FI121387B - Edge ruler for use in a sheet forming machine and method for making a sheet ruler for a sheet forming machine - Google Patents

Description

BORDER GUIDE FOR USING A BRAINING MACHINE AND METHOD

FOR MAKING AN EDGE RULER ON A FRAME MAKING MACHINE

The present invention relates to a border ruler for use with a web forming machine 5, and the border ruler includes a machine direction body of the web forming machine.

Many different border guides for use in the wire section of a web making machine are known in the art. The edge ruler 10 prevents the mass applied from the headbox to the wire from spreading on the wire. Border guides have been developed over the long term. Currently, border edges are typically used, the body of which is mainly plastic, for example HDPE plastic. This plastic profile is reinforced with angles. The angle-15 irons ensure the straightness of the plastic profile. In other words, the plastic border ruler is twisted without massive iron. Even with support structures, the edge ruler may warp. A distorted borderline, in turn, causes edge ripple. In addition, the edge guides are very heavy, which makes it very difficult to handle, for example, when changing the wire. When changing the fabric, the border guides have to be lifted off, which makes it difficult to handle long and heavy edge guides. Typically, the edge ruler is manually lifted out of position. The edge ruler is adapted to be attached to the headstock 25 at the attachment point. When a border ruler is used, it creeps up, typically forming a counter-cradle between the headbox and the border ruler. Such a backstop causes lateral flows and further deviations in the flow behavior of the pulp applied to the wire.

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The object of the invention is to provide a new kind of border ruler. It is a feature of this invention that the body is an extrusion molding body. It is a further object of the invention to provide a novel method for making a border ruler. It is a feature of this invention that the body is manufactured by extrusion molding.

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In a web forming machine, pulp is sprayed onto the wire to form a web. "Web" means cardboard and paper webs from headbox to roller production throughout the production process. In other words, the pulp applied to the wire 5 is referred to as the web. By contrast, a web-making machine refers to machines for making paper or board. Border spreading prevents the mass from spreading on the wire. The edge ruler includes a machine direction body of the web forming machine. The frame includes plastic. In addition, reinforcing fibers are added to the frame 10 during manufacture. In other words, the body is made of reinforced plastic. In this case, the body is made of a composite material with a plastic binder. The reinforcing fibers in the binder may be, for example, glass, aramid or carbon fiber. The reinforced plastic makes a lightweight borderline 15 frame which is also durable and rigid.

In one embodiment, the body is manufactured by extrusion molding. The body is an extrusion die. Extrusion molding refers to both extrusion, or extrusion, or pult-20 rusting. In these manufacturing methods, a binder remains on the surface of the structure to be manufactured. When the binder is on the surface of the structure to be manufactured, the surface is free of reinforcing fibers. In this case, the surface is smoother than, for example, manufacturing a structure by machining. The smoothness of the surface is important because the rough surface affects the flow in the width direction of the forming machine more widely than the smooth surface. The smoothness of the surface also has an effect on keeping the surface clean, for example, a rough surface is easier to adhere to than a smooth surface. When soiled, the surface typically becomes more uneven. The uneven surface causes lateral currents and affects the velocity profile of the pulp. Wear resistance is also improved when the fibers are bonded.

In another embodiment, the body is manufactured by extrusion light or pultrusion. During pultrusion, a release agent is used during manufacture 35, which results in an even smoother and more wear-resistant surface. Furthermore, in the manufacture of the body by pultrusion, the directions of the fibers in the reinforced plastic are desired in the body, thereby making the structure more rigid than when the directions of the fibers are random. Fibers longer than 5 extrusion may also be used in pultrusion. Longer fibers provide better dimensional stability than short fibers.

In a third embodiment, extrusion molding produces a water control design for the body of the border ruler. At the boundary line 10, water is directed to both sealing and lubricating water. The sealing water seals the edge ruler to the wire, preventing the mass from passing significantly between the edge ruler and the wire. The lubricating water, in turn, lubricates the surface of the border. The lubrication effect is on both the mass surface of the border ruler and on the wire surface of the 15 border rulers. The mass surface of the border ruler is in contact with the mass. In turn, the wire surface of the border ruler is connected to the wire. In addition, water acts as a sealing water between the boundary and the wire. The guide design is on the surface of the border ruler, whereby it can be formed by extrusion molding 20 simply. In forming the control design by extrusion, the entire structure can be economically manufactured.

The invention will now be described in detail with reference to the accompanying drawings, in which:

Figure 1 schematically illustrates a border ruler according to the invention with a wire section, Figure 2a schematically shows a part of a border ruler according to the invention, viewed in the machine direction from the side of the edge ruler web,

Fig. 2b is a schematic sectional view A-A of Fig. 2a according to the inventive edge ruler, 35 Fig. 3a is a schematic sectional view in another MD edge contour of the invention, 4

Fig. 3b is a schematic sectional view C-C of the border ruler of Fig. 3a according to the invention, and Fig. 4 shows an embodiment of the border ruler according to the invention on a forming machine.

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Figure 1 schematically illustrates an edge rib 16 of the invention with a wire portion 10 of a forming machine. The wire portion 10 and further of the forming machine include a headbox 12, a wire 14 and an edge ruler 16. The headbox 12 spreads 10 pulp 20 onto a wire 14. The pulp 20, which is applied to the web 40, is dewatered by the dewatering means 24. The machine direction of the forming machine is indicated by arrow 34. The wire 14 is supported by a roll of rolls 28. The edge ruler 16 is positioned on the edge of the wire 14 The edge ruler belongs to both edges of the fabric. The edge ruler 16 leaves the connection of the headbox 12, extending in a machine direction to a substantial portion of the wire section 10. shows a cut to the structure of the borderline frame. The surface of the border ruler 16 is made of plastic 13. The reinforced plastic allows for a lightweight, easy-to-handle borderline. The weight of the edge ruler per meter is less than 3 kg, preferably less than 2 kg.

The body 17 of the border ruler 16 shown in Figure 1 is a pultrusion piece, i.e. made by pultrusion. Thanks to the release agent used in pultrusion, very smooth surfaces can be produced by pultrusion. When making a border ruler by pultrusion, reinforcing fibers are not on the surface of the border ruler. Further, in pultrusion, the fibers applied to the reinforcing plastic forming the body are oriented substantially parallel to the forming machine. 35 This maximizes the stiffness of the borderline. On the other hand, the edge straightness in the machine direction improves.

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The binder used in the border ruler, i.e. plastic, is substantially water-absorbent. By water-absorbent binder is meant, for example, a binder which absorbs up to 0.1% by weight, preferably 0.05% by weight. In this case, the absorption of water in the binder 5 is so low that it is possible to speak of a water-absorbent material. When the bonding agent of the body reinforcing plastic is water-absent, the edge ruler provides good dimensional stability with respect to moisture. Preferably, the binder has a surface energy such that it is hydrophobic. In this case, the mass adheres to the boundary ruler 10 less than when the boundary ruler is hydrophilic.

In the edge ruler, the thermal expansion coefficient of the body, which is a reinforced plastic formed of plastic and reinforcing fibers, is less than 10-10 ~ 6 1 / ° C, preferably less than 5-10 "6 1 / ° C. The expansion may even be negative in certain fiber directions, meaning that there is a slight decrease instead of expansion. If the thermal expansion is not linear, the thermal expansion coefficient means the average thermal expansion coefficient, between 0 and 70 ° C.

With a low coefficient of thermal expansion, the thermal expansion does not cause deflection between the attachment points. Also, the attachment to the headbox of the boundary ruler remains in place during the service life when the thermal expansion coefficient of the reinforcing plastic used in the boundary ruler is low. With the attachment still in place, there is no transverse stair between the borderline and the headbox. 25 As a whole, the wire section exhibits less harmful side streams than known edge streaks.

Fig. 2a is a schematic cross-sectional view of a system 32 using an edge ruler 16 according to the invention 30. The cross-section is illustrated on the side 42 of the web 40 of the edge ruler 16. At this point only the wire 14 is actually cross-sectioned. Fig. 2b is a schematic cross-sectional view of the system 32 in transverse direction CD in Fig. 2a. 35 A-A is a cross-sectional view of the headbox. Fig. 2b shows a web 40 made of pulp, the lower part 44 of which is depicted with a more frequent line than the upper part 46, because when the web 40 drains on a flat wire, a fiber network is first formed in connection with the wire 14. The cross-section shown in Fig. 2a is the section B-B in Fig. 2b and the machine direction of the forming machine 5 is indicated by arrow 34. The system according to the invention can also be used in conjunction with a kitformer.

The fabric of the system shown in Figures 2a and 2b has an edge 30 in the machine direction. The system 32 includes an edge ruler 16 10 along the edge 30 of the fabric 14. The edge ruler 16 includes a machine directional control design 38 manufactured by a pultrusion, thereby simply controlling the water control design 38. The pultrusion-shaped control design is substantially the entire length of the boundary line, whereby water can be uniformly discharged into the wire and / or web. Of course, the control design may be blocked by its head connection, but even so, the control design is substantially the entire length of the borderline. The guide design 38 is on the surface 36 of the wire 14 on the edge 14 of the edge ruler 16. On the other side 20 of the wire 14 is a water member 18 to guide water 22 to the edge 16 through the wire 14.

Figure 3a is a schematic cross-sectional view of a system 32 using an edge ruler 16 according to the invention 25. The cross-sectional view is illustrated on the side 40 of the web 40 of the edge ruler 16 at a point where the machine channel 62 and intermediate channels 64 are cut. Through the machine direction passage 62 and intermediate passages 64, water is led to the control shaping 38. Figure 3b schematically shows a system 32 of Figure 3a as a cross-section C-C in the CD direction. The cross section shown in Figure 3a is a section D-D.

The wire portion 10 shown in Figs. along the border 16. Also, the surface 42 of the web 40 on the edge 40 of the edge ruler 16 has a control design 38. Hereby, seal water 22 '' is provided between the wire 14 and the edge ruler 5 16 for the entire distance of the edge ruler.

The edge ruler shown in Figures 3a and 3b includes a duct system 60 for conducting water 22. In addition, the ductwork 60 is within the boundary ruler 1610 and the walls 61 of the ductwork 60 consist of plastic. The duct system 60 consists of a machine duct 62 and an intermediate duct 64. In its entirety, the duct 60 provides water 22 for control design 38. Figure 3b schematically illustrates how the reinforcing resin 11 includes the plastic 13 as the binder 15 and the reinforcing fibers 15. 15. In this case, the walls of the intermediate passageways 64 consist of plastic 13.

Fig. 4 shows an embodiment of the 20 border ruler 16 of the invention on the wire section 10 of the forming machine. The border ruler 16 includes a machine directional pultrusion channel 62 for transporting water in the machine direction. The boundary ruler 16 also includes a control design 38 for guiding water along the longitudinal direction of the boundary ruler 16. The water is directed in the longitudinal direction of the boundary ruler 25 into lubricating and sealing water. Between the machine direction channel 62 and the machine direction control design 38 there are intermediate channels 64. In the intermediate channels, water is conveyed from the machine channel to the machine direction control design. 1 2 3 4 5 6

The machine direction channel and the machine directional control design are the same across 2 sections. In turn, the sizes of the intermediate channels 3 may vary as they are subsequently machined to the profile 4, for example by drilling. In order to balance the flow 5 as desired, the intermediate channels can be drilled larger at the other end of the boundary ruler 6, since the flow in the machine channel decreases as it exits the headbox.

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In the wire section 10 shown in Figure 4, the edge ruler 16 is secured to the body portion 70 of the wire section 10 by fastening members 72. The fastening members 72 consist of a fastening section 74 attached to the frame section 70 and a clamping member 78 , which adjust the border ruler 16 exactly to the desired position. When the edge ruler is reinforced plastic, the edge ruler does not significantly bend between the fastening members. A retaining member 80 is also attached to the body portion 70. The retention member 10 is pivoted from the body portion to the side when the edge line is disengaged, for example, during wire change. During the wire change, the border ruler is retained on the retaining members which are turned to the side.

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Claims (8)

An edge ruler for use in a web forming machine, and the edge ruler (16) comprising a machine direction 5 body (17) of plastic forming web (13) and reinforcing fibers (15), characterized in that the body (17) is an extrusion molding body. Edge ruler according to claim 1, characterized in that the body (17) is a pultrusion piece. Edge ruler according to Claim 2, characterized in that the edge ruler (16) has a pultrusion machine direction (MD) design (38). 15 Edge ruler according to one of Claims 1 to 3, characterized in that the reinforcing fibers are substantially longitudinal (S) of the body (17). Edge ruler according to one of Claims 1 to 4, characterized in that the plastic is substantially waterproof. Edge ruler according to one of Claims 1 to 5, characterized in that the coefficient of thermal expansion of the 25 reinforced plastic formed by the plastic and reinforcing fibers is less than 10-16T / 6 ° C, preferably less than 5, 10 < 6 > Edge ruler according to any one of claims 1 to 5, comprising a duct grid (60) for conducting water, characterized in that the duct grid (60) is inside the boundary ruler (16) and the walls (61) of the duct system (60) consist of plastic. A method for manufacturing a border ruler for a web forming machine, and the border ruler (16) comprises a machine direction (17) plastic (MD) body (17) of the web forming machine 35, and reinforcing fibers are added to the body, characterized in that the body (17) Method according to claim 8, characterized in that the body (17) is manufactured by pultrusion.