed PLA-PHB polymer, resulting in less thermal degradation. This is because it employs a filament drawing step in the SB process, which is not included in the MB process, and therefore produces filaments that are significantly larger than MB filaments produced using the same polymer, although the average diameter of the fibers in the SB web is typically 12-25 μm, compared to 2-8um for MB webs. The second MB operation and SB operation of these polymer components will minimize the effects of thermal degradation, such that the degradation observed during the biodegradation process is primarily from biodegradation. Furthermore, due to the large difference in fiber diameter between MB and SB nonwoven fabrics, smaller MB fibers will have a larger surface area making them expected to biodegrade more readily and more rapidly.

MB 100% 2002D type MB fabric, 85% 2002D type PLA/15% PHB and 75% 2002D/25% PLA were rolled into 12.5 inches wide by 50g/m²The American nonwoven Fabric textile Industry Fabric technology (Dongguan) Co., Ltd (U.S. Pacific Nonwovens) which is located in Dongchong district of Dongguan city, Guangdong, China under the genus Biax-Fiberfilm Co., Ltd (U.S. Pacific Nonwovens Industrial Limited)&Technical Textile Technology (DongGuan) Limited). In which 1.5 metres of each fabric is selected for immersion in a different treatment method, which is then removed from each treatment tankAre exposed to different treatment solutions together and are subjected to respective repeated treatments at 4 weeks, 8 weeks, 12 weeks, 16 weeks and 20 weeks

The test procedure was as follows, first adding wet wipe cleaning solution to MB PLA and PLA-PHB fabrics and storing in a porous steel basket, exposing them to a treatment cabinet, after four weeks of treatment, gently washing MB samples from humus in nylon socks, and after washing and drying, the degradation could be observed. River water was added to the MB fabric in the same manner as the wet wipe cleaning solution and placed on a perforated steel basket in a lidded treatment cabinet, and after every 4 weeks up to 20 weeks 100% MB PLA, 85% PLA-15% PHB, and 75% PLA-25% PHB were removed from all treatment cabinets. First, the fabric exposed to river mud and sludge/sand/manure humus is laid in a treatment tank and is immersed and completely penetrated by the treatment liquid. The fabric is then placed in nylon pantyhose, half of the 1.5 meter sample is added to one leg and the other half is added to the other leg, then the sock is gently stretched in the sample, then the sock containing the fabric is embedded in a suitable box containing river mud or humus, and each sock is attached with a label by nylon thread outside the treatment box. Every 4 weeks the removed fabric samples were placed in a metal box with a screen at the bottom, a nylon knitted fabric was placed on the screen, and the treated fabric was gently washed by applying a low pressure water spray directly on the palm of the hand. A second nylon knit fabric was then placed over the cleaned sample and gently turned over to the other side for cleaning. All treated fabrics were then placed on a laundry dryer for more than two days to dry until dried before being sent to the laboratory for testing. A portion of each sample dried after treatment was sent to an external laboratory for testing the extent of fiber breakage by scanning electron microscopy analysis, as a result of an experiment during the treatment, and additionally gel permeation chromatography was used to detect if the molecular weight of the polymer had changed and its approximate loss in the case of being subjected to different treatments, and again differential thermal analysis was performed to detect any change in the crystalline phase.

The results of the physical property tests of the fabrics after 4 weeks of different treatments are shown in the table, wherein Table 6A is a 100% 2002D PLA MB fabric, Table 7A is an 85% 2002D PLA/15% PHB MB sample, and Table 8A is a 75% 2002D/25% PHB fabric. The 100% MB PLA sample lost 6% of the mechanically oriented tensile strength (MD) after 4 weeks of exposure to the wet wipe cleaning solution, while the 85% PLA/15% PHB and 75% PLA/PHB fabrics lost only 4% and 1% of the mechanically oriented tensile strength, respectively, in the wet wipe cleaning solution. But the cross-machine orientation trapezoidal tear resistance (CD) was lost at 50%, 32% and 65% for 100% PLA, 85% PLA/15% PHB and 75% PLA/25% PHB, respectively. After 4 weeks in river water, 100% MB PLA lost 26% of MD tensile strength and 64% CD tear strength, while 85% PLA/15% PHB and 75% PLA/25% PHB lost 19% and 22% MD tensile strength, and 77% and 80% CD tear strength, respectively. After 4 weeks in river mud, 100% PLA fabric lost 91% MD tensile and 98% CD tear strength, while 85% PLA/15% and 75% PLA/25% PHB lost 76% and 75% MD tensile, and 96% and 87% CD tear strength, respectively. After 4 weeks in sludge/sand/cow dung humus, 100% PLA fabric lost 94% MD tensile strength and 99% CD tear strength, while 85% PLA/15% and 75% PLA/25% PHB lost 76% and 86% MD tensile strength, and 99% and 83% CD tear strength, respectively. All samples exposed to river mud and humus have enhanced gas permeability with higher gas permeability values, indicating that more open structures are created with increasing biodegradation. The increase in gas permeability of the MB 100% PLA fabrics treated individually was less than that of the PLA-PHB hybrid fabrics. There is no weight loss of the fabric, but in fact there is some increase because it is difficult to remove all of the process fragments without causing deeper damage to the fabric.

TABLE 1 formulation of wet towel cleaning solution loaded in two different boxes

TABLE 2 river composition loaded by two cartridges

Composition (I)	Quality (Kg)
River water	380
		River mud	20
Total of	400Kg

TABLE 3 river mud composition loaded in two cases

Composition (I)	Quality (Kg)
River mud	300
		River water	100
Total of	400

TABLE 4 Mass composition of sludge, sand, cow dung and distilled water loaded in the two cases

Description of table 4:

69Kg of dry sludge (obtained from a river by the USP Garden) was added to a large mixing vessel;

adding 69Kg of dried cow dung which is broken into small pieces by slow stirring with a large electric stirrer;

during mixing, 69Kg of dry sand is slowly added;

83Kg of distilled water is slowly added while stirring;

after complete mixing, the pH was checked using litmus paper or a pH meter and 10% sodium hydroxide (prepared with distilled water) was added slowly until the pH reached 7.5;

the remaining distilled water was added to make the total amount of water in the added calcium hydroxide 93Kg, and the pH was measured and adjusted to 7.5.

TABLE 5 pH and percent solids (%)

TABLE 6 A.100% PLA (2002D) weight, thickness, air permeability and Strength Properties after production and after 4 weeks of exposure to cleaning fluids, river water, river mud and silt/sand/manure humus

TABLE 7A weight, thickness, air permeability and Strength Properties of 85% PLA (2002D)/15% PHB after production and after 4 weeks of exposure to washing liquids, river water, river mud and sludge/sand/manure humus

TABLE 8A weight, thickness, air permeability and Strength Properties of 75% PLA (2002D)/25% PHB after production and after 4 weeks of exposure to wash, river water, river mud and silt/sand/manure humus

As will be appreciated by those skilled in the art, in addition to the use of P polymerized from 3HB and 4HB (3HB-co-4HB) as in the above examples, the PHAs contained in the biodegradable materials of the present application can be PHBs or PHVs, or copolymers or blends of PHBs and PHVs.

It will be appreciated by those skilled in the art that the biodegradable materials of the present application can be thermoformed, injection molded or melt spun to produce films, containers for solids and liquids, rigid or flexible packaging, woven, knitted and non-woven fabrics in filament and staple form, and composite products of fabrics and films. In a preferred embodiment of the invention, the melt spinning comprises a non-woven process of spunbond and meltblown. In another preferred embodiment of the present invention, the nonwoven fabric is bonded by wet bonding or dry bonding. In a further preferred embodiment of the invention, the nonwoven fabric is obtained by a needle-punching process, a spunlacing process, hot calendering, hot air deposition or the following heat treatment: microwave, ultrasonic, welding, far infrared and near infrared heating.

It is further known to those skilled in the art that the above fabrics and film composites are laminated films or fabrics in combination with spin deposition, needle punching, air deposition of pulp or fibers, or hydroentangling. Wherein the calendering comprises a thermal spunbond-meltblown-spunbond, or an ultrasonically bonded nonwoven treatment. The composite products are useful in protective fabrics for industrial and medical applications. For example, the composite product includes a spunbond-meltblown-spunbond, or ultrasonically bonded nonwoven for use as a sling, a duffle, or a stretcher for a patient. In addition, the composite product includes melt blown filter media as both the inner and outer surfaces by spun bonding, the product being stitched at the edges or heat or ultrasonically bonded to the melt blown filter media.

The above operations are fully accomplished by the skilled person in the art in light of the teachings of the present invention, in combination with the prior art, and will not be described in further detail herein. While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (6)

1. The recycled regeneration material is characterized by comprising PHAs and PLA, wherein the PHAs are PHBs (polyhydroxybutyrate-hydroxyvalerate), the PHBs are P (3HB-co-4HB) polymerized by 3HB and 4HB, and the mole percentage of the 4HB is 28%; the PLA is 85% by mass, the PHB is 15% by mass, the blend of the PLA and the PHB is melted, mixed and extruded into particles, then melt spinning is carried out to produce melt-blown fabric, and the quantitative amount of the melt-blown fabric is 50g/m²The average diameter of the fibers in the melt-blown fabric is 2-8um, the melt spinning comprises the non-woven treatment of spun bonding and melt blowing, and the melt-blown fabric is roller compactionAnd combining a spin deposition process, a needle punching process, an air deposition process or a water punching process of pulp or fiber, wherein the rolling process comprises a thermal spun-bond-melt-bond-spun-bond process or an ultrasonic bonding non-woven process, the melt-blown fabric comprises melt-blown filter media with the inner surface and the outer surface of the melt-blown fabric through spun-bond, the melt-blown filter media are sewn or thermally bonded or ultrasonically bonded at the edge of a product, the melt-blown fabric is used for preparing a biodegradable covering film or a woven or knitted or non-woven fabric, and the biodegradable covering film or the woven or knitted or non-woven fabric can prolong the shelf life under a clean environment and accelerate the degradation under a microbial environment.

2. The recycled reclaimed material of claim 1 wherein the clean environment is wet wipe cleaning solution and the microbial environment is river water or river mud.

3. The recycled regenerative material of claim 1, further comprising cellulose fibers.

4. The recycled reclaimed material of claim 1 wherein the meltblown fabric is obtained from a needle punching process, a hydroentangling process, thermal calendering, hot gas stream deposition or heat treatment of: microwave, ultrasonic, welding, far infrared and near infrared heating.

5. The recycled regrind of claim 1, wherein the meltblown fabric is wet bonded or dry bonded.

6. The recycled regenerative material of claim 1, wherein said nonwoven fabric comprises a spunbond-meltblown-spunbond or ultrasonically bonded nonwoven fabric for use as a sling, a dupuck or a stretcher for a patient.