US3772495A - Method for manufacturing needles for fibrillating rollers - Google Patents

Method for manufacturing needles for fibrillating rollers Download PDF

Info

Publication number
US3772495A
US3772495A US00234813A US3772495DA US3772495A US 3772495 A US3772495 A US 3772495A US 00234813 A US00234813 A US 00234813A US 3772495D A US3772495D A US 3772495DA US 3772495 A US3772495 A US 3772495A
Authority
US
United States
Prior art keywords
rollers
wire
pair
fed
tube
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00234813A
Other languages
English (en)
Inventor
P Klaase
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
Original Assignee
Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO filed Critical Nederlandse Organisatie voor Toegepast Natuurwetenschappelijk Onderzoek TNO
Application granted granted Critical
Publication of US3772495A publication Critical patent/US3772495A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21G—MAKING NEEDLES, PINS OR NAILS OF METAL
    • B21G1/00—Making needles used for performing operations
    • B21G1/003—Needles for special purposes, e.g. knitting, crochet, hat-pins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21G—MAKING NEEDLES, PINS OR NAILS OF METAL
    • B21G1/00—Making needles used for performing operations

Definitions

  • Such needles are used for assembling needle rollers for the fibrillation of plastic films and must be very thin for example 50 p. m and straight, with a view to the desired rate of fineness and uniformity of the rollers. Because they, moreover, must have a great resistance to wear so as not to lose their torpedo-like pointed shape, only needles of hardened steel, molybdenum, iridium, tungsten and the like metals that are difficult to machine are eligible.
  • the method according to the invention is, characterized in that a continuous wire, whose thickness and material correspond with those of the needles to be manufactured and which is fed through a first driven pair of rollers, is brought again and again with its front end between the rollers of a second pair of rol lers, an. increasing tensile force is exerted on the part of the wire that hereafter is situated between the pairs of rollers by driving the second pair of rollers at a speed that is greater than that of the first pair of rollers, and then such an electric current is fed through the said part of the wire that this part of the wire is heated to a temperature at which it breaks off under the influence of the tensile stress.
  • the part of the wire which is broken off forms a needle and is collected at the discharge side of the second pair of rollers.
  • the front part of the wire is again brought between the rollers in order to form a next needle.
  • This method yields needles with a point on each end. It has been found that the shape of the points is mainly determined by the temperature of the wire on the location of the breakage at the moment of breaking and that there is a temperature range within which the desired torpedo shape of the point is obtained. At lower temperatures of breakage the needle point has a more or less flat end face and at higher temperatures of breakage a globular end. Needles with these shapes of the point are not usable for the designed application in fibrillating rollers.
  • the temperature at which the wire breaks can be chosen arbitrarily with the aid of the time interval with which the electric current is delayed and that in order to obtain usable needles it is sufficient to determine experimentally at the given speed of the pairs of rollers and at the given properties of the wire, at which delay time the needles have the desired pointed shape.
  • the wire is guided between the two pairs of rollers with the aid of a straight tube that is situated with its ends near the place of output of the first pair of rollers and the place of intake of the second pair of rollers.
  • This guidance simplifies bringing the wire end into the second pair of rollers and at the same time offers the possibility to protect the wire against oxidation by the surrounding atmosphere.
  • a gas inert to the material of the wire is fed into the tube, so that the air is driven out of it and cannot affect the material of the wire.
  • the gas stream has a cooling effect upon the wire and has been found to be a means to influence the place where the wire is heated most quickly and the breakage finally arises.
  • the invention also relates to a device for the manufacture, according to the method described, of thin needles with at least at one end a torpedo-shaped point.
  • This device is characterized by a drafting device of which the two pairs of rollers, which are driven at different circumferential speeds, are electrically insulated from each other and connected to the opposite poles of a sourceof current.
  • the device according to the invention is preferably still characterized in that in the connection of one of the pairs of rollers with the source of current a time-delay relay is inserted that prevents the passage of current up to a certain interval of time after an electrical connection has been made between the pairs of rollers.
  • rollers 3 and 4 are situated on baseplate 1 .
  • Roller 3 has its hearings in arms 2 and roller 4 has its bearings in two blocks 5, which are slidable in slots 6 of arms 2.
  • compression springs 7 operate, which press roller 4 against roller 3 with a force adjustable by means of screws 8.
  • a motor 9 provided with a reduction gear drives roller 3 clockwisely at a constant speed.
  • Roller 4 is coupled with roller 3 by means of a set of cog wheels not shown in the drawing and rotates anticlockwisely at the same speed. 1
  • roller 11 has its bearings in arms 2 and roller 12 in two blocks 13, slidable in slots 14 and on towhich springs 15 exert a force adjustable with the aid of screws 16.
  • a motor 17 drives roller 11 clockwisely and roller 12 anticlockwisely at a speed greater than that of rollers 3 and 4. Consequently the device described so far forms a drafting device.
  • a funnel-shaped inlet pipe 18 is situated with its lower end as close as possible to the tangent of rollers 3 and 4.
  • guiding tube 19 is placed such that its narrowed upper end 20 is as close as possible to the tangent of rollers 3, 4 and its likewise narrowed lower end 21 as close as possible to the tangent of rollers 11, 12.
  • the tube is provided with a side tube 22, which is connected to a duct (not shown) for the supply of argon or another inert gas.
  • Baseplate 1 is of pertinax and guiding tube 19 of glass, so that the metal assembly of bearing arms 2 with the pair of rollers 3, 4 is electrically insulated from the likewise metal assembly of bearingarms 10 with the pair of rollers ll, 12.
  • the pair of rollers 3, 4 is connected to the negative terminal of a direct current source 26.
  • the pair of rollers 11, 12 is connected to the positive terminal of direct current source 26 via arms 10 and duct 27.
  • Metal wire 28 from which theneedles must be manufactured is situated on a bobbin 29 above the pair of rollers 23, 4.
  • Wire 28 is brought with its end into tube 18, caught by rollers 3 and 4 and transported by them into tube 19.
  • wire 28 with current source 26 and relay 24 forms a closed circuit with the result that in relay 24 a condenser 30 is charged via an adjustable resistor 31.
  • the increasing voltage of condenser 30 is transmitted on to the control electrode of a thyristor 33 by a transistor 32 connected as an emitter-follower.
  • This thyristor 33 initially is in a non-conducting condition but as soon as condenser 30 has been charged so far that its voltage exceeds a certain threshold value, the thyristor becomes conductive and in the circuit a current begins to pass, which quickly heats the part of the wire that is situated between the pairs of rollers 3, 4 and 11, 12.
  • This period of time and herewith also thestress in wire 28 at the moment of heating can be adjusted with the aid of resistor 31
  • the increase in temperature of the wire as a result of the electric current that passes through it is not the same in all places, because the cooling efiect of the stream of argon that is guided via tube 22 into and through guiding tube 19, differs from place to place.
  • the cooling is the most effective on the location where the argon enters into tube 19, because there the flow has an important transverse component.
  • the openings atends 20 and 21 of tube 19 are dimensioned such that the gas stream towards upper end 20 is stronger than that to lower end 21, while for both ends 20 and 21 holds that the gas stream in the narrowed end is faster and cools. stronger than in the part of tube 19 that is not narrowed.
  • Loose wire parts 34 are the needles for the manufacture of which the described device is meant. At both ends they have a point, whose shape is determined by the temperature at which these points were formed as planes of breakage. The temperature that yields the desired torpedo-shaped points is adjusted empirically with the aid of adjustable resistor 31.
  • the described device was applied for manufacturing needles out of tungsten wire with a diameter of 50 p, m.
  • the circumferential speed of rollers 3 and 4 amounted to 8.8 mm/sec., that of rollers 11 and 12 15.8 mm/sec.
  • The-distance between the pairs of rollers was mm.
  • the current source was adjusted to a terminal voltage of 12Vs. and was found to yield approximately 0.8 As. while the wire was heated.
  • a method for manufacturing thin metal needles with at least at one end a torpedo-shaped point wherein a continuous wire, whose thickness and material correspond with those of the needles to be manufactured and which is fed through a first driven pair of rollers, is brought again andagain with its front end between the rollers of a second pair of rollers, an increasing tensile stress is exerted on the part of the wire that hereafter is situated between the pairs of rollers by driving the second pair of rollers at a speed that is greater than that of the first pair of rollers, and then such an electric current is fed through the said part of the wire that this part of the wire is heated to a temperature at which it breaks off under the influence of the tensile stress.
  • a method according to claim 4 wherein a stream of gas is brought into the tube-in a place between the ends and is allowed to flow away to both ends.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Textile Engineering (AREA)
  • Heat Treatment Of Strip Materials And Filament Materials (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
US00234813A 1971-03-19 1972-03-15 Method for manufacturing needles for fibrillating rollers Expired - Lifetime US3772495A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7103724A NL7103724A (fr) 1971-03-19 1971-03-19

Publications (1)

Publication Number Publication Date
US3772495A true US3772495A (en) 1973-11-13

Family

ID=19812725

Family Applications (1)

Application Number Title Priority Date Filing Date
US00234813A Expired - Lifetime US3772495A (en) 1971-03-19 1972-03-15 Method for manufacturing needles for fibrillating rollers

Country Status (10)

Country Link
US (1) US3772495A (fr)
AT (1) AT319712B (fr)
BE (1) BE780836A (fr)
CA (1) CA961376A (fr)
DE (1) DE2212391A1 (fr)
FR (1) FR2130308B1 (fr)
GB (1) GB1382666A (fr)
IT (1) IT952987B (fr)
NL (1) NL7103724A (fr)
ZA (1) ZA721621B (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2706231A (en) * 1952-12-24 1955-04-12 Alfred W Tyler Apparatus for producing discontinuous conductors
US3401723A (en) * 1966-08-08 1968-09-17 Fabri Tek Inc Needle making method and apparatus
US3431384A (en) * 1965-09-24 1969-03-04 Sperry Rand Corp Means for cutting wire by wire-melting electrical pulses

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2706231A (en) * 1952-12-24 1955-04-12 Alfred W Tyler Apparatus for producing discontinuous conductors
US3431384A (en) * 1965-09-24 1969-03-04 Sperry Rand Corp Means for cutting wire by wire-melting electrical pulses
US3401723A (en) * 1966-08-08 1968-09-17 Fabri Tek Inc Needle making method and apparatus

Also Published As

Publication number Publication date
FR2130308A1 (fr) 1972-11-03
DE2212391A1 (de) 1972-10-05
AT319712B (de) 1975-01-10
NL7103724A (fr) 1972-09-21
GB1382666A (en) 1975-02-05
FR2130308B1 (fr) 1975-10-24
ZA721621B (en) 1972-11-29
CA961376A (en) 1975-01-21
BE780836A (nl) 1972-09-18
IT952987B (it) 1973-07-30

Similar Documents

Publication Publication Date Title
US3684474A (en) Conveying and forming methods and apparatus for fibers having bulbous ends
US2734252A (en) Crimping apparatus
US3160923A (en) Crimping apparatus
US3367261A (en) Apparatus for continuous heat-sealing of thermoplastic sheets
US20080284050A1 (en) Method and Device for Production of Nanofibres Through Electrostatic Spinning of Solutions or Melts of Polymers
IL46879A (en) Method for the manufacture of an electret fibrous filter
ZA8091B (en) Process and apparatus for making an elongate article from electrically conductive powder material
US3772495A (en) Method for manufacturing needles for fibrillating rollers
US2187637A (en) Apparatus for the electrostatic separation of particles having different electrical susceptibilities
US3881346A (en) Process for measuring the modulus of elasticity
US2562358A (en) Apparatus for making sheet or web material
US2418804A (en) Electrical resistor and method of making same
US4081575A (en) Method of flux coating metal wick
US3556758A (en) Method for making an electrolyte guide member
US4337725A (en) Apparatus for coating wires with insulator
US1116951A (en) Process of electrical separation.
JPS58132420A (ja) ワイヤカツト放電加工機におけるワイヤセツト方法及び装置
US2641025A (en) Apparatus and method for drafting fibers
US1734737A (en) Method of and apparatus for coating strand material
US3473196A (en) Apparatus for the transfer and injection molding of synthetic thermosetting and thermoplastic resins
GB837910A (en) Improvements in the continuous spinning of glass or like thermoplastic masses from rods
FR2413765A1 (fr) Procede de reglage de la capacite et du diametre d'un conducteur electrique, et regulateur pour la mise en oeuvre de ce procede
US3158899A (en) Apparatus for continuously producing sheets of thermosetting artificial resins
US3931375A (en) Production of metal powder
US3379808A (en) Method and apparatus for fibrillating synthetic thermoplastic yarn