KR100223115B1 - A multi-ply web forming apparatus - Google Patents

Abstract

The present invention relates to a multi-ply web forming apparatus for forming a top layer on a base ply. The device cooperates with a looped undercarriage net 16 and undercarriage for receiving the base fabric and is disposed on the undercarriage, having a first end 22 and a second end 24 therebetween. It generally includes a looped forming net 18 of the top forming the forming portion 20 arranged horizontally. Turning bar 26 forms a curved surface 28 that guides the underlay. The second headbox 30 ejects the stock onto the base layer towards the base layer. The curved dewatering contact 34 is disposed below the lower net 16 to allow water to drain from the upper layer through the upper net 18. A vacuum slot 38 collects water upwards from the top net. The inverted vacuum box 40 is disposed downstream of the vacuum slot 38 and the plurality of dewatering braids 44-56 disposed between the curved surface 42 and the top mesh 18 of the vacuum box are at the top passing there. Guide the net. A number of dewatering foils 58-61 are disposed on opposite sides of the net to the braid to increase the concentration of stock forming the top layer while passing through the formation, while increasing the concentration of the top layer in the Z-axis direction. The concentration is kept constant to prevent damage to the final web.

Description

[Name of invention]

Multilayer web forming apparatus

[Background of invention]

[Field of Invention]

The present invention relates to a multi-ply web forming apparatus. More specifically, the present invention relates to a multilayer web forming apparatus for forming an upper layer on a base layer.

[Description of Related Information]

The top wire former, sold under the trade name Bel Bond (registered trademark) from Beloit Technologies, Inc., removes water upwards from the stock, resulting in the final web. This gives more uniform surface properties.

More specifically, when the stock is sprayed from the headbox onto a fourdrinier wire, water is drained downwards leaving a fibrous web on the top of the wire. Thereafter, the fibrous web is transferred to the press section to further remove water from the formed web.

Due to the above mentioned drainage of the water, the final web has non-uniform surface properties. The bell-bond (registered trademark) unit is a looped top wire unit in which a loop-shaped forming wire is mounted, and the loop-shaped forming wire mounted on the upper portion interacts with the lower mesh-type wire so A molded part is formed between the wires.

While the water passes through the molding, the water is removed upwards from the stock, giving the final molded web more uniform surface properties.

However, in forming a multilayer web, the underlying long wire is initially formed with a base layer, and a second headbox is placed immediately upstream to the upper wire bell bond (registered trademark) device.

Although the above arrangement has proven successful in forming multilayer webs, the upper layer tends to crumple during subsequent web pressing.

More specifically, when the stock is sprayed from the second headbox, a fibrous mat tends to be formed below the upper forming wire, and the fibrous mat detains a low density stock below it ( traps, causing the web to crumple in subsequent pressing operations.

The present invention is to overcome the above-mentioned problems by uniformly removing water from the upper layer in order to obtain a more uniform concentration of paper in the Z direction.

Therefore, the main object of the present invention is to provide a multilayer web forming apparatus which overcomes the above-mentioned disadvantages of the apparatus described above, making a significant contribution to the multilayer web forming technique.

Another object of the present invention is to provide a multi-layer web forming apparatus which prevents wrinkling of a final web, in particular a heavy web.

It is a further object of the present invention to provide a multilayer web forming apparatus comprising a vacuum slot to assist in the upward removal of water.

Other objects and advantages of the present invention will be readily apparent to those skilled in the art upon consideration of the following detailed description with reference to the accompanying drawings.

[Summary of invention]

The present invention relates to a multilayer web forming apparatus for forming an upper layer on a base layer. The shaping device includes a looped bottom shaping wire disposed underneath the device and receiving a substrate thereon. The loop-shaped upper forming wire disposed above the lower forming wire interacts with the lower forming wire to form a substantially horizontal forming section having a first end and a second end therebetween. To form. A turning bar disposed upstream with respect to the first end of the forming part below the lower forming wire forms a curved surface to guide the lower forming wire. A second headbox is disposed very close to the turning bar, and the stock injected from the second headbox toward the first end of the forming portion is laminated on the base layer to form the upper layer.

A curved dewatering shoe is disposed below the lower forming wire adjacent to the first end of the forming portion. The center of curvature of the curved dewatering shoe is disposed below the lower forming wire so that some of the water is discharged through the upper forming wire.

Immediately downstream of the dewatering shoe above the upper forming wire, a vacuum slot means is arranged to recover a portion of the water removed upwards from the upper forming wire.

Immediately downstream of the vacuum slot means, an inverted vacuum box is arranged on the opposite side of the upper forming wire with respect to the dewatering shoe. This inverted vacuum box forms a curved surface with a center of curvature positioned over the upper forming wire.

A plurality of dewatering blades are arranged at regular intervals along the curved surface in the machine direction. A blade is disposed between the curved surface and the upper forming wire, each blade extending transversely to guide the upper forming wire through it.

A plurality of dewatering foils are arranged on the opposite side of the wire with respect to the blade, whereby the concentration of the stock forming the upper layer increases while the stock passes through the forming section, while the concentration of the upper layer in the Z direction is increased. It remains uniform to prevent the final web from creasing.

In a more specific embodiment of the present invention, the turning bar is adjustable to position the second headbox very close to the lower forming wire, whereby the stock sprayed from the second headbox is applied to the dewatering shoe at the turning bar. Sprayed almost parallel to the bottom forming wire.

In one embodiment of the invention the curved surface of the turning bar is ceramic.

The curved dewatering shoe also includes a plurality of space bars arranged at regular intervals in the machine direction. Each space bar extends laterally in the machine, the space bars including an upstream space bar.

The curved dewatering shoe also includes a vacuum box in fluid communication with the space formed between each adjacent space bar.

The stock is ejected from the second headbox to impinge on an worm adjacent to the upstream space bar of the plurality of space bars arranged at regular intervals.

In one embodiment of the present invention, the radius of curvature of the dewatering shoe is in the range of 12-18 meters.

The vacuum slot means is an auto-slice comprising lip means for guiding a portion of the water exiting the upper forming wire from the top layer. The automatic slice also comprises a recovery tank means coupled with the lip means to recover a portion of the water therein.

In an embodiment of the invention, the vacuum slot means comprise a plurality of vacuum slots arranged at regular intervals from each other in the machine direction, each vacuum slot having an adjustable lip. In addition, the vacuum slot means has a recovery tank arranged on top of each lip, and according to this arrangement, when the device according to the invention is in operation, the tension of the lower forming wire and between the upper and lower forming wires are formed. Part of the water removed from the upper layer through the upper forming wire due to the converging wire wedge is removed via the vacuum slot means, so that the fibrous mat is formed on the opposite side to the vacuum slot means of the upper forming wire. To prevent detaining stocks with low concentration.

The radius of curvature of the inverted vacuum box is longer than the radius of curvature of the dewatering shoe.

Each of the plurality of dewatering blades is arranged at regular intervals relative to the adjacent dewatering blade. The distance is greater than the distance between adjacent space bars of the dewatering shoe.

Each of the plurality of foils is disposed between adjacent blades of the plurality of dewatering blades such that the blades and foils exert dewatering pressure pulses on the multilayer web while the web passes between the blades and the foils.

More specifically, the foil interacts with the blade and is disposed facing the blade along a portion of the machine direction length of the vacuum box from the upstream blade.

In another embodiment of the invention, the foils facing the blades and arranged downstream with respect to these blades from blades upstream to downstream of the vacuum box interact with the blades.

Each dewatering foil comprises a pair of threaded rods arranged at regular intervals parallel to each other, which rods are disposed adjacent one end of the foil.

The other pair of threaded rods are arranged at regular intervals parallel to each other, which rods are disposed adjacent to opposite ends of the foil.

The yoke portion interacts with a pair of rods, and thus can adjust the yoke perpendicular to the rod.

The additional yoke interacts with the pair of additional rods so that the additional yoke can be adjusted vertically with respect to the additional rods.

The foil bar is arranged such that the first end is journaled in the first yoke and the second end is journaled in the second yoke, allowing vertical adjustment of the foil bar. The journal allows for rotatable adjustment of the foil bar relative to the bottom forming wire. Pneumatic tube means are disposed below the foil bar to adjustably load the foil bar against the lower forming wire.

Many variations and modifications of the invention will be readily apparent to those skilled in the art upon consideration of the following detailed description. However, such changes and modifications will be included within the spirit and scope of the invention as defined by the appended claims.

Detailed description of the invention

In various embodiments of the present invention, like reference numerals denote like parts.

1 shows a side view of a multilayer web forming apparatus 10 according to the present invention for forming an upper layer 12 over a base layer 14.

Multilayer web forming apparatus 10 includes a looped bottom forming wire 16 disposed underneath the apparatus and receiving base 14 thereon.

The loop-shaped upper forming wires 18 disposed above the lower forming wires 16 interact with the lower forming wires 16 and between the first and second ends 22 and the lower forming wires, respectively. It forms a molded part 20 having two ends 24 and arranged generally horizontally.

A turning bar 26 disposed upstream of the first end 22 of the forming portion 20 below the lower forming wire 16 forms a curved surface 28 to guide the lower forming wire 16.

The second headbox 30 is disposed very close to the turning bar 26, and the stock 32 sprayed from the second headbox 30 toward the first end 22 of the molding part 20 is formed. The upper layer 12 is formed by stacking on the base layer 14.

A curved dewatering shoe 34 is disposed below the lower forming wire 16 adjacent to the first end 22 of the forming portion 20. The center of curvature of the curved dewatering shoe 34 is disposed below the lower forming wire 16 such that a portion of the water is discharged through the upper forming wire 18 as indicated by arrow 36.

Immediately downstream of the dewatering shoe 34 above the upper forming wire 18, a vacuum slot means 38 is arranged to recover a portion of the water removed upwards from the upper forming wire 18.

Immediately downstream of the vacuum slot means 38, an inverted vacuum box 40 is arranged on the opposite side of the upper forming wire 18 with respect to the dewatering shoe 34. This vacuum box 40 forms a curved surface 42 whose center of curvature is located above the upper forming wire.

A plurality of dewatering blades 44 to 56 are arranged at regular intervals along the curved surface 42 in the machine direction MD. Blades 44 to 56 are disposed between the curved surface 42 and the upper forming wire 18, with each blade 44 to 56 extending transverse to the machine to guide the upper forming wire through it.

2 shows a side view of a multilayer web forming apparatus 10A according to another embodiment of the present invention.

The web forming apparatus 10A shown in FIG. 2 increases the concentration of the stock forming the upper layer 12A while the stock passes the forming section 20A, while the concentration of the top layer 12A in the Z direction. A plurality of dewatering foils 58, 59, 60, disposed on opposite surfaces of the lower forming wire 16A and the upper forming wire 18A with respect to the blades 44A to 56A to keep the constant constant. It is almost identical to the forming web device shown in FIG. 1 except that it further comprises 61).

As shown in FIGS. 1 and 2, the turning bars 26, 26A are adjustable to position the second headbox 30, 30A very close to the lower forming wires 16, 16A. Accordingly, the stocks 32 and 32A sprayed from the second headboxes 30 and 30A are almost applied to the lower forming wires 16 and 16A from the turning bars 26 and 26A to the dehydrating shoe 34 and 34A. Sprayed in parallel.

The curved surfaces 28, 28A of the turning bars 26, 26A are made of ceramic material.

3 shows a side view of another embodiment of the present invention. FIG. 3 shows a multilayer web forming apparatus 10B that includes all the essential features shown in the embodiment of FIG. However, the curved dewatering shoe 34B includes a plurality of space bars 62 to 77 arranged at regular intervals in the machine direction MD. Each space bar extends laterally in the machine, such as space bar 62, and space bars 62 to 77 disposed at regular intervals include an upstream space bar 62.

More specifically, the curved dewatering shoe includes a vacuum box 78 in fluid communication with a space formed between adjacent space bars, such as between space bars 62 and 63.

The stock 32B injected from the second headbox 30B collides with the base layer 14B adjacent to the upstream space bar 62 among the plurality of space bars 62 to 77.

The radius of curvature of the dewatering shoe 34B is in the range of 12-18 meters.

4 is an enlarged view of the vacuum slot means 38 shown in FIG. As shown in FIG. 4, the vacuum slot means 38 has a lip means 82 shown in FIG. 4 for guiding the water 36 ′ discharged through the upper forming wire from the upper layer 12. Automatic slice 80. The automatic slice 80 also has a recovery tank means 84 coupled with a lip means 82 to recover water therein.

More specifically, as shown in FIG. 4, the automatic slice 80 includes a plurality of slots 86 to 90, each having ribs 82, 92, 93, 94, and 95, which slots. They are arranged at a distance from each other in the machine direction.

Each slot 86-90 has recovery tanks 84, 97-100, respectively disposed over associated lips 82, 92-95. When the device according to the invention is in operation, it is removed from the upper layer through the upper forming wire 18 due to the tension of the lower forming wire and the converging wire wedge formed between the lower forming wire 16 and the upper forming wire 18. Water is removed via the vacuum slot means 38 to form a fiber mat on the opposite side of the upper forming wire 18 with respect to the vacuum slot means 38 so that the low density stock is retained in the upper layer 12. To prevent them.

In each embodiment shown in FIGS. 1 to 3, the radius of curvature of the inverted vacuum box 40 is longer than the radius of curvature of the dewatering shoe 34.

As an example, the blades 44B of the plurality of dewatering blades 44B-56B are spaced a distance D away from the adjacent dewatering blade 45A, as shown in FIG. The distance D is greater than the distance d between the adjacent space bars 62, 63 of the dewatering shoe 34B shown in FIG.

In the embodiment shown in FIG. 3, each of the plurality of foils 58B-61B is disposed between adjacent blades of the plurality of dewatering blades 44B-56B, thus blades 44B-56B and foil 58B. -61B) applies a multilayer pressure pulse to the multilayer web while the web passes between the blade and the foil.

5 shows a side view of a preferred embodiment of the present invention, very similar to the embodiment shown in FIG. However, the foils 58C-61C interact with the blades 44C-47C and are disposed opposite the blades 44C-47C along a portion of the machine length of the vacuum box 40C from the upstream blades 44C. It is.

As shown in the embodiment of FIG. 3, the blades 44B to 56B face each other downstream from these blades 44B upstream of the vacuum box 40B to downstream blades 56B. The disposed foils 58B-61B interact with the blades 44B-56B.

In the embodiment shown in FIG. 2, the foils 59 to 61 are arranged to face the automatic slice 80 upstream with respect to the dewatering shoe 34A.

In the operation of the apparatus according to the invention, the stock forming the upper layer 12 in each embodiment shown more clearly in FIGS. 1 to 3 and 5 and 4 is a slot 86. Impinge on the upper forming wire 18 near its leading lip 82.

As the top forming wire 18 extends around the lips 82, 92-95, the ribs 82, 92-95 have a radius of curvature of about 15 meters of the top forming wire 18 around the automatic slice 80. Can be adjusted.

In addition, the water present in the bell bond (wire) wire 18 due to the tension of the lower forming wire 16 and the converging wire wedge 102 is removed.

The recovery tanks 84, 97-100 are not in vacuum. It is an object of the present invention to introduce a low concentration of fibrous mat held underneath by the base layer 14 to the outside of the bell bond (wire) wire 18, but to be introduced in a uniform manner throughout the slurry. It is to increase the concentration of stock. The present invention eliminates the wrinkling that occurs when under heavy loads in conventional devices.

In addition, both the auto slice 80 and the lead-in roll in front of the auto slice are fully adjustable for optimal performance.

The invention is similar to the arrangement shown in FIG. 5, but also includes an apparatus in which the automatic slice unit is removed so that only the vacuum slot is installed in the loop of the upper forming wire to remove water upwards.

Further, the radius of curvature of the curved surface upstream of the inverted vacuum box, ie the radius of curvature of the portion with the opposing foil, is about 15 meters, while the remaining curved surface of the inverted vacuum box has a radius of curvature of 5 meters.

Also, in another embodiment of the present invention, the portion of the inverted vacuum box adjacent to the opposing foil is flat while the remainder of the curved surface is curved.

Various embodiments of the present invention enable uniform dehydration of the upper layer in the multilayer molding apparatus, so that the concentration of the paper forming the upper layer while the paper passes through the forming portion is increased, while the concentration of the upper layer is constant in the Z direction. Is maintained to prevent wrinkling of the final web.

[Brief Description of Drawings]

1 is a side view of a multilayer web forming apparatus according to the present invention.

2 is a side view of a multilayer web forming apparatus according to another embodiment of the present invention.

3 is a side view of a multilayer web forming apparatus according to another embodiment of the present invention.

4 is an enlarged view of the automatic slice shown in FIG.

5 is a side view of a preferred embodiment according to the present invention.

Claims (11)

A multilayer web forming apparatus for forming an upper layer on a base layer, A looped bottom forming wire 16 which receives the base layer 14 thereon, Disposed above the lower forming wire and interacting with the lower forming wire to form a generally horizontal forming portion 20 having a first end 22 and a second end 24 therebetween. A loop-shaped upper forming wire 18 to be formed, A turning bar disposed below the lower forming wire 16 upstream of the first end 22 of the forming part 20 to form a curved surface 28 for guiding the lower forming wire 16; 26), Disposed adjacent to the turning bars 26 and 26A to spray the stock 32 toward the first end of the forming section 20 so that the stock is formed on the substrate 14 to form the upper layer 12. Second headboxes 30 and 30B, Water disposed below the lower forming wire 16 adjacent to the first end 22 of the forming part 20 and having a center of curvature below the lower forming wire 16 to discharge water from the upper layer. Curved dewatering shoes 34 and 34B to be discharged through the upper forming wire 18; A vacuum slot means (38) disposed directly downstream of the dewatering shoe (34) above the upper forming wire (18) to recover water removed upwardly from the upper forming wire; Directly downstream of the vacuum slot means 38 is disposed on the opposite side of the upper forming wire 18 with respect to the curved dewatering shoe 34, 34B, the center of curvature being located above the upper forming wire 18. An inverted vacuum box 40 forming a curved surface 42, The upper part disposed along the curved surface 42 at a predetermined interval in the machine direction, each extending laterally in the machine, between the curved surface 42 and the upper forming wire 18 and passing therethrough. A plurality of dewatering blades 44B to 56B, 44C to 56C for guiding the forming wire, The blades 44B to 56B and 44C to 56C increase the concentration of the paper forming the upper layer while the paper passes through the forming part, while maintaining the concentration of the upper layer in the Z direction to prevent the final web from being wrinkled. In the multi-layer web forming apparatus comprising a plurality of dewatering foils 58B to 61B and 58C to 61C disposed on opposite surfaces of the wires 16 and 18 with respect to Each of the plurality of foils 58B to 61B, 58C to 61C is disposed between adjacent blades of the plurality of dewatering blades 44B to 56B and 44C to 56C so that the web passes through the blades and foils. Multilayer web forming apparatus, characterized in that the blades and foil apply dewatering pressure pulses to the multilayer web. The turning bar 26 is adjustable to position the second headbox in close proximity to the lower forming wire, so that the stock sprayed from the second headbox is mounted on the turning bar. Multi-layer web forming apparatus, characterized in that it is sprayed almost parallel to the lower forming wire up to the dewatering shoe. 3. Apparatus according to any one of the preceding claims, wherein the curved surface of the turning bar (26) is ceramic. The curved dewatering shoe (34, 34B) further comprises a plurality of space bars (62 to 77) arranged at regular intervals in the machine direction (MD), respectively. And each space bar extends in the machine transverse direction, the space bar including an upstream space bar. 5. The apparatus of claim 4, wherein the dewatering shoe (34, 34B) further comprises a vacuum box (78) in fluid communication with the space formed between each adjacent space bar. 5. Apparatus according to claim 4, characterized in that the stock injected from the second headbox (30, 30B) impinges on a substrate (14) adjacent the upstream space bar (62). 2. Apparatus according to claim 1, wherein the radius of curvature of the dewatering shoe (34, 34B) is in the range of 12 to 18 meters. The apparatus of claim 1, wherein the radius of curvature of the inverted vacuum box (40) is longer than the radius of curvature of the dewatering shoe. 5. The apparatus of claim 4 wherein each dewatering blade is at a distance from an adjacent dewatering blade, the distance being greater than the distance between adjacent space bars of the dewatering shoe. The foils 58C-61C interact with the blades 44C-47C and extend from the blades 44C upstream along a portion of the machine direction length of the vacuum box 40C. Multilayer web forming apparatus, characterized in that arranged facing. The foils 58B-61B according to claim 1, wherein the foils 58B-61B facing the blades and disposed downstream with respect to these blades, from blades 44B upstream of the vacuum box to blades 56B downstream. 44B to 56B).