DE102020107183A1 - Method and device for the continuous production of foam blocks - Google Patents

Abstract

The invention relates to a method for the continuous production of foam blocks (1), in which a reactive mixture is applied to a lower separating web and conveyed in a conveying direction (R), an upper separating web being applied to the foaming reactive mixture and at least one flat cover mat (2) is placed from above onto the upper separating sheet in order to give the foam block (1) a flat upper surface. In order to automate the process of placing the at least one cover mat on the upper separating web and to achieve the desired block shape of the material produced as well as possible, the invention provides that the at least one cover mat (2) is in operative connection with a lifting drive (3), wherein the lifting drive (3) is connected to a control device (4) which controls the vertical height of the at least one cover mat (2) so that the force (F) exerted by the lifting drive (3) on the cover mat (2) is measured and the Control device (4) is fed and that the control device (4) maintains the force (F) exerted on the cover mat (2) at a predetermined value by activating the lifting drive (3). The invention also relates to a device for the continuous production of foam blocks.

Description

The invention relates to a method for the continuous production of endless foam blocks, in which a reactive mixture is applied to a lower separating path and conveyed in a conveying direction, an upper separating path being applied to the foaming reactive mixture and at least one flat cover mat from above onto the upper one The release liner is applied to provide a flat top surface to the foam block; d. H. the foam block produced should have a cross-section that is as rectangular as possible. The invention also relates to a device for the continuous production of foam blocks.

A generic method and a corresponding device are disclosed in the EP 1 683 618 A2 . A similar solution is shown by the DE 21 23 216 C3 .

The best-known processes of this type are known as the "Petzetakis process" and "Hennecke-Planibloc process" (see Prof. Dr. Gerhard W. Becker et al. "Kunststoffhandbuch", Volume 7, "Polyurethane", 2. Edition, ISBN 3-446-13614-2, pages 176-177) . In the Hennecke Planibloc process, mats are placed on the foam block or on the separating lane running above the foam block with the help of cables and counterweights with an adjustable force. In 2 of the mentioned EP 1 683 618 A2 it can be seen how the rope is guided over pulleys, with the mat hanging on one end of the rope, which is placed on the foam block, and with counterweights being placed on the other end of the rope in order to set the desired bearing force.

As a rule, the mats each hang on an articulated frame, which in turn is suspended in a larger frame. The articulated frame ensures that the mats perform a guided movement during lowering or lifting and cannot simply pivot freely on the rope. Alternatively, the mats can also be guided using a linear guide.

The start of the process is not unproblematic, namely when the so-called starting device, which is required to start the process, has passed the respective mats and the mats then have to be placed on the foam block. This requires staff, with one or more employees manually lowering the mats onto the foam block, whereby it must be assessed visually how much counterweight has to be placed on the respective mat in order to achieve the desired result, i.e. H. to achieve the most rectangular shape possible for the cross-section of the foam block.

In light of the situation described above, the present invention is based on the object of developing a generic method and a corresponding device so that it is possible to automate the process of placing the at least one cover mat on the upper separating sheet and the desired block shape of the material produced to be reached as easily as possible.

The solution to this object by the invention is characterized according to the method that the at least one cover mat is in operative connection with a lifting drive, the lifting drive being connected to a control device that regulates the vertical height of the at least one cover mat that the lifting drive on the force exerted on the cover mat is measured and fed to the control device and that the control device maintains the force exerted on the cover mat at a predetermined value by activating the lifting drive.

Specifically, it can be provided that if the force exerted is too low compared to a specified setpoint, the at least one cover mat is raised by the lifting drive, initiated by the control device, or if the force exerted is too high compared to the specified setpoint, the at least one cover mat is raised by the control device caused by the lifting drive is lowered.

The vertical position of the at least one cover mat can be recorded and transmitted to a process control station or a machine control system. In this case, it is advantageously provided that the actual height of the foam block produced at the location of the cover mat is determined and output in the process control room or in the machine control based on the transmitted vertical position of the at least one cover mat, which can be done, for example, by displaying it on a screen.

A further development of the proposed method provides that at the start of production of the foam block, the lowering of the at least one cover mat from an out-of-service position to the upper separating line is automated by a process control station or by a machine control as soon as a predetermined time has elapsed after the start of production and / or a predetermined conveying path of the lower separating path is reached. This allows the production process to be automated in an improved manner. Furthermore, does not have to be based on subjective impressions of Employees are turned off, so that there is an improved product quality.

The proposed device for the continuous production of foam blocks has: conveyor elements for conveying a lower separating web in a conveying direction to which the reactive mixture can be applied, conveying elements for applying an upper separating web to the foaming reactive mixture and at least one flat cover mat which is applied from above to the upper separating sheet can be placed in order to give the foam block a flat upper surface. The proposal according to the invention is characterized by a lifting drive for vertical lifting and lowering of the at least one cover mat, a control device for controlling the lifting drive and at least one force sensor with which the force acting on the at least one cover mat from the lifting drive can be measured, the force sensor with the Control device is in communication.

Furthermore, measuring means can be arranged with which the vertical height of the at least one cover mat can be detected, in particular in relation to a predetermined reference line.

Conveying elements are also preferably provided for conveying two lateral separating tracks in the conveying direction, so that the lower separating track together with the two lateral separating tracks form a section perpendicular to the conveying direction U-shaped and upwardly open receiving area for the reactive mixture. The upper parting sheet is preferably narrower than the clear width between the two lateral parting sheets.

At least three cover mats are advantageously arranged following in the conveying direction. Furthermore, it can be provided that at least three cover mats are arranged in the foaming zone of the foam block, with at least one further cover mat following the foaming zone.

The lifting drive preferably comprises an electric motor which drives a drum with which a rope or cable can be wound which is connected to the cover mat. The force sensor can, but does not have to, be arranged at the transition from the rope or cable to the cover mat. The electric motor is preferably a servo motor and / or the drum is preferably connected to an incremental encoder in order to detect the angle of rotation of the drum. This makes it possible in a simple manner to determine the effective vertical height of the cover mat and thus the height of the foam block at the location of the cover mat.

The at least one cover mat is preferably connected to a guide arrangement which guides the cover mat relative to a stationary machine part during its upward and downward movement, the guide arrangement preferably being an articulated frame or a linear guide.

The guide arrangement is preferably provided with roller bearings or roller guides for the purpose of low-friction movement of the cover mat.

Thanks to the proposed procedure, it becomes possible to automate the process of placing the mats on the foam block. As a result, fewer personnel are advantageously required at the start of the manufacturing process. Furthermore, it is advantageous that, as a result of the proposed procedure, it is not based on the visual impression of an employee, but instead is based on a measurable physical variable.

In addition, the timing of the laying of the mats is reproducible through the automation. In this way, the lowering of the individual mats can be triggered depending on the conveyor speed at a defined time before the start of production. This makes it possible to optimize the process so that the desired block shape is achieved as early and reproducibly as possible.

When the mats are in place, the force of the mat on the foam can be determined or precisely maintained by measuring the force of the rope. The desired rope force is regulated by a control loop in which the torque of the motor or, alternatively, the positioning of the motor axis is set according to the measured rope force or in which, alternatively, the motor axis is positioned according to the measured rope force.

• 1 schematisch einen Teil einer Vorrichtung zur Herstellung von Schaumstoffblöcken, wobei auf die Oberseite des Schaumstoffblocks eine Abdeckmatte aufgelegt ist, gesehen in Förderrichtung des Schaumstoffblocks,
• 2 die seitliche Ansicht des Teils der Vorrichtung gemäß 1, wobei eine Führungsanordnung zur Führung der Abdeckmatte in Form eines gelenkig ausgebildeten Gestells schematisch dargestellt ist,
• 3 den Teil der Vorrichtung gemäß 1, wobei eine Führungsanordnung zur Führung der Abdeckmatte in Form von Linearführungen schematisch dargestellt ist, und
• 4 schematisch den Teil der Vorrichtung gemäß 1, wobei in der oberen Darstellung die sich auf einer Referenzlinie befindliche Abdeckmatte und in der unteren Darstellung die auf den Schaumstoffblock abgesenkte Abdeckmatte dargestellt ist.

Exemplary embodiments of the invention are shown in the drawings. Show it:

• 1 schematically part of a device for the production of foam blocks, a cover mat being placed on top of the foam block, viewed in the conveying direction of the foam block,
• 2 the side view of the part of the device according to 1 , a guide arrangement for guiding the cover mat in the form of an articulated frame is shown schematically,
• 3 the part of the device according to 1 , wherein a guide arrangement for guiding the cover mat is shown schematically in the form of linear guides, and
• 4th schematically the part of the device according to 1 , wherein the cover mat located on a reference line is shown in the upper illustration and the cover mat lowered onto the foam block is shown in the lower illustration.

In the figures, a part of a device is shown with the foam blocks 1 can be produced. The basic procedure provided here is in the above-mentioned EP 1 683 618 A2 and therefore does not need to be explained in more detail here. In principle, a lower separating path (not shown) is provided in the conveying direction via a conveying device R. promoted; The lower separating sheet is laterally limited by two separating sheets (not shown), so that an upwardly open U-shaped “receiving trough” is formed, into which a liquid reactive mixture is introduced, which then foams up and the foam block 1 forms.

Specifically, a mixing head applies a liquid and foamable reactive mixture to the surface of the lower separating web. This foams up to form a foam block, while the lower separating path moves continuously in the conveying direction, for which purpose a corresponding conveying device is used, which is well known as such in the prior art; The same also applies to lateral parting sheets.

At the same time, an upper separating web (not shown) is applied to the foaming material from above, which also runs in the direction of conveyance R. is conveyed so that during the production process the foaming reactive mixture is located within the total of four separating tracks and in the conveying direction R. is promoted.

So that this in a section perpendicular to the conveying direction R. has as rectangular a shape as possible, at least one cover mat is placed on the top of the upper separating sheet 2 placed, which smooths the upper surface and thus promotes the formation of the rectangular shape.

• Die Abdeckmatte 2 ist mit einem Kabel oder Seil 10 verbunden, welches von einer Trommel 9 aufgewickelt werden kann. Die Trommel 9 ist mit einem Elektromotor 8 verbunden, der sie antreibt. Ferner ist eine Regeleinrichtung 4 vorhanden, die den Motor 8 ansteuert und mit einem Drehmoment M beaufschlagt. Zwischen dem Seil 10 und der Abdeckmatte 2 ist ein Kraftsensor 5 angeordnet, der die gemessene Seilkraft F einer Regeleinrichtung 4 zur Verfügung stellt; mit dem zwischen dem Seil 10 und der Abdeckmatte 2 angeordneten Kraftsensor 5 kann also die vom Seil 10 auf die Matte 2 wirkende Kraft F ermittelt werden. Über die Regeleinrichtung 4, die mit dem Kraftsensor 5 verbunden ist, ist auch der Elektromotor 8 signaltechnisch mit dem Kraftsensor 5 gekoppelt. Der Elektromotor 8, die Trommel 9 und das Seil bzw. Kabel 10 bilden insofern einen Hubantrieb 3, mit dem die Abdeckmatte 2 in gewünschter Weise angehoben und abgesenkt werden kann.

To automate and optimize the production process of the block foam, the arrangement outlined in all figures is provided, which is designed as follows:

• The cover mat 2 is with a cable or rope 10 connected, which from a drum 9 can be wound up. The drum 9 is with an electric motor 8th connected who drives them. There is also a control device 4th present that the engine 8th controls and with a torque M. applied. Between the rope 10 and the cover mat 2 is a force sensor 5 arranged that the measured rope force F. a control device 4th provides; with the one between the rope 10 and the cover mat 2 arranged force sensor 5 so can the rope 10 on the mat 2 Acting force F. be determined. Via the control device 4th that came with the force sensor 5 connected, is also the electric motor 8th signaling with the force sensor 5 coupled. The electric motor 8th , the drum 9 and the rope or cable 10 in this respect form a lifting drive 3 with which the cover mat 2 can be raised and lowered as desired.

With the arrangement explained, the cover mat is in place 2 with the lifting drive 3 in operative connection, the lifting drive 3 with the control device 4th communicates. Here the lift drive 3 on the cover mat 2 force exerted F. measured and the control device 4th forwarded. This ensures that the control device 4th by controlling the lifting drive 3 (and especially its electric motor 8th ) on the cover mat 2 force exerted F. can be kept at a predetermined value. The contact force of the cover mat during production can thus be measured using the force sensor 5 precisely adjusted, ie regulated. This is done via the electric motor 8th the rope 10 if the rope force is too high F. Lowered a little further and with too little rope force F. winds up a little further.

It is advantageous to provide (and for this purpose see 4th Reference) that at the same time the rope length relative to a reference point is automatically recorded and processed in a machine control system in such a way that the actual rise profile of the foam is determined on the basis of this data. To do this, in 4th a measuring device 6th for measuring the vertical height of the cover mat 2 sketched as well as a reference line 7th from which the vertical height H (see lower illustration in 4th ) the cover mat 2 certainly.

So that the control device 4th does not have to permanently readjust, it can be provided that the rope force F. is only readjusted if it deviates from the setpoint by a certain minimum value. This tolerance field is preferably in an interval between +/- 2 N and +/- 5N, based on the target value for the rope force F. .

The time at which the at least one cover mat is drained 2 after the start of production is preferably done automatically. In this process, after the start of production, the reactive mixture usually first flows against a so-called starter device (this is a barrier that prevents the liquid reactive mixture from flowing in the production direction indefinitely at the start of production) and then begins to expand according to its foaming characteristics. The laying of the mats 2 usually only takes place when the starting device has passed the area of the respective mat. With the help of the start position of the starting device and the production length (this can either be calculated using the production time after starting the conveyor device and the production speed or the paper length is measured directly with the help of an incremental encoder), the timing of the laying of the mats can be determined 2 thus fully automate.

In a preferred embodiment of the device described, there are at least three mats in the area of the foaming zone 2 and at least one mat immediately behind the foaming zone 2 intended.

As already mentioned above, the measuring device 6th the actual vertical height H the cover mat 2 with respect to a reference line 7th to be established. In this respect, the device described then contains means with the aid of which the rope length relative to the reference line 7th can be captured. This is given automatically, for example, when it comes to the electric motor 8th is a servo motor. Alternatively, the drum 9 on which the rope 10 is wound, can also be coupled with an incremental encoder. First of all, the reference point or the reference line must be 7th be determined. If the drum diameter is known, then only the number of revolutions of the drum is required 9 relative to this reference position, whereby the rope length can easily be calculated relative to this reference point and thus also the effective vertical height H the cover mat 2 .

As a result, the device can be used at the same time to determine the actual rise profile of the foaming reactive mixture and to make this data available to the operator as information in graphical or tabular form. This gives the operator valuable information about the process that he can use to adjust chemical or mechanical process parameters if necessary. If necessary, such adjustments could also be automated or partially automated.

The proposed device thus makes it possible in a simple manner to implement measures for optimizing the process for producing foam in a continuous block foam process.

It is important that the height adjustment of the cover mat 2 is designed to be low-friction. Due to the static friction forces, the force sensor 5 depending on the last direction of rotation of the rope drum 9 different rope forces for the same support forces F. measure up. In addition, the static friction ensures that in the event of readjustment, in which only the rope force initially changes, the static friction must first be overcome before the cover mat moves or before the actual contact force of the mat on the foam block changes.

Since the block shape in the corners reacts very sensitively to the actual contact forces of the mat, it is important to keep this effect as low as possible.

The guidance of the cover mat 2 relative to a stationary machine part 13th (Frame) must therefore be designed with low friction. Two embodiments of such guide arrangements 11 , 12th are in the 2 and 3 illustrated. In 2 is as a guide arrangement 11 an articulated frame is provided. In 3 come linear guides 12th for use.

Rolling bearings or rolling guides are preferred for the bearing points 14th (in particular designed as ball bushings) used to keep the friction low.

List of reference symbols

1

Foam block

2

Cover mat

3rd

Lifting drive

4th

Control device

5

Force sensor

6th

Measuring equipment for measuring the vertical height of the cover mat (incremental encoder)

7th

Reference line

8th

Electric motor

9

drum

10

Cable / rope

11, 12

Guide arrangement

11

articulated frame

12th

Linear guide

13th

stationary machine part

14th

Rolling bearings / rolling guides

R.

Conveying direction

F.

force

M.

Torque

H

vertical height

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1683618 A2 [0002, 0003, 0022]
• DE 2123216 C3 [0002]

Non-patent literature cited

• The best-known processes of this type are known as the "Petzetakis process" and "Hennecke-Planibloc process" (see Prof. Dr. Gerhard W. Becker et al. "Kunststoffhandbuch", Volume 7, "Polyurethane", 2. Edition, ISBN 3-446-13614-2, pages 176-177) [0003]

Claims (15)

Process for the continuous production of foam blocks (1), in which a reactive mixture is applied to a lower separating web and conveyed in a conveying direction (R), an upper separating web being applied to the foaming reactive mixture and at least one flat cover mat (2) of is placed on top of the upper separating web in order to give the foam block (1) a flat upper surface, characterized in that the at least one cover mat (2) is in operative connection with a lifting drive (3), the lifting drive (3) with a Control device (4) is connected, which regulates the vertical height of the at least one cover mat (2), that the force (F) exerted by the lifting drive (3) on the cover mat (2) is measured and fed to the control device (4) and that the control device (4) by activating the lifting drive (3) keeps the force (F) exerted on the cover mat (2) at a predetermined value. Procedure according to Claim 1 , characterized in that in the case of a force (F) which is too low in comparison with a predetermined target value, the at least one cover mat (2) is raised by the lifting drive (3) caused by the control device (4) and that in the case of a in comparison with the predetermined Setpoint too high exerted force (F) which at least one cover mat (2) caused by the control device (4) is lowered by the lifting drive (3). Procedure according to Claim 1 or 2 , characterized in that the vertical position of the at least one cover mat (2) is detected and transmitted to a process control station or a machine control. Procedure according to Claim 3 , characterized in that the actual height of the foam block produced at the location of the cover mat (2) is determined and output, in particular displayed on a screen, in the process control room or in the machine control based on the transmitted vertical position of the at least one cover mat (2). Method according to one of the Claims 1 until 4th , characterized in that at the start of production of the production of the foam block (1) the lowering of the at least one cover mat (2) from an out-of-service position to the upper separating path takes place automatically from a process control station or from a machine control, as soon as a specified one after the start of production Time has elapsed and / or a predetermined conveying path of the lower separating path has been reached. Device for the continuous production of foam blocks (1), which has: - conveying elements for conveying a lower separating path in a conveying direction (R) to which the reactive mixture can be applied, - conveying elements for applying an upper separating path to the foaming reactive mixture and - at least one flat formed cover mat (2) which can be placed from above on the upper separating sheet in order to give the foam block (1) a flat upper surface, in particular for carrying out the method according to one of the Claims 1 until 5 , characterized by a lifting drive (3) for vertical lifting and lowering of the at least one cover mat (2), a control device (4) for controlling the lifting drive (3) and at least one force sensor (5) with which the lifting drive (3) is triggered the force (F) acting at least one cover mat (2) can be measured, the force sensor (5) being connected to the control device (4). Device according to Claim 6 , characterized in that measuring means (6) are arranged with which the vertical height (h) of the at least one cover mat (2) can be detected, in particular with reference to a predetermined reference line (7). Device according to Claim 6 or 7th , characterized in that conveyor elements are provided for conveying two lateral separating tracks in the conveying direction (R), so that the lower separating track together with the two lateral separating tracks have a U-shaped receiving area open at the top in a section perpendicular to the conveying direction (R) form the reactive mixture. Device according to Claim 8 , characterized in that the upper separating strip is narrower than the clear width between the two lateral separating strips. Device according to one of the Claims 6 until 9 , characterized in that at least three cover mats (2) are arranged following in the conveying direction (R). Device according to Claim 10 , characterized in that at least three cover mats (2) are arranged in the foaming zone of the foam block (1), with at least one further cover mat (2) following the foaming zone. Device according to one of the Claims 6 until 11 , characterized in that the lifting drive (3) comprises an electric motor (8) which drives a drum (9) with which a rope or cable (10) can be wound, which is connected to the cover mat (2). Device according to Claim 12 , characterized in that the electric motor (8) is a servo motor and / or that the drum (9) is connected to an incremental encoder in order to detect the angle of rotation of the drum (9). Device according to one of the Claims 6 until 13th , characterized in that the at least one cover mat (2) is connected to a guide arrangement (11, 12) which guides the cover mat (2) relative to a stationary machine part (13) during its upward and downward movement, the guide arrangement (11 , 12) is preferably an articulated frame or a linear guide. Device according to Claim 14 , characterized in that the guide arrangement (11, 12) is provided with roller bearings or roller guides (14) for the purpose of low-friction movement of the cover mat (2).

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