A high-frequency hot pressing device for arc-shaped bamboo recombined materials and a method for using the same

Abstract

The present invention provides a high-frequency hot pressing device for arc-shaped reorganized bamboo materials and a method for using the same. The device includes a high-frequency generator connected to a control circuit, the output voltage of the high-frequency generator is controlled by a transformer, the hot pressing platform includes a pressing plate platform, a vertical pressing cylinder and a side pressing cylinder, a vertical pressing plate is arranged above the pressing plate platform, which is connected to the anode of the high-frequency generator, the vertical pressing plate and the pressing plate platform form an electric field, the vertical pressing plate is connected to the vertical pressing cylinder, a side pressing plate is arranged on a side edge of the pressing plate platform, the side facing the pressing plate platform is an inwardly concave arc surface, the side pressing plate is connected to the side pressing cylinder, and a pad is fixed on the frame on the other side of the pressing plate platform and is arranged opposite to the side pressing plate. The device and method can greatly improve the production efficiency of reorganized materials.

Description

Technical Field

[0001] The invention belongs to bamboo material processing equipment, and in particular provides a high-frequency hot pressing equipment for arc-shaped reorganized bamboo materials and a use method thereof. Background Art

[0002] Bamboo arc reconstructed material refers to the board made of arc-shaped bamboo boards with smooth inner and outer surfaces, which are placed side by side in the same direction of the arc and pressed and bonded. In the production of this reconstructed material, the performance of the hot press determines the product quality, production capacity and production cost, and is one of the key equipment in production.

[0003] In the prior art, curved bamboo materials are all pressurized and reorganized using conventional heating methods, which takes a long time and has low work efficiency. Summary of the invention

[0004] The purpose of the present invention is to improve the problems of the prior art and provide a high-frequency hot pressing device for arc-shaped recombined bamboo materials which can greatly improve the production efficiency.

[0005] The object of the present invention is achieved in that:

[0006] A high-frequency hot-pressing device for arc-shaped recombined bamboo materials, comprising an independent high-frequency generator and its control cabinet, a hot-pressing platform, a hydraulic system and a cylinder cabinet; the high-frequency generator is connected to a control circuit, the control circuit outputs voltage to the high-frequency generator and is controlled by a transformer, so that the high-frequency generator can work under different voltages; the control circuit is independent of the hot-pressing platform and is arranged in the control cabinet;

[0007] The hot pressing platform is arranged on a frame, and the hot pressing platform includes a pressing plate platform, a vertical pressing cylinder and a side pressing cylinder. The pressing plate platform is a horizontal plate, which is arranged on the frame and is connected to the grid of the high-frequency generator. A vertical pressing plate is arranged above the pressing plate platform, and the vertical pressing plate is connected to the anode of the high-frequency generator. The vertical pressing plate and the pressing plate platform form an electric field. The vertical pressing plate is fixed on the piston rod of the vertical pressing cylinder. A side pressing plate is arranged on one side edge of the pressing plate platform. The side surface of the side pressing plate facing the pressing plate platform is a concave arc surface. The side pressing plate is fixed on the piston rod of the side pressing cylinder. A pad is fixed on the frame at the other side edge of the pressing plate platform and is arranged opposite to the side pressing plate.

[0008] The pipeline included in the hydraulic system connects the vertical pressure cylinder and the side pressure cylinder, the hydraulic motor included in the hydraulic system is connected to a motor, and a hydraulic valve is arranged on the pipeline;

[0009] The cylinder cabinet is connected to the hydraulic system.

[0010] Preferably, the vertical pressure cylinder is arranged on the top of the frame; and / or the side pressure cylinder is arranged on the frame so as to be movable up and down.

[0011] Preferably, the side pressure cylinder is arranged on a slider which can slide up and down relative to the frame, the slider is provided with a screw hole, which is screwed to a lead screw, and the lead screw is rotatably fixed on the frame, so that the side pressure cylinder can be raised and lowered by rotating the lead screw.

[0012] Preferably, a metal sheet is arranged on the lower bottom surface of the pressure plate platform, connected to the copper sheet of the grid in the high-frequency generator, serving as the grid of the high-frequency electric field; and / or the pad is detachably mounted on the frame; and / or the vertical pressure plate is wrapped with a metal sheet, and a groove is opened on the metal sheet at the lower end of the front and rear side surfaces of the vertical pressure plate.

[0013] Preferably, the depth of the groove is 3-4 mm; and / or the width of the groove is 5-8 mm; and / or the thickness of the metal sheet is 5-10 mm.

[0014] Preferably, it further comprises a temperature sensor, which is arranged on the frame to detect the temperature of the heated arc-shaped slab; and / or the high-frequency generator is connected to a transformer so that the output voltage has multiple gears.

[0015] A method for making a bamboo arc-shaped reconstituted material using the above-mentioned bamboo arc-shaped reconstituted material high-frequency hot pressing equipment comprises the following steps:

[0016] Step 1: feeding, bending a plurality of curved bamboo materials coated with adhesive in the same direction to form a curved slab, and placing the curved slab on the pressing plate platform of the hot pressing platform;

[0017] Step 2: Pressurizing, starting the vertical pressure cylinder and the side pressure cylinder, so that the side pressure plate presses against the arc-shaped side surface of the arc-shaped slab, and the other side opposite to the arc-shaped slab presses against the pad, so that the vertical pressure plate presses against the upper top surface of the arc-shaped slab;

[0018] Step 3: Heating, starting the high frequency generator to form an electric field and heating the slab for a set time;

[0019] Step 4: Keep warm, turn off the high-frequency generator, and maintain the pressure of the vertical pressure cylinder and the side pressure cylinder on the curved slab for a set time;

[0020] Step 5: Reduce pressure and discharge the material, start the vertical pressure cylinder and the side pressure cylinder, so that the side pressure plate and the vertical pressure plate leave the arc-shaped slab, and the slab becomes a bamboo arc-shaped reconstituted material and is taken out of the pressure plate platform.

[0021] Preferably, in step 2, the pressure applied by the vertical pressure plate to the curved slab is less than the pressure applied by the side pressure plate to the curved slab; and / or the pressure applied by the side pressure plate to the curved slab is 3-5MPa, and the pressure applied by the vertical pressure plate to the curved slab is 2-3MPa.

[0022] Preferably, in step 3, an optical fiber temperature sensor is used for heating, and the probe is inserted into the core of the slab. When it is detected that the temperature of the core of the slab reaches the required temperature, the electric field is turned off; and / or the heating time is 5-10 minutes; and / or if urea-formaldehyde adhesive is coated in the corresponding slab, the heating temperature is 100°C-110°C; if phenol-formaldehyde adhesive is coated in the corresponding slab, the heating temperature is 120°C-130°C; and / or the output voltage provided by the high-frequency generator is 3-7Kv, and the operating frequency is 6-8MHz.

[0023] Preferably, in step 4, the insulation time is 10-20 minutes.

[0024] The high-frequency hot-pressing equipment for arc-shaped reorganized bamboo materials provided by the present invention and the use method thereof can manufacture arc-shaped reorganized materials from arc-shaped bamboo slabs through a specific hot-pressing platform. The present invention innovatively uses high-frequency pressurizing means in the reorganization of arc-shaped reorganized bamboo materials, which greatly improves production efficiency. In the method for manufacturing the arc-shaped reorganized materials, a pressurizing method is proposed in which lateral pressure is applied vertically and on one side and on one side of the convex arc surface of the slab, thereby improving product quality.

[0025] Furthermore, a pressurization method in which the vertical pressure is less than the lateral pressure is proposed, which can better ensure the production quality of the curved reconstituted material. The curved slab has the problem of obstructed water transport and movement during heating, and the use of a high-frequency generator for heating is particularly prone to excessive local energy and electric field breakdown due to the difficulty in discharging water. The present invention solves this problem well and has made a groundbreaking breakthrough in the efficient and high-quality production of bamboo curved reconstituted materials.

[0026] The present invention is described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the three-dimensional structure of the high-frequency hot pressing equipment for arc-shaped reconstituted bamboo provided by the present invention.

[0028] Figure 2 for Figure 1 The structural schematic diagram of the front side of the high-frequency hot pressing equipment for arc-shaped reconstituted bamboo is shown.

[0029] Figure 3 for Figure 1 The structural schematic diagram of the back side of the high-frequency hot pressing equipment for arc-shaped reconstituted bamboo is shown.

[0030] Figure 4 for Figure 1 The front structural schematic diagram of the part of the high-frequency hot pressing equipment for arc-shaped reconstituted bamboo materials excluding the high-frequency generator is shown.

[0031] Figure 5 This is a schematic structural diagram of the pressure plate platform in the high-frequency hot pressing equipment for arc-shaped reconstituted bamboo provided by the present invention.

[0032] Figure 6 It is a structural schematic diagram of the high-voltage copper sheet of the grid and anode that connects the high-frequency generator to the pressure plate platform and the vertical pressure plate on the hot pressing platform.

[0033] Figure 7 It is a structural schematic diagram of the vertical pressure plate.

[0034] Figure 8 This is a schematic diagram of the structure of the water storage groove on the vertical pressure plate.

[0035] Fig. 9 It is a schematic diagram of the structure of the side pressure plate.

[0036] Fig.10 It is a schematic diagram of the structure in which the side pressure plate can be raised and lowered relative to the frame. DETAILED DESCRIPTION

[0037] like Figures 1 to 3 As shown, the high-frequency hot-pressing equipment for arc-shaped recombined bamboo materials provided by the present invention includes an independent high-frequency generator and its control cabinet, a hot-pressing platform, a hydraulic system and a cylinder cabinet;

[0038] The high-frequency generator is arranged in a control cabinet 1, connected in a circuit, and connected to a power supply. The circuit basically belongs to the prior art, and includes a power supply, a rectifier circuit, a high-frequency oscillation circuit, a matching circuit, and a control circuit. The matching circuit includes a transformer. Controlled by the transformer, the control circuit outputs voltages of different gears to the high-frequency generator, thereby enabling the high-frequency generator to work at different voltages; the circuit board and the high-frequency generator are arranged in the control cabinet 1 independently of the hot pressing platform, and are connected to the corresponding components on the hot pressing platform through the gate 2 and the anode 3 made of copper sheets.

[0039] The function of the high-frequency generator is to provide the molding hot press with the heat energy required for adhesive curing. A cooling system is also provided in the control cabinet to cool the control cabinet and ensure the normal operation of the control cabinet.

[0040] The device provided by the present invention adopts high-frequency electric field heating. Its principle is to apply a high-frequency electric field to the slab, so that the polar molecules in the slab and the adhesive, including water molecules, move rapidly and repeatedly under the action of the high-frequency electric field, resulting in intense friction between molecules to generate heat, thereby causing the adhesive to cure quickly. This press has a short hot pressing time and a fast curing speed of the adhesive, especially for thicker workpieces, which has higher production efficiency.

[0041] The hot pressing platform is arranged on a frame A, and the hot pressing platform includes a pressing plate platform 4, a vertical pressing cylinder 5 and a side pressing cylinder 6. The pressing plate platform 4 is a horizontal plate, which is arranged on the frame 1 and is connected to the grid 2 of the high-frequency generator. A vertical pressing plate 51 is arranged above the pressing plate platform 4, and the vertical pressing plate 51 is connected to the anode 3 of the high-frequency generator. An electric field is formed between the vertical pressing plate 51 and the pressing plate platform 4, which also serves as a heating space. The vertical pressing plate 51 is fixed on the piston rod of the vertical pressing cylinder 5, and the vertical pressing cylinder 5 is arranged on the top of the frame A. A side pressing plate 61 is arranged on a side edge of the pressing plate platform 4, and the side surface of the side pressing plate 61 facing the pressing plate platform 4 is a concave arc surface 61a (see Fig. 9 ), the side pressure plate 61 is fixed on the piston rod of the side pressure cylinder 6, and a pad 7 is fixed on the frame A at the other side edge of the pressure plate platform 4 and is set opposite to the side pressure plate 61, and the pad 7 can be detachably installed on the frame A.

[0042] The pipeline B included in the hydraulic system connects the vertical pressure cylinder 5 and the side pressure cylinder 6, the hydraulic motor included in the hydraulic system is connected to a motor 8, and a hydraulic valve 9 is arranged on the pipeline;

[0043] The cylinder cabinet 10 is connected to the hydraulic system to store hydraulic oil.

[0044] In order to adapt to bamboo slabs of various chord lengths, the side pressure plate 61 and the side pressure cylinder 5 connected thereto are arranged on the frame A so as to be movable up and down. Figure 2 and Fig.10 As shown, the side pressure cylinder 6 is arranged on a slider which can slide up and down relative to the slide rail on the frame A. The slider is provided with a screw hole, which is screwed with a lead screw a. The lead screw a is rotatably fixed on the frame A. A hand wheel a1 is arranged on the upper part of the lead screw. The side pressure cylinder 6 can be raised or lowered by rotating the lead screw a with the hand wheel.

[0045] A metal sheet is arranged on the lower bottom surface of the pressing plate platform 4, connected to the copper sheet of the grid 2 in the high-frequency generator, and serves as the grid of the high-frequency electric field.

[0046] like Figure 7 As shown, the vertical pressure plate 51 is wrapped with a metal sheet 51a, and a groove 51b is opened on the metal sheet at the lower end of the front and rear side surfaces of the vertical pressure plate 51. The depth of the groove 51b can be 3-4mm; the width of the groove 51b can be 5-8mm. In this embodiment, the depth of the groove 51b is 3mm and the width is 6mm. Correspondingly, the thickness of the metal sheet 51a is 5mm.

[0047] The groove is provided on the metal sheet 51a on the vertical pressing plate 51 because during the electric field heating process, water inside the arc-shaped bamboo sheet will evaporate and adhere to the metal sheet to form water droplets. In order to prevent the water droplets from condensing and flowing into the arc-shaped bamboo sheet to form a breakdown, the groove is provided to store a small amount of evaporated water. After the arc-shaped recombinant material is pressed, the water in the groove is wiped dry. Some water-absorbing materials can also be provided in the groove to increase the water storage capacity of the groove.

[0048] The equipment provided by the present invention separates the high-frequency generator and its control system and places them separately on the left side of the hot pressing platform, thereby reducing the complexity of the hot pressing and gluing operation and simplifying the hot pressing and gluing equipment.

[0049] The device may also include an optical fiber temperature sensor 11, which is arranged on the frame A to detect the temperature of the heated curved slab. When in use, the probe of the optical fiber temperature sensor 11 is brought into contact with or close to the temperature measurement area of ​​the curved slab to measure the temperature value of the area.

[0050] Preferably, the high frequency generator is connected to a transformer so that the output voltage has multiple levels.

[0051] The method for making a bamboo arc-shaped reconstituted material using the above-mentioned bamboo arc-shaped reconstituted material high-frequency hot pressing equipment comprises the following steps:

[0052] Step 1: Feeding: several curved bamboo materials coated with adhesive are bent in the same direction to form a curved slab, and then fed into the feed port C (see Figure 1 ) is placed on the pressing plate platform 4 of the hot pressing platform.

[0053] Step 2: Apply pressure, start the vertical pressure cylinder 5 and the side pressure cylinder 6, so that the side pressure plate 6 presses against the curved side surface of the curved slab (not shown in the figure), and the other opposite side of the curved slab presses against the pad 7; the vertical pressure plate 51 presses against the upper top surface of the curved slab.

[0054] In step 2, the pressure applied by the vertical pressing plate 51 to the curved slab is less than the pressure applied by the side pressing plate 61 to the curved slab. Generally, the pressure applied by the side pressing plate 61 to the curved slab is 3-5MPa, and the pressure applied by the vertical pressing plate 51 to the curved slab is 2-3MPa. In the present invention, when the above-mentioned equipment is used, the vertical and lateral pressures are different. During the hot pressing process, it is mainly necessary to apply a larger pressure to the lateral direction of the slab to promote its compaction and gluing; a relatively small pressure in the vertical direction is sufficient to keep the slab from deforming during the hot pressing process.

[0055] Step 3: Heating, start the high-frequency generator, form an electric field, according to the pre-treatment of the arc bamboo piece, the output voltage of the high-frequency generator is divided into five gears of 3-7Kv. If the voltage is too high, the electric field strength is too large. Due to the shape of the arc itself, the water transport in the direction of the electric field is blocked, which is easy to cause excessive local energy, resulting in electric field breakdown. If the voltage is too low, the electric field strength is too small, and the heating time is too long, so different voltage gears are selected according to the size specifications of different arc bamboo pieces. The bamboo piece is thick and long, so a high voltage gear is used. The operating frequency is, for example, 6.78MHz, which belongs to the high frequency range. The load form uses a high-frequency feeder connected to a parallel plate working capacitor. The insulating materials are epoxy resin and polytetrafluoroethylene. Due to the high frequency and high power of the current, the insulating material must have a certain thickness, so epoxy resin is selected as the main body.

[0056] In step 3, if urea-formaldehyde adhesive is coated on the corresponding slab, the heating temperature is preferably 105°C; if phenol-formaldehyde adhesive is coated on the corresponding slab, the heating temperature is preferably 125°C.

[0057] The set time for heating the slab can be determined based on experiments or by using an optical fiber temperature sensor 11, inserting the probe into the core of the slab, and measuring that the temperature of the core reaches the set temperature, then the electric field can be turned off and heating can be stopped. A high-frequency generator is used to reach the set temperature, and the required heating time is 5-10 minutes. The conventional method used in the prior art to make recombinant materials usually takes several hours to heat, while the present invention uses a high-frequency heater, which is more than ten times or even dozens of times more effective than the prior art.

[0058] Step 4: Keep warm, turn off the high-frequency generator, and maintain the pressure of the vertical pressure cylinder 5 and the side pressure cylinder 6 on the curved slab for the set time; the keeping warm time is generally 10-20 minutes.

[0059] Step 5: Decompression and discharging, start the vertical pressure cylinder 5 and the side pressure cylinder 6, so that the side pressure plate 61 and the vertical pressure plate 51 leave the arc-shaped slab, and the slab becomes a bamboo arc-shaped recombinant material and is discharged from the discharging port D (see Figure 3 ) is taken out of the pressure plate platform 4.

[0060] The above are preferred embodiments of the present invention and the technical principles used therein. For those skilled in the art, any obvious changes such as equivalent transformations, simple replacements, etc. based on the technical solution of the present invention, without departing from the spirit and scope of the present invention, are within the scope of protection of the present invention.

Claims

1. A high-frequency hot pressing device for arc-shaped reconstituted bamboo, characterized in that: It includes an independent high-frequency generator and its control cabinet, a hot pressing platform, a hydraulic system and a cylinder cabinet; the high-frequency generator is connected to a control circuit, the control circuit outputs voltage to the high-frequency generator and is controlled by a transformer, so that the high-frequency generator can work under different voltages; the control circuit is independent of the hot pressing platform and is arranged in the control cabinet; The hot pressing platform is arranged on a frame, and the hot pressing platform includes a pressing plate platform, a vertical pressing cylinder and a side pressing cylinder. The pressing plate platform is a horizontal plate, which is arranged on the frame and is connected to the grid of the high-frequency generator. A vertical pressing plate is arranged above the pressing plate platform, and the vertical pressing plate is connected to the anode of the high-frequency generator. The vertical pressing plate and the pressing plate platform form an electric field. The vertical pressing plate is fixed on the piston rod of the vertical pressing cylinder. A side pressing plate is arranged on one side edge of the pressing plate platform. The side surface of the side pressing plate facing the pressing plate platform is a concave arc surface. The side pressing plate is fixed on the piston rod of the side pressing cylinder. A pad is fixed on the frame at the other side edge of the pressing plate platform and is arranged opposite to the side pressing plate. The pipeline included in the hydraulic system connects the vertical pressure cylinder and the side pressure cylinder, the hydraulic motor included in the hydraulic system is connected to a motor, and a hydraulic valve is arranged on the pipeline; The cylinder cabinet is connected to the hydraulic system; The vertical pressure cylinder is arranged on the top of the frame; The side pressure cylinder is arranged on the frame so as to be movable up and down; The side pressure cylinder is arranged on a slider which can slide up and down relative to the frame, the slider is provided with a screw hole, a lead screw is screwed, and the lead screw is rotatably fixed on the frame, so that the side pressure cylinder can be raised and lowered by rotating the lead screw; A metal sheet is arranged on the lower bottom surface of the pressing plate platform, connected to the copper sheet of the grid in the high-frequency generator, as the grid of the high-frequency electric field; the pad is detachably mounted on the frame; the outer surface of the vertical pressing plate is wrapped with a metal sheet, and a groove is opened on the metal sheet at the lower end of the front and rear side end surfaces of the vertical pressing plate; The depth of the groove is 3-4 mm; The width of the groove is 5-8 mm; The thickness of the metal sheet is 5-10 mm.

2. The high-frequency hot pressing equipment for arc-shaped reconstituted bamboo materials according to claim 1 is characterized in that: Also includes a temperature sensor, which is arranged on the frame and is used to detect the temperature of the heated curved slab; and / or The high frequency generator is connected to a transformer so that the output voltage has multiple gears.

3. A method for making a bamboo arc-shaped reconstituted material using the high-frequency hot pressing device for bamboo arc-shaped reconstituted material as claimed in claim 1 or 2, characterized in that: The steps include: Step 1: feeding, bending a plurality of curved bamboo materials coated with adhesive in the same direction to form a curved slab, and placing the curved slab on the pressing plate platform of the hot pressing platform; Step 2: Pressurizing, starting the vertical pressure cylinder and the side pressure cylinder, so that the side pressure plate presses against the arc-shaped side surface of the arc-shaped slab, and the other side opposite to the arc-shaped slab presses against the pad, so that the vertical pressure plate presses against the upper top surface of the arc-shaped slab; Step 3: Heating, starting the high frequency generator to form an electric field and heating the slab for a set time; Step 4: Keep warm, turn off the high-frequency generator, and maintain the pressure of the vertical pressure cylinder and the side pressure cylinder on the curved slab for a set time; Step 5: Reduce pressure and discharge the material, start the vertical pressure cylinder and the side pressure cylinder, so that the side pressure plate and the vertical pressure plate leave the arc-shaped slab, and the slab becomes a bamboo arc-shaped reconstituted material and is taken out of the pressure plate platform.

4. The method according to claim 3, characterized in that In step 2, The pressure applied by the side pressure plate to the curved slab is 3-5 MPa, and the pressure applied by the vertical pressure plate to the curved slab is 2-3 MPa.

5. The method according to claim 3, characterized in that In step 3, Use an optical fiber temperature sensor during heating, insert the probe into the core of the slab, and turn off the electric field when it is detected that the temperature of the core of the slab reaches the required temperature; and / or The heating time is 5-10 minutes; and / or If the corresponding slab is coated with a urea-formaldehyde adhesive, the heating temperature is 100°C-110°C; if the corresponding slab is coated with a phenolic adhesive, the heating temperature is 120°C-130°C; and / or The high frequency generator provides an output voltage of 3-7Kv and an operating frequency of 6-8MHz.

6. The method according to claim 3, characterized in that In step 4, the insulation time is 10-20 minutes.

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