A simple startup method for a production system for manufacturing extrusion plates

Abstract

The present invention relates to an easy startup method for a production line for manufacturing extrusion plates. The present invention provides a method for starting a production line (10) for manufacturing extrusion plates (36), wherein an extruded semi-finished product (20) is pressed at a free end (48) toward a conveyor device (22), the conveyor device (22) is configured to transport the semi-finished product (20) to a separation device (32), a conveyor belt (40) extending in the direction of transport is provided on the conveyor (22), the free end (48) of the semi-finished product (20) is pressed onto the conveyor belt (40), the conveyor belt (40) is pulled toward the separation device (32) together with the semi-finished product (20), the free end (48) of the semi-finished product reaching the separation device (32) is introduced into the separation device (32), while the conveyor belt (40) is pulled away from the semi-finished product (20) upstream of the separation device (32). This allows for the cost-effective production of panels made from plates.

Description

Technology Field

[0001] The present invention relates to a method for facilitating the start-up of a production line for manufacturing extrusion plates. In particular, extrusion plates can be used to manufacture panels for covering the surface of a room. Background Technology

[0002] A production line for panels made of wood is known from WO 07 / 079845 A1, and the desired panel length can be separated from a longer semi-finished product by a cutting tool.

[0003] From EP 3 578 384 A1, a production line for panels made of plastic is disclosed, in which an infinite profile in the shape of a plate is first produced.

[0004] There is a continuous need to be able to produce panels cost-effectively.

[0005] The objective of the present invention is to demonstrate measures that enable the panel to be manufactured cost-effectively.

[0006] This objective is achieved by a method having the features of claim 1.

[0007] Preferred embodiments of the present invention are provided in the dependent claims and the following description, each of which may constitute an aspect of the present invention individually or in combination.

[0008] One aspect of the present invention relates particularly to a method for starting a production line for manufacturing extruded plates for panels to cover the surface of a room, wherein the extruded semi-finished product is pressed at its free end toward a conveyor, and the conveyor is configured to transfer the semi-finished product to a separating device for cutting plates separated from the semi-finished product, which is cooled and solidified into an infinite base profile, along a cutting line extending particularly transversely to the direction of transfer, and a conveyor belt extending in the direction of transfer is disposed on the conveyor, and the free end of the semi-finished product is pressed onto the conveyor belt, and the free end of the semi-finished product reaching the separating device is introduced into the separating device, while the conveyor belt is pulled away from the semi-finished product, particularly downward, upstream of the separating device.

[0009] The production line may include an extruder designed specifically as a wide-slit extruder, to which the extruded material is pressurized. The extruded material may be fed to a calender, which includes several, preferably temperature-controlled, calender rollers, whereby the extruded material may be solidified by cooling and rolled into a desired shape for the semi-finished product. The semi-finished product is pressurized onto a conveyor by the extruder and / or calender with pressure directed in the conveying direction. The semi-finished product may be transported via a conveyor from the extruder and / or calender to a separator, whereby the semi-finished product may be cooled and solidified, particularly by natural convection, in the area between the extruder and / or calender located at the inlet end of the conveyor and the separator located at the outlet end of the conveyor, to the extent that the semi-finished product can be cut into individual plates at an optimal temperature range by the separator. For example, the separator includes an infeed to which a pulling force is applied in the conveying direction to feed the semi-finished product, which has been cooled and solidified into an infinite base profile, into the separator at a predetermined conveying speed. Preferably, the pulling force acting on the outlet end of the conveyor is adapted to the compressive force acting on the inlet end of the conveyor so that the compression and stretching caused by the thermal expansion effect during cooling of the semi-finished product are compensated to at least a large degree.

[0010] For example, when the production line needs to be started after an operational malfunction and / or product change, there is no semi-finished product on the conveyor initially. Consequently, it is also impossible to apply a pulling force to the semi-finished product at the start of the extruder. The compressive forces present at the start of the extruder would instead strongly compress the semi-finished product, which is still relatively soft on the conveyor, and thus ultimately prevent further movement of the semi-finished product through the conveyor or hinder the threading of the free end of the semi-finished product into the separation device. During continuous normal operation, the pulling force acting on the semi-finished product is applied specifically only to the exit end of the conveyor, so that the semi-finished product maintains its shape as an infinite plate-shaped material. In principle, it would be possible to provide rollers on the conveyor that are actively driven along its entire length in the conveying direction, so that a defined withdrawal of the semi-finished product as a plate-shaped infinite profile is also possible during the start-up phase before reaching continuous normal operation. However, this would entail significant costs for the conveyor and increase the manufacturing cost of the panels produced using the production line.

[0011] Instead of equipping the conveyor with rollers that are actively driven along its extension, a conveyor belt is placed on the conveyor. The free end of the extruded semi-finished product can thus strike the upper side of the conveyor belt, which is directed upward with respect to the direction of gravity. In this case, at least a sufficient frictional connection can be established between the semi-finished product and the conveyor belt through a fleece provided between them, where appropriate, so that the semi-finished product can be pulled away from the extruder and / or calender by the pulling force acting on the conveyor belt together with the conveyor belt. The pulling force acting on the conveyor belt can be provided, in particular, by a pull device of the conveyor provided at any time. With the help of the conveyor belt, the semi-finished product can be pulled up to just before the separator. During the time required for the free end of the semi-finished product to travel from the inlet end of the conveyor to the outlet end of the conveyor, the semi-finished product is cooled and solidified to the extent that it can be easily threaded into the separator automatically and / or manually. In this case, the conveyor belt can be withdrawn from the semi-finished product so that the conveyor belt, which would otherwise be attached to the semi-finished product, does not simultaneously enter the separator. Therefore, damage to the conveyor belt within the separation device and operational failures caused by the conveyor belt present within the separation device can be prevented. After the free end of the semi-finished product is threaded into the separation device, and preferably after the plate is separated from the semi-finished product that has been solidified into an infinite base profile for the first time in the separation device, a sufficient pulling force can be applied to the semi-finished product without the aid of the conveyor belt. Subsequently, the conveyor belt can be completely removed so that it no longer contacts the semi-finished product. Once the conveyor belt is removed, continuous normal operation of the production line can essentially begin, and the startup phase can be terminated.Appropriately, for example, because a specified temperature profile has not yet been reached within the calendar or other controlled variables have not yet settled, the start phase may be extended beyond the time for threading the free end of the semi-finished product into the separation device.

[0012] The conveyor belt is a highly cost-effective and easy-to-operate auxiliary means for threading semi-finished products into a separation device in the form of a plate-shaped infinite profile during the startup phase of the production line. Here, there is no need to equip the conveyor with multiple actively driven rollers and / or provide an actively driven conveyor belt that runs along the entire length of the conveyor. Consequently, the manufacturing costs of the production line, particularly the manufacturing costs of the conveyor, can be kept low. Since the conveyor belt can be designed as a belt with two free ends rather than a closed loop, the conveyor belt can be prepared for the start of the startup phase, and after threading the free ends of the semi-finished products into the separation device, the conveyor belt can be pulled out. When the conveyor belt is not required during continuous normal operation, it can be wound up to save space and temporarily stored in a space-saving manner for the next use in another startup phase. By detaching the free ends of the semi-finished products with the help of the conveyor belt during the startup phase, the conveyor can be designed to be cost-effective for the continuous normal operation of the production line, thereby enabling cost-effective panel production.

[0013] Suitable compositions for the extruded semi-finished product are provided, for example, in EP 3 578 384 A1, the contents of which are referred to herein as part of the invention. Suitable materials for the semi-finished product are, in particular, thermoplastics, e.g., polypropylene (PP), as well as homopolymers, copolymers, or terpolymers of PP, polyethylene (PE), thermoplastic elastomers, e.g., thermoplastic polyolefin (TPO), thermoplastic styrene (TPS), thermoplastic polyurethane (TPU), thermoplastic vulcanizates (TPV), or thermoplastic copolyesters (TPC). All of the aforementioned thermoplastic materials may include fillers such as chalk, layered silicates, or rock flour in a conventional manner. To adapt the physicochemical properties of the plastic, the plastic may also be provided to include additional additives that modify the corresponding properties of the plastic, such as plasticizers, UV stabilizers, antioxidants, flame retardants, antistatic agents, impact modifiers, and / or colorants.

[0014] The separation device can cut plates from a continuous base profile along a separation line by means of a cutting tool. The cutting of each plate is performed particularly by a chipless cutting process, specifically by shearing at the knife edge, thereby avoiding cutting chips that could contaminate and damage the separation device or damage the surface of the plate and / or the infinite base profile. Here, the knowledge is utilized that the infinite base profile can still remain within the optimal temperature range even after some intermediate cooling and is relatively soft and pliable, so low-wear cutting of the plate can be easily performed by chipless shearing. In particular, the cutting tool of the separation device is configured to move in the feed direction along with the feed rate of the infinite base profile. By moving the cutting tool in the feed direction along with the continuous base profile at the same speed, a clean cutting edge can be created, as would otherwise be produced by cutting a workpiece that is not moving. Thus, an inclined cutting surface of the plate can be prevented, and thus the plate essentially corresponds to a rectangular prism.

[0015] In particular, the separated panels can be further processed into panels capable of covering the surface of a room. For example, the panels can be used as floor laminates to form a visually attractive floor of the room. The panel may comprise a panel body having a rectangular shape as its basic form, wherein the longitudinal extension is significantly larger than the transverse extension, and the thickness in the thickness direction of the panel body is generally smaller than in the transverse direction. In particular, the panel body may be formed by a separated panel or a panel body existing after at least one additional separation of the panel.

[0016] The panel body may include a bung shoulder that extends longitudinally and is particularly continuous in the longitudinal direction and protrudes transversely on one long side extending longitudinally, and a bung groove formed transversely in the panel body on another side, so that panels designed essentially identically can be connected to each other by a tongue-groove connection in the form of a tongue-groove joint. In addition, a locking hook may protrude longitudinally from a short side of the transversely extending panel body, while a spring body may protrude from another short side of the panel body, and the spring body defines a receiving groove so that panels configured essentially identically can also be interlocked to each other at the short sides by a tongue-groove joint. During assembly, one panel may be laid flat on a subsurface defining the plane of use, for example, the floor, side wall, or ceiling of a room. If necessary, additional panels may be positioned at a slight angle of about 30°, for example, so that the already mounted panel extends laterally next to the panel on the long side and then pivots onto the subsurface, thereby establishing a tongue-groove joint between the hook of the panel and the receiving groove of the additional panel.

[0017] In the continuous normal operation of the production line, at the end of the conveyor facing the extruder, a compressive force directed in the conveying direction may be applied to the semi-finished product, particularly in an essentially pasty and / or molten state, and at the end of the conveyor facing the separator, a pulling force directed in the conveying direction may be applied to the infinite profile of the semi-finished product, particularly in an essentially solid state, wherein the applied compressive force and the applied pulling force are dimensioned in such a way that the compression and elongation caused by the thermal expansion effect during the cooling of the semi-finished product are compensated to at least a large degree. In particular, the conveying speed in the conveying direction may be applied locally to compensate for the thermal expansion effect due to cooling in the conveying direction and the shrinkage of the semi-finished product in the conveying direction. The compressive force acting on the soft end of the semi-finished product may be built up particularly by the subsequent material of the semi-finished product leaving the calender, whereas the pulling force in the area of ​​the semi-finished product that is already sufficiently solidified may be provided by a pulling device comprising an actively colliding conveying element of the conveyor, particularly actively driven rolls. Accordingly, unnecessary internal stress in the semi-finished product can be avoided, and consequently, unwanted deformation of the semi-finished product, such as waveform formation, can be prevented. In particular, the conveyor belt transport speed during the startup phase can essentially correspond to the average transport speed of the semi-finished product during continuous normal operation. In this way, unnecessarily large compression and elongation of the semi-finished product during the startup phase can be avoided, which simplifies the threading of the semi-finished product into the separation device.

[0018] In particular, the conveyor may be composed of different sub-units, each of which may have the same or different transfer speeds. By setting different transfer speeds in different sub-regions, the reduction in length of each transferred profile caused by cooling, particularly to the extent of thermally induced shrinkage, can be compensated, and thus unnecessary stresses on the transferred profile caused by thermal expansion effects can be compensated. In particular, the conveyor may be interrupted in the area of ​​the separation device so that the separation device can perform continuous separation cutting extending transversely in the transfer direction. In this case, the sub-unit located downstream of the separation device may have a faster transfer speed than the conveyor sub-unit located upstream of the separation device in the transfer direction, thereby improving the separation of the cut plates. Preferably, the end of the conveyor facing the separation device is spaced apart from the separation device to form a free space that can be easily bridged by an infinite base profile, and is large enough for the conveyor belt to withdraw the semi-finished product solidified into an infinite base profile.

[0019] Each conveyor or each sub-unit of the conveyor may include, for example, a belt that moves in the conveying direction to convey each profile in the conveying direction and / or rollers that are actively driven and / or passively co-rotating. If the conveyor comprises only driven rollers as a driving means for conveying the semi-finished product, it may provide a distance between the rollers to promote natural convection for cooling the semi-finished product, wherein the distance between the consecutive rollers is small enough to prevent wrinkling of the semi-finished product in some areas that are not yet solidified and are rather soft. The conveyor is straight at least up to the separator, that is, constructed without curves or bends, so that the semi-finished product can be conveyed along a straight line without bends, preferably in a straight line lying on a horizontal plane.

[0020] Downstream of the extruder and / or calender in the conveying direction, the production line may include a smoothing unit for smoothing the upper and / or lower surfaces of a semi-finished product having a particularly defined surface quality. The smoothing unit may be provided, particularly, immediately downstream of the calender. The smoothing unit may include, particularly, a lower press tool, particularly a flat plate or roller, and an upper press tool, particularly a flat plate or roller, which may be pressed toward each other to imprint the desired shape and / or surface quality onto the semi-finished product, which is still smooth. Preferably, the feed is not imparted to the semi-finished product by the press tool, so that the feed in the conveying direction through the smoothing unit at the start stage is essentially achieved only by the conveyor belt. In particular, since the smoothing unit can press the belt against the semi-finished product, adhesion between the semi-finished product and the conveyor belt and / or with the fleece provided therein may be improved.

[0021] After cooling and solidification into an infinite profile, the semi-finished product can be fed to an edge cutting device for cutting edge regions of the semi-finished product arranged transversely to the conveying direction. Downstream of the edge cutting device, the semi-finished product exists in the conveying direction as an infinite profile of a plate shape including a predetermined base plate width extending transversely to the conveying direction, and the edge regions cut by the edge cutting device are discarded as defects. If necessary, the cut edge regions are crushed, and the crushed edge regions can be easily further transported, particularly as pourable granules. Thus, further processing of the cut edge regions, particularly recycling, is simplified.

[0022] The edge cutting device can continuously cut edge regions that exceed the desired base plate width. For this purpose, the semi-finished product can be driven, for example, against a fixed knife or a cutting roller. The edge regions are cut, particularly by a chipless cutting process, specifically by shearing at the knife edge, thereby avoiding cut chips that could contaminate and damage the edge cutting device or damage the surfaces of the infinite profile. Here, knowledge is utilized that the semi-finished product is relatively soft and ductile within an optimal temperature range, so low-wear cutting of the edge regions can be easily performed by chipless shearing. Additionally, the separated edge regions can be cut into strip-shaped infinite profiles, which can be ground into sections of the same size and shape, particularly into granules. This facilitates further processing of the cut edge regions.

[0023] Sufficient installation space may be provided between the edge cutting device and the separation device to further process the edge areas cut by the edge cutting device. To this end, the present invention may provide installation space between the edge cutting device and the separation device below the stepless profile and the transfer elements provided for transferring the stepless profile in the transfer direction. Thus, additional processing of the cut edge areas can follow the edge cutting device directly without the need to significantly increase the installation space of the production line in the transverse direction relative to the transfer direction. Instead, additional processing of the cut edge areas may be provided on an installation surface that is already being used by the conveyor anyway, where a height area that is rather less used by the conveyor may be provided for the additional processing of the cut edge areas. Thus, additional processing of the cut edge areas can be performed in a manner that is essentially nearly neutral in terms of installation space.

[0024] In the conveying direction between the edge cutting device and the separation device, preferably, a collection container may be placed to collect the edge regions cut by the edge cutting device. The edge regions cut as a strip-shaped infinite profile may still be connected to the semi-finished product upstream of the separation tool of the edge cutting device, so that the cut edge regions may extend slightly laterally in the conveying direction from the continuous profile downstream of the separation tool of the edge cutting device. Thus, the cut edge regions can be easily fed into the collection container provided between the edge cutting device and the separation device without the edge regions cut as a strip-shaped infinite profile that could be destroyed in an uncontrolled manner. Thus, the cut edge regions can be easily discharged continuously and collected in the collection container. The edge regions cut as a strip-shaped continuous profile can be broken into smaller pieces or shredded in a predetermined manner within the collection container. Preferably, the cut edge regions are crushed in at least one grinding device, particularly a cutting mill, specifically designed for pourable granulation, and are fed as granules to a collection container and / or a recirculation container. The collection container may be moved away by relative movement, particularly across the conveying direction, and may be replaced by a still empty collection container, so that the cut edge regions can be discharged in batches. Preferably, the cut edge regions are discharged continuously.

[0025] In particular, the collection container can be positioned below the infinite profile in the direction of gravity, and the infinite profile covers the collection container to at least a large extent, especially when viewed in the direction of gravity. The collection container can be provided at a level sufficiently low to accommodate potentially already fragmented cut edge strips of the infinite profile that are at least partially offset laterally and / or covered by the infinite profile below the infinite profile. Lateral protrusions of the collection container beyond the lateral extension of the infinite profile can therefore be kept low or even completely avoided. Thus, installation space requirements can be minimized. Additionally, it is easy to configure the collection container to be open at the top, and the need for replacement of the collection container can be easily determined through visual inspection. The conveyor components provided above the collection container, in particular the rolls, and / or the material of the infinite profile can cover the opening of the top-open collection container and retain fragments of the cut edge area jumping up from the inside of the collection container.

[0026] In particular, the conveyor applies a pulling force to the semi-finished product in the conveying direction only in a portion facing the separator. In principle, the pulling force applied to the semi-finished product can be applied solely by the separator during continuous normal operation after the completion of the startup phase. If the pulling force applied to the semi-finished product is provided by the conveyor in addition to the separator or as an alternative to the separator to press the semi-finished product—for example, cooled and solidified into an infinite base profile—in proportion to at least the compressive force, it is sufficient that actively driven conveying elements are provided in only a portion of the area. In this case, the actively driven conveying elements are provided at the end of the conveyor facing the separator, in the form of a pull-out device including actively driven rolls, and only passively co-driven conveying elements may be provided between a portion of the area having the extruder and / or calender on one side and the actively driven conveying elements on the other, particularly over a large portion of the extension of the conveyor in the conveying direction. This allows compression and expansion in the semi-finished product material caused by thermal expansion effects during cooling to be avoided on the conveyor. Furthermore, the conveyor can be designed to be particularly cost-effective.

[0027] The conveyor and / or actively driven conveying element of the separation device provides a conveying speed v1 of, in particular 4.5 m / min ≤ v1 ≤ 21.0 m / min, in particular 5.0 m / min ≤ v1 ≤ 8.0 m / min, preferably v1 = 5.5 m / min ± 0.5 m / min or v1 = 7.5 m / min ± 0.5 m / min. Such conveying speeds enable high productivity without causing unnecessary internal stress in the semi-finished product. Additionally, or alternatively, the conveying speed v1 is set in such a way that a specific, particularly essentially constant extruder throughput, such as 6000 kg / h or 8500 kg / h, is achieved for a given thickness of the plates to be produced and a given base plate width. Thus, the conveying speed v1 can be adapted to the maximum extruder throughput that can be provided by the extruder, thereby achieving particularly high productivity.

[0028] Preferably, at the end of the conveyor away from the separator, a compressive force is applied to the semi-finished product in the conveying direction by the extruder and / or calender. The compressive force applied at any time during extrusion and / or within the calender can therefore be used to initially push the extruded product or semi-finished product along the conveyor without requiring an actively driven conveying element of the conveyor. Thus, the conveyor can be designed to be particularly cost-effective.

[0029] In particular, at the outlet of the extruder, the free end of the semi-finished product is pressurized onto the conveyor belt in a substantially molten state, and the conveyor belt leads specifically to the calender. A fleece is provided between the semi-finished product and the conveyor belt to bond the semi-finished product to the conveyor belt. As a result, the extruder, which is still in a molten form, can strike the conveyor belt directly at the outlet of the extruder during the start-up phase, which can pull the still very soft extruder to the calender. Therefore, the extruder and calender can be provided horizontally, one behind the other, specifically at substantially the same height level, allowing the semi-finished product to move through the production line only in the horizontal direction. The extruder is provided above the calender in the direction of gravity, and there is no need to transfer the extruder from the extruder to the calender by gravity. A 90° deviation of the semi-finished product from the vertical to the horizontal direction is avoided. This keeps the vertical installation space requirements of the production line low and improves the geometric accuracy and quality of the infinite profile. To prevent very soft extruded material from flowing and to ensure that the relatively narrow conveyor belt is sufficient, a fleece may be provided between the conveyor belt and the molten semi-finished product exiting the extruder, and its width perpendicular to the conveying direction may essentially correspond to the width of the infinite profile, and the fleece may be somewhat wider or somewhat narrower than the width of the infinite profile, for example, ± 5 cm. In addition, the fleece may facilitate the subsequent removal of the semi-finished product from the conveyor belt. In particular, the fleece may be configured with open holes and / or otherwise rough so that the fleece can still form a good bond with the very soft semi-finished product and provide a good frictional connection with the conveyor belt.

[0030] Particularly preferably, the conveyor belt is essentially pulled at a conveying speed intended for continuous normal operation, particularly by motor and / or manual means. Accordingly, unnecessary compression and elongation of the semi-finished product during the start-up phase are avoided. Additionally, the temperature and / or cooling conditions during the start-up phase are similar to those during continuous normal operation, so that the free end of the semi-finished product can be fed to the separator relatively easily. It can be ensured that the semi-finished product fed to the separator during the start-up phase is not too warm and too soft, nor too cold and too hard. In particular, this prevents the semi-finished product from becoming thickened by an excessively low conveying speed, which could make plate separation within the separator more difficult or hindered. Furthermore, it prevents shrinkage of the semi-finished product, which could be damaged during the start-up phase, especially when threaded into the separator, due to an excessively high conveying speed. This avoids or at least reduces the risk of causing operational malfunctions during the start-up phase.

[0031] In particular, it is expected that exactly one conveyor belt is used, or that the movements of multiple conveyor belts provided in the conveying direction are positively coupled with each other. This makes it possible to avoid local conveying speeds that vary across the width of the semi-finished product extending across the conveying direction. Therefore, warping or lateral running of the semi-finished product from the conveyor is avoided, and thus unnecessary difficulties are avoided in supplying the free end of the semi-finished product solidified into an infinite base profile to the separation device.

[0032] Preferably, the conveyor belt comprises a pulling end facing the separator and a loose end facing away from the pulling end, and the extension(s) of the conveyor belt between the pulling end and the loose end corresponds at least to the extension(l) of the conveyor between the point of contact of the free end of the semi-finished product on the conveyor and the separator, particularly 1.0 < s / l ≤ 2.0, preferably 1.1 ≤ s / l ≤ 1.8, and particularly preferably 1.3 ≤ s / l ≤ 1.5. The pulling end of the conveyor belt may protrude slightly from the end of the conveyor belt facing the separator to better introduce a pulling force into the conveyor belt. Here, the pulling force may be applied mechanically, for example by the use of a motor, or manually. The loose end of the conveyor belt may be provided at the end of the conveyor facing the extruder so that the free end of the semi-finished product that first strikes the conveyor strikes the upper side of the conveyor belt. In principle, a small overlap between the conveyor belt and the semi-finished product during the start-up phase may be sufficient to complete the start-up phase as quickly as possible and transition to continuous normal operation, particularly after threading the free end of the semi-finished product into the separator. However, to reliably prevent the conveyor belt from loosely tearing away from the semi-finished product when pulling it using the conveyor belt, a larger overlap in the conveying direction may be provided between the conveyor belt and the semi-finished product to ensure better adhesion between them. At the same time, the width of the conveyor belt can be kept small in the transverse direction of the conveying, and since the adhesion with the semi-finished product is excellent, handling and storage of the conveyor belt are simple.

[0033] Particularly preferably, when the semi-finished product collides on the conveyor, 0.01 ≤ b / B ≤ 0.90, particularly 0.05 ≤ b / B ≤ 0.50, preferably 0.10 ≤ b / B ≤ 0.25, and particularly preferably 0.15 ≤ b / B ≤ 0.20 are applied to the total width (b) of at least one conveyor belt crossing the conveying direction at the average width (B) of the semi-finished product. It has been recognized that there is no need to apply a pulling force across the entire width of the semi-finished product during the starting stage, and it is sufficient if the conveyor belt is configured to be narrow relative to the width of the semi-finished product. In particular, when a calender is provided between the extruder and the conveyor, the material of the semi-finished product has sufficient strength so that any deformation of the semi-finished product introduced by the conveyor belt is too small, so that deformation along the length of the conveyor and also deformation in the separator does not cause difficulties. Thus, the cost of the conveyor belt and the storage of the conveyor belt can be kept low.

[0034] In particular, the conveyor belt is pressed at least partially into the material of the semi-finished product. The material of the semi-finished product, which remains soft when colliding with the conveyor belt or the fleece provided between the semi-finished product and the conveyor belt, can adapt to the shape of the conveyor belt at its lower portion facing the conveyor belt due to its own weight. The material of the semi-finished product can pass along the side of the conveyor belt facing the direction of transfer and reach the upper portion of the conveyor. This improves the bonding between the conveyor belt and the semi-finished product.

[0035] Preferably, the conveyor belt is made of a fabric material, and the fabric material has a release layer on the upper and / or lower side of the conveyor belt to provide release of the conveyor belt from the semi-finished product. The release layer can be designed, for example, as sprayed onto a coating, or as bonded onto a separate layer of material. The fabric material can impart particularly high tensile strength to the conveyor belt. Furthermore, the fabric material can intentionally impart a non-uniform surface structure, which improves bonding with the semi-finished product. The release layer can prevent the conveyor belt from adhering to the semi-finished product, for example by adhesion or chemical bonding, so that the conveyor belt can easily pull out the solidified semi-finished product. For example, the conveyor belt can be easily pulled from the lower surface of the semi-finished product just upstream of the separator.

[0036] Particularly preferably, the conveyor includes at least one active drive roll, which is part of a pulling device for providing a pulling force, particularly to the semi-finished product, and the conveyor belt is pulled along the active drive roll. The conveyor belt can be pulled by the active drive roll, for example, about 90° or more from the lower side of the semi-finished product. In this case, the active drive roll can not only press the semi-finished product toward the separator but also apply force to the conveyor belt to help pull the conveyor belt away from the semi-finished product. When an operator wishes to withdraw the conveyor belt, the belt can be pulled along the active drive roll, making the removal of the conveyor belt simple.

[0037] In particular, the conveyor belt is tempered to a predetermined operating temperature before coming into contact with the semi-finished product. This can facilitate adhesion between the conveyor belt and the semi-finished product. For example, the conveyor belt can be preheated to a temperature at which it can be easily pressed into the still unsolidified material of the semi-finished product. Alternatively, if the conveyor belt is supplied at ambient temperature, that may already be sufficient.

[0038] Preferably, the portion of the semi-finished product that extends in the conveying direction and comes into contact with the conveyor belt is separated as a plate within the separation device and then discarded as a rejected item. It cannot be ruled out that the surface of the semi-finished product that came into contact with the conveyor belt does not possess the intended surface quality. For this reason, this portion of the semi-finished product may be discarded as a rejected item and is not processed as a product. Here, since testing of material properties is not required, the determination of the plates separated as rejected items is simplified and cost-effective.

[0039] In particular, the conveyor belt is conveyed at a conveying speed v1 of 4.5 m / min ≤ v1 ≤ 21.0 m / s, particularly 5.0 m / min ≤ v1 ≤ 8.0 m / min, preferably v1 = 5.5 m / s ± 0.5 m / min or v1 = 7.5 m / s ± 0.5 m / min. Accordingly, the conveyor belt and the semi-finished product towed by the conveyor belt can already be moved during the start phase at a conveying speed corresponding to the conveying speed provided during essentially continuous normal operation, depending on the intended product for the separated plate.

[0040] Particularly preferably, the conveyor belt is pulled from the semi-finished product in a non-destructive manner. Thus, damage to the conveyor belt and breakage of the solidified semi-finished product are avoided. For this purpose, the conveyor belt can be pulled particularly sharply downward from the lower surface of the semi-finished product, having a component of movement in the direction of gravity. Thus, the conveyor belt can be easily reused and recycled. Cleaning of the conveyor belt may not be required to reuse the conveyor belt during the newly occurring startup phase.

[0041] In particular, the pulled conveyor belt is reused for a new execution of the method, which can be designed and further developed as described above. Particularly preferably, the pulled conveyor belt is reused not only once but several times, preferably repeatedly, for an updated execution of the method. Since the conveyor belt according to the present invention is used only during the start-up phase of the production line, the service life of the conveyor belt can be extended beyond the service life of the production line, so the conveyor belt can be used according to the method described above for all start-up phases occurring in the production line, in particular. It is assumed that significant wear of the conveyor belt beyond normal aging defects is generally not expected. As long as the wear condition of the conveyor belt and / or the production line permits, the same conveyor belt can be reused repeatedly during the start-up phase occurring in the production line according to the method described above.

[0042] Preferably, cooling of the infinite base profile between the extruder and / or the calender and the separation device requires cooling by convection, particularly by natural convection. Accordingly, the cost of active cooling, particularly the use of additional coolants, is avoided and reduced. Furthermore, internal stress caused by excessive cooling can be avoided.

[0043] Particularly preferably, a cutting device is provided for cutting a plate into individual panels, particularly chipless, along at least one cutting line extending in the conveying direction, downstream of a separation device in the conveying direction. Thus, cutting into panels or panel bodies for manufacturing panels can still occur in a temperature range that is within the optimal temperature range or slightly lower. Since the cutting device does not process an infinite profile and the plate is already separated, preferably in a chipless state, good cutting results with a uniform cut surface can be obtained even at lower temperatures. Instead of continuous cutting, the cutting device can provide batch cutting using at least one knife, and can easily press the panel to be cut using at least one downholder without causing deformation of the waveform of the panel and plate to be cut due to the low temperature. Thus, the cutting process in the cutting device can be implemented with higher precision and good cutting quality.

[0044] The separated plates and / or panels can be stacked in a packaging device, preferably on a pallet, toward the end of the conveyor. The stacked plates and / or panels can be fed to an additional process, particularly machining, to form a plug-type shoulder, a plug-type groove, a locking hook, or a spring body within the sides connecting the upper and lower sides, for example, after cooling to ambient temperature.

[0045] Hereinafter, the present invention will be described based on preferred embodiments with reference to the accompanying drawings, and the features illustrated below may each constitute an aspect of the present invention individually or in combination. Brief explanation of the drawing

[0046] The drawings are as follows: Figure 1 illustrates a schematic representation of the principle of a production line. Figure 2 shows a schematic plan view of a part of the production line of Figure 1 during the startup phase. Specific details for implementing the invention

[0047] The production line (10) illustrated in FIG. 1 includes a storage container (12) and a recirculation container (14), from which an extract to be extruded to at least one extruder (16) may be supplied. The extruder (16) may supply the extract as an extruder through a wide slot die to a calender (18), so that a semi-finished product in the form of a plate-like infinite profile exists downstream of the calender, which can be transported by a conveyor (22) in the transport direction at a predetermined transport speed. Here, the semi-finished product (20) may be cooled during transport, particularly by natural convection, and the local transport speed of the conveyor (22) may be adapted in such a way that the thermal expansion effect caused by shrinkage of the material of the semi-finished product can be compensated. The semi-finished product may be supplied from the conveyor (22) to a smoothing unit for smoothing the upper side and / or lower side of the semi-finished product having a limited surface quality, where appropriate. After optionally provided smoothing, the semi-finished product is fed by a conveyor (22) to an edge cutting device (24) that cuts the edge strip (28) particularly by the use of a rolling knife (26), so that an infinite base profile (30) having a straightened side edge and a limited base plate width across the conveying direction remains on the conveyor (22). Then, the infinite base profile (30) is fed to a separation device (32) that cuts the plate (36) which can be supplied as a product for further processing particularly by the use of a guillotine knife (34) that moves together in the conveying direction. The average temperature of the semi-finished product in the edge cutting device (24) and the average temperature of the infinite base profile (30) in the separation device (32) are both within a relatively narrow optimal temperature range in which the mechanical resistance to penetration by a cutting tool is low due to the material of the semi-finished product and the ductility of the infinite base profile (30) that still exists, but which is hard enough so that the material does not deform too much under the shear stress generated during cutting.

[0048] The cut edge region (28) as an infinite profile in the shape of a strip is fed to a crushing device (38), where the edge region (28) can be crushed into edge pieces (42) of essentially the same size and fed to a collection container (44). The crushing device (38) and the collection container (44) are provided between the separation device (32) and the edge cutting device (24) at a height level less than the height of the continuous base profile (30). From the collection container (44), the edge pieces (42) can be transported to a recirculation container (14), for example, by the use of a conveyor, and reused. Additionally or alternatively, the separated, particularly crushed edge pieces (42) can be fed to a container different from the recirculation container (14), and preferably can be fed continuously to an extruder (16) via a metering device as extracts.

[0049] When the production line is started, no semi-finished product has yet been placed on the conveyor, and no infinite base profile (30) has yet been threaded into the separation device (32). In order to facilitate the supply of the semi-finished product that first reaches the conveyor (22) during the start phase to the separation device (32) and to allow for continuous normal operation, a conveyor belt (40) is provided only for the start phase, which extends along the entire length of the conveyor (22) in the direction of transport from the beginning of the start phase. The conveyor belt (40), together with the fleece (41) provided between the conveyor belt (40) and the semi-finished product, can be supplied upstream of the calender (18) and smoothing unit at the outlet of the extruder (16), so that the semi-finished product leaving the extruder (16) as a still-meltable extruder can be pulled horizontally into the calender (18) by the conveyor belt (40) and the fleece (41).

[0050] As illustrated in FIG. 2, the free end (48) of the semi-finished product (20), which is pressed from the extruder (16) with a compressive force (46) toward the calendar (18), may collide with the conveyor belt (40) and the fleece (41), where at least the conveyor belt (40) is positioned behind the calendar (18) on the conveyor device (22). At the pull end of the conveyor belt (40) toward the separation device (32), a pulling force (50) may be introduced into the conveyor belt by a pulling device of the conveyor (22) comprising active drive rolls so as to pull the free end (48) of the semi-finished product (20) and subsequent material of the semi-finished product (20). However, the pulling force (50) may also be applied manually or, for example, by a winder (50) driven by an electric motor to automatically wind the conveyor belt (40). By joining the conveyor belt (40) to the semi-finished product (20) through the fleece (41), the semi-finished product (20) can be pulled by the conveyor belt (40) through the conveyor (22), particularly through a portion of the conveyor (22) that includes rolls (44) that are passively co-rotating toward the separation device (32). In this case, the width (b) of the conveyor belt (40) may be significantly smaller than the average width (B) of the semi-finished product (20), but the width of the fleece (41) may correspond approximately to the average width (B) of the semi-finished product (20). When the free end (48) of the semi-finished product (20) reaches the separation device (32) with the support of the conveyor belt (40), the semi-finished product (20) is rapidly cooled and solidified downward from the semi-finished product (20), particularly up to the infinite base profile (30), to the extent that the conveyor belt can be pulled between the conveyor device (22) and the separation device (32). In this case, the free end (48) can be pulled in the conveying direction downstream of the pulling device having active drive rolls and upstream of the separating device (32).The free end (48) of the infinite base profile (30) can be supplied to the separation device (32) without a conveyor belt (40), thereby allowing continuous normal operation to begin.

[0051] The fleece (41) may remain attached to the infinite base profile (30) or be pulled from the infinite base profile (30) to match the conveyor belt (40). The remaining length of the conveyor belt (40) may be pulled further for safety reasons until the conveyor belt (40) can be completely released and removed from the semi-finished product (20). In principle, normal operation will be delayed until all relevant process parameters are within the target range for normal operation, and consistently high product quality can be ensured during continuous normal operation, and in particular, the waveform of the separated plate (36) can be placed within the intended tolerance range. The plate (36) that comes into contact with the conveyor belt (40) and enters the material to which the conveyor belt (40) can pressurize can be discarded as a rejected item without more detailed time-consuming inspection and, preferably, crushed and returned to the recirculation container (14). If the fleece (41) remains attached to the plate (36) to be discarded, recognizing the plate (36) to be discarded as a rejected item is further simplified.

Claims

Claim 1 As a method of starting a production line (10) for manufacturing extruded plates (36), an extruded semi-finished product (20) is pressed with its free end (48) toward a conveyor (22), and the conveyor (22) is configured to transport the semi-finished product (20) to a separating device (32) for cutting plates (36) separated from the semi-finished product (20) which has been cooled and solidified into an infinite base profile (30), along a cutting line extending transversely to the transport direction, and a conveyor belt (40) extending in the transport direction is disposed on the conveyor (22), and the free end (48) of the semi-finished product (20) is pressed onto the conveyor belt (40), and the conveyor belt (40) is pulled toward the separating device (32) together with the semi-finished product (20), and the free end (48) of the semi-finished product reaching the separating device (32) is separated A method in which the conveyor belt (40) is introduced into the device (32), while being pulled away from or downward from the semi-finished product (20) upstream of the separation device (32). Claim 2 A method according to claim 1, wherein the conveyor (22) applies a pulling force (50) in the conveying direction to the semi-finished product (20) only in a portion of the area facing the separator (32). Claim 3 A method according to claim 1, wherein at the end of the conveyor (22) facing away from the separation device (32), a compressive force (0) is applied in a conveying direction by the extruder (16) and / or calendar (18) onto the semi-finished product (20). Claim 4 A method according to any one of claims 1 to 3, wherein the free end (48) of the semi-finished product (20) at the outlet of the extruder (16) is pressed in a substantially molten state onto the conveyor belt (40) leading to the calender (18), and between the semi-finished product (20) and the conveyor belt (40), a fleece (41) is provided to bond the semi-finished product (20) to the conveyor belt (40). Claim 5 In any one of claims 1 to 3, the conveyor belt (40) is substantially pulled at a conveying speed provided for continuous normal operation, by a motor and / or manually. Claim 6 A method according to any one of claims 1 to 3, wherein exactly only one conveyor belt (40) is used, or the movement of several provided conveyor belts (40) in the conveying direction is positively coupled to each other. Claim 7 A method according to any one of claims 1 to 3, wherein the conveyor belt (40) comprises a pull end facing the separating device (32) and a loose end facing away from the pull end, and the extension (s) of the conveyor belt (40) between the pull end and the loose end is at least equal to the extension (l) of the conveyor device (22) between the point of collision of the free end (48) of the semi-finished product (20) in the separating device (32) and the conveyor device (22), and 1.0 < s / l ≤ 2.0, or 1.1 ≤ s / l ≤ 1.8 or 1.3 ≤ s / l ≤ 1.

5. Claim 8 A method according to any one of claims 1 to 3, wherein, for the total width (b) of at least one conveyor belt (40) crossing the conveying direction at the average width (B) of the semi-finished product (20) when the semi-finished product (20) collides on the conveyor device (22), 0.01 ≤ b / B ≤ 0.90, or 0.05 ≤ b / B ≤ 0.50, or 0.10 ≤ b / B ≤ 0.25, or 0.15 ≤ b / B ≤ 0.20 is applied. Claim 9 A method according to any one of claims 1 to 3, wherein the conveyor belt (40) is at least partially pressed into the material of the semi-finished product (20). Claim 10 A method according to any one of claims 1 to 3, wherein the conveyor belt (40) is made of a fabric material, and the fabric material has a release layer on the upper and / or lower side of the conveyor belt to provide release capability of the conveyor belt (40) from the semi-finished product (20). Claim 11 A method according to any one of claims 1 to 3, wherein the conveyor device (22) comprises at least one active drive roll that is part of a pull-off device for providing a pulling force to the semi-finished product (20), and the conveyor belt (40) is pulled out along the active drive roll. Claim 12 A method according to any one of claims 1 to 3, wherein the portion of the semi-finished product that extends in the conveying direction and contacts the conveyor belt (40) is cut into plates (36) in the separation device (32) and then discarded as a reject. Claim 13 A method according to any one of claims 1 to 3, wherein the conveyor belt (40) is pulled to v1 at a conveying speed of 4.5 m / min ≤ v1 ≤ 21.0 m / min, or 5.0 m / min ≤ v1 ≤ 8.0 m / min, or v1 = 5.5 m / min ± 0.5 m / min, or v1 = 7.5 m / min ± 0.5 m / min. Claim 14 A method in which, in any one of claims 1 to 3, the withdrawn conveyor belt (40) is reused for the reapplication of the method according to any one of claims 1 to 3.

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