阅读说明：本技术 台阶辊及数码印花机 (Step roller and digital printing machine ) 是由 岳婷 卢明杰 于 2019-11-07 设计创作，主要内容包括：本发明公开了一种台阶辊及数码印花机,属于数码印花技术领域,目的在于克服现有数码印花机中的光辊容易使喷墨后的喷印介质褶皱的缺陷。台阶辊的表面具有相互间隔的凹面和凸面。本发明所提供的台阶辊及数码印花机,由于台阶辊的表面具有凹凸结构,能够增加和喷印介质的接触面,从而具有舒张喷印介质的作用,能够减少或阻止褶皱的出现。(The invention discloses a step roller and a digital printing machine, belongs to the technical field of digital printing, and aims to overcome the defect that a smooth roller in the conventional digital printing machine is easy to wrinkle a jet printing medium after ink is jetted. The surface of the step roller has a concave surface and a convex surface spaced from each other. According to the step roller and the digital printing machine provided by the invention, as the surface of the step roller is provided with the concave-convex structure, the contact surface with the jet printing medium can be increased, so that the function of relaxing the jet printing medium is achieved, and the wrinkles can be reduced or prevented.)

1. A stepped roller, characterized in that the surface of the stepped roller has a concave surface (100) and a convex surface (200) spaced from each other.

2. Step roll according to claim 1, characterized in that the convexity (200) is 0.1-2.0mm higher than the concavity (200).

3. Step roll according to claim 2, characterized in that the convexity (200) is 0.3, 0.4 or 0.5mm higher than the concavity (100).

4. Stepped roller according to claim 1, characterised in that between the convex (200) and concave (100) surfaces there is a chamfer having the same value as the height of the convex (200) above the concave (100).

5. Stepped roller according to claim 1, characterized in that the convex (200) and concave (100) surfaces are both annular.

6. Stepped roll according to claim 1, characterised in that the width of the raised surface (200) is 5-40 mm.

7. Step roll according to claim 1, characterized in that the width of the concave surface (100) is 10-80mm, the width of the concave surface being 1.5-2.5 times the width of the convex surface.

8. Step roller according to claim 1, characterized in that the diameter of the step roller at the concave surface (100) is 110-130 mm.

9. Step roller according to claim 1, characterized in that both ends of the step roller are provided with a scale (300).

10. Step roller according to claim 9, characterized in that the scale (300) spans 2-7 concave (100) and/or convex (200) surfaces.

11. A digital printing machine comprising a step roller according to any one of claims 1 to 10, characterized by comprising a frame and an inkjet printing zone (17), said step roller (18) being arranged on said frame downstream of said inkjet printing zone (17), said step roller (18) being adjacent to said inkjet printing zone (17).

12. Digital printing machine according to claim 11, characterized in that an electromagnetic brake is arranged between the frame and the step roller (18).

13. The digital printing machine according to claim 11, comprising an unwinding roller (11), a first guide roller (12), a first floating roller (13), a first expanding roller (14), an angle wrapping roller (15), a rubber roller (16), a spray printing area (17), a step roller (18), a second floating roller (19), a second guide roller (20), a second expanding roller (21) and a winding roller (22) in sequence from upstream to downstream, wherein a drying device (23) is arranged below between the second guide roller (20) and the second expanding roller (21).

14. Digital printing machine according to claim 13, characterised in that said first floating roller (13) is a step roller.

15. Digital printing machine according to claim 13, characterised in that between the first dancer (13) and the frame a guide is arranged, in which guide the first dancer (13) can be moved up and down and swung to and from the left and right.

16. The digital printing machine according to claim 15, wherein the guide mechanism comprises a first guide frame (131) and a second guide frame (132), the first guide frame (131) and the second guide frame (132) are provided with guide grooves (133), two ends of the first floating roller (13) are respectively embedded in the guide grooves (133) of the first guide frame (131) and the second guide frame (132), and two side walls of the guide grooves (133) for forming a constraint on the first floating roller (13) are planes.

17. The digital printing machine according to claim 16, wherein the guide groove (133) penetrates upward from the first guide frame (131) and the second guide frame (132) to form a mounting opening, and a cover plate is disposed at the mounting opening.

18. Digital printing machine according to claim 13, characterized in that it comprises a controller and a distance sensor (135) able to detect the position of said first dancer (13), said controller being connected to said distance sensor (135); when the distance sensor (135) detects that the first floating roller (13) is higher than a preset highest position, the controller controls the unwinding roller (11) to accelerate unwinding; when the distance sensor (135) detects that the first floating roller (13) is lower than the preset lowest height, the controller controls the unwinding speed of the unwinding roller (11) to be reduced.

Technical Field

The invention belongs to the technical field of digital printing, and relates to a step roller and a digital printing machine.

Background

Digital printing machine is through spouting the seal with the ink and spout on the seal medium in order to realize the stamp function, spout the seal medium and mainly transmit through the roller, among the current digital printing machine, the ink spouts the seal to spout the back on the seal medium, spout the seal medium and pass through smooth roll transmission, spout the seal medium and just take place the fold easily, especially paper medium, the ink makes the humidity of paper medium increase, and paper medium can produce the certain degree and is the diastole, when the smooth roll, produces the fold very easily.

Disclosure of Invention

The invention provides a step roller and a digital printing machine aiming at the problems in the prior art and aims to overcome the defect that a smooth roller in the prior digital printing machine is easy to wrinkle jet printing media after ink is jetted.

The invention is realized by the following steps:

a stepped roller, characterized in that the surface of the stepped roller has a concave surface and a convex surface spaced from each other.

The partial jet printing medium, especially paper jet printing medium, after the inkjet printing, the jet printing medium can be moistened by ink, the jet printing medium can produce certain diastole, wrinkles can be easily produced directly through the smooth roller, the surface area of the roller on the same length is increased by the arrangement of the concave surface and the convex surface, the jet printing medium which can provide enough contact surface for relaxation can be attached, and the outgoing line of the wrinkle condition of the jet printing medium can be reduced or even avoided.

Preferably, the convex surface is 0.1-2.0mm higher than the concave surface. The different step rollers with different height differences are selected for the different thicknesses of the jet printing medium, and the thicker the jet printing medium is, the larger the height difference between the convex surface and the concave surface is.

Preferably, the convex surface is 0.3, 0.4 or 0.5mm higher than the concave surface. 30-48g of jet printing medium is most commonly used for paper jet printing medium, and a step roller with the height difference of 0.3-0.5mm is optimally adopted for the jet printing medium commonly used in the interval, so that the condition that the jet printing medium is wrinkled due to relaxation is reduced, and meanwhile, the jet printing medium is prevented from generating too deep marks due to the concave and convex of the step roller.

Preferably, a chamfer is arranged between the convex surface and the concave surface, and the chamfer value of the chamfer is the same as the height of the convex surface higher than the concave surface. The chamfer is convenient for the gentle transition of the jet printing medium, and reduces concave-convex traces.

Preferably, the convex and concave surfaces are both annular. After the annular concave-convex surface is transmitted to the jet printing medium, the downstream expanding roller is convenient to expand to two sides.

Preferably, the width of the convex surface is 5-40 mm.

Preferably, the width of the concave surface is 10-80mm, and the width of the concave surface is 1.5-2.5 times of the width of the convex surface. The fold is easily produced to convex surface and concave surface width undersize, and the surface area undersize that increases is then too big, and the multiple relation of convex surface and concave surface width can provide better tension for spouting the seal medium, makes to spout the seal medium more level and smooth.

Preferably, the diameter of the step roller at the concave surface is 60 to 150 mm.

Preferably, the two end parts of the step roller are provided with scales. The scale is helpful for checking the position of the jet printing medium, and is also convenient for a user to judge whether the parameters of the convex surface and the concave surface of the step roller are proper, for example, when the width displayed on the step roller is smaller than the normal width, the height difference between the convex surface and the concave surface of the surface is too large.

Preferably, the scale spans 2-7 concavities and/or convexities.

The digital printing machine comprising the step roller is characterized by comprising a rack and a jet printing area, wherein the step roller is arranged on the rack and positioned at the downstream of the jet printing area, and the step roller is adjacent to the jet printing area. The adjacent means that no other transmission roller is arranged between the step roller and the spray printing area, when the digital printing machine is a conduction band type digital printing machine, the spray printing area is positioned on the conduction band, the step roller is adjacent to the conduction band, namely the next transmission roller is the step roller after the spray printing medium is guided out of the conduction band. The jet printing medium has less folds or no folds on the step roller, so that the smoothness of the jet printing medium on a jet printing area is facilitated, the jet printing is accurately performed, the step roller cannot be replaced by an expanding roller with a soft surface such as a brush roller, the jet printing medium is easy to deviate through the expanding roller with the soft surface, the instability is high, and the jet printing medium is not favorable for accurate jet printing.

Preferably, an electromagnetic brake is disposed between the frame and the step roller. The step roller can better follow the transmission speed of spouting the seal medium like this, avoids spouting the circumstances such as seal medium scram, and the excessive transmission of step roller.

Preferably, the digital printing machine includes unwinding roller, first deflector roll, first floating roll, first expander roll, cornerite roller, rubber roll, spouts seal district, step roller, second floating roll, second deflector roll, second expander roll and wind-up roll in proper order from the upper reaches to low reaches, the second deflector roll with below between the second expander roll sets up drying device. Drying device can adopt double fan circulation drying device, particularly, drying device includes the casing, first fan and second fan are installed respectively to the both ends of casing, the air outlet of first fan and the air intake intercommunication of second fan, the air outlet of second fan and the air intake intercommunication of first fan, the air outlet department of first fan sets up heating device, heating device can be infrared heating or ceramic heating, the wind that first fan blew off heats through heating device and forms hot-blastly, the air intake of second fan is inhaled behind the hot-blast flow-through jet printing medium, the air outlet outflow from the second fan gets into first fan again, realize heated air circulation and utilize, reduce the stoving energy consumption.

Preferably, the first floating roller is a step roller. Can carry out preliminary expanding and location to spouting the seal medium like this, the concave-convex structure on the step roller can avoid spouting seal medium along step roller axial skew, guarantees the stability of first floating roll transmission.

Preferably, a guide mechanism is arranged between the first floating roller and the frame, and the first floating roller can move up and down and swing left and right in the guide mechanism. The first floating roller can swing left and right, usually slightly, and the condition that the tightness of the jet printing media at the two ends of the first floating roller is inconsistent can be avoided.

Preferably, the guide mechanism comprises a first guide frame and a second guide frame, the first guide frame and the second guide frame are respectively provided with a guide groove, two ends of the first floating roller are respectively embedded in the guide grooves of the first guide frame and the second guide frame, and two side walls of the first floating roller, which are restrained by the guide grooves, are planes. The two side walls are planes instead of step surfaces or tooth surfaces, so that the first floating roller can swing left and right conveniently.

Preferably, the guide groove penetrates upwards through the first guide frame and the second guide frame to form a mounting opening, and a cover plate is arranged at the mounting opening. The cover plate can prevent the first floating roller from being separated from the mounting opening, and after the cover plate is disassembled, the first floating roller can be disassembled and assembled from the mounting opening.

Preferably, the digital printing machine comprises a controller and a distance sensor capable of detecting the position of the first floating roller, and the controller is connected with the distance sensor; when the distance sensor detects that the first floating roller is higher than a preset highest position, the controller controls the unwinding roller to accelerate unwinding; when the distance sensor detects that the first floating roller is lower than the preset minimum height, the controller controls the unwinding speed of the unwinding roller to be reduced. This avoids the first dancer roller being too high or too low to lose tension or control the effect of the tension of the print media.

According to the step roller and the digital printing machine provided by the invention, as the surface of the step roller is provided with the concave-convex structure, the contact surface with the jet printing medium can be increased, so that the function of relaxing the jet printing medium is achieved, and the wrinkles can be reduced or prevented.

Drawings

FIG. 1 is a schematic view of a first angular configuration of a step roll;

FIG. 2 is a second angular configuration of the step roll;

FIG. 3 is an enlarged view of portion A of FIG. 2;

FIG. 4 is an enlarged view of portion B of FIG. 2;

FIG. 5 is a schematic structural diagram of a digital printing machine;

FIG. 6 is a schematic structural view of a first dancer assembly;

FIG. 7 is a schematic view of a brush roller configuration;

FIG. 8 is an enlarged view of detail C of FIG. 7;

FIG. 9 is a schematic view of the arrangement of the brush strips on the roller body;

fig. 10 is a schematic view of the structure in which the brush bar is fixed to the brush holder.

Reference is made to the accompanying drawings in which: 100. a concave surface; 200. a convex surface; 300. calibration; 11. unwinding rollers; 12. a first guide roller; 13. a first dancer roll; 14. a first spreader roll; 141. a brush bar; 142. a roller body; 143. a strip-shaped groove; 144. a brush holder; 145. a brush hole; 146. a baffle plate; 147. a deformation hole; 15. a wrap angle roller; 16. a rubber roller; 17. a spray printing area; 18. a step roller; 19. a second dancer roll; 20. a second guide roller; 21. a second spreader roll; 22. a wind-up roll; 23. a drying device; 24. spray printing the medium; 131. a first guide frame; 132. a second guide frame; 133. a guide groove; 134. a mounting frame; 135. a distance sensor.

Detailed Description

The following detailed description of the embodiments of the present invention is provided in connection with the accompanying drawings for the purpose of facilitating understanding and understanding of the technical solutions of the present invention. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment provides a digital printing machine, and the step roller is used on this digital printing machine, spouts the first roller of seal medium inkjet back contact, and digital printing machine includes the frame promptly and spouts the seal district, and the step roller sets up in the frame and lies in the low reaches that spout the seal district, and the step roller is adjacent with spouting the seal district. Other locations for the digital printing machine are not excluded.

Referring to fig. 1-4, the surface of the step roller is provided with a concave surface 100 and a convex surface 200 which are spaced from each other, the concave surface 100 and the convex surface 200 form a concave-convex structure, and compared with a smooth roller with the same size, the concave-convex structure can increase the contact area between the roller and a jet printing medium, so that a spreading effect is formed on the jet printing medium, the generation of wrinkles of the jet printing medium is reduced or even avoided, the step roller is particularly effective for paper jet printing media, and the step roller can also avoid the deviation of the jet printing medium left and right. The difference between the concave surface 100 and the convex surface 200 is formed in a step shape, and is called a step roller.

The height of the convex surface 200 higher than the concave surface 100 is h, h is more than or equal to 0.1 and less than or equal to 2.0mm (millimeter), and h in the embodiment is selected to be 0.3mm, which can be 0.2, 0.4, 0.5, 0.6, 0.7, 1, 1.5 and 2.0 mm. The chamfer is provided between the convex surface 200 and the concave surface 100, and the chamfer value (chamfer value C) of the chamfer is the same as the height of the convex surface 200 above the concave surface 100, i.e. the chamfer value of the chamfer in this embodiment is 0.3 mm.

Convex surface 200 and concave surface 100 may be in the form of a flat spiral. The convex surface 200 and the concave surface 100 of the present embodiment are both ring-shaped, and the convex surface 200 and the concave surface 100 are both integrally formed by a step roller. Alternatively or additionally, a smooth roll may be wound with tape to form a convex surface 200 and an un-taped portion may form a concave surface 100.

The width of the convex surface 200 is w1, w1 is more than or equal to 5 and less than or equal to 40mm, the width of the concave surface 100 is w2, w2 is more than or equal to 10 and less than or equal to 80mm, and the width of the concave surface is 1.5-2.5 times of the width of the convex surface. In the present embodiment, w1 is 20mm, w2 is 40mm, and the width of the concave surface is 2 times of the width of the convex surface, i.e. the space between two adjacent convex surfaces 200 is 40 mm. The diameter of the step roller at the concave surface 100 is 110-130mm, and the diameter of the step roller in the embodiment is 120 mm.

Referring to fig. 1, scales 300 are provided at both ends of the step roller, and the scales 300 facilitate observation of the sizes of the convex surface 200 and the concave surface 100 of the step roller and observation of the spreading condition of the inkjet printing medium. The scale 300 spans 2-7 of the concave surfaces 100 and/or the convex surfaces 200, and in this embodiment, the scale spans 5 of the concave surfaces 100 and the convex surfaces 200.

As shown in fig. 5, the digital printing machine sequentially includes an unwinding roller 11, a first guide roller 12, a first floating roller 13, a first expanding roller 14, a wrap angle roller 15, a rubber roller 16, a spray printing area 17, a step roller 18, a second floating roller 19, a second guide roller 20, a second expanding roller 21 and a winding roller 22 from upstream to downstream, and a drying device 23 is arranged below a space between the second guide roller 20 and the second expanding roller 21. The jet printing medium 24 to be printed is arranged on the unwinding roller 11, the unwinding roller 11 is driven by a motor to discharge, the jet printing medium 24 on the unwinding roller 11 is reduced along with the use of the jet printing medium 24, the inclination angle of the jet printing medium 24 on the feeding side of the first floating roller 13 can be prevented from being changed greatly by the first guide roller 12, and the uniformity of feeding tension is ensured. The first floating roller 13 can tension the printing medium of the first floating roller 13 and the jet printing area 17, so that the jet printing medium 24 can keep flatness after reaching the jet printing area 17, and the printing precision is improved. The first spreader roll 14 can reduce wrinkles of the inkjet media 24 and improve the flatness of the inkjet media 24 entering the inkjet region 17. The angle wrapping roller 15 is inclined backward relative to the rubber roller 16, so that the contact area between the jet printing medium 24 and the rubber roller 16 can be increased, the rubber roller 16 is driven by a motor and is a driving roller, and larger contact area between the rubber roller 16 and the jet printing medium 24 can form larger friction, thereby being beneficial to conveying the jet printing medium 24. The jet printing medium 24 passes through the jet printing area 17, the digital printing machine performs jet printing operation on the jet printing medium 24, the jet printing medium 24 after jet printing is wetted by ink to generate a certain degree of relaxation, and the step roller 18 can reduce or even avoid the condition that the jet printing medium 24 wrinkles due to wetting relaxation. The second floating roller 19 can tension the jet printing medium 24 between the second floating roller 19 and the jet printing area 17, and is beneficial to the flatness of the jet printing medium 24 in the jet printing area 17. The jet printing medium 24 is transmitted between the second guide roller 20 and the second spreading roller 21 and is dried by the drying device 23, the dried jet printing medium 24 can generate certain deformation, the wrinkle condition of the jet printing medium is avoided through the second spreading roller 21, the jet printing medium is finally wound by the winding roller 22, and the winding roller 22 is also driven by a motor and belongs to a driving roller. The second dancer roll 19 is a brush roll having a spreading function, and the first spreading roll 14 and the second spreading roll 21 are also brush rolls.

Further, an electromagnetic brake is provided between the frame and the step roller 18. Therefore, the step roller 18 can better follow the transmission speed of the jet printing medium 24, and the conditions that the jet printing medium 24 stops suddenly and the like and the step roller 18 excessively transmits are avoided. First floating roll 13 adopts the step roller, can carry out preliminary expanding and location to spouting printing medium 24 like this, and the concave-convex structure on the step roller can avoid spouting printing medium 24 along step roller axial skew, guarantees the stability of first floating roll 13 transmission.

As shown in fig. 5 to 6, a guide mechanism is provided between the first dancer 13 and the frame, and the first dancer 13 can move up and down and swing left and right in the guide mechanism. Specifically, the guide mechanism includes a first guide frame 131 and a second guide frame 132, the first guide frame 131 and the second guide frame 132 each have a guide groove 133, both ends of the first dancer roller 13 are respectively embedded in the guide grooves 133 of the first guide frame 131 and the second guide frame 132, and both side walls of the guide groove 133 that form a constraint on the first dancer roller 13 are flat. The both side walls are flat surfaces instead of step surfaces or tooth surfaces to facilitate the side-to-side swinging of the first dancer roller 13. The guide groove 133 is upwardly penetrated through the first guide frame 131 and the second guide frame 132 to form a mounting opening, and a cover plate, not shown in fig. 6, is disposed at the mounting opening and detachably fixed to upper end portions of the first guide frame 131 and the second guide frame 132 by screws. The cover plate can prevent the first floating roller 13 from separating from the mounting opening, and after the cover plate is disassembled, the first floating roller 13 can be disassembled and assembled from the mounting opening. The first guide frame 131 and the second guide frame 132 are provided with reinforcing plates in the guide groove 133, the first guide frame 131 and the second guide frame 132 are made of aluminum materials, and the reinforcing plates can be made of stainless steel or aluminum alloy with high strength, so that the first guide frame 131 and the second guide frame 132 are prevented from being damaged by movement or swinging of the first floating roller 13.

As shown in fig. 6, the digital printing machine includes a controller and a distance sensor 135 capable of detecting the position of the first dancer roller 13, the controller is connected to the distance sensor 135, a mounting bracket 134 is provided at the upper end of the first guide frame 131, and the distance sensor 135 is mounted on the mounting bracket 134; when the distance sensor 135 detects that the first floating roller 13 is higher than the preset highest position, the controller controls the unwinding roller 11 to accelerate the unwinding speed; when the distance sensor 135 detects that the first floating roller 13 is lower than the preset minimum height, the controller controls the unwinding speed of the unwinding roller 11 to be reduced. This avoids the first dancer 13 being too high or too low to lose tension or control the effect of the tension of the print media.

As shown in fig. 7 to 9, the brush roller includes a roller body 142 and a plurality of rows of brush bars 141 provided on the roller body 142. The roller body 142 may be assembled by a plurality of components or may be an integral piece. For example, when the roller body 142 is formed by assembling a plurality of components, the roller body 142 includes a roller and a mandrel, the roller is sleeved outside the mandrel and connected with the mandrel through a bearing, the roller and the mandrel can rotate relatively, and the mandrel is fixed on the frame; when the roller body 142 is formed by assembling a plurality of components, the roller and the mandrel can also be in linkage connection, and the mandrel is rotationally connected with the frame through a bearing, so that the roller and the mandrel can be made of different materials; when the roller 142 is a unitary member, the roller 142 is mounted to the frame by bearings, and the entire roller 142 rotates relative to the frame. Fig. 9 shows 22 rows of brush strips 141 arranged around the roll body 142, which may be 20 rows, 15 rows, 10 rows, 8 rows, etc. The brush strips 141 protrude from the surface of the roller body 142, the single-row brush strips 141 extend axially along the roller body 142, the single-row brush strips 141 are arranged in a manner of inclining from the middle of the roller body 142 to two ends, as shown in fig. 8, the left brush strips 141 incline to the left from the end connected with the roller body 142 to the free end, the right brush strips 141 incline to the right from the end connected with the roller body 142 to the free end, when the print medium 24 is attached to the brush strips 141, the brush strips 141 on two sides further incline to the two sides, so that the print medium 24 expands outwards to eliminate wrinkles, and when the brush strips 141 are separated from the print medium 24, the brush strips 141 recover the preset inclination angle based on self elasticity.

The brush strip 141 may be fixed to the roller 142 by bonding, welding, or the like. The brush strip 141 of the present embodiment is detachably fixed to the roller body 142, and specifically, as shown in fig. 7 to 10, the roller body 142 has a strip groove 143 axially disposed, a brush holder 144 is detachably embedded in the strip groove 143, and the brush strip 141 is fixed to the brush holder 144. Thus, the brush strip 141 can be detachably mounted, the brush strip 141 with different toughness or inclination angle can be replaced according to the material, hardness and other conditions of the jet printing medium 24, and the cleaning and maintenance of the brush strip 141 are facilitated. As shown in fig. 8, the blocking piece 146 is disposed in the middle of the strip-shaped groove 143, the brush strips 141 on both sides of the blocking piece 146 are opposite in inclination direction, and the brush strips 141 inclined to both sides are symmetrically disposed, so that the middle portion is a boundary, and the blocking piece 146 can prevent the brush base 144 from passing through the middle portion boundary when the brush base 144 is inserted, thereby improving the mounting accuracy of the brush base 144 and improving the assembling efficiency.

The cross section of the strip-shaped groove 143 is T-shaped or dovetail-shaped, so that the strip-shaped groove 143 comprises a wide groove and a narrow groove, the shape of the brush seat 144 is matched with the wide groove, and the brush strip 141 penetrates out of the narrow groove; in addition, the shape of the brush holder 144 may match the shape of the entire T-shaped slot. So that the brush holder 144 does not come off the groove 143 from the roller body 142 in the radial direction. As shown in fig. 9, the strip-shaped groove 143 is a T-shaped groove, and the brush holder 144 is inserted into the wide groove and penetrates out of the narrow groove. As shown in fig. 10, the brush holder 144 has a deformation hole 147 axially penetrating the brush holder 144 along the roller body 142. The deformation holes 147 facilitate the brush holder 144 to better contact with the groove wall of the bar-shaped groove 143, so that the brush holder 144 is more stably fixed.

The brush holder 144 is provided with a plurality of brush holes 145 arranged along the axial direction of the roller body 142, and the brush strips 141 are fixed to the brush holes 145. A brush hole 145 may fix a thicker brush bar 141. In this embodiment, as shown in fig. 8 and 10, the brush hole 145 fixes a plurality of brush strips 141 to form a brush cluster, that is, a plurality of brush clusters are disposed on the brush base 144, and a single brush cluster includes a plurality of brush strips 141. The brush cluster can improve the overall toughness of the brush strip 141, and avoid the condition that the single brush strip 141 is easy to bend. The preset included angle between the axes of the brush strip 141 and the roller body 142 is 15-85 degrees, such as 80 degrees, 70 degrees, 60 degrees, 50 degrees, 45 degrees and the like, the included angle is too small to be easily recovered, and the included angle is too large and the spreading effect is poor. The vertical height of the brush strip 141 to the surface of the roller body 142 is 2-10mm, for example, 3mm, 5mm, 6mm, 7mm, etc., and the effect of expanding width is poor when the height is too small, and the height is not easy to recover when the height is too large.