Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/60—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in dry state, e.g. thermo-activatable agents in solid or molten state, and heat being applied subsequently
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31511—Of epoxy ether
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]

Definitions

• the invention relates to a method for producing resin-bonded nonwovens, the nonwovens of which consist of organic fibers such as wool, cotton, rayon, polyester or acrylic fibers. Much of the fiber material used here is obtained from textile waste through a tearing process.
• Aerodynamic fleece formation is preferably used.
• the pre-opened fiber material is further divided, caught by an air stream, transported and continuously deposited on a perforated screen roller to the fleece.
• the binder is sprinkled in powder form into the fleece via rollers, vibrating troughs or similar metering devices.
• an intensive and uniform distribution of the binder in the nonwoven material must be ensured by swirling.
• the fiber material, which now contains binder is then brought back under suction onto the cross-section of the fiber web into a gap formed between suction rolls and laid down again to form the nonwoven.
• the hardening of the binders and thus the final consolidation of the nonwovens to form the nonwoven can also be carried out using various techniques.
• the nonwoven is preferably passed continuously between two wire mesh belts through a long hardening channel in which the curing takes place by means of hot air at 160 to 220 ° C. which is sucked or blown through the nonwoven. This process provides web and plate-shaped nonwovens.
• Another way of strengthening the nonwovens is to harden the binders by hot pressing, which is particularly useful for the production of more compacted plates and molded parts is applied.
• the fleece is only pre-dried and pre-hardened in the hardening channel at substantially lower temperatures and the material is subsequently shaped accordingly in hot presses.
• the textile nonwovens obtained in this way have the unpleasant property that they occasionally, especially after exposure to elevated temperatures (30 to 60 ° C.) and moisture, spread a perturbing amine odor which results from the curing agent (hexamethylenetetramine) or its amine decomposition products.
• the curing agent hexamethylenetetramine
• the textile nonwovens produced in this way have a sufficient level of strength and thermal behavior as are known and appreciated from the nonwovens bonded with novolak and hexamethylenetetramine to date. This is surprising insofar as it has hitherto been assumed that larger amounts of hexamethylenetetramine are required as hardeners for novolaks in order to achieve a sufficient level of strength.
• the binders used according to the invention are a mixture of at least two powdered resins, a non-heat-reactive phenolic resin and a heat-reactive resin.
• the non-heat-reactive resin is a phenolic resin of the general formula condensed in an acid medium wherein R and R ⁇ are the same or different and are hydrogen or an alkyl chain having 1 to 9 carbon atoms.
• the starting products are phenol, cresols, xylenols or longer-chain alkylphenols, which are condensed in an acidic medium with formaldehyde or a compound which releases formaldehyde under condensation conditions, the phenol / formaldehyde ratio being in the range from 1.06 to 1.09.
• the heat-reactive resins which can be used individually or in combination, can come from three different groups: the phenolic, amino and epoxy resins.
• the non-heat-reactive phenolic resin is mixed with one or more of these heat-reactive condensation products in a weight ratio of 30:70 to 90:10 and this mixture is used as a binder.
• Heat-reactive phenolic resins are reaction products from the alkaline condensation of a phenolic component with formaldehyde or a compound that releases formaldehyde under the condensation condition.
• Mono- or polynuclear phenols or mixtures of the aforementioned can be used as the phenolic component Classes of compounds are used, both mononuclear and polynuclear phenols.
• phenol itself, and its alkyl-substituted homologs, such as o-, m- or p-cresol, xylenes or higher alkylated phenols, also halogen-substituted phenols such as chloro- or bromophenol and polyhydric phenols such as resorcinol or pyrocatechol, and multinuclear phenols such as naphthols, bisphenol A or bisphenol F.
• alkyl-substituted homologs such as o-, m- or p-cresol, xylenes or higher alkylated phenols
• halogen-substituted phenols such as chloro- or bromophenol and polyhydric phenols such as resorcinol or pyrocatechol
• multinuclear phenols such as naphthols, bisphenol A or bisphenol F.
• the phenolic components and formaldehyde are preferably used in a molar ratio of 1: 1.0 to 1: 4.0.
• the phenolic resins to be used according to the invention, the heat-reactive and the non-heat-reactive, must have a free phenol content of less than 1%, and they must be in powder form.
• Both melamine and benzoguanamine or urea-formaldehyde condensation products and their mixed condensates are to be used as heat-reactive amino resins. They can be used alone, but preferably in a mixture (in any mixing ratio) with the phenolic resoles, as the heat-reactive binder component. All commercially available solid epoxy resins based on bisphenol A and bisphenol F can be used as epoxy resins.
• All resins used are used dry and in powder form. The various resin components are mixed together as a powder.
• the binder mixtures thus obtained in particular those containing epoxy resin as the heat-reactive component, 0.1 to 2 wt .-% of a curing accelerator, such as. As dicyandiamide or imidazole derivatives, are added.
• the binders according to the invention are incorporated into the fiber material using customary methods.
• the ratio of binder to fiber material varies depending on the application between 10 to 40 to 90 to 60; the resin content is preferably in the range from 20 to 40%.
• the resin bond in the fleece consists essentially in point-like connections of the fibers at their crossing points.
• the individual binder components melt in the same temperature range. It is advantageous if the non-heat reactive phenolic resin and melt the heat-reactive condensation product in the temperature range from 60 to 100 ° C.
• phenol novolak a phenol-formaldehyde condensation product with a phenol-formaldehyde ratio of 1: 0.77 was used, which was produced under the usual technical conditions and a melting point according to DIN 53181 (capillary method) from 90 to 95 ° C and a content of free phenol according to DIN 16916-02-L2 of approx. 0.3%.
• the melamine resin used is a melamine-formaldehyde condensation product with a melamine-formaldehyde ratio of 1: 2.5 and a melting point of 69 - 72 ° C.
• the epoxy resins used are commercially available products (e.g. Rütapox 0194 or Epikote 1004) based on bisphenol A with an epoxy equivalent of 900 to 1000 g / equivalent.
• a polymer powder (polypropylene) with a flower oil (60%) was used as an odor masking agent.
• the flexural strength was measured on sand bodies (140 ⁇ 20 ⁇ 15 mm), which were obtained by hot pressing (2 min at 170 ° C.) a mixture of 90 parts by weight. Quartz sand and 10 parts by weight Powder resin were produced (weight per rod: approx. 75 g).
• a nonwoven fabric made with 30% powder resin on the basis of a textile fiber mixture is pressed at 180 ° C. to form approximately 10 mm thick, square plates (dimensions 250 ⁇ 250 mm).
• 3 test specimens (90 ⁇ 200 mm) are punched out of each of the plates and stored together in sealed 3-liter glass vessels containing 30 ml of water for 16 hours at 40 ° C and then the vessels are opened and assessed by an odor team .

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Nonwoven Fabrics (AREA)
• Laminated Bodies (AREA)
• Reinforced Plastic Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6306115

Family Applications (1)

Country Status (4)

Cited By (3)

Families Citing this family (7)

Family Cites Families (9)

• 1986
  • 1986-07-28 DE DE19863625443 patent/DE3625443A1/de not_active Withdrawn
• 1987
  • 1987-04-09 EP EP87105254A patent/EP0254807B1/fr not_active Expired - Lifetime
  • 1987-04-09 DE DE8787105254T patent/DE3782286D1/de not_active Expired - Lifetime
  • 1987-04-09 ES ES198787105254T patent/ES2000999T3/es not_active Expired - Lifetime
  • 1987-07-20 US US07/075,111 patent/US4745024A/en not_active Expired - Lifetime

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