FI87254C - Procedure for repairing the groove worn by the suction roll end seal in a paper machine - Google Patents

Description

87254

Method for molding a groove worn by the end seal of a suction roll of a paper machine Förfarande for reparation av repreation som slitits av sugvalsens ändtätning i en pappersmaskin 5

The invention relates to a method for testing the groove worn by the end seal of a suction roll of a paper machine.

10 The end seal of the suction roll casing wears the roller casing as it drags onto the inner surface of the groove roll casing. According to the state of the art, the grooving of the groove has taken place by grinding the groove off or spray-coating the wear groove with metal. The retention of the coating has not been optimal. When an spray coating is used, there are often pores in the coating and adhesion to the base material is uncertain due to internal stresses. As a result, the quality of the 15 groove fillings is not optimal.

This application presents a new improved method for repairing a groove worn by a suction roll end seal. According to the invention, it has been realized to use a coating which is sufficiently viscous and flexible and which passes into the holes at the groove to be filled before it hardens. The advantage in this case is that the coating stays in the groove better, because at the point of contact between the filler and the holes, a detachable force is applied to the joint surface in the direction of the joint surfaces. The strength properties of the joint are at their best in the specifically mentioned tensile direction, and thus a very stable and hole-locked filling of the wear grooves 25 can be formed by utilizing the contact surfaces of the holes.

When a harmful groove is formed in the suction roll due to the drag of the end seal, the groove must be filled as harmful with a groove depth of 1-2 mm. The width of the groove is typically 20-30 mm. According to the invention, the groove is filled using nozzle sections 30 of groove width. The width of the groove can also be a multiple of the nozzle part. The groove is filled by rotational casting by rotating the roller on support rollers, the casting head moving in the axial direction.

2 87254

According to the invention, it is possible to use as a filler a multicomponent polymer mixture which is flowable in the filling step and hardens only in its application due to the chemical reaction caused by the mixing of the components.

The method according to the invention for removing the wear groove provided by the suction roll end seal of a paper machine is mainly characterized in that the method introduces viscous and flowable filler into the groove of the suction roll end in place by the joint between the filler and the holes.

Preferably, a filler is used whose components are mixed, in which case the application of the filler to the groove takes place only after that.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figure 1 shows in principle an axonometric representation of a 20-groove rotary infill casting according to the invention.

Figure 2 shows a section I-I of Figure 1 and after filling casting.

Figure 3 shows the arrangement of the equipment used in the casting.

25

Figure 1 shows the method according to the invention axonometrically. The device arrangement for introducing the multicomponent filler E into the groove 10a of the jacket 10 comprises the filler application arrangement 11 shown in Fig. 1. The filler E application arrangement 11 comprises a filler mixing unit 12 through which the substance is guided into the groove 10a. 30 The feed rate of the filler, the rotational speed of the roll and the lateral movement of the mixing unit li 3 87254 are kept such that the filling in the groove 10a takes place evenly. The roller 10 is rotated by means of a drive motor M on rollers Ct and C2.

Figure 2 shows a section I-I of Figure 1 and after filling casting. As shown in the figure, when applied, the viscous flowable filler E has immediately passed into the groove 10a when it enters the hole 10b adjoining the groove and has passed over a part of the length of the hole or through it, especially in the case of a notched hole. Thus, the filler E is firmly locked to the roll surface by means of the connection B between the holes 10b and the filler E. The forces are applied to the joint B only in the direction of the joint surface (direction S). The connection between the filler E and the roll surface 10 is sensitive to forces in the direction parallel to the plane of the joint point but strong precisely in the direction of the plane of the joint surfaces (direction S).

In the most preferred embodiment of the invention, polyurethane is used as filler E. Before filling the groove, the wear groove is blasted and / or activated.

15

Figure 3 shows a mixing unit 12 of a two-component filler E application arrangement 11 used in rotational molding, to which channels L1 and L2 lead, which are further connected to the pump devices P1 and P2. Through the channels L 1, and various filler components X 1, X 2 are introduced into the mixing chamber D of the mixing unit 12, which comprises a mixing device 20 F, the shaft of which rotates at a speed of 3000 rpm. With the pressure provided by the pump devices P1 and P2, the mixed filler E is pushed out of the nozzle head 12a and directly into the wear groove 10a of the suction roll of the paper machine.

The filler E is preferably a multicomponent adhesive or most preferably polyurethane. 25 Once the filler E has hardened to its final strength, the filled groove is machined. When a multicomponent adhesive is used, for example, a two-component adhesive X1, X2 comprises an adhesive hardener component X1, and a plastic raw material mixture component X2. When polyurethane is used, the polyurethane comprises an isocyanate component X3 and a polyol component X4 or a single polyol component X4.

30 4 87254 Numerous advantages are obtained when polyurethane is used as filler E. The polyurethane travels well into the holes passing through the roll at the groove point and thus the holes are used to lock the polyurethane in place as described above. Since the groove to be filled is rotationally asymmetric, it is particularly suitable for the application of so-called polyurethane. a rotational molding 5 in which the roll is rotated and the nozzle 12a of the mixing unit 12 is moved axially with respect to the roll 10 (Fig. 1). When filling the groove with this casting, no molds are required and the workpiece does not heat up, because the temperature of the coating mixture is only 20-30 ° C. Prior to filling the polyurethane, the surfaces of the groove are cleaned of grease and dirt, and then an adhesive layer is blown and / or activated on the surface, after which the polyurethane is applied to the groove.

In the rotational molding, when the liquid raw material components X3, X4 of the polyurethane are pumped to the mixing unit 12, where the components mix and react with each other, the curing of the polyurethane takes place immediately thereafter. Thus, the polyure-15 should be led from the mixing unit 12 to the immediate fillable groove 10a. The polyurethane introduced into the groove 10a hardens rapidly and the polyurethane achieves good abrasion resistance. Polyurethane also has good adhesion and does not crack. The coating is post-treated by grinding or turning. In the final stage, the roll is balanced.

Claims (6)

A method of repairing a latch (10a) on the inner surface of a roller which is worn out by the end seal of a suction roller (10) in a paper machine, characterized in that in the process a filler (E) is provided, which at the propagation is viscous and fluid, to the barrier worn out by the end seal of the suction roll and to allow the filler (E) to flow to the head (10a) of the suction roll, whereby the filler (E) after the propagation is cured in the process and attached to the latch (10a) and read in place by means of a connection (B) between the filler (E) and the heel 10 (10b). Method according to claim 1, characterized in that in the process the filler (E) is guided to the groove (10a) to be filled from a spreading system (11) comprising a filler mixing unit (12) via the mouth of which piece (12a) of the filler after mixing is immediately guided into the slot (10a) by the roller (10) where it is fastened and cured. Method according to claim 1 or 2, characterized in that in the method a mixing unit (12) is moved in the axial direction in relation to the roll (10) and the roll (10) is caused to rotate. Method according to any one of the preceding claims, characterized in that before the filling material (E) is led into the latch (10a) its components (X [, X2; X3, X4) are mixed in the mixing unit (12) and after this the filler (E) is passed. with a pressure exerted by a pump or pump devices (PlsP2) in the slot (10a) to be filled. Process according to any one of the preceding claims, characterized in that the process uses a cross-component or multi-component material, preferably a cross-component adhesive comprising component X 2 and X 2, where X is a curing agent and X 2 is a plastic raw material mixture. 87254 Process according to any one of the preceding claims 1-4, characterized in that the method uses polyurethane as a filler (E) comprising components X3 and X4, where X3 is isocyanate and X4 is one or more polyols. 5 I: