DE4409465A1 - Biodegradable nonwovens and nonwoven composite materials - Google Patents

Description

From the published documents DE 40 14 176 A1 and DE 42 42 538 A1 are biodegradable molding compounds or fiber mats known, which are mainly made of renewable raw materials exist and often under Pressure and heat through activation of the lignins or Glue the pectins together in the tool and with the Expose to rot in a biological environment. However, time is important for this product technology Factor, especially since the problem with renewable raw materials in technical use, mainly those not given are thermoplastic properties of these materials.

The object of the invention was now for the nonwoven area, mainly where there is purity and therefore hardly any recycling is possible, a largely customizable decomposable thermoplastic polymer fiber find which, processed into fleece, molding, but also z. B. as a nonwoven film composite, through the connections of plastic and natural properties rapid technical Treatment steps in z. B. vacuum or Preßverfor measurements, but also HF, ultrasound, thermal welding Allows boys and the like, for uses such. B. in Geographic area, but also in connection and additional Use of renewable raw materials such as jute, flax, Sisal, wool etc., or mixtures thereof, as well as in Combination with further degradable organic aggregate fabrics, e.g. B. foamed starch. This many times permeable nonwovens or composite materials Despite these requirements, under the influence of a natural environment in whole or in part, also as Compound rotable, water soluble, or in one preferred version can also be compostable, and in the latter case the microorganisms are not toxic Endanger components or degradation products.  

In the applications of these nonwovens or Alliances are about shaping them so that they almost for the whole area of geotextiles, such as B. when consolidating embankments, in tunnels or water road construction, for filtration, in heat and sound insulation area, as well as in gardening needs, e.g. B. for Composting plants and plant pots, for packaging, e.g. B. Apples, and in agriculture as e.g. B. plowable Cover mats, or carved z. B. as floor loosening and improvement, such as when used in Hygiene and medical area, e.g. B. as diapers and Plasters are suitable.

After such, also through different filling quantities made of starch, designed for controlled degradability Polymer fibers are not offered by the textile market, must foil manufacturers with foils z. B. from Starch are extrudable or easier to fill, or are multi-layered, e.g. B. with PE / PP or PET / PE layers (and thus the properties of Bicomponent fibers), and then fibrillated can be, for the time being appropriate film fibers Make available because these, e.g. B. also with more than 15% Starch shares, as with composite materials accordingly modified foils, solve the composting can, because the comparatively inexpensive composting, Would relieve landfills and incineration plants.

These different tasks are then also mainly due to different strengths in the synthetic polymer film fibers used and / or Copolymer fibers or with natural or modified natural polymer film fibers and / or biomodified Polymer staple fibers, Type A, achieved by under different arrangement and combinations of fibers within the non-woven fabric, or z. B. by layered Structure, or with other decomposable materials combined, but also through a wide variety of mixtures conditions in the attached fibers, the z. Legs Customizable customizable initial strength or z. B. rapid deformability to the molded part enable.  

They are compostable and degradable as a supplement to the from or with starch used fiber materials according to Claim 1, Type A, products from the following areas particularly suitable as matrix products B, provided that they are made from come from renewable raw materials or from synthetic ones Polymers from cellulose, polyhydroxy fatty acids (PHB / PHBV), gelatin (polypeptides), polycaprolactone, poly lactides and the like, as well as, if specific water-soluble products are in demand from z. B. aligates, Polyvenyl alcohol or unsaturated carboxylic acids represents are. For the also possible photo degradation of Fibers or fiber foil combinations are particularly considered Matrix products B, e.g. B. with covers in the farmer economic area, materials based on ethylene / Carbon monoxide as well as ethylene and styrene with vinyl ketones or olefins with those that react specifically to UV exposure Additives particularly suitable. As aggregates are e.g. B. foams, schnitzel or any other conceivable Conceivable formats from the materials mentioned.

In addition to products based on starch, as well as more natural ones or naturally modified polymers made of polyester, which are mainly made from starch, by fermentation, or plants modified via bacterial strains, such as, for. B. Potatoes or rapeseed, and often are already water-soluble, they are preferred Execution to achieve maximum advantages through the sought solutions thermoplastic rotten Fibers, which consist mainly of an olefin film Fibrillations are made because these are inexpensive Polyolefin films high additions from also cheaper biological starch of more than 50% from corn, Potatoes and the like can be added to what quantitative for spun synthetic polymer fibers is only possible in much smaller quantities, and what then with such fibers spun with starch this also means that the rotting times are much longer leads.  

For the packaging sector have been around for some time Packaging films offered from starch or with such Starch bio-modified polyolefins. For the inventive tasks and applications across the Non-woven market, it is therefore necessary to use these films fibrillate, sometimes also cut to length to make it usable in order to get the required produce processable fibers. With these It should be bio-modified thermoplastic film fibers are mainly those that are associated with selected proportions, starch and if necessary other additives from z. B. vegetable soft like unsaturated biological oils or also Additives to form peroxides, mainly as Prooxidants that occur when the surface area is enlarged improved warmth and oxygenation at one Reduction of the mechanical properties of the polymers lead, the oxidative chain degradation then up to one Degree takes place, which then by breaking down the molecular weight (<1000 for e.g. composting) when it comes about a bacterial environment, so only on the landfill, in the soil, in the regulated composting area the type and proportions of starch and zu used Impact materials, largely constructed for breakdown time can disintegrate as planned, or else are water soluble.

In this way, this material, e.g. B. at Use of at least one other biological matrix fiber such as jute, coconut, flax and the like, or an exclusive use of this strength synthetic synthetic, staple or foil fibers, or natural or naturally modified, largely starch based polymer fibers to mat, or in Combination with other degradable polymer fibers, e.g. B. copolyesters (CPEE) and copolyamides such as z. B. from the University of Lodz, Poland; to the Techtex symposium 1992, Frankfurt, lecture 402, have been published, without damage to earth and water, thus from Groundwater problems in the soil area, in the landfill, such as used in compost, through conversion to biomass become.  

In the geospatial area it can e.g. B. in tunnel or train Embankment consolidation may be useful, not just flame to spray protective agents, but also these materials in a mixture with e.g. B. inorganic materials, such as Glass fabrics and the like, or organic polymer to connect fiber structures, on the one hand via the biodegradable fibers a drainage, separation, or z. B. also to form planting layer on the starch containing thermally fixable polymer fibers to have medium-term strength component, however on the other hand also z. B. against fire or earth pressure additional stability and reinforcement layer to get.

In the hygiene area, especially with diapers, Finding solutions to the enormous space or scorching need to solve. Here are solutions in particular Combination of fiber layers, if bio modified, at least briefly hydrophobic thermo plastic fibers, and those with high storage ability from z. B. viscose, or biomodified Thermoplastics through additional so-called superabsorbers, e.g. B. polyacrylate cores with and without fiber components, and in Connection with another layer of a biological degradable film conceivable.

The use of these materials was also for to strive for deformed parts such. B. plant pots or Food packaging or filtering where e.g. B. also the Separation properties of different liquids with super absorber shares can be used, and wherever for rapid deformation, e.g. B. in the pressing process the thermoplastic binding fibers work faster cycles are made possible.

example 1

These fiber mats are used for molded parts for the Packaging area (apples) from a mixture 30% Fiber A with at least 20% starch in it too e.g. B. keep compostable with the food content, and 70% jute needled 400-500 g m², then  predominantly in one or more work steps placed between intact plates, or z. B. radiant heat exposed, preheated thermally, and then in one cooled tool stored and deformed. You can go after short pressing time, sufficiently solidified, removed, punched, and used for further use.

Example 2

For embankment consolidation, 20% is a film fiber Type A with more than 50% starch, 60% one Flax fiber and 20% superabsorbent components possible, needled and heat-set, the superabsorbents share the task of providing nutrient fluid for one To bind plant seeds and through the permanent Moisture absorption and dispensing capacity for a quick Rooting z. B. to care for sown grasses.

Example 3

In the area of coverable mats you can find here mainly also because of air and moisture permeability casual as well as insulating non-woven products instead Use foils with a mixture of 20%, one with at least 20% starch-filled LDPE film fiber type A and 80% of a film fiber B made from ethylene / Carbon monoxides, thermally bound, in particular the majority of the matrix fibers by the action of Light, especially UV, is photo-degradable, and according to the Usage time can thus be picked up easily.

Example 4

For the diaper area are as the top Dry fiber and sweat layer, for example with Starch modified spun polyethylene fibers or also spun polyester fibers (CPEE), at least are initially hydrophobic, conceivable, or mixtures of PP and PE fibers, mainly thermally bonded. When  Absorber layer for absorbing liquid can e.g. B. viscose with or without superabsorbent are used, but also z. B. modified PP or PE fibers with super absorbers, thermal or with degradable acrylic dispersions bound, and as final seal and for hiding one bio-modified polyethylene film made of LDPE.

Claims (6)

1. Nonwoven fabric containing at least one polymer / copolymer fiber type A that is degradable from or by contained and / or fermented starch, also in combination with several, also different types of biodegradable polymer fibers and / or natural fibers or additives B, primarily for use in geotextiles, Packaging, medical, filtration and hygiene area, characterized in that the fibers of type A are natural polymers or natural polymers modified with synthetic polymers and / or synthetic polymer fibers which have been modified by biological starch, in particular those made from polyolefins and / or polyester / copolyesters, which as a fleece mechanically, by z. B. needling, or thermally, or solidified by binders, or a mixture of all of these possibilities, the biodegradability in the fiber type A based on synthetic polymers by additions of biological starch, beets, sugar cane, corn, wheat and the like, and made of natural polymers, especially polyester, mainly z. B. from starch, fermented starch products, or over bacterial strains of modified plants, such as potatoes, rapeseed, etc., and these special fibers, mainly from a film, by z. B. fibrillation can be made, but can also consist of spun fibers, and thereby in connection with other degradable polymer fibers = type B, z. B. copolyamides and / or biological fibers such as jute or the like and / or degradable additives and / or degradable films, dissolving in water or rotting of the nonwoven fabric, or of the composite, or parts thereof. 2. Nonwoven fabric according to claim 1, characterized in that that the fleece from one or more, even under different layers. 3. Nonwoven fabric according to claim 1 and 2, characterized in that the nonwoven fabric consists of several together connected non-woven fabrics, according to one of the previous Claims exists. 4. nonwoven fabrics according to claim 1 to 3, characterized in that one or both within the nonwoven fabric on the surfaces and / or between the Layers, full or partial, at least one functional and / or stabilizing layer or Reinforcement material also consists of ver rotting material, such as fibers, foils, Lattice fabrics, laid, meshes, sprayed Substances or the like. 5. Nonwoven fabric according to claims 1-4, characterized characterized in that one or on both sides of the surfaces and / or between the Layers, full or partial, at least one functional and / or stabilizing layer or Reinforcement material in the form of fibers, fleeces, Foils, fabrics, meshes, sprayed Substances or the like, from non-rotting Materials. 6. Use of a nonwoven fabric after a or more of claims 1-5.