Apparatus and method for producing insulation panels

Abstract

The invention relates to an apparatus and a method for producing insulation panels or sound protection panels from a pressed stock mat (2) consisting at least partially of lignocellulosic particles wetted with binding agents, wherein the apparatus has an inlet zone (Z1) between two revolving screening belts (5a, 5b), the distance between which becomes smaller in the pressed stock mat running direction, and a calibration zone (Z2) for heating and curing the pressed stock mat (2) with the aid of at least two opposite calibration plates (3a, 3b; 3c, 3d; 3e, 3f), i.e. at least one pair of calibration plates (7a, 7b), wherein revolving screening belts (5a, 5b) driven in the calibration zone (Z2) are movable in the pressed stock mat running direction through a calibration gap (20) between the at least two calibration plates (3a, 3b; 3c, 3d; 3e, 3f) in contact with the upper and the lower pressed stock mat surface. In order to keep the peak loadings on the screening belts as low as possible, it is provided that the at least two calibration plates (3a, 3b; 3c, 3d; 3e, 3f) are not parallel to one another at least in an entry region (E) to the calibration zone (Z2).

Description

[0001] The invention relates to a device for producing insulating or soundproofing panels from a pressed mat consisting at least partially of lignocellulosic particles wetted with binders, wherein the device has an inlet zone between two circumferential screen belts whose distance decreases in the direction of travel of the pressed mat and a calibration zone for heating and hardening the pressed mat with the aid of at least two opposing calibration plates, wherein in the calibration zone driven circumferential screen belts in contact with the upper and lower surfaces of the pressed mat are movable through a calibration gap in the direction of travel of the pressed mat between the at least two calibration plates.

[0002] The invention further relates to a method for producing insulating or soundproofing panels from a pressed mat consisting at least partially of lignocellulosic particles wetted with binders, using the aforementioned device.

[0003] Such a device has been published, for example, in DE 10 2008 039 720 B4. In some cases, such devices are connected in series with pre-compression devices or post-pressing devices, e.g., continuous presses, but these are not relevant to the invention. Products manufactured using this device are offered, for example, by SOPREMA GmbH under the name Pavatex or by H. Henselmann GmbH + Co KG under the name Gutex.

[0004] Suitable binders include those based on the principle of polycondensation or polyaddition, such as PMDI.

[0005] Another example from the prior art is provided by DE 10 2008 057 557 A1, which already clearly names the two zones. In the first zone, the circulating screen belts transporting the mat to be pressed run in a wedge shape, compacting the mat of material to be pressed, until they reach the second zone, where they guide the mat of material through a calibration zone formed by at least two parallel heated plates.

[0006] Furthermore, a method for producing insulating and / or soundproofing panels from wood fibers is known from DE 10 2007 044161 A1. In this method, the scattered mat is deaerated and pre-compacted in a pre-compaction unit before the final compaction takes place in a calibration and curing unit.

[0007] Finally, a method and a device for manufacturing wood-based panels are also known from DE 20 58 820 A1. There, a pre-compacted mass is introduced into a plasticizing gap into which a hot gas is introduced, before the mass is pressed to its final density in a subsequent parallel calibration gap.

[0008] The invention aims to enable the production of insulation boards with densities of 100-240 kg / m². A key focus is also on the manufacture of particularly thin insulation boards, down to a thickness of 5 mm. The sieve belts – or simply sieves – serve to guide the compressed material mat through the device at a desired speed by being driven at the same speed as the mat is to be transported. Steam can be introduced into the compressed material mat from the outside through the sieve, or liquid and air can be removed.

[0009] In the infeed zone, where the screens converge in a wedge-shaped fashion (achieved, for example, by an oscillating motion of the upper or lower belt), the height of the material mat to be calibrated is reduced. This reduction is typically already 100 to a maximum of 120% of the final thickness of the product before the mat enters the second zone, the calibration zone. Although steam can also be applied in this first zone, the infeed zone, the material mat is only softened on the surface. Thus, the material mat's modulus of elasticity is not yet significantly reduced in this infeed zone of the device.Although the vapor deposition in the inlet zone softens the surface of the mat, thereby reducing friction in the calibration zone, it is unfortunately observed that both the mat and the device are subjected to particularly high, almost impact-like forces as they enter the calibration zone, specifically the area between the first calibration plates. This, in turn, causes the screens to be pressed against the pressing mat and the calibration plates with considerable force. The resulting increase in friction is only tolerable to a limited extent for the screens. Additionally, this creates local compaction at the edges of the pressing mat.

[0010] It has been found that with such devices, the screens, which consist of plastic or wire mesh, reach their tensile strength limits when a certain drive power is exceeded. This inevitably leads to limited productivity (currently limited to approximately 8 t / h for a 60 mm thick pressing mat). When the permeable screens reach their maximum tensile strength, this results in a limitation on the length of the curing section, which depends on the initial pressing force on the screen at the beginning of the calibration zone. The required curing time of the binder thus determines the maximum length of the curing section and the achievable speed for a rotating screen.

[0011] On the other hand, to increase production, one would also like to increase the production speed. Therefore, the purpose of the invention is to keep the peak loads on the sieve as low as possible so that it has a longer service life.

[0012] With regard to the device, the problem is solved by the features of claim 1 and in particular by the fact that the at least two calibration plates (at least in the entry area) of the calibration zone are not parallel to each other and that the non-parallel opposing calibration plates are followed by calibration plates that are parallel to each other, wherein a joint is provided between the non-parallel pair of calibration plates and a following parallel pair of calibration plates on at least one calibration plate.

[0013] The non-parallelism must preferably, but not necessarily, be formed by two flat calibration plate surfaces facing the pressing mat; it can also be achieved to a certain extent by curved surfaces. This would, for example, result in a progressive or degressive change in the height of the calibration gap along its length in the direction of travel of the pressing mat.

[0014] The inventors, taking into account that the load on the pressing mat and screen is greatest immediately at the entrance to the calibration zone, i.e., at the point where the calibration plates meet, and thus represents the bottleneck preventing an increase in transport speed because the frictional forces on the screen would be too great, recognized that this can be mitigated by a slight inclination, i.e., a non-parallel alignment of at least two opposing calibration plates to each other, without compromising the calibration effect. It is of great importance that, in addition to reducing the belt load, the technological properties of the product are maintained, in particular a desired thickness or density profile across the cross-section at the outlet of the device.This is precisely what can be achieved with the upper and lower calibration plates positioned at an angle to each other at the entrance to the calibration zone.

[0015] Especially when, preferably, an angle other than 0° is provided between the at least two sides of the calibration plates facing the pressing mat, the transition from the entry zone, in which only the surfaces of the mat can be vaporized and thus no change in elasticity and hardening penetrating the pressing mat has yet taken place, to a greatly reduced mat thickness can be reduced in terms of force.

[0016] Preferably, the distance between the at least two calibration plates forming the calibration plate pair narrows in the direction of travel of the compressed material mats. Tests have shown that, understandably depending on the composition of the compressed material mats and their existing compression or thickness, the pressure on the mat or the sieves can be kept largely uniform even in the entry area into the calibration plate pair.

[0017] For this purpose, it is advantageous if the maximum difference in distance between the widest and narrowest gap of the calibration plate pair is 50%, preferably 25% of the mat thickness in the entry area.

[0018] For this to happen, at least one calibration plate must be positioned at an angle to the horizontal in the entry area of ​​the calibration zone.

[0019] This is possible with a pre-defined angle limited to the product, whereby, for example, one of the calibration plates is permanently installed at an angle to the horizontal in the entry area of ​​the calibration zone.

[0020] Alternatively, a calibration plate is provided which is arranged to be tiltable via a joint and where the tilting of this calibration plate from the horizontal plane is achieved by means of a defined, insertable wedge.

[0021] Preferably, a joint and a motorized angle adjustment, for example an actuator cylinder, are used on a calibration plate. This is particularly advantageous because the angle can be adjusted automatically.

[0022] In accordance with the currently used calibration plate lengths, it is sufficient if an adjustment device is provided with which an angle between 0.1 and 15° can be set.

[0023] The angle adjustment can be automated, for example, if the thickness of the pressing mat is measured using an optoelectronic measuring device and the angle is adjusted based on this measurement via a control unit of an angle adjustment device. Since the thickness of the pressing mats can vary between 5 and 300 mm, and producers frequently change their product, such automatic adjustment is advantageous.

[0024] According to the invention, only the calibration plates in the entry area to the calibration zone are arranged at an angle to the horizontal. It is entirely possible for pairs of calibration plates to follow, arranged parallel and at a constant distance. However, an angled position that causes a relaxation effect, for example at the exit of the calibration zone, is also not excluded by the invention.

[0025] The calibration plates are heated. Several methods are available for this. Heating via internal channels using a temperature control fluid, such as oil, water, steam, or hot air, is particularly common. Alternatively, a different or the same hot medium, preferably steam, a steam-air mixture, or hot air alone, can be introduced into the pressing mat from below and / or above the calibration plates. If this introduction of steam (or hot air) into the pressing mat, particularly in the case of thick mats, only reaches half its thickness, steam (or hot air) can also be introduced from the opposite calibration plate to heat the mat through.With thinner pressing mats, it is also quite possible to introduce steam or hot air into the mat from one side and then extract the warm steam, condensate, or warm air again using a calibration plate with a suction device on the opposite side. In this way, the pressing mat can also be heated completely.

[0026] The penetrating of heat and moisture into the pressed material mat can cause the binder (e.g. PMDI) to harden quickly.

[0027] It is also possible to introduce a gas that reacts differently with the binder into the pressed material mat instead of the hot medium, so that the binder hardens.

[0028] The object of the invention is achieved with regard to the method by the features of claim 11 and in particular by the fact that the calibration gap between the at least two calibration plates (at least in the entry area) is not set to a constant height in the direction of travel of the press mats and that the calibration plates are set at an angle to each other, at least in the entry area of ​​the calibration zone, so that the distance between the at least two calibration plates decreases in the direction of travel of the press mats, wherein the angle is automatically set based on a measurement of the thickness of the press mats via an angle adjustment device.

[0029] The method has dependent method claims analogous to the device claims, so that the advantages can be derived from the device already described.

[0030] The invention will now be explained in more detail with reference to exemplary embodiments illustrated in the drawings. These show Fig. 1 a side view of a complete device according to the invention, Fig. 2 a section of the front part of a device according to the invention as shown in Fig. 1 As an example, circled in Fig. 3 is a schematic cutaway view of two consecutive pairs of calibration plates.

[0031] Fig. 1Figure 1 shows a side view of the device according to the invention for the production of insulation boards and soundproofing boards. The device has a frame 13 on both sides of the treatment section for the production of the insulation boards, of which only one side is visible due to the side view of the device. The device has an upper system section 6a and a lower system section 6b, in each system section having at least one driven screen belt (hereinafter referred to as a screen) rotating. Each screen 5a, 5b is guided and tensioned by deflecting rollers 8. Between the upper rotating screen belt 5a and a lower rotating screen belt 5b, i.e., between the upper and lower system sections, a pressable mat 2, which consists at least partially of lignocellulosic particles wetted with binders, is treated in an entry zone Z1, a calibration zone Z2, and a cooling zone Z3.The pressing mat is guided, at least partially, by the sieves 5a and 5b, which are positioned above and below, respectively. The calibration zone Z2 begins at the point where it enters between the first two calibration plates 3a and 3b, which are positioned opposite each other and thus form a calibration plate pair 7a. This is clearer in the section of the figure. Figure 2 to recognize. The pressing mat 2 has almost reached its final thickness at the end of the inlet zone Z1 before it enters the calibration zone Z2.

[0032] The complete device according to Fig. 1 The device thus has an inlet zone Z1 in which the two sieves 5a and 5b converge in a wedge-shaped manner and guide the pressing mat 2, compressing it, into the first gap between two calibration plates 3a and 3b. However, according to the invention, another pair of circumferential sieves could also guide the pressing mat 2 through the calibration zone Z2.

[0033] Steam blow boxes 4 are arranged on both sides of the gusset in the inlet zone Z1, which soften the surface of the pressing mat. The number of these steam blow boxes 4 depends on the composition of the pressing mat 2. Since the thickness of the pressing mat can vary considerably, the angle of the gusset can be adjusted via the inlet height adjustment 10. This design of the inlet zone Z1 is essentially known from the prior art.

[0034] The inclusion of a cooling zone Z3 at the outlet of the device, where the hot, now calibrated and hardened, hot insulation plate is cooled via an air cooling system 12, is also in accordance with the state of the art.

[0035] In the past, production speeds were severely limited by the tensile strength limits of the screens 5a and 5b, as the friction of the screens at the entrance to the calibration zone was very high. The calibration plate pairs (for example, 3a and 3b, or 3c and 3d, or 3e and 3f) were always formed by parallel calibration plates. This resulted in a very high force being applied to the screens or the pressing mat at the transition from the entrance zone to the calibration zone. According to the invention, therefore, at least in the inlet area E of the calibration zone Z2, two calibration plates are arranged at an angle α to each other. In the direction of travel of the pressing mat (from left to right in the figures), the calibration gap narrows, so that the pressure on the screen remains approximately constant. Nevertheless, the pressing mat 2 is already calibrated in this inlet area E by means of heat and moisture acting on the binder in the pressing mat.This is achieved using the first two opposing calibration plates 3a and 3b. These are followed by pairs of calibration plates (3c and 3d, or 3e and 3f) where the parallel alignment of the surfaces is predetermined. This constant distance between the pairs of calibration plates is adjusted via height adjustments 16.

[0036] The circled area of Fig. 1 and the enlarged representation according to Fig. 2 have a distinguishing feature for the same adjustability of the angle α of the calibration plate 3a. In Fig. 1 This adjustment is made via an adjustment device 15, which also adjusts the gusset 11. The angle adjustment device 15 and the inlet height adjustment 10 thus form a single unit. In contrast, in Fig. 2A separate adjusting cylinder is provided on both sides of the angle adjustment device 15. In both cases, an angle between 0.1 and 15° can be set for the inclination of the calibration plate 3a from the horizontal. Naturally, the invention is not limited to the angular adjustability of the first upper calibration plate 3a in the entry area E of the calibration zone Z2. To achieve the same force-impact-minimizing effect, other calibration plates can, of course, also be angle-adjustable or angle-adjustable. The entire calibration gap 20 along the length of the device can therefore change.

[0037] The angle α can also be set fully automatically based on a measured value of the press mat thickness. Such a measuring device, for example an optoelectronic measuring device 21, can be installed upstream of the calibration zone Z2.

[0038] Fig. 3Figure 1 schematically shows the first four calibration plates 3a, 3b, 3c, and 3d. Calibration plates 3a and 3b, as well as calibration plates 3c and 3d, are positioned opposite each other. The calibration plates are shown in schematic section and, in this embodiment, either have a channel system with steam heating 17 and steam outlets 18 facing the calibration gap 20, i.e., in the case of a press mat being passed through, in the direction of the mat. Or they have a suction device 19 with which steam (or a steam-air mixture and / or liquid) passing through the mat can be extracted. Alternatively, warm air or another reactive gas can simply be used to heat the press mat 2 and to harden the binder.

[0039] The essential concept of the invention is again clearly evident in the calibration plate 3a. It is located at the front (in the direction of travel of the press mats) in the inlet area E. Fig. 3The gap height difference h is raised by the angle adjustment device 15 (not shown) around the joint 14 from the horizontal position, i.e., the position parallel to the calibration plate 3b, by a gap height difference amount h. This results in an angle α, which can be fixed, adjustable, or even controllable. The gap height difference h should be a maximum of 50% of the pressed material mat height in front of the entry area E before the calibration zone Z2, preferably even a maximum of 25%.

[0040] The opposing calibration plates 3c and 3d are then arranged parallel again for the final curing of the binder.

[0041] In Fig. 3 It is also shown that the flow direction of the steam can change from a calibration plate 3b, 3c with steam outlet 18 to an extracting calibration plate 3a, 3d (but does not necessarily have to).

[0042] Since the entry area E, with its non-parallelism of the opposing calibration plates 3a and 3b, extends in this case to the joint 14, while the calibration plates 3b and 3d on the other side of the calibration gap 20 are virtually in a line, the invention is also intended to cover situations where two calibration plates 3a and 3c are provided above the pressing mat with the joint 14 between them, and the calibration plates 3b and 3d are combined into one below the calibration gap 20. Accordingly, the arrangement could also be reversed if the joint 14 is located below the calibration gap 20. Fig. 3 so it would be turned upside down.

[0043] For a fixed angle setting, it is also possible to combine calibration plates 3a and 3c into a single calibration plate. This means that a calibration plate would be used that is already manufactured bent or folded at an angle α. Reference symbol list 1 Device for the production of insulation boards 2 Pressed material mat 3a, 3b, 3c, 3d, 3e, 3f calibration plate 4 Steam blow box 5a, 5b screen belt 6a, 6b Upper or lower part of the plant 7a, 7b Calibration plate pair 8 deflection roller 9 Plant frame 10 Inlet height adjustment 11 gore 12 Air cooling 13 frame 14 joint 15 Angle adjustment device 16 Height adjustment calibration plate 17 Steam heating 18 Steam outlet 19 Suction device 20 Calibration gap 21 Measuring device Z1 Entrance area Z2 Calibration zone Z3 Cooling zone E Entry area into calibration zone h Gap height difference α Angle of a calibration plate to the horizontal

Claims

1. Device for the manufacture of insulation or noise protection panels from a pressed material mat (2) consisting at least partially of lignocellulosic particles coated with binding agents, wherein the device comprises an inlet zone (Z1) between two circulating screen belts (5a, 5b), the space between which decreases in the direction of travel of the pressed material mat, and a calibration zone (Z2) for heating through and hardening the pressed material mat (2) by means of at least two calibration plates (3a, 3b; 3c, 3d; 3e, 3f), arranged opposite each other, i.e. at least one calibration plate pair (7a, 7b), wherein in the calibration zone (Z2) driven circulating screen belts (5a, 5b) in contact with the upper and lower pressed material mat surface are moveable between the at least two calibration plates (3a, 3b; 3c, 3d; 3e, 3f) through a calibration gap (20) in the direction of travel of the pressed material mat, wherein the at least two calibration plates (3a, 3b) are not in parallel to each other, at least in an inlet area (E) of the calibration zone (Z2), and the non-parallel opposite calibration plates (3a, 3b) are followed by calibration plates (3c, 3d) that are in parallel to each other, wherein between the non-parallel calibration plate pair (7a) and a following parallel calibration plate pair (7b), a joint (14) is provided on at least one calibration plate (3a).

2. Device according to claim 1, characterised in that an angle (α) not equal to 0° is provided between the at least two sides of the calibration plates (3a, 3b) facing the pressed material mat (2), at least in the inlet area (E).

3. Device according to claim 1 or 2, characterised in that the distance between the at least two calibration plates (3a, 3b) forming the calibration plate pair (7a), decreases in the direction of travel of the pressed material mat.

4. Device according to claim 3, characterised in that the maximum difference in distance (h) between the widest and the narrowest gap of the calibration plate pair is 50 %, preferably 25 % of the mat thickness directly before the inlet area (E).

5. Device according to any one of claims 2 to 4, characterised in that the angle (α) can be set between 0.1° and 15.0° by way of an angle adjustment device (15).

6. Device according to any one of claims 2 to 5, characterised in that angle (α) can be automatically set depending on the height of the pressed material mat.

7. Device according to any one of claims 1 to 6, characterised in that the calibration plates (3a, 3b; 3c, 3d; 3e, 3f) are heatable plates8. Device according to claim 7, characterised in that at least one of the calibration plates (3b, 3c) can be heated with steam.

9. Device according to claim 8, characterised in that the at least one calibration plate (3b, 3c) is designed so that steam can flow out of the steam outlet openings (18) in the direction of the pressed material mat (2).

10. Device according to claim 9, characterised in that the calibration plate (3a, 3d) opposite the calibration plate (3b, 3c) with steam outlet (18) is designed so that the steam penetrating through the pressed material mat (2) can be extracted by suction.

11. Method of manufacturing insulation or noise protection panels from a pressed material mat (2) consisting at least partially of lignocellulosic particles coated with binding agents, wherein the device comprises an inlet zone (Z1) between two circulating screen belts (5a, 5b), the space between which decreases in the direction of travel of the pressed material mat, and a calibration zone (Z2) for heating through and hardening the pressed material mat (2) by means of at least two calibration plates (3a, 3b, 3c, 3d, 3e, 3f), arranged opposite each other, i.e. at least one calibration plate pair (7a, 7b), wherein in the calibration zone (Z2) driven circulating screen belts (5a, 5b) in contact with the upper and lower pressed material mat surface are moveable between the at least two calibration plates (3a, 3b; 3c, 3d; 3e, 3f) through a calibration gap (20) in the direction of travel of the pressed material mat, wherein the calibration gap (20) between the at least two calibration plates (3a, 3b) in the direction of travel of the pressed material mat is not set at a constant height and the calibration plates (3a, 3b), at least in the inlet area (E) of the calibration zone (Z2), are set at an angle (α) with regard to each other so that the distance between the at least two calibration plates (3a, 3b) decreases in the direction of travel of the pressed material mat, wherein the angle (α) is automatically set by an angle adjustment device (15) on the basis of a measurement of the pressed material mat thickness.

12. Method according to claim 11, characterised in that the angle (α) is set so that the pressure on the pressed material mat (2) remains essentially constant over the length of the calibration plate pair (7a) in the direction of travel of the pressed material mat.

13. Method according to any one of claims 11 or 12, characterised in that steam is applied to the pressed material mat (2) between the at least two calibration plates (3a, 3b; 3c, 3d; 3e, 3f).

14. Method according to any one of claims 11 to 13, characterised in that arranged after the inlet area (E) is a section of calibration plate pairs (3c, 3d) extending in parallel.

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