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
  • D04H1/42—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 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4209—Inorganic fibres
• • 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
  • D04H1/42—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 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4326—Condensation or reaction polymers
  • D04H1/435—Polyesters
• • 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
  • D04H1/44—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/46—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
• • 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
  • D04H1/44—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling
  • D04H1/46—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
  • D04H1/498—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 the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres entanglement of layered webs

Definitions

• the present invention relates to a process for producing a ceramic fiber blanket, and more particularly to a simple process for making a ceramic fiber blanket has adequate strength.
• a process for producing a ceramic fiber blanket comprising alumina and silica is disclosed in Japanese Patent Publication No. 153/65.
• a fine falling stream of molten kaolin or like material is converted into staple fibers by blowing, spinning or other suitable method, the filaments are blended with a lubricant, and a web of the blend is placed on a belt conveyor and pressed between wire screens as it is heated to evaporate the lubricant.
• the individual fibers are not interlinked with each other and disintegrate easily, so the web provides only a laminar structure of a very low strength that is difficult to handle.
• a meshed or roller conveyor is used to facilitate the evaporation of the lubricant during compression, and as a result, in case of the meshed conveyor a replica of the mesh pattern is left on both surfaces of the blanket and the recessed part is so thin that it can be seen through, while in case of the roller conveyor there provides an error in the dimension of the blanket, as the process is carried out in the heated condition.
• fibers sufficiently short to be uniformly dispersed in water are dispersed in water in the presence of a binder and a sheet of ceramic fiber is produced by the conventional paper-making method. This wet process however needs much labor and has low fiber utility due to loss of fiber dust that accompanies the fiber cutting step.
• the primary object of the present invention is to provide a simple process for making a ceramic fiber blanket which has adequate strength.
• firsb a laminar pile of ceramic fibers is made that comprise 35 to 65 wt% of alumina, 35 to 65 wt% of silica, less than 10 wt% of another metal oxide and a lubricant. Then, a web of organic fibers is superimposed on one or both sides of the pile, the resulting assembly is punched with barbed needles, and then the lubricant is removed.
• Japanese Patent Publication No. 43946/77 describes a process for making a ceramic fiber blanket wherein a laminar pile of ceramic fibers treated with a lubricant is punched with barbed needles and then the lubricant is removed under pressure.
• This process provides a product having a greater tensile strength than the blanket made by removing the lubricant under pressure without needle punching.
• the meshed or roller conveyor as above mentioned is used as means to compress the pile during elimination of the lubricant.
• the pile is stretched in four directions and ruptures.
• a thin pile has inherently smaller tensile strength than a thick one and increasing the punching density to provide the thin pile with the same tensile strength as that of the thick one only results in a ruptured blanket.
• Japanese Patent Application (OPI) No. 77665/75 (the symbol OPI here used means an unexamined published Japanese patent application) describes a method of punching barbed needles through a mat of inorganic nonwoven fibers that is free from a lubricant and and on which a web of organic nonwoven fibers is superimposed.
• OPI Japanese Patent Application
• the mat of nonwoven inorganic fibers is sewn with organic fibers, and as mentioned on page 5, upper right column, lines 14 - 18 of the published specification, the mat of the inorganic fibers will return to its initial bulk density by itself after the organic fibers are eleminated. Therefore, the cited part of OPI No. 77665/75 shows that this method does not cause the inorganic fibers to be interlinked with each other..
• the present invention if a lubricant is removed from the laminar pile of punched ceramic fibers in the absence of pressure and if the web of organic fibers is then removed by incineration, the bulk density of the pile will not return to the initial value before the punching and the resulting product retains the effect of the punching and has a great tensile strength. This is probably because the lubricant is removed from . the laminar pile of ceramic fibers that are sewn tightly with the organic fibers and pressure is not particularly needed to retain the punching effect given the ceramic fibers.
• Fats and oils are generally used as the lubricant in 1 the present invention. They are evaporated from the pile of ceramic fibers by heating before the organic fibers are incinerated, and throughout the evaporation of the lubricant, the organic fibers retain their effect to clamp the ceramic fibers.
• the web of organic fibers is generally made by a carding staple fibers of a fineness of usually 1.5 to 5 deniers which are 30 to 100 mm long, and the web can have a density of 30 g/m 2 or more.
• the carded web can be immediately used in the present invention, but more preferably, for assuring easy handling, the web is punched by barbed needles, and a web having a density of 30 g/m 2 can be used with satisfactory results.
• a ceramic fiber blanket having a satisfactory tensile strength and a uniform thickness of 5 mm or less can be produced by punching the above characterized pile of ceramic fibers with 50 to 200 needles per square centimeter that could not be used in the conventional technique without rupturing the pile. Needless to say, the process of the present invention can also be applied to the making of a thicker ceramic fiber blanket with providing substantially the same effects.
• a composition made of 48 wt% alumina, 52 wt% silica and a trace amount of impurities was melted in an electric furnace and converted into staple fibers by blowing.
• the ceramic fibers were sprayed with a lubricant which was a 0.5 wt% aqueous emulsion of a 1 : 5 (by volume)' of aliphatic acid amine acetate (Armac HT® ) and kerosene, and they were then piled on a belt conveyor to form a laminar structure of ceramic fibers.
• the pile had a density of about 530 g/m 2 (without the lubricant), an average fiber diameter of 2.8 ⁇ m and a maximum fiber length of about 250 mm.
• Polyester fibers having a fineness of 3 deniers and a length of 76 mm were carded into a web which was punched with 80 needles per square centimeter to give a density of 50 g/m 2 .
• the punched web was unrolled and superimposed on either top or both surfaces of the laminar ceramic fiber pile, and the assembly was punched through the cross section both from above and from below with the number of needles varied as indicated in Table 1.
• the punched assembly was heated in an oven at 500°C for 30 minutes in the absence of pressure to thereby remove the lubricant and polyester fibers successively.
• Five ceramic fiber blankets (or sheets) were produced by the above procedure, and the bulk density, weight per unit area and tensile strength of each blanket are listed in Table 1.
• a ceramic fiber blanket was prepared by the method of Japanese Patent Publication No. 43946/77, wherein a laminar pile of ceramic fibers containing a lubricant was punched without laying a web of organic fibers on the pile and was then heated under pressure to remove the lubricant.
• a maximum tensile strength was obtained when the punching density was about 20 needles per square centimeter, but a product having a bulk density of 0.13 and a thickness of 6 mm had a tensile strength of only 0.35 kg/cm 2 and a product having a bulk density of 0.16 and a thickness of 20.2 mm had a tensile strength of 0 .9 kg/cm 2 .
• a ceramic fiber blanket having a great tensile strength that has been unobtainable by the conventional technique is produced, and what is more, a thin blanket that can only be produced by the conventional paper-making method can also be obtained.
• the punching density should not exceed 200 needles per square centimeter for making a product thinner than about 4 mm, since otherwise the tensile strength of the product is lower than that obtained by a punching density of 150 needles/ cm 2 and the ceramic fibers in the blanket begin to deteriorate.
• the web of organic fibers to be laid up on the ceramic fiber pipe may be treated with a lubricant.
• the blanket produced by the process of the present invention is usually incinerated as in the Example of remove the organic fibers and used as a product containing of only ceramic fibers. If necessary, only the lubricant may be removed to provide a blanket with a web of organic fibers which may be removed by incineration attendant to the blanket service.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Nonwoven Fabrics (AREA)
• Inorganic Fibers (AREA)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (2)

Family

ID=8192518

Family Applications (1)

Country Status (3)

Cited By (8)

Citations (2)

• 1984
  • 1984-01-06 EP EP84300092A patent/EP0148539B1/de not_active Expired
  • 1984-01-06 DE DE8484300092T patent/DE3467783D1/de not_active Expired
  • 1984-01-06 AT AT84300092T patent/ATE31091T1/de active

Patent Citations (2)

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