FI112268B - Apparatus and method for making tissue paper - Google Patents

Description

112268

Apparatus and Method for Making Tissue Paper 5

The present invention relates to a tissue paper manufacturing apparatus for producing tissue paper from pulp. More particularly, the present invention is directed to a tissue paper manufacturing apparatus which includes a Yankee dryer.

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In the manufacture of tissue paper, the web is usually formed by injecting pulp from the headbox onto a forming wire. The formed wire is then subjected to a pressing operation to remove at least part of the water from the formed web.

The partially dried web is then guided around the heated surface of the Yankee dryer. The Yankee dryer is mainly a rotatable cylinder with a diameter of about 25 »· *, * 20 feet (about 7.62 m). The cylinder is connected to a source of superheated steam from the heated cylinder ♦ »> ·! ! the web guided around the peripheral surface dries.

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The dried web is then scraped off the surface of the cylinder * * · 25 and rolled up. To aid drying of the wire around the Yankee dryer, at least part of the circumferential, * ··, surface of the cylinder is covered with a hood. From these hoods, hot air is applied to the surface of the web to improve the drying process of the web.

By using through-drying means which include blowing hot air through the formed web, the present invention avoids the need for an expensive press member for initial drying of web 112268.

Not only does the omission of the press portion significantly reduce the total cost of the tissue paper machine installation, the above-mentioned drying or air blowing system according to the present invention also significantly increases the speed at which the tissue paper can be produced.

10 U.S. Patent 4,036,684, British Patent 1,600,518 and British Patent Application 2,0001,370 do not disclose a transfer felt for transferring a nipple web from a former to a dryer felt.

Furthermore, thanks to the aforementioned air drying means, the diameter of the subsequent Yankee dryer can be made much smaller than the diameter of a normally installed Yankee dryer. Not only does the reduction in diameter reduce the resulting tissue paper making device. . overall height, it also avoids problems that »· ·

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20 occur when transporting known large diameter Yankee dryers * »· * 1 hour to the installation site.

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Thus, it is a primary object of the present invention to overcome the aforementioned drawbacks of known tissue paper machines and to provide tissue paper manufacturing; V, a device which represents a remarkable and substantially new * ». ·· 1, an advance in the technology of making tissue paper.

* »I» · »! t i !!! It is an object of the present invention to provide a tissue paper making machine which can operate at a substantially higher speed than the tissue paper machines available hitherto.

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Another object of the present invention is to provide a tissue paper making device which avoids the need for a press section.

It is an object of the present invention to provide a tissue paper making device in which the diameter of the Yankee dryer is substantially smaller than the diameter of the Yankee dryer installed on known machines.

Other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and the accompanying drawings. The invention is better explained in the appended claims.

The present invention relates to a tissue paper making apparatus and to a process for making tissue paper from a pulp. The apparatus includes a mold for forming a wet nipple web from the pulp. Immediately downstream of the Former are air-drying means for drying the wet distillate. With regard to drying equipment, a Yankee dryer is placed underneath the HV dryer! I complete it.

· · * !!! In a more detailed embodiment of the present invention, the former includes first and second loop-two closed forming wires which cooperate with a forming part having a first and a second end. Near the first end of the forming member * · * is a headbox for injecting mass into the forming | 'I' 30 through its first end.

The molder also includes a forming roll which cooperates with the second wire so that the second wire is between the first wire and the forming roll as the second wire passes through the forming part. The forming roll is preferably an open roll.

5 The headbox includes a plurality of hetula elements to attenuate the turbulence of the mass as the mass passes through the headbox.

The tissue paper making machine also includes transfer webs for transferring a wet pile web from another forming wire to air drying means.

More specifically, the transfer means comprise a looped transfer felt and a plurality of guide rollers disposed within the looped transfer felt to guide the transfer felt. The guide rolls include a suction roll located near the second forming wire with the transfer felt between the second forming wire and the suction roll. The arrangement is such that, when the suction roll is connected to an underpressure source, the wet nipple web is transferred from another forming / t: 20 weave to a transfer felt. A downstream guide roll is disposed near the air drying means such that, * wet nipple web is between the transfer felt and air drying means * · · • 1 · * "/ so that the wet nipple web moves from the transfer felt to the air drying means.

'' 25 y · 'Air drying means includes a looped dry, ··· men blanket to support the wet nipple between the former and the Yankee dryer. Looped Dryer Felt ;;; a set of support rollers is inserted inside to support the dryer '1 * 30 felts. The support rollers are positioned such that the dryer felt forms an upwardly curved surface for carrying a wet breast web. The curved surface cooperates with the hot air blowing means so that the wet nipple web supported by the felt of the dryer 112268 5 is between the curved surface and the air blowing means. The arrangement is such that, when the blowing means are connected to a source of hot compressed air, this air is blown onto the wet 5 nipple web and through the dryer felt to dry the nipple web.

The air drying means further includes vacuum means located near the curved surface. The vacuum means is positioned relative to the air blowing means on the opposite side of the dryer blanket so that when the vacuum means is combined with the vacuum source, it enhances the flow of hot air from the blowing means through the wet nipple web and the dryer blanket.

15 The looped dryer felt is made from materials that can withstand high temperatures. Further, the hot air blowing means is disposed above the curved surface and the air drying means includes lifting means coupled to the air blowing means for lifting the air blowing means from the curved surface to facilitate the removal of heat in case the web breaks.

In a particular embodiment of the present invention, a source of hot compressed air supplies air having a temperature in the range of from 500 ° to 800 ° F (about 260 ° to 427 ° C) and more particularly to about 700 ° F (approx. 371 ° C) so that the web reaches a dry solids content of 45 to 90%, depending on its type, on a dry substance content which is achieved as the web passes through the air drying means. .

More specifically, the air drying means dries the wet nipple web from a dry content level of between 25 and 35% dry solids to a dry content level of 45 to 90% solids as the wet nipple web passes through the air drying means.

The vacuum level of the vacuum source connected to the vacuum means is in the range of 124 to 497 Pa (0.5 to 2 inches of water column (VP)).

In an alternative embodiment of the present invention, the transfer means include suction means cooperating with one wire to intercept a wet nipple web from the other wire. The suction means cooperate with the air drying means to transfer the wet nipple web directly to the air drying means.

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The air drying means also includes a pick-up roll located near the suction means such that the wet distillate web is located between the suction means and the pick-up roll so that when the pick-up roll is connected to a vacuum source,. 20 wet nipple webs will be pulled out of the suction means sil-, * enclosed with a blanket dryer blanket that is wet tis-! between the web and the pick-up roll.

The tissue paper making device also includes a transfer belt 1 to # 25 for transferring the web from air drying means to Yankee dry. melle.

The Yankee dryer includes a rotatable cylinder, which is connected from the inside to a source of pressurized steam for the final drying of the tis-30 grit. In cooperation with the cylinder, there are • * * '·' * 'hood means connected to a source of hot compressed air such that hot compressed air flows from the hood means supported by and around the cylinder 112268 per 7 spring nipple webs. The arrangement is such that the effect of direct surface contact of the nipple web supported by the cylinder heats the nipple web on one side. The other side of the web is also heated by hot compressed air, which flows from the blanket to the nipple as it passes around the cylinder.

The following detailed description and accompanying drawings will readily modify and modify the present invention by one of ordinary skill in the art.

However, such changes and modifications are within the scope and scope of the invention as defined in the appended claims.

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Fig. 1 is a side view of a tissue paper making device according to the present invention; Fig. 2 is an enlarged view of the form seas shown in Fig. 1; ·. Figure 3 is an enlarged view of the transducers shown in Figure 1. tools; t; * | Fig. 4 is an enlarged view of the apparel drying means shown in Fig. 1, Fig. 5 is a side view corresponding to Fig. 1 showing an alternative embodiment of the present invention in which the web is transferred from the forming part to the drying means, Fig. 6 is an enlarged partial view of Fig. 5 showing alternative transfer means for transferring the web to a Form 112268 8 fabric dryer and Fig. 7 is an enlarged view of the Yankee dryer shown in Fig. 1.

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Similar parts are indicated by like reference numerals in all embodiments of the present invention.

Fig. 1 is a side elevation view of a tissue-making machine generally designated 10 for producing tissue paper T from pulp S. The apparatus 10 includes a former generally designated 12 to form a wet pulp web W from pulp S.

Immediately downstream of the Former 12, air drying means generally designated 14 are disposed so that there is no clamping member therebetween. The air drying means 14 dry the wet nipple web W.

: 20 A Yankee dryer, generally designated 16, is disposed downstream of the drying means 14 to complete drying of the nipple web W.

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Figure 2 is an enlarged view of the for- shown in Figure 1; 1 ': 25 of the seas 12. The mold 12 comprises first and second braided forming wires 18 and 20 which cooperate to form a forming member 22 having a first 24 and a second end 26.

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• »· • t. * ··, 30 Close to the first end 24 of the forming member 22 is disposed

·, A headbox of mass S, generally designated 28

»I t I”. for injection into the forming member 22 through its first end 241i.

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The former 12 further includes a forming roll 30 cooperating with the second wire 20 such that the second wire 20 is between the first wire 18 and the forming roll 30 as the second wire 20 passes through the forming portion 22.

As shown in Figure 2, the forming roll 30 is an open roll.

Headbox 28 includes a plurality of hetero elements 32, 33, 34 for attenuating mass S turbulence as it passes through headbox 28.

Fig. 3 is an enlarged view of the transfer means generally designated 36 in Fig. 1. The transfer means 36 transfer the amount of nipple web W 15 represented by the dashed line from the second forming wire 20 to the air drying means 14.

More specifically, the transfer means 36 include a looped transfer felt 38 and a plurality of guide rollers 40, 41, 42, and 43 disposed within the loop controlled transfer felt 38 to guide the transfer felt 38.

A plurality of guide rolls 40-43 include a suction roll 40 which is positioned near the second forming wire 20 such that »1 *; ·· transfer felt 38 is located between the second forming wire 20 and the suction roll 40 · the suction roll 40 is connected to the vacuum source 44, the wet breast web W moves from the second forming wire 20 to the transfer felt 38.

A downstream * ·· ** 30 guide roller 41 is positioned near the air drying means 14 so that the wet nipple web W is! between the transfer felt 38 and the air drying means 14 so that the wet nipple web W moves from the transfer felt 38 to the air drying means 14.

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Fig. 4 is an enlarged view of the air-drying means 14 shown in Fig. 1. The air-drying means 14 includes a looped dryer blanket 46 for supporting a wet nipple web W between former 12 and Yankee dryer 16. A set of support rollers 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67 are disposed within the looped dryer blanket 46. , 68, 69 to support the dryer felt 46. The support rolls 48 to 69 are disposed such that the dryer felt 46 forms an upwardly curved surface 70 for carrying the wet breast web W.

Generally, the air blowing means indicated by reference numeral 72 cooperate with the curved surface 70 such that the wet nipple web W supported by the dryer blanket 46 is between the air blowing means 72 and the curved surface 70. The arrangement is such that when the air blowing means 72 is connected to the hot compressed air source 74, this air 76, 77, 78 is blown as shown by the arrows on the wet nipple web W and through the dryer blanket 46 on the nipple web W

; to dry.

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As shown in Figure 4, the air drying means 14 includes:. in addition, generally, under pressure numerals 80 * 25 are disposed near the curved surface 70. Vacuum means 80 is disposed with respect to air blowing means 72 at the opposite jV of the dryer blanket 46. side, so that when the vacuum means 80 is connected to the vacuum source 82, the hot M air flow 76-78 passing through the wet blower means 72 through the wet web 46 to the dryer blanket 46 is enhanced.

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The vacuum means 80 comprises a box-like arrangement, which surrounds most of the surface of the support rolls. The suction 112268 11 has machine transverse slots through which at least a portion of the circumferential surface of the support rollers may penetrate to assist in supporting the dryer felt. The box also has a plurality of openings which allow air to flow from hot air blowing means 72 through web W to vacuum means 80.

The loop-closed dryer blanket 46 is made of materials that withstand high temperatures.

The hot air blowing means is located above the curved surface 70 and the air drying means 14 further includes lifting means generally designated 84 for lifting the blowing means 72 from the curved surface 70 to facilitate removal of the wreckage in case the web breaks.

The hot compressed air source 74 supplies compressed air 76 to 78 having a temperature in the range of 500 ° to 800 ° F (about 260 ° to 427 ° C), so that the web reaches 45 to 90 percent dry matter. »: The concentration as the web passes through the air drying means 14.

· · More specifically, the air drying means 14 dries ;;; the wet nipple web W from the dry solids level where '25 solids percentage is in the range of 25-35% dry solids to the dry solids content range of 45 to' .K 90 while the wet nipple web W passes through the air drying means 14 ' h through.

*; * '30 The vacuum level of the vacuum source 82 connected to the vacuum means 80 is in the range of 124 to 497 Pa (0.5 to 2 inches of water (VP)).

112268 12

Figure 5 illustrates an alternative embodiment of the present invention in which the transfer means generally designated 36A transfer the web WA directly from the second wire 20A of former 12A to the dryer blank 46A of the air drying means 14A.

Figure 6 is an enlarged view of the transfer means 36A shown in Figure 5. The transfer means 36A includes suction means 40A cooperating with a second wire 20A to intercept a plurality of nipple web WA from the second wire 20A. Suction means 40A cooperate with air drying means 14A to transfer wet wet web WA directly to air drying means 14A.

More specifically, the air drying means 14A includes a looped dryer blanket 46A for supporting the wet breast web WA between former 12A and Yankee dryer 16A. A plurality of support rolls are disposed within the looped dryer blanket 46A to support the dryer '· 20 blankets 46A, wherein the support rolls are positioned such that

:; the dryer blanket 4 6A forms an upwardly curved surface 70A

for transporting wet breast tissue WA.

;; The support rolls include a pick-up roll 86 which is positioned close to the suction means 40A so that the wet dips. the filter web WA is between the suction means 40A and the pick-up roll 86 so that when the pick-up roll 86 is connected to the sub-pressure source 88, the wet nipple web WA is pulled out of the suction means 40A to a closed dryer blank 46A which is wet nipple strip WA and pick-up roll 86.

Fig. 7 shows a transfer belt 90 for transferring web W 112268 13 from air drying means 14 to a Yankee dryer 16.

As shown in Figure 7, the Yankee dryer 16 comprises a rotatable cylinder 92 connected from the inside 5 to a pressurized steam source 94 to complete drying of the nipple web W.

In cooperation with the cylinder 92, the hood means generally designated 96 are provided. The hood means 96 is connected to the hot compressed air source 98 such that the hot compressed air flows from the hood means 96 towards the nipple web W supported and rotated by the cylinder 92 as indicated by the arrow 100. The arrangement is such that the direct surface contact of the nipple web W supported by the cylinder 92 heats the nipple web from one side while the other side of the web is heated by hot compressed air 100 flowing from the felt means 96 towards the nipple web as it passes around the cylinder 92.

· 20 In operation, the method comprises the steps of: 1) injecting a mass of sponge onto a former forming wire, 2) transferring the formed wet nipple web to a dryer felt supported by a plurality of rollers such that the dryer felt forms an upwardly curved surface; to dryer felt without pressing between them; 3) hot air blowing! and 4) transferring the web from the dryer blanket to the Yankee dryer to complete the web drying, which Yankee only completes the web drying without any air passage through the Yankee dryer barrel wall, allows the utilization of thermal energy 112268 14 more efficiently than a blow-through dryer.

The present invention greatly increases the rate of production of nipple paper as the web is progressively dried as it advances over the curved surface of the drying means without the need to change the direction of the web as in some known nipple paper machines employing a pre-Yankee dryer.

It also follows from the effectiveness of the air drying means that a very small Yankee dryer is sufficient to complete the drying operation.

The present invention also avoids the need for expensive purine-15 tin.

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Claims (17)

112268 A tissue paper making device (10) for producing a tissue paper (T) 5 from a pulp (S), comprising: a former (12) for forming a wet breast web (W) from a pulp (S), said first and second looped forming wire (18, 20) 10 cooperating with each other to form a forming part (22), air drying means (14) disposed downstream of the former (12) for drying the web (W), a Yankee dryer (16) disposed on said drying means (16); (14) downstream to complete the drying of the tissue paper (T), the air drying means (14) including: • a loop-closed dryer blanket (46) to support the web (W) • * • · · the former (12) and Yankee dryer (16); ) between, <f 2. a set of support rollers (48-69) disposed within the loop _)! means (72) for blowing hot air through a web (W) supported by a dry, blanking felt (46) so that when the blowing means (72) is connected to a source (74) of hot compressed air, this air is blown onto the web (W). ) and dryer through the felt (4 6) for drying the web (W), characterized in that it further comprises a looped transfer felt (38) for transferring wet wet tissue web (W) from the former (12) directly to the air drying means 112268 (14) and suction roll (40). disposed within the loop of the transfer felt (38) near the second forming wire (20) such that the transfer felt (38) is between the second forming wire (20) and the suction roll (40) so that the suction roll (40) is connected to the vacuum source (44). ), the wet teat web (W) moves from the second forming wire (20) to the transfer felt (38) 10, which support rolls (48-69) are disposed such that the dryer felt (46) forms an upwardly curved surface (70) and the hot air blowing means (72) cooperating with the curved surface (70) such that the wet nipple web (W) supported by the dryer felt (46) is between the air blowing means (72) and the curved surface (70). A tissue paper making device (10) according to claim 1, characterized in that the former (12) comprises: a headbox (28) located on the forming part (22); near the first end (24) for injecting the mass (S) into the forming part (22) through its first end (24). I f 25 The tissue paper making device (10) according to claim 2, characterized in that the former (12) further comprises a forming roll (30) which cooperates with the second wire (20) so that the second wire (20) (20) is *: 30 between the first wire (18) and the forming roll (30) as the second wire (20) passes through the forming section (22). The tissue paper manufacture of claim 3:; 35 (10), characterized in that the forming roll (30) is: '·; open roller. 112268 A tissue paper making device (10) according to claim 2, characterized in that the headbox (28) comprises a plurality of chamfer elements (32-34) for attenuating the turbulence of the pulp (S) as it passes through the headbox (28). 5 The tissue paper making device (10) according to claim 1, characterized in that it further comprises a downstream guide roll (41) disposed near the air drying means (14) such that the wet tissue 10 (W) is a transfer felt (38) and air between the drying means (14) so that the wet nipple web (W) moves from the transfer felt (38) to the air drying means (14). A tissue paper making device (10) according to claim 1, characterized in that the air drying means (14) further comprises vacuum means (80) located near the curved surface (70) with the vacuum means (80) located relative to the air blowing means (72). 46) on the opposite side such that when. the vacuum means (80) is connected to the vacuum source (82), the hot, * air flow (76-78) passing through the wet distillate (72) from the hot air blowing means (W) and the dryer felt (46). 25 A tissue paper making device (10) according to claim 1, characterized in that the looped dryer felt (46) is made of materials which: withstand high temperatures. '. 30 A tissue paper making device (10) according to claim 1, characterized in that. the hot air blowing means (72) being located above the curved surface (70), the air drying means (14) further comprising lifting means 112268 (84) coupled to the air blowing means (72) to lift the air blowing means (72) from the curved surface (70) in case the web breaks. 5 A tissue paper making device (10) according to claim 1, characterized in that the hot compressed air source (74) supplies compressed air (76-78) at a temperature between 260 ° and 427 ° C (500 ° to 800 ° F), such that the web 10 reaches a dry solids content of 45 to 90% as it passes through the air drying means (14). Tissue paper making device (10) according to claim 1, characterized in that the air drying means (14) 15 dries the wet pile web (W) from a dry substance content level in the range of 25-35% dry matter to a dry matter content level in which The material percentage is in the range of 45 to 90 as the wet nipple web (W) passes through the air drying means (14). 20 A tissue paper making device (10) according to claim 7, characterized in that the vacuum level of the vacuum source (82) combined with the vacuum means (80) is in the range: 124 to 497 Pa (0.5 to 2 inches VP of water). . 25 A tissue paper making device (10) according to claim 1, characterized in that the suction roll (40A) cooperates with the second wire (20A) to intercept the wet dewatering web (WA) from the second wire (20A) 30 suction rolls (40A). ) cooperating with the air drying means (14A) to transfer the wet nipple web (WA) directly to the air drying means (14A). Tissue paper making device (10) according to claim 13, characterized in that the plurality of support rolls include: 112268 a pick-up roll (86) disposed near the suction roll (40A) so that the wet breast web is located between the suction roll (40A) and the pick-up roll (86) so that when the pick-up roll (86) is connected to the vacuum source (88), the wet nipple web 5 (WA) is pulled away from the suction roll (40A) a felt (46A), located between the wet nipple web (s) and the pick-up roll (86). A tissue paper making device (10) according to claim 1, further comprising a transfer belt (90) for transferring the web (W) from the air drying means (14) to the Yankee dryer (16). A tissue paper manufacturing device (10) according to claim 1, characterized in that the Yankee dryer (16) comprises: a rotatable cylinder (92) connected internally to a pressurized steam source (94) to complete drying of the tissue web, 96) cooperating with the cylinder (92), the hood means (96) being connected to the hot compressed air source (98) such that the hot pressure stream flows from the hood means (96) towards and supported by the cylinder (92); a circumferential nipple web (W) such that the direct pin contact of the nipple web (W) supported by the cylinder (92) heats the nipple web (W) on one side and V, on the other side, is heated by hot compressed air (100) flowing from the felt means (96) towards the nipple web (W) as it passes around the cylinder (92). * i «! I I 17. A process for making high bulk tissue paper. ·, From the pulp (S), the method comprising the steps of: injection of 35 pulp (S) onto the former (12) forming wire (20), transferring the wet bobbin web (W) formed on 112268 onto a dryer felt (46) supported by a plurality of rollers ), transferring the wet nipple web (W) from the former (12) to the dryer blanket (46) without the intermediate compression delivery, blowing hot air through the web (W) supported by the dryer blanket (46) to dry the web (W); Transferring the web from the dryer felt (46) to the Yankee dryer (16) to complete drying of the web (W), which completes drying of the web without the flow of air through the cylinder wall of the Yankee dryer (16). Characterized in that the transfer felt (38) transfers the wet breast tissue (W) from the former (12) directly to the dryer felt (38), the suction roll (40) is located inside the loop of the transfer felt (38). near the forming wire (20) for transferring the wet nipple web (W) from the forming wire (20) to the transfer felt (38), the tumble dryer blanket (46) forms an upwardly curved surface: 25 (70) for conveying the wet nipple web (W) 46) the supported wet nipple web (W) is between the curved surface (70) and the air blowing means (72) and »·. 30 hot air, supported by a curved surface (70), is blown through the web (W) so that the web reaches a dry solids content of up to 90%. • · · i 112268