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EP-4547900-B1 - METHOD OF FORMING REELS AND RELATIVE ROVING FRAME

EP4547900B1EP 4547900 B1EP4547900 B1EP 4547900B1EP-4547900-B1

Inventors

  • Assenza, Rosario
  • Raccagni, Daniele
  • Sangaletti, Pietro

Dates

Publication Date
20260513
Application Date
20230620

Claims (12)

  1. A method of forming reels on a roving frame (1) for processing a fiber web and forming a roving wound on reels, said roving frame being provided with a drawing device (10) of the fiber web for forming the roving and a flyer-spindle unit for winding said roving into reels, wherein the method provides applying, to the fibers exiting the drawing device (10) and entering the flyer-spindle unit, an initial torsion (Ti) at the start of reel forming and a final torsion (Tf) at the end of reel forming, characterized in that it passes from the initial torsion (Ti) to the final torsion (Tf) while providing at least one step of increasing the torsion.
  2. A method of forming reels according to claim 1, wherein there is provided to increase said initial torsion (Ti) in reel forming step up to reaching a final torsion (Tf) at reel forming ending which is greater than the initial torsion (Ti).
  3. A method of forming reels according to claim 1 or 2, wherein said flyer-spindle unit has a unit rotation speed and the drawing device (10) has a drawing speed, and wherein the increase of the initial torsion (Ti) is obtained by increasing the flyer-spindle unit rotation speed with respect to the drawing speed.
  4. A method of forming reels according to claim 3, wherein the increase of the initial torsion (Ti) is obtained by increasing the flyer-spindle unit rotation speed while keeping unaltered the drawing speed.
  5. A method of forming reels according to any one of the preceding claims, wherein said flyer-spindle unit comprises a flap (30) having a flat rotation speed and a spindle (40) having a spindle rotation speed, and the increase of the initial torsion (Ti) is obtained by increasing the flap rotation speed while keeping unaltered the flap rotation speed and spindle rotation speed ratio.
  6. A method of forming reels according to any one of the preceding claims, wherein said initial torsion (Ti) is increased by 10%, preferably by 5%, even more preferably by 3%.
  7. A method of forming reels according to any one of the preceding claims, wherein said initial torsion (Ti) increases in a linear manner.
  8. A method of forming reels according to any one of claims 1 to 6, wherein said initial torsion (Ti) remains constant up to a torsion raising point (P) at which it is directly increased to reach the final torsion (Tf).
  9. A method of forming reels according to claim 8, wherein said torsion raising point (P) is provided in the final reel forming step.
  10. A method of forming reels according to claim 9, wherein said torsion raising point (P) is provided at between 60% and 70% of the reel forming step.
  11. A method of forming reels according to any one of claims 1 to 6, wherein said initial torsion (Ti) has at least one torsion raising point (P) at which it increases.
  12. A roving frame (1) for processing a fiber web and forming a roving wound on reels, comprising: - a drawing device (10) of the fiber web for forming the roving; - a flyer-spindle unit for winding said roving into reels; - characterized by management means adapted to control a torsion of the fibers exiting the drawing device (10) and entering the flyer-spindle unit according to the reel forming method according to any one of the preceding claims.

Description

The present invention relates to the sector of textile machines for the transformation of ball fiber into a yarn wound on reels. In a roving frame, the fiber web obtained from the roving or combing and deposited in cans, is drawn using a drawing device thereby obtaining a roving. In a reel forming device downstream of the drawing device, the roving is wound around small tubes thereby obtaining reels of roving to be sent to the spinning machine. The drawing that occurs in the roving frame is highly driven, so that the velocity of the roving downstream of the drawing device is extremely elevated. Furthermore, the roving is subject to oscillations between the drawing device and the device that forms the reels, and is therefore subject to possible breakages. In particular, it is noted that the greatest number of roving breakages occur during the final step of forming the reels. It is evident that the roving breakage, during the step of winding the reel results in a machine stoppage and a consequent slowdown in production. Today, in order to reduce the number of breakages, action is taken in reducing the roving frame production velocity, thereby accepting a certain slowdown in production. Patent document JP S62 85037 A discloses a method of forming reels on a roving frame according to the preamble of claim 1 and a corresponding roving frame according to the preamble of claim 12. The object of the present invention is that of providing a method of forming reels and a relative roving frame that reduces roving breakages during the step of winding the reel without compromising the roving frame production velocity. This object is achieved by a method of forming reels according to claim 1 and a relative roving frame according to claim 12. The dependent claims describe additional advantageous embodiments. The features and advantages of the method and of the roving frame according to this invention will be apparent from the description below, given by way of non-limiting example, according to the figures in the accompanying drawings, wherein: Figure 1 shows a roving frame according to a preferred embodiment of the present invention;Figure 2 shows an enlargement of the roving frame of Figure 1 highlighting the perforated platform wherethrough the rovings exiting the drawing device move from the upper area to the lower area of the roving frame;Figure 3 shows a schematic cross-section view of a portion of the roving frame of Figure 1 highlighting the perforated platform wherethrough the rovings exiting the drawing device move from the upper area to the lower area of the roving frame;the Figures from 4 to 7 show a control scheme for the roving torsion parameter as a function of the reel forming percentage, in various embodiments. With reference to the figures in the attached drawings, the numeral 1 has been used overall to indicate a roving frame of a spinning line. Typically, upstream of the roving frame 1, a drawframe is arranged that produces a drawn fiber web that is then fed to the roving frame 1. Said frame 1 processes the web and produces a roving that is wound onto appropriate small tubes in order to form reels that are intended to be transported to a spinning machine, downstream of the roving frame 1, for further processing. The roving frame 1 has a storage region 200 located to the rear of the body of the machine 2. The web, as provided by the drawer, wound and conserved in cans 4, is deposited within the storage region 200. Also arranged within said storage region 200 is a creel 6 consisting of a frame provided with rollers 8 having a prevalent extension along a longitudinal direction X, generally having a hexagonal section and typically being motorized, arranged above the cans 4. The web supplied from the cans 4 is located above the rollers 8 and fed to the roving frame 1. The roving frame 1 comprises a machine body 2 that supports a drawing device 10. The drawing device 10 is formed from pairs of superimposed drawing rollers 11, engaged under pressure and having peripheral speeds of rotation that increase from upstream to downstream, so as to progressively draw the web that passes between the coupled drawing rollers 11. In particular, the drawing device 10 comprises motorized lower rollers 111, for example in the number of three or four, wherein each thereof extends in the longitudinal direction X along the frame 1. Each lower roller cooperates with a plurality of separate upper, idling rollers 112, generally supported, in pairs, by pressure arms 113. Preferably, the pressure arms 113 are pushed pneumatically so as to ensure the pressure coupling between the lower roller 111 and the upper rollers 112. In one embodiment, the drawing device 10 is provided with a support band that is in contact with at least one drawing roller 11 in order to guide the rotation thereof. The drawing device 10 processes the fiber web and produces a roving that must subsequently be wound onto appropriate small tubes for reel forming.