Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D4/00—Spinnerette packs; Cleaning thereof
  • D01D4/02—Spinnerettes
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/28—Cleaning or pickling metallic material with solutions or molten salts with molten salts
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D4/00—Spinnerette packs; Cleaning thereof
  • D01D4/04—Cleaning spinnerettes or other parts of the spinnerette packs
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/08—Melt spinning methods
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/27—Cleaning; Purging; Avoiding contamination

Definitions

• spinnerets are subjected during spinning to a treatment with liquid polyorganosiloxanes to guarantee that the spinning process may be carried on for an extended period without interruption.
• This material is usually intermittently sprayed onto the spinneret surface throughout the spinning operation.
• Polyorganosiloxanes useful for this purpose have the following formula:
• R is'an alkyl group, aryl group, alkaryl group, or aralkyl group, and n is an integer greater than 1.
• Particularly preferred polysiloxanes for use in this treatment are the polymethylsiloxanes having a viscosity ranging from 500 to 1000 centistokes at 25 C.
• a further object of this invention is to provide a process for cleaning spinnerets that have been treated with a polyorganosiloxane during the melt spinning of polymeric materials that will remove not only contaminants and deposits originating with the polymeric material extruded, but will also remove the polyorganosiloxane and decomposition products thereof from the spinneret.
• a still further object of this invention is to provide a spinneret cleaning method which is simple, efficient, and inexpensive, and that will not damage the spinneret.
• polyorganosiloxane deposits on the spinneret can be removed utilizing the known salt bath cleaning method if, prior to immersing the spinnerets in the alkali-metal nitrate and nitrite bath, the spinneret is subjected to a pretreatment with white mineral oil. Such a pretreatment is easy to incorporate in the normal spinneret cleaning routine customarily used.
• the contaminated spinnerets are either immersed in a white mineral oil such as a parafiin oil orsimply smearedwith the oil,and"then soaked in a molten salt bath consisting of a mixture of alkali metal nitrate and alkali metal nitrite for asufiicient period of time to dislodgeand decompose all foreign matter on the spinneret surfaces. Soaking time may range from /z'hour to 6 hours, depending on the degree of contamination. Upon withdrawal of the spinneret from the bath, all foreign deposits, including polyorganosiloxane contaminants, have been removed from the spinneret surfaces.
• a white mineral oil such as a parafiin oil
• a molten salt bath consisting of a mixture of alkali metal nitrate and alkali metal nitrite for asufiicient period of time to dislodgeand decompose all foreign matter on the spinneret surfaces. Soa
• the purpose of the mineral oil in the inventive process is to provide a solvent action on the surface of the spinneret which aids the oxidation reaction carried out by the molten alkali salts.
• the only requirement as to the type of mineral oil used to produce this solvent effect during submersion into molten salt bath is that the hydrocarbon mineral oil must have a boiling point, i.e., vaporize, higher than the ambient temperature. This is necessary to enable the spinneret to be coated with the mineral oil when it is contacted by the molten salt bath.
• Example I A 'polyamide prepared from hexamethylene .diamine' and adipic acid was'melt spun into filaments using two separate spinnerets. During the spinning process, each spinneret was from time to time sprayed with polymethylsiloxane. After the spinnerets had been used in this manner for two weeks, they were removed from the machine. One spinneret was immersed in a melt maintained at 450 C. containing about 50% by weight potassium nitrate and 50% by weight sodium nitrite for about 5 hours. The spinneret was thereafter cooled in air and washed with warm water to remove the salt. All polyamide contaminants previously adhering to the spinneret were removed by this treatment.
• the other spinneret after removal from the spinning machine was dipped in a white mineral oil bath, whose viscosity at 20 C. was about 35 centistokes, having a specific gravity of about .87. It was thereafter immersed in a 50% by weight potassium nitrate and 50% by weight sodium nitrite melt maintained at 450 C. for about 5 hours and then washed with warm water to remove traces of the salt. The spinneret was completely free from all polyamide and polymethylsiloxane deposits.
• Example II A polyamide prepared from hexamethylenediamine and adipic acid was melt spun into filaments. Two spinnerets utilized in the spinning process were both sprayed with polymethylsiloxane throughout the spinning. After they had been used for about three weeks, they were removed from the spinning apparatus. One spinneret was immersed for about 5 hours in a melt containing 50% by weight sodium nitrate and 50% by weight sodium nitrite maintained at about 500 C. The spinneret was cooled and rinsed with warm water. No trace of the polyamide remained on the spinneret. However, the polymethylsiloxane deposits were still present.
• the other spinneret was dipped in a white mineral oil bath identical with that of Example I, and then immersed for about 5 hours in the sodium nitrate, nitrite bath under the same conditions as the spinneret which had not received the mineral oil pretreatment. After it had been cooled and rinsed with warm water, it was found to be perfectly clean.
• a method for cleaning apparatus used in the melt extrusion of polymeric material said apparatus having been coated with a polyorganosiloxane during the extrusion process, consisting essentially of coating said apparatus with a white mineral oil and thereafter immersing the apparatus in a molten salt bath consisting of a mixture of alkali metal nitrite and alkali metal nitrate for a sufiicient period of time to dislodge and decompose all foreign matter on the spinneret surfaces.
• alkali metal salts are selected from the group consistingof potassium and sodium salts.
• a method for cleaning spinnerets used in the melt extrusion of polymeric materials said spinnerets being contaminated with the polymeric material extruded together with a polyorganosiloxane applied to the spinneret during-the extrusion operation, having the formula:
• R is a member selected from the group consisting of alkyl, aryl alkaryl and aralkyl groups and it an integer greater than 1, consisting essentially of coating the spinnerets with a white mineral oil and thereafter immersing them in a molten salt bath consisting of a mixture of alkali metal nitrite and alkali metal nitrate for a period of time sutlicient to dislodge and decompose all foreign matter on the spinneret surfaces.
• alkali metal salts are selected from the group consisting of sodium and potassium salts.
• a method for cleaning spinnerets used in the melt spinning of polymeric materials said spinnerets being contaminated with the said polymeric material and polymethylsiloxane applied during the spinning operation consisting essentially of coating the spinneret with a paraflin oil and thereafter immersing the spinneret in a molten salt bath consisting of by weight potassium nitrate .and 50% by weight sodium nitrite for a sufiicient period of time to dislodge and decompose all foreign matter on the spinneret surfaces.
• the salt bath comprises a mixture of 50% by weight sodium nitrate and 50% by weight potassium nitrite.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Textile Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Detergent Compositions (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19753614

Family Applications (1)

Country Status (8)

Cited By (5)

Families Citing this family (1)

Citations (3)

• 0
  • NL NL274929D patent/NL274929A/xx unknown
  • BE BE627561D patent/BE627561A/xx unknown
  • NL NL123335D patent/NL123335C/xx active
  • DE DENDAT1250592D patent/DE1250592B/de active Pending
• 1963
  • 1963-01-31 CH CH120763A patent/CH420477A/de unknown
  • 1963-02-04 US US256144A patent/US3188239A/en not_active Expired - Lifetime
  • 1963-02-12 GB GB5633/63A patent/GB965870A/en not_active Expired
  • 1963-02-14 FR FR924807A patent/FR1348143A/fr not_active Expired
  • 1963-02-15 ES ES285145A patent/ES285145A1/es not_active Expired

Patent Citations (3)

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