Uniform forming method and forming equipment for surface layer vacuum panel

Abstract

The invention discloses a surface layer vacuum panel uniform forming method and forming equipment thereof. The method comprises the steps that 1, paper pulp flows to a forming net through a pulp flowing box; 2, the paper pulp passes through a first water scraping and dewatering part to be greatly dewatered, and pulp flow is stabilized; 3, the paper pulp passes through a second water scraping and dewatering part; 4, the paper pulp passes through a passive negative pressure dehydration part; 5, the paper pulp passes through a first active negative pressure dehydration part and a second active negative pressure dehydration part; 6, the paper pulp passes through a vacuum dewatering part along with the forming net. A step-by-step dewatering gradient is formed through the first water scraping and dewatering part, the second water scraping and dewatering part, the passive negative pressure dewatering part, the first active negative pressure dewatering part, the second active negative pressure dewatering part and the vacuum dewatering part and corresponds to the water content and the flowing state when upper paper pulp passes through, so that efficient dewatering is effectively achieved, the evenness of a surface layer of the dewatered paper pulp is high, and the quality of the paper pulp is improved. The product quality is improved.

Description

Technical Field

[0001] The invention relates to the field of papermaking, and in particular to a method for uniformly forming a surface layer vacuum panel and a forming device thereof. Background Art

[0002] With the improvement of people's living standards, people's requirements for product packaging are getting higher and higher. Now people not only require strong packaging, but also print relevant information of various contents and some exquisite pictures on the outer packaging. Uniformly formed paper often brings better printing and appearance effects, and the strength index of paper will also be more uniform, and the performance will be better. However, the paper produced by existing equipment is not uniform enough. The lateral deviation of the paper weight reaches 2.5g / m2, and the longitudinal deviation of the paper weight reaches 3.0g / m2. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide a method for uniformly forming a surface vacuum panel and a forming device thereof, so as to solve the above-mentioned problems.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a method for uniformly forming a surface layer vacuum panel, step S01: introducing pulp into the interior of a headbox, and evenly distributing the pulp onto a forming wire after passing through the headbox;

[0005] Step S02: The pulp moves along the forming wire and passes through the first scraper and dewatering section at the bottom of the forming wire. The angle of the top panel of the first scraper and dewatering section is set to 0°, which greatly dewaters the pulp and stabilizes the pulp flow.

[0006] Step S03: The pulp passes through the second scraping and dewatering section along with the forming wire. The angle of the top panel of the second scraping and dewatering section is set between 0.5° and 5° to facilitate dewatering and generate turbulence in the pulp, thereby increasing the dewatering amount and preventing the fibers from re-flocculating.

[0007] Step S04: The pulp passes through the passive negative pressure dewatering section along with the forming wire. A slow flow pipe is provided at the bottom of the passive negative pressure dewatering section. The bottom of the slow flow pipe extends into the water. When the water flows down the slow flow pipe, negative pressure is generated inside the passive negative pressure dewatering section, thereby achieving passive negative pressure dewatering.

[0008] Step S05: The pulp passes through the first active negative pressure dewatering section and the second active negative pressure dewatering section along with the forming wire. The interiors of the first active negative pressure dewatering section and the second active negative pressure dewatering section are respectively connected to a first vacuum pumping assembly with low negative pressure. A slow flow pipe is provided at the bottom of the first active negative pressure dewatering section and the second active negative pressure dewatering section. The slow flow pipe and the first vacuum pumping assembly increase the negative pressure suction force.

[0009] Step S06: The pulp passes through the vacuum dehydration section along with the forming wire. The interior of the vacuum dehydration section is connected to a second vacuum pumping component with high negative pressure, which is used for terminal vacuum negative pressure forced dehydration to improve the dehydration degree.

[0010] Furthermore, in step S04, the angle of the top panel of the passive negative pressure dewatering section is set to be between 0.5° and 5°, so that the speed of the pulp passing through is slowed down and the negative pressure is increased.

[0011] Furthermore, in step S05, the angle of the top panel of the first active negative pressure dehydration section is set to between 0.5° and 2°, and the angle of the top panel of the second active negative pressure dehydration section is set to between 0.1° and 1°.

[0012] Furthermore, in step S04, the vacuum degree inside the passive negative pressure dehydration part is 200~500Pa, in step S05, the vacuum degree generated by the first vacuum pumping component is 10~30KPa; in step S06, the vacuum degree generated by the second vacuum pumping component is 20~40KPa.

[0013] Also provided is a surface layer vacuum panel uniform forming equipment, including a forming net, a guide roller, a breast roller, a flow box, a first scraping and dewatering component, a second scraping and dewatering component, a passive negative pressure dewatering component, a first active negative pressure dewatering component, a second active negative pressure dewatering component, a vacuum dewatering component and a water receiving basin; the breast rollers in pairs are arranged above several guide rollers, the forming net is wound around the breast rollers and the guide rollers, the flow box is located above the breast rollers and the bottom is close to the forming net; the bottom of the forming net between the breast rollers is sequentially provided with a first scraping and dewatering component, a second scraping and dewatering component, a passive negative pressure dewatering component, a first active negative pressure dewatering component, a second active negative pressure dewatering component and a vacuum dewatering component along the forward direction of the forming net; the water receiving basin is arranged below the two breast rollers; the first active negative pressure dewatering component and the second active negative pressure dewatering part are internally connected to the first vacuum pumping component, and the vacuum dewatering component is internally connected to the second vacuum pumping component.

[0014] Furthermore, the first wiper and dehydration assembly, the second wiper and dehydration assembly, the passive negative pressure dehydration assembly, the first active negative pressure dehydration assembly, the second active negative pressure dehydration assembly and the vacuum dehydration assembly all include a dehydration box, a dehydration panel arranged on the top, a plurality of wiper strips arranged at intervals on the surface of the dehydration panel, a support plate arranged inside the dehydration box, a plurality of threaded columns passing through the support plate, and a height adjustment nut arranged on the threaded column.

[0015] Furthermore, a forming plate is provided on a side of the dewatering panel of the first scraping and dewatering assembly close to the headbox.

[0016] Furthermore, the dehydration boxes of the passive negative pressure dehydration component, the first active negative pressure dehydration component and the second active negative pressure dehydration component are all provided with a slow flow pipe, the bottom of the slow flow pipe extends outward through the dehydration box, and an overflow cover is provided at the bottom of the slow flow pipe, and the bottom of the slow flow pipe extends into the water surface below the internal part of the overflow cover.

[0017] Furthermore, the vacuum degree of the second vacuum pumping component is greater than the vacuum degree of the first vacuum pumping component.

[0018] Furthermore, the forming plate is tilted at -1°, the dehydration panel of the first wiper and dehydration component is tilted at 0°, the dehydration panel of the second wiper and dehydration component is tilted at 1°, the dehydration panel of the passive negative pressure dehydration component is tilted at 2°, the dehydration panel of the first active negative pressure dehydration component is tilted at 1°, the dehydration panel of the second active negative pressure dehydration component is tilted at 1°, and the dehydration panel of the vacuum dehydration component is tilted at 0°.

[0019] The technical effect of the present invention is mainly reflected in: a step-by-step dehydration gradient is formed through the first scraping and dehydrating section, the second scraping and dehydrating section, the passive negative pressure dehydrating section, the first active negative pressure dehydrating section, the second active negative pressure dehydrating section, and the vacuum dehydrating section, corresponding to the moisture content and flow state of the pulp when passing through, thereby effectively achieving efficient dehydration and making the surface layer of the dehydrated pulp highly uniform; the lateral deviation of the paper basis weight is reduced by 2.5g / m 2 Reduced to 1.5g / m 2 , the longitudinal deviation of the paper weight is 3.0g / m 2 Reduced to 2.0g / m 2 ; The paper is formed more evenly, improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the method of the present invention;

[0021] Figure 2 It is a structural diagram of the device of the present invention;

[0022] Figure 3 for Figure 2 Partial enlarged image.

[0023] The figures are marked as follows: 11-forming mesh, 12-guide roller, 13-breast roller, 2-heading box, 3-first wiper and dewatering assembly, 31-dewatering box, 32-dewatering panel, 33-wiping bar, 34-support plate, 35-threaded column, 36-height adjustment nut, 37-forming plate, 4-second wiper and dewatering assembly, 5-passive negative pressure dewatering assembly, 51-slow flow pipe, 52-overflow cover, 6-first active negative pressure dewatering assembly, 61-first vacuum pumping assembly, 7-second active negative pressure dewatering assembly, 8-vacuum dewatering assembly 81-second vacuum pumping assembly, 9-water receiving basin. DETAILED DESCRIPTION

[0024] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings to make the technical solutions of the present invention easier to understand and grasp.

[0025] In this embodiment, it should be understood that the terms "middle", "upper", "lower", "top", "right", "left end", "above", "back", "middle", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0026] In addition, in this specific embodiment, if the connection or fixing method between components is not specifically described, the connection or fixing method can be through bolt fixing or pin fixing, or pin shaft connection, etc. commonly used in the prior art, so it will not be described in detail in this embodiment.

[0027] The present invention provides a method for uniformly forming a surface layer vacuum panel. Figure 1 As shown, step S01: pulp is introduced into the interior of the headbox, and the pulp is evenly distributed onto the forming wire after passing through the headbox;

[0028] Step S02: The pulp moves along the forming wire and passes through the first scraper and dewatering section at the bottom of the forming wire. The angle of the top panel of the first scraper and dewatering section is set to 0°, so that the first scraper and dewatering section is used to scrape the bottom of the forming wire, thereby achieving significant dewatering. The angle of the top panel of the first scraper and dewatering section is set to 0°, thereby stabilizing the pulp flow and preventing excessive pulp flow ripples.

[0029] Step S03: The pulp passes through the second scraping and dewatering section along with the forming wire. The angle of the top panel of the second scraping and dewatering section is set between 0.5° and 5° to facilitate dewatering and generate turbulence in the pulp, thereby increasing the dewatering amount and preventing the fibers from re-flocculating.

[0030] Step S04: The pulp passes through the passive negative pressure dewatering section along with the forming wire. A slow flow pipe is provided at the bottom of the passive negative pressure dewatering section. The bottom of the slow flow pipe is immersed in water, so that there is no air in the slow flow pipe, making the slow flow pipe function as a communicating vessel. When the water flows down the slow flow pipe, negative pressure is generated inside the passive negative pressure dewatering section, thereby achieving passive negative pressure dewatering.

[0031] Step S05: The pulp passes through the first active negative pressure dewatering section and the second active negative pressure dewatering section along with the forming wire. The interiors of the first active negative pressure dewatering section and the second active negative pressure dewatering section are respectively connected to the first vacuum pumping assembly with low negative pressure. The bottoms of the first active negative pressure dewatering section and the second active negative pressure dewatering section are provided with slow flow pipes. At this time, the moisture content of the pulp has been greatly reduced. It is necessary to increase the negative pressure suction force through the slow flow pipe and the first vacuum pumping assembly to enhance the dewatering effect.

[0032] Step S06: The pulp passes through the vacuum dehydration section along with the forming wire. The interior of the vacuum dehydration section is connected to a second vacuum pumping component with high negative pressure, which is used for terminal vacuum negative pressure forced dehydration to improve the dehydration degree.

[0033] Furthermore, in step S04, the angle of the top panel of the passive negative pressure dewatering section is set to be between 0.5° and 5°, so that the speed of the pulp passing through is slowed down and the negative pressure is increased.

[0034] Furthermore, in step S05, the top panel angle of the first active negative pressure dehydration section is set to between 0.5° and 2°, and the top panel angle of the second active negative pressure dehydration section is set to between 0.1° and 1°, so that the slope between the first active negative pressure dehydration section and the second active negative pressure dehydration section becomes gentler, thereby maintaining smooth and uniform dehydration of the pulp and improving the uniformity of the pulp.

[0035] Furthermore, in step S04, the vacuum degree inside the passive negative pressure dehydration part is 200~500Pa, in step S05, the vacuum degree generated by the first vacuum pumping component is 10~30KPa; in step S06, the vacuum degree generated by the second vacuum pumping component is 20~40KPa.

[0036] The present invention also provides a surface layer vacuum panel uniform forming device, such as Figure 2-3As shown, it includes a forming wire 11, a guide roller 12, a breast roller 13, a headbox 2, a first scraping and dewatering component 3, a second scraping and dewatering component 4, a passive negative pressure dewatering component 5, a first active negative pressure dewatering component 6, a second active negative pressure dewatering component 7, a vacuum dewatering component 8 and a water receiving basin 9; the breast rollers 13 in pairs are arranged above a number of guide rollers 12, the forming wire 11 is wound around the breast rollers 13 and the guide rollers 12, the headbox 2 is located above the breast rollers 13 and the bottom is close to the forming wire 11; the bottom of the forming wire 11 between the breast rollers 13 is sequentially provided with the first scraping and dewatering component 3, the second scraping and dewatering component 4, the passive negative pressure dewatering component 5, the first active negative pressure dewatering component 6, the second active negative pressure dewatering component 7, the vacuum dewatering component 8 and the water receiving basin 9. Water component 6, second active negative pressure dehydration component 7 and vacuum dehydration component 8; the water receiving basin 9 is arranged below the two breast rollers 13; the first active negative pressure dehydration component 6 and the second active negative pressure dehydration part are internally connected with the first vacuum component 61, and the vacuum dehydration component 8 is internally connected with the second vacuum component, through the first wiper dehydration component 3, the second wiper dehydration component 4, the passive negative pressure dehydration component 5, the first active negative pressure dehydration component 6, the second active negative pressure dehydration component 7, and the vacuum dehydration component 8 to form a step-by-step dehydration gradient, corresponding to the moisture content and flow state of the pulp when it passes through, thereby effectively achieving efficient dehydration and making the surface uniformity of the dehydrated pulp high; wherein the lateral deviation of the paper basis weight is 2.5g / m 2 Reduced to 1.5g / m 2 , the longitudinal deviation of the paper weight is 3.0g / m 2 Reduced to 2.0g / m 2 ; The paper is formed more evenly, improving product quality.

[0037] Furthermore, the first wiper and dehydration component 3, the second wiper and dehydration component 4, the passive negative pressure dehydration component 5, the first active negative pressure dehydration component 6, the second active negative pressure dehydration component 7 and the vacuum dehydration component 8 all include a dehydration box 31, a dehydration panel 32 arranged on the top, a plurality of wiper strips 33 arranged at intervals on the surface of the dehydration panel 32, a support plate 34 arranged inside the dehydration box 31, a plurality of threaded columns 35 passing through the support plate 34, and a height adjustment nut 36 arranged on the threaded column 35. By adjusting the height adjustment screw, the height of the dehydration box 31 and the dehydration panel 32 can be adjusted, so that they are closer to the forming net 11 and generate downward pressure on the forming net 11, which is conducive to improving and maintaining the vacuum degree.

[0038] Furthermore, a forming plate 37 is provided on the side of the dewatering panel 32 of the first scraping and dewatering assembly 3 close to the headbox 2 for receiving the pulp just flowing out of the headbox 2 to slow down the flow rate of the pulp.

[0039] Furthermore, the dewatering box 31 of the passive negative pressure dewatering component 5, the first active negative pressure dewatering component 6 and the second active negative pressure dewatering component 7 are all provided with a slow flow pipe 51. The bottom of the slow flow pipe 51 extends outward through the dewatering box 31. The bottom of the slow flow pipe 51 is provided with an overflow cover 52. The bottom of the slow flow pipe 51 extends into the water surface below the overflow cover 52, so that the slow flow pipe 51 and the overflow cover 52 form a communicating vessel. There is no air in the slow flow pipe 51. When the water in the slow flow pipe 51 overflows from the overflow cover 52, negative pressure is formed inside the dewatering box 31 and more water is negatively adsorbed from the pulp, thereby realizing negative pressure dewatering.

[0040] Furthermore, the vacuum degree of the second vacuum pumping component 81 is greater than the vacuum degree of the first vacuum pumping component 61 .

[0041] Furthermore, the forming plate 37 is tilted at -1°, the dehydration panel 32 of the first wiper and dehydration component 3 is tilted at 0°, the dehydration panel 32 of the second wiper and dehydration component 4 is tilted at 1°, the dehydration panel 32 of the passive negative pressure dehydration component 5 is tilted at 2°, the dehydration panel 32 of the first active negative pressure dehydration component 6 is tilted at 1°, the dehydration panel 32 of the second active negative pressure dehydration component 7 is tilted at 1°, and the dehydration panel 32 of the vacuum dehydration component 8 is tilted at 0°.

[0042] The technical effect of the present invention is mainly reflected in: a step-by-step dehydration gradient is formed through the first scraping and dehydrating section, the second scraping and dehydrating section, the passive negative pressure dehydrating section, the first active negative pressure dehydrating section, the second active negative pressure dehydrating section, and the vacuum dehydrating section, corresponding to the moisture content and flow state of the pulp when passing through, thereby effectively achieving efficient dehydration and making the surface layer of the dehydrated pulp highly uniform; the lateral deviation of the paper basis weight is reduced by 2.5g / m 2 Reduced to 1.5g / m 2 , the longitudinal deviation of the paper weight is 3.0g / m 2 Reduced to 2.0g / m 2 ; The paper is formed more evenly, improving product quality.

[0043] Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementation methods. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A method for uniformly forming a surface vacuum panel, characterized in that: The following steps are involved: Step S01: Pulp is introduced into the headbox, and the pulp is evenly distributed onto the forming wire after passing through the headbox; Step S02: The pulp moves along the forming wire and passes through the first scraper and dewatering section at the bottom of the forming wire. The angle of the top panel of the first scraper and dewatering section is set to 0°, which greatly dewaters the pulp and stabilizes the pulp flow. Step S03: The pulp passes through the second scraping and dewatering section along with the forming wire. The angle of the top panel of the second scraping and dewatering section is set between 0.5° and 5° to facilitate dewatering and generate turbulence in the pulp, thereby increasing the dewatering amount and preventing the fibers from re-flocculating. Step S04: The pulp passes through the passive negative pressure dewatering section along with the forming wire. A slow flow pipe is provided at the bottom of the passive negative pressure dewatering section. The bottom of the slow flow pipe extends into the water. When the water flows down the slow flow pipe, negative pressure is generated inside the passive negative pressure dewatering section, thereby achieving passive negative pressure dewatering. Step S05: The pulp passes through the first active negative pressure dewatering section and the second active negative pressure dewatering section along with the forming wire. The interiors of the first active negative pressure dewatering section and the second active negative pressure dewatering section are respectively connected to a first vacuum pumping assembly with low negative pressure. A slow flow pipe is provided at the bottom of the first active negative pressure dewatering section and the second active negative pressure dewatering section. The slow flow pipe and the first vacuum pumping assembly increase the negative pressure suction force. Step S06: The pulp passes through the vacuum dehydration section along with the forming wire. The interior of the vacuum dehydration section is connected to a second vacuum pumping component with high negative pressure, which is used for terminal vacuum negative pressure forced dehydration to improve the dehydration degree.

2. A method for uniformly forming a surface vacuum panel according to claim 1, characterized in that: In step S04, the angle of the top panel of the passive negative pressure dewatering section is set to be between 0.5° and 5°, so that the speed of the pulp passing through is slowed down and the negative pressure is increased.

3. A method for uniformly forming a surface vacuum panel according to claim 1, characterized in that: In step S05 , the angle of the top panel of the first active negative pressure dehydration section is set to between 0.5° and 2°, and the angle of the top panel of the second active negative pressure dehydration section is set to between 0.1° and 1°.

4. A method for uniformly forming a surface vacuum panel according to claim 1, characterized in that: In step S04, the vacuum degree inside the passive negative pressure dehydration part is 200-500 Pa, in step S05, the vacuum degree generated by the first vacuum pumping component is 10-30 KPa; in step S06, the vacuum degree generated by the second vacuum pumping component is 20-40 KPa.

5. A surface layer vacuum panel uniform forming device using the surface layer vacuum panel uniform forming method according to claim 1, characterized in that: The invention comprises a forming wire, a guide roller, a breast roller, a headbox, a first scraping and dewatering component, a second scraping and dewatering component, a passive negative pressure dewatering component, a first active negative pressure dewatering component, a second active negative pressure dewatering component, a vacuum dewatering component and a water receiving basin; the breast rollers are arranged in pairs above a plurality of guide rollers, the forming wire is wound around the breast rollers and the guide rollers, the headbox is located above the breast rollers and its bottom is close to the forming wire; The bottom of the forming net between the breast rollers is provided with a first water wiping and dehydration component, a second water wiping and dehydration component, a passive negative pressure dehydration component, a first active negative pressure dehydration component, a second active negative pressure dehydration component and a vacuum dehydration component in sequence along the forward direction of the forming net; the water receiving basin is arranged below the two breast rollers; the interiors of the first active negative pressure dehydration component and the second active negative pressure dehydration component are connected to a first vacuum pumping component, and the interior of the vacuum dehydration component is connected to a second vacuum pumping component.

6. The surface layer vacuum panel uniform forming equipment according to claim 5, characterized in that: The first wiper and dehydration component, the second wiper and dehydration component, the passive negative pressure dehydration component, the first active negative pressure dehydration component, the second active negative pressure dehydration component and the vacuum dehydration component all include a dehydration box, a dehydration panel arranged on the top, a plurality of wiper strips arranged at intervals on the surface of the dehydration panel, a support plate arranged inside the dehydration box, a plurality of threaded columns passing through the support plate, and a height adjustment nut arranged on the threaded column.

7. The surface layer vacuum panel uniform forming equipment according to claim 6, characterized in that: A shaping plate is further provided on one side of the dewatering panel of the first scraping and dewatering assembly close to the headbox.

8. The surface layer vacuum panel uniform forming device according to claim 5, characterized in that: The dehydration boxes of the passive negative pressure dehydration component, the first active negative pressure dehydration component and the second active negative pressure dehydration component are all provided with a slow flow pipe, the bottom of the slow flow pipe extends outward through the dehydration box, and an overflow cover is provided at the bottom of the slow flow pipe, and the bottom of the slow flow pipe extends into the water surface below the internal part of the overflow cover.

9. The surface layer vacuum panel uniform forming device according to claim 5, characterized in that: It is characterized by: The vacuum degree of the second vacuum pumping component is greater than the vacuum degree of the first vacuum pumping component.

10. The surface layer vacuum panel uniform forming device according to claim 7, characterized in that: The forming plate is tilted at -1°, the dehydration panel of the first wiper and dehydration component is tilted at 0°, the dehydration panel of the second wiper and dehydration component is tilted at 1°, the dehydration panel of the passive negative pressure dehydration component is tilted at 2°, the dehydration panel of the first active negative pressure dehydration component is tilted at 1°, the dehydration panel of the second active negative pressure dehydration component is tilted at 1°, and the dehydration panel of the vacuum dehydration component is tilted at 0°.

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