FI122590B - Method and equipment for temperature measurement in the manufacture of glulam or similar product - Google Patents

Abstract

The object of the invention is a method and an apparatus for measuring temperatures in connection with the manufacturing of glue board (10) or a corresponding product, wherein the glue board (10) is manufactured from wooden laths (2) that are placed adjacent to each other and glued together, in the gluing stage of which the wooden laths (2) and the glued joints are heated and pressed against each other with a press apparatus (7). According to the invention the temperature of at least the glued joints of the glue board (10) is measured after pressing by imaging the glue board with a thermographic camera (9).

Description

METHOD AND APPARATUS FOR MEASURING TEMPERATURES IN THE CONTEXT OF MANUFACTURE OF ADHESIVE PLATE OR SIMILAR PRODUCT

The invention relates to a method as described in the preamble of claim 1 and to an apparatus for measuring temperatures in the manufacture of an adhesive board or the like product as claimed in the preamble of claim 8.

In the sawmill industry, one of the products to be manufactured is the so-called "glue board", which is made from sawn pieces of wood, such as sawmills, which are glued together in parallel. Ready-made adhesive boards are used for wide plate surfaces such as tables, doors, cabinets and shelves. In such large sheet surfaces, wood living must be controlled such that the sheet does not deform due to, for example, air temperature and humidity. In order to prevent warping, the parallel pieces of the glue board made of logs are placed so that the heartwood is alternately lower and higher.

20 The gluing board is made by sawing the wood strips to the desired length before gluing, and edging and planing the sides. Thereafter, glue is applied to the sides of the ribs and they are glued side by side, whereupon the pieces glued together are fitted to a press which is arranged to press the pieces together as the glue dries. As is known in the sawing press industry, there are also generally means for heating the adhesive joints between the pieces glued together to a suitable temperature, which improves the final result of the gluing and accelerates the drying of the glue. In order to obtain sufficient process speed in the compression step, for example, so-called. radio frequency-x presses, also known as shorter RF-° · presses. The advantage of these presses is high speed because

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In addition to 35 compression, the RF presses heat up virtually only rC fluid-containing adhesive joints in electromagnetic fields

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with the heat generated. For the best gluing, the temperature should remain substantially the same for all glue joints throughout the gluing sheet, which in turn requires that the electromagnetic field producing the heat energy be as homogeneous as possible. However, a homogeneous electric field is difficult to implement and often the temperature varies at different points on the seam seams of the adhesive plate 5 in the press. Large temperature fluctuations in adhesive joints can cause gluing failure. Therefore, it is advisable to monitor temperatures during or after compression so that large temperature deviations can be detected and possibly unsuccessfully bonded adhesive plates can be redirected from the press to non-successful adhesive plates.

As is known, the temperature of the adhesive sheets has been monitored by manually measuring the adhesive sheet from the press at a few points, for example with a spot thermometer or an infrared thermometer. However, such measurements cannot in any way measure the temperatures at any point on the adhesive board, but only certain selected measurement points provide temperature values. As a result, any gluing error can easily be overlooked. Otherwise, such a measurement is not very practical, since measurements have to be made in-line when the adhesive plate has come out of the press.

It is an object of the present invention to eliminate the above-mentioned drawbacks and to provide a method and apparatus for measuring temperatures in connection with the manufacture of an excess sheet or the like, which is as cheap and simple as possible. It is also intended that the temperatures d - of the adhesive sheet and its adhesive seams can be observed during the application of the adhesive sheet throughout the adhesive sheet. 30 areas in real time. For the method according to the invention

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is characterized by what is disclosed in the Q characterization portion of claim 1 cc. Correspondingly, the apparatus according to the invention is characterized by what is claimed

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In the solution according to the invention, the temperatures of the logs and glue joints are determined by digital imaging. In this case, the temperature displayed by each pixel of the resulting image is obtainable separately, each pixel being, in principle, a separate 5 temperature gauge. Thus, substantially all temperatures in the entire image area are seen on the screen at substantially the same time, even at a glance. The image area to be imaged can be very large, for example 6 * 2 m = 12 m2, whereby it is important that the image area temperatures can be analyzed very quickly. It is also an advantage of the solution according to the invention that it can be used to observe the temperatures of the adhesive board and its adhesive seams during or immediately after the pressing of the entire area of the adhesive board. A further advantage is that the temperature of the adhesive board does not need to be measured manually on site, but the measurement is done automatically and the measurement results can be viewed in real time from, for example, a monitor in the control room. It is also an advantage that the solution combines two existing prior art technologies which have been previously used and have been tested, developed and found to work well. A further advantage is that the solution according to the invention is simple and inexpensive to implement.

The invention will now be explained in more detail by means of two different embodiments, with reference to the accompanying drawings, in which:

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Fig. 1 is a diagrammatic view of an adhesive sheet manufacturing line τΐ employing one embodiment of the solution of the present invention;

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Fig. 2 is a diagrammatic view of an adhesive sheet manufacturing line employing another embodiment of the solution of the present invention and ...

lo Figure 3 shows an image taken by the thermal camera of an adhesive plate from the press o 35.

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Fig. 1 is an exemplary diagram of an adhesive board manufacturing line using one embodiment of the solution of the invention. The apparatus includes a line 1 with at least one or more conveyors for transporting the raw material of the glue board, such as the logs 2 and the manufactured glue board. At the beginning of the line 1 is a temperature measuring apparatus 3 for the logs 2 to be taken into line 1, such as a first infrared thermal camera recording a substantially continuous video image to a digital imaging sensor connected to a control and recording equipment 4 in the control room. further provided with a first display 5a for displaying in real time the temperature of the logs 2. The line 1 has, after the first thermal camera 3, a return conveyor 1a for returning to the intermediate storage 15 the logs 2a whose temperature is outside the permissible range. Such returnable wood strips 2a are guided to the return conveyor 1a either manually or automatically by suitable means. The direction of transport of the return conveyor 1a is indicated by dotted arrows.

After the first thermal camera 3, the line 1 has a gluing station 6, and thereafter, in the conveying direction of the line, a press apparatus 7 for clamping the glued logs 2 against each other and for heating and drying the glue joints between them. The press assembly 7 is, for example, a cm-high RF press in which, in addition to pressing, the glue joints of the adhesive plate are heated by means of an electromagnetic field. The clamping apparatus 7 is also connected to a computer 4 operating on the control and recording apparatus fsL 30. After the clamping apparatus 7

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in the direction of the line 1, its second measuring apparatus 9 operating in the infrared region for measuring the temperatures of the newly manufactured glue sheet 10, and in particular the glue joints, which, like the apparatus 3 for measuring the temperature of the logs 2, also has a substantially continuous video image.

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thermal imaging camera. The second thermal camera 9 is coupled to a control and training computer 4 in the control room equipped with a second display 5b for displaying substantially in real time the temperatures of the adhesive plate 10 and its adhesive seams. Further, at the end of line 1 there is a receiving station 5 Ib for the adhesive sheets 10 manufactured.

The method according to the invention is adapted to operate that the raw materials of the adhesive board, which in this embodiment are pre-flanged and planed logs 2, are initially guided from the intermediate storage to the first measuring element 3 arranged at the beginning of the line 1. Before being taken into the manufacturing process, the wood strips 2 are kept in an intermediate storage for a period of time at a substantially uniform temperature 15 to equalize their temperatures and to allow them to reach the permissible range. At the start of the line 1, substantially uniform heat drill rails 2 are arranged to pass beneath the first thermal camera 3 and thermal camera 3 is arranged to capture a substantially real-time video image showing the temperature of the upper surface 20 of each drill ridge 2 at various points throughout the surface. Different temperatures appear in pixels of different colors at a predetermined resolution. The first thermal camera 3 is connected, for example, to a computer 4 located in a control room or the like, on which the thermal camera 3 is arranged to transmit 25 video images it imposes. If, for example, the batches 2 of the raw material batches have a very different temperature or the burrs cvj are too cold for good gluing, o the burrs 2a which are too cold and deviate from the specified values of τΐ by the return conveyor la

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^ 30 back to intermediate storage to get the right temperature. Oh-

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The wood strips 2 belonging to the high temperature fork are guided from line 1 by the conveyors for stacking, gluing, pressing and measuring the temperature.

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Is § 35 A first display 5a is connected to the computer 4 which

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followed by the person assigned to look at the temperatures of the incoming wood 2. The temperature of the raw material 6 influences, among other things, how the RF press 7 placed downstream of the line 1 is adjusted to operate. For example, in the winter the raw material can be frozen and in the summer it can be warm, so the temperature of the raw material can vary very much, even within the permitted limits, in different seasons. Also, the RF press 7 is connected to a computer 4, by means of which the parameters of the press 7 are adjusted on the basis of the temperature observations made from the logs 2 by the first thermal camera 3. This adjustment can be made manually or auto-10, whereby the apparatus includes means for automatic adjustment. The heating energy adjustment is made, for example, by adjusting the electromagnetic field by changing the anode / cathode current.

The computer 4 further comprises means adapted, if necessary, to modify the image imaged by the thermal camera 3 to display, for example, temperatures corresponding to the colors shown in the image and possibly to suggest how the press 7 should be adjusted in each case.

20

From the first thermal camera 3, the logs 2 are led by a conveyor 1 through a conveyor to the gluing point 6, where glue is applied to the sides of the logs 2 and the logs 2 are placed in parallel. Thereafter, the glued wood strips 2 are led to an RF press 7 where the glued wood strips 2 are pressed against each other. In addition, heating means 8 are provided in connection with the press 7, by means of which the glued joints 2 and the glue joints between them are heated to a suitable temperature in order to achieve a maximum gluing. 30 well. The heating means 8 are, for example, metal plates,

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which are used to create an electromagnetic field that produces heat energy. Once the glued wood strips 2 have been in the press 7 for a predetermined period, they are guided on line 1 by means of a suitable carrier to the second measuring element 9 behind the press 7, in which the glued sheet 10, beneath one thermal camera 9 and another thermal camera 9 imaging an adhesive sheet 7 10, i.e., depicting a real-time video image of the adhesive sheet showing, for example, pixels across the entire area of the adhesive sheet 10 and its adhesive seams. The video image captured by the second thermal camera 9 is transmitted in substantially real-time 5 to the computer 4 and based on the data the temperatures of the adhesive plates 10, and in particular their seam joints, from the press 7 are analyzed. If the temperatures of all or just some of the adhesive joints on any of the adhesive sheets 10 deviate too much from the predetermined limits, the adhesive sheet is moved to the side of the line of adhesive sheets to be sold. Again, the temperature analysis and offset can be done either manually or automatically, in which case the equipment includes means for performing an automatic offset.

15

In manual monitoring, the second display 5b is followed, for example, by a person instructed to view the temperatures of the adhesive plates 10 and their adhesive seams from the press 7. If the temperature of one of the adhesive sheets 10, or particularly of its adhesive seams 20, deviates from normal, the person controlling the temperature may take a still image of that adhesive sheet 10, for example, by pressing a button for this purpose in computer 4. The images taken from the abnormal adhesive plates can be subsequently analyzed, which has resulted in abnormal temperatures and, for example, whether the gluing has failed due to abnormal temperatures. The resulting imaging result also easily shows if any seam or seam portion has no or no glue at all.

In this way, glue sheets that have been glued unsuccessfully can be removed from the list of successful ones. Successfully bonded C11 adhesive sheets are routed to finalization after imaging and analysis of the adhesive seams.

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I '- 00 ιλ As mentioned above 10, 10

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as well as monitoring the temperature of their adhesive seams and the actions taken on the basis thereof, such as adjusting the heating power of the press 7 and taking still pictures of abnormal adhesive sheets and pruning failed adhesive sheets can also be made fully automatic. In this case, there is no need for a person to monitor the temperatures and, based on the temperature-5 observations, take the necessary action manually.

Fig. 2 is an exemplary schematic view of an adhesive board manufacturing line using another embodiment of the solution 10 of the invention. In this solution, the displays 5a and 5b are not connected to a computer 4, but are directly connected to their own thermal cameras, wherein the first display 5a is connected to the first thermal camera 3 and the second display 5b is connected to the second thermal camera 9. Imaging data from the thermal cameras 15 and 4 in substantially the same manner as in the embodiment shown in Figure 1. Similarly, the connection between the computer 4 and the press assembly 7 is substantially similar to that of the solution of Figure 1.

Figure 3 is a simplified view of a single still image taken from the imaging data of another thermal camera 9 on a single glue sheet 10. In the figure, different temperatures appear in different shades of gray. In reality, there are many more colors and temperatures. The thermal states of the cooler portions of the adhesive board 10, i.e. the wood flues 2, are shown in Figure 3 and the temperatures of the warmer adhesive seals 11 are lighter. At one point in the adhesive cvj there is a colder region 12 where the temperature of the adhesive seams differs from that of the other adhesive seams 11. This difference is very clear in real-time video and in color. In addition, Fig. 3 shows the boundaries as transverse deviations 13 which

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may be due, for example, to the non-homogeneity of the generated electric field. The aim is to have an electric field as homogeneous as possible, so that in the case of Fig. 3, the piston assembly 7 needs new adjustments.

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It will be apparent to one skilled in the art that the invention is not limited to the above embodiment, but may vary within the scope of the claims set forth below. Thus, for example, the lineage may be different from that described above.

It will also be apparent to one skilled in the art that imaging means may be used in place of thermal cameras, other than a digital video camera operating in the infrared range, such as a corresponding analog video camera.

Furthermore, one of ordinary skill in the art will recognize that other suitable equipment may be used as an adhesive sheet press and heating device instead of an RF press. For example, heat discs using hot oil or the like, but slower than the RF press.

15

It will also be apparent to one skilled in the art that the apparatus may be automatically configured to record a thermal image and / or provide an alarm if a temperature below a predetermined threshold is detected in the subject being imaged.

The apparatus then has appropriate means and actuators for executing the recording and issuing the alarm.

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Claims (15)

A method for measuring temperatures in the manufacture of an adhesive board (10) or a similar product, wherein the adhesive board 5 (10) is produced from parallel-mounted and glued-together drill bits (2) in which the bark presses (2) and glue joints are heated and pressed against each other, characterized in that at least the temperature of the glue joints (11) between the logs (2) of the glue board (10) is measured after compression by imaging the glue board (10) with a thermal camera (9) and imaging data of the thermal camera (9) and recording equipment (4) for substantially real-time processing and analysis of imaging data. 15 Method according to Claim 1, characterized in that the imaging data produced by the thermal camera (9) is displayed in substantially real-time as a video image on the display (5b). Method according to claim 1 or 2, characterized in that the imaging data produced by the thermal camera (9) is processed such that different temperatures of the imaging object are displayed in different colors. A method according to any one of the preceding claims, characterized in that the imaging data provided by the thermal camera (9) is used to control the thermal energy output of the press apparatus (7). and i-30 Method according to one of the preceding claims, characterized in that, before being glued to the line (1), the temperature of the boreholes (2) is measured prior to gluing by the first thermal camera (3), and the battens (2a) o 35 outside the permissible temperature range are separated from the battens (2) to be glued and recycled to the intermediate storage. Method according to claim 5, characterized in that the imaging data produced by the first thermal camera (3) is displayed as a video image in substantially real-time on the display (5a). Method according to Claim 5 or 6, characterized in that the imaging data provided by the first thermal camera (3) adjusts the thermal energy production of the press apparatus (7) according to the temperatures of the raw wood (2). 10 Apparatus for measuring temperatures in connection with the manufacture of an adhesive board (10) or a similar product having an assembly (1) with at least one or more conveyors for conveying the adhesive board raw materials, such as burrs (2) 15 and the manufactured adhesive board (10). ) and a heating device (7) for producing heat energy in the conveying direction of the line (1) after the gluing station (6), followed by at least one temperature measuring device (9) for the manufactured glue board (10) and its glued seams (10). temperature measurement arranged to be performed by imaging the adhesive plate (10), characterized in that the measuring apparatus (9) is arranged to take a substantially real-time thermal camera image of the adhesive seams (11) between at least the raw materials of the adhesive plate (10), such as and that the law includes a road-c \ j token as a control and storage device ( 4) to which a thermal camera (9) for measuring the temperature of the manufactured adhesive plate (10) and its adhesive seals (11) is connected. rL 30 (M Apparatus according to Claim 8, characterized in that the temperature measuring apparatus (9) is a thermal imaging camera operating in the infrared region of a substantially continuous K video image on a digital imaging sensor. °, c o 35 cv Apparatus according to one of claims 8 to 9, characterized in that the apparatus comprises at least a display (5b) arranged to display imaging data produced by a thermal camera (9) measuring the temperature of the adhesive plate (10) in substantially real-time video. Apparatus according to any one of claims 8 to 10, characterized in that the apparatus comprises means for displaying different temperatures of the imaging objects in different colors. Apparatus according to one of claims 8 to 11, characterized in that the apparatus comprises means for adjusting the thermal energy output of the press apparatus (7) based on the imaging data provided by the thermal camera (9) measuring the temperature of the adhesive plate (10). 15 Apparatus according to one of Claims 8 to 12, characterized in that the apparatus comprises a temperature measuring device for the logs (2) to be glued before the gluing station (6), such as a thermal imaging camera (3) adapted for imaging. to your computer (4). Apparatus according to claim 13, characterized in that the apparatus comprises a display (5a) arranged to display imaging data produced by the thermal camera 25 (3) measuring the temperature of the logs (2) in substantially real-time video. c \ j Apparatus according to Claim 13 or 14, characterized in that the apparatus comprises means for adjusting the thermal energy output of the press apparatus (30) based on the imaging data produced by the thermal camera (3) which measures the temperature of the log mills (2). (M r ^. Oo LO r ^. O o {M