Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F26—DRYING
  • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
  • F26B13/00—Machines and apparatus for drying fabrics, fibres, yarns, or other materials in long lengths, with progressive movement
  • F26B13/001—Drying and oxidising yarns, ribbons or the like
• • 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
  • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
  • D01D10/04—Supporting filaments or the like during their treatment
  • D01D10/0409—Supporting filaments or the like during their treatment on bobbins
• • 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
  • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
  • D01D10/06—Washing or drying

Definitions

• my present; invention concerns a new and novel method of drying the yarn so that aneven shrinkage is produced.
• the present method may also be applied to yarn spun or extruded upon the so-called collapsible spools, including slottedsnOQlS with collapsible holders and those spools whose shell or surface portion is adapted to contract, and
• -It is the principal object of the present invention to set forth several methods of evaporating or extracting the moisture from yarn bodies derived from cellulosic solutions, such methods being designed so that an evenly shrunk yarn may be produced.
• Certain processes for the produc-' tion of an evenly shrunk yarn are covered by 00- pending applications, the property of the same assignee, namely, in co-pending applications S. N. 560,226,. (Bitter and Elssner); S. N. 548,474, (Bitter and Elssner); S. N. 560,225, (Elssner); S. N. ($20,724:, (Oppenlaender and Elssner); S. N.
• Spools of untwisted yarn, after wet treatment, are loaded on or into a suitable conveying medium, preferably one which will permit free circulation of the air, or other drying medium, 4 in and around all portions of the spools, and the conveying medium is then placed into a drying chamber for the first drying operation.
• a suitable conveying medium preferably one which will permit free circulation of the air, or other drying medium, 4 in and around all portions of the spools, and the conveying medium is then placed into a drying chamber for the first drying operation.
• My new invention lies, broadly, when used in connection with rigid spools, in two dryings of the spooled yarn, as pointed out above, but the inventiveconcept lies in the method in which these dryings are accomplished.
• the two dryings are usually similar, and therefore a description of one of them should suffice to disclose my invention.
• twisted yarn on spools may give up or absorb tive humidity below 100% is usually continued to a point which will dry the-yarn to a given moisture content by weight. For example, if a yarn body with a moisture content, by weight, of from 4 to 6% is desired, the relative humidity during the drying may be reduced to approximately 25%. At 70 C. dry bulb, the difference between the internal and external vapor pressures is usually very slight. It must be understood, however, that I do not desire to limit my invention to the exact percentages, temperatures, and times given, since the process, of itself, is essentially novel, and I wish to be limited in the present method, and those alternative methods following, only by the scope of the appended claims.
• Method #2 The yarn is placed in the drying chamber in the manner outlined in the discussion of Method #1. Heat is applied, as in Method #1, at a relativehumidity of 100%, until the yarn-body is thoroughly and uniformly heated throughout. The relative humidity is then reduced, as above, at a given rate of speed in excess of the speed at which the yarn body will give up its moisture. Thus, as outlined above, a certain amount of drying is accomplished. This drying may be continued until the yarn has, for example, a moisture content by weight of approximately 75%. The yarn is thus not dried to the extent named in Method #1. Then the relative humidity is again increased to 100% for a certain length of time. I have found that a time of approximately 2 hours gives good results.
• This step results in the moistening of the outside layers to some extent.
• the reduction of relative humidity is then repeated, as at first, until a lower relative humidity is reached, namely approximately 50%.
• These steps or cycles may then be repeated until the proper moisture content of the yarn is reached.
• the relative humidity is lowered a slight amount below the relative humidity reached in the preceding cycle.
• Method #3. This method is a modification of that in Method #2, above. It has been found preferable, in some cases, instead of increasing thewet bulb temperature to the dry bulb-temperature, to decrease the dry bulb to the wet bulb reading, at the end of the said cycles, because it has been found that at a lower temperature a better moistening effect may be obtained at 100% relative humidity.
• the wet and dry bulb readings are then raised together to approximately 70 C. and 100% relative humidity, and the gradual depression of the wet bulb reading restarted.
• I may mention from 70 C. to 45 C.
• Method #4 The yarn upon rigid spools is placed in the drying chamber, and brought to 100% relative humidity for a certain length of time, as indicated'in Methods #1, 2, and 3.
• the temperature at which the yarn is maintained at first, in the manner indicated in the other methods, is approximately 45 C.
• the dry bulb temperature is then increased to a given point, for example, 70 C. and the wet bulb reading decreased to a given point, for example, 40 C.,
• wet and dry bulb hygrometers comprise a pair of ordinary thermometers which are similar, except that there is a piece of muslin tied about the bulb of one. The muslin is in contact with a wick, the lower end of which is in a vessel By virtue of the capillary action of the wick and muslin, the bulb is kept moist.
• thermometer The moisture evaporating from the bulb cools it, causing this thermometer to read several degrees cooler than the other one. If the air is very dry, this evaporation will be very rapid, and the difference between the reading of the two thermometers will be large; whereas, if,the air is almost saturated with moisture, the evaporation will be slow, and the two thermometer readings will vary but slightly.
• the velocities of the air or other drying medium which may be used also plays an important part in the drying or extraction of moisture from the yarn bodies to be treated. For example, when air is circulated at a relatively high velocity, e. g., 500 .feet a minute it has a tendency to defeat the purpose of the method since it practically blows the moisture from the yarn bodies. When very low velocities are used, the drying requires too much time. I have found that velocities of from 25 to 400 feet per minute may be used. In carrying out the processes just described, I regulate the velo'city'of the drying medium according to the nzoisture content of the yarn bodies being dried, e c.
• the process of drying artificial silk yam wound on spools comprising the steps of placing the moisture-laden yarn bodies in a drying chamber, heating the said yarn bodies with a circulating drying medium having a relative humidity of approximately 100%, maintaining a relative humidity in the drying chamber at approximately the saturation point of the drying medium until the yarn is uniformly heated throughout, and then gradually reducing the relative humidity of the drying medium at such a rate that the moisture coming to the outside surface of the yarn body is evaporated at the same rate as the rate at which the moisture comes to the surface.
• the process of drying artificial silk yarn wound on spools comprising the steps of placing the moisture-laden yarn bodies in a drying chamber, heating the said yarn bodies with a circulating drying medium having a temperature of from 60 to '70 degrees C. and which has a relative humidity of approximately 100%, maintaining this temperature and relative humidity at approximately the saturation point of the drying medium until the yarn is uniformly heatedthroughout, and then gradually reducing the.
• a process of drying artificial silk wound on spools comprising steps of placing moisture-laden yarn bodies in a drying chamber, heating the said yarn bodies with a circulating drying medium having a dry and wet bulb temperature of approximately 60 to 70 degrees C., maintaining this relative humidity until the yarn body is uniformly heated throughout, then reducing the wet bulb temperature at such a rate that the moisture on the surface of the yarn body is evaporated at a faster rate than the rate that said moisture comes to the surface of the yarn body, continuing this last step until the outside layers of theyarn body are approximately dry, then decreasing the dry bulb temperature to the wet bulb temperature.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Treatment Of Fiber Materials (AREA)
• Drying Of Solid Materials (AREA)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24496398

Family Applications (1)

Country Status (3)

Cited By (1)

• 0
  • NL NL35492D patent/NL35492C/xx active
• 1932
  • 1932-07-16 US US623007A patent/US1955323A/en not_active Expired - Lifetime
• 1933
  • 1933-07-14 DE DEV29726D patent/DE680287C/de not_active Expired

Also Published As

Similar Documents