High-strength double-medium corrugated paperboard sheet and apparatus and method for manufacturing same

Abstract

An apparatus for manufacturing a high-strength double-medium corrugated paperboard sheet according to the present invention comprises: a first supply device which supplies a first corrugated medium and a first surface liner from one side; a second supply device which supplies a second corrugated medium and a second surface liner from another side; a first roller and a second roller which thermally press the first corrugated medium so that peaks and valleys are formed at certain intervals while corrugating the supplied first corrugated medium; a first thermal pressing portion which forms a first single-side corrugated paperboard by bonding the first corrugated medium on which the peaks and valleys are formed and the supplied first surface liner; a third roller and a fourth roller which thermally press the second corrugated medium so that peaks and valleys are formed at certain intervals while corrugating on the supplied second corrugated medium; a second thermal pressing portion which forms a second single-side corrugated paperboard by bonding the second corrugated medium on which the peaks and valleys formed and the supplied second surface liner; and a thermal bonding portion which allows the peaks and valleys on the first single-side corrugated paperboard and the second single-side paperboard to face each other such that the valley at one side is to be inserted and fitted into the peak at the other side and inclined surfaces of corresponding peaks and valleys are thermally bonded to each other.

Description

High-strength double-core corrugated cardboard sheet, apparatus for manufacturing the same, and method for manufacturing the same

[0001] The present invention relates to a high-strength double-core corrugated cardboard sheet that can be manufactured at a single station without a separate adhesive application device and adhesive drying device, and furthermore, the corrugated cardboard sheet itself has cushioning, waterproofing, and cooling functions, as well as a manufacturing device and a manufacturing method thereof.

[0002] Generally, conventional packaging boxes have been made of double-sided corrugated cardboard to facilitate the storage and transportation of goods.

[0003] Generally, corrugated cardboard is broadly classified into single-sided corrugated cardboard (i.e., composed of two sheets of base paper) in which a surface liner is bonded to one side of a corrugated core paper having ridges and corrugations formed thereon, double-sided corrugated cardboard (i.e., composed of three sheets of base paper) in which a surface liner is additionally bonded to the other side of the single-sided corrugated cardboard, and double-sided corrugated cardboard (i.e., composed of five sheets of base paper) in which the single-sided corrugated cardboard is additionally bonded to one side of the double-sided corrugated cardboard.

[0004] A conventional method for manufacturing double-sided corrugated cardboard, as illustrated in FIG. 1(a), involves a pair of interlocking rollers (2a, 2b) rotating together to form ridges and valleys on a supplied corrugated core sheet (1). Next, a first adhesive application roller (4a) applies adhesive to the ridges formed on one side of the corrugated core sheet (1). Then, a pressure belt (6) rotating through a pair of rollers (6a, 6b) presses an additionally supplied surface liner (1') against one side of the corrugated core sheet (1) to which the adhesive has been applied, thereby manufacturing a single-sided corrugated cardboard (1a) [single facer].

[0005] As shown in FIG. 1(b), the above single-sided corrugated cardboard (1a) is supplied continuously again, and the second adhesive application roll (4b) applies adhesive again to the ridge formed on the other side of the single-sided corrugated cardboard (1a). Then, the heat-tightening part (8) heat-presses the additionally supplied surface liner (1'') onto the other side of the corrugated core sheet to which the adhesive has been applied, thereby finally manufacturing a double-sided corrugated cardboard (1b) [double facer].

[0006] As such, conventional methods for manufacturing double-sided corrugated cardboard must include single facers and double facers that are carried out continuously in separate spaces and facilities, which requires a large installation space for the device. Additionally, there were problems that increased device costs and reduced work efficiency due to the adhesive application and adhesive drying processes required for each single facer and double facer.

[0007] Meanwhile, Korean Registered Patent No. 10-0181564 (hereinafter referred to as the prior art) discloses a method for forming a double-core corrugated cardboard, which comprises the steps of: continuously supplying a first corrugated cardboard and a first surface liner to a first stacking station, then continuously forming the first corrugated cardboard to have predetermined peaks and valleys while applying an adhesive to the peaks of the first corrugated cardboard, and stacking a first surface liner on the formed first corrugated cardboard to form a single-sided corrugated cardboard; continuously supplying the single-sided corrugated cardboard and a second corrugated cardboard to a second stacking station, then continuously forming the second corrugated cardboard to have predetermined peaks and valleys while applying an adhesive to the peaks of the second corrugated cardboard, and stacking the formed second corrugated cardboard on the single-sided corrugated cardboard to form a double-core corrugated cardboard; and continuously supplying the double-core corrugated cardboard and a second surface liner to a third stacking station, then continuously stacking a second surface liner on the double-core corrugated cardboard to form a double-core corrugated cardboard.

[0008] However, the above-mentioned conventional technology consists of a process in which a first corrugated core, a first surface liner, a second corrugated core, and a second surface liner are likewise supplied continuously to first, second, and third lamination stations, and sequentially laminated and dried through the application of adhesive. Therefore, the conventional technology necessarily requires an adhesive application device and a drying device (e.g., a heating plate, etc.), and the manufacturing efficiency is reduced due to the adhesive application and drying processes, the overall corrugated cardboard manufacturing facility becomes very complex, and the installation equipment is arranged continuously, requiring a considerably large installation space.

[0009] Furthermore, the adhesive application device of the aforementioned prior art generally applies adhesive to the ridges of the corrugated cardboard. Consequently, it is difficult to apply adhesive to the inclined surfaces connecting the ridges and valleys, making adhesion on the inclined surfaces structurally difficult; as a result, sufficient strength cannot be secured through the robust mutual adhesion between the first and second corrugated cores.

[0010] Furthermore, even when some adhesive is applied to the inclined surface, unlike the adhesive applied to the outer surface of the corrugated core facing the first surface liner and the second surface liner respectively, the adhesive applied to the laminated inclined surface between the first corrugated core and the second corrugated core is difficult to dry and requires a considerable amount of time; therefore, considering manufacturing efficiency and manufacturing costs, it has limitations in that the device cannot be commercially implemented.

[0011] The objective of the present invention is to provide a double-core corrugated cardboard having high strength due to the bonding of the inclined surfaces of the two corrugated core sheets and cold insulation due to the cavity (i.e., air layer) formed inside the corrugated core sheets, while simultaneously having high strength in the longitudinal and transverse directions due to the continuous corrugated structure inside the corrugated cardboard sheet. This is achieved by configuring the corrugated core sheets of the first single-sided corrugated cardboard and the second single-sided corrugated cardboard so that the ridges and corrugations formed therein face each other in a corresponding manner, the corrugation of one side is inserted and fitted into the ridge of the other side, and the corrugations are heat-bonded on the inclined surfaces of the corresponding ridges and corrugations.

[0012] Another objective of the present invention is to eliminate the need for conventional adhesive application and drying devices in the entire manufacturing process, thereby reducing the overall installation length of the device so that it can be installed in a relatively narrow single station, and also to reduce the installation cost of the device, so that a significant overall cost reduction effect can be achieved. In other words, the objective of the present invention is to enable the manufacturing of double-core corrugated cardboard sheets directly at a single station without passing through conventional single-facers and double-facers.

[0013] Another objective of the present invention is to enable the additional securing of a total of eight layers of heat-sealing material (i.e., protective layers) in addition to the four sheets of paper in the corrugated cardboard, by having the heat-sealing material coated on each side of the four sheets of paper itself provide an air-blocking function, a waterproof function, and a heat-blocking function in addition to the heat-sealing function.

[0014] A manufacturing apparatus for a high-strength double-core corrugated cardboard sheet according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a first supply device that supplies a first corrugated core sheet and a first surface liner from one side, wherein a heat bonding material is coated on at least one side of the first corrugated core sheet and / or the first surface liner; a second supply device that supplies a second corrugated core sheet and a second surface liner from the other side, wherein a heat bonding material is coated on at least one side of the second corrugated core sheet and / or the second surface liner; a first roller and a second roller configured to rotate in interlocking manner, wherein the first roller and the second roller are configured to heat-press the first corrugated core sheet supplied so that the first corrugated core sheet is formed with creasing and bending at regular intervals with the crests and valleys; and a first heat-pressing unit configured to bond the first corrugated core sheet with the crests and valleys formed thereon and the first surface liner supplied thereon to form a first single-sided corrugated cardboard. A third roller and a fourth roller configured to rotate by interlocking with each other, wherein the third roller and the fourth roller are configured to heat-press the supplied second corrugated core so that the peaks and valleys are formed at regular intervals and are corrugated; a second heat-pressing unit configured to bond the second corrugated core with the formed peaks and valleys and the supplied second surface liner together to form a second single-sided corrugated board; and a heat-bonding unit configured such that the peaks and valleys of the first single-sided corrugated board and the second single-sided corrugated board face each other, and the valley of one side is inserted into the peak of the other side to be heat-bonded on the inclined surface of the corresponding peaks and valleys.

[0015] A method for manufacturing a high-strength double-core corrugated cardboard sheet according to another embodiment of the present invention comprises: a step of coating a heat-bonding material on at least one surface of a first corrugated core sheet, a first surface liner, a second corrugated core sheet, and a second surface liner; a step of supplying the first corrugated core sheet and the first surface liner from one side; a step of supplying the second corrugated core sheet and the second surface liner from the other side; a step of forming crests and valleys at regular intervals on the first corrugated core sheet by applying heat and pressing the heat-bonding material coated on the supplied first corrugated core sheet; a step of forming crests and valleys at regular intervals on the second corrugated core sheet by joining the first corrugated core sheet with the crests and valleys formed thereon and the supplied first surface liner together to form a first single-sided corrugated cardboard; a step of forming crests and valleys at regular intervals on the second corrugated core sheet by applying heat and pressing the heat-bonding material coated on the supplied second corrugated core sheet; and a step of forming a second single-sided corrugated cardboard by joining the second corrugated core sheet with the crests and valleys formed thereon and the supplied second surface liner together. The method is configured to include the step of inserting and fitting the ridges and valleys of the first single-sided corrugated cardboard so as to correspond to the valleys and ridges of the second single-sided corrugated cardboard, respectively, and thermally joining them on the inclined surfaces of the corresponding ridges and valleys.

[0016] According to another embodiment of the present invention, a high-strength double-core corrugated cardboard sheet composed of four sheets of paper laminated together comprises, wherein two sheets of paper located on the outer surface of the high-strength double-core corrugated cardboard sheet each form a first surface liner and a second surface liner made of flat surfaces, and two sheets of paper located on the inner surface of the high-strength double-core corrugated cardboard sheet form a first corrugated core sheet formed by bending the ridges and valleys at regular intervals in a straight line, and a second corrugated core sheet formed by bending the ridges and valleys at regular intervals in a straight line, and the first corrugated core sheet and the second corrugated core sheet are inserted and fitted such that the ridges and valleys of the first corrugated core sheet correspond to the valleys and ridges of the second corrugated core sheet, and are heat-bonded on the inclined surfaces of the corresponding ridges and valleys, thereby interconnecting the ridges of the first corrugated core sheet, the inclined surfaces being heat-bonded, and the ridges of the second corrugated core sheet to form a continuous corrugated structure inside the corrugated cardboard sheet.

[0017] According to the present invention, a pair of facing single-sided corrugated cardboard sheets are thermally bonded on the inclined surfaces of corresponding peaks and valleys, thereby providing a double-core corrugated cardboard that has high strength due to the bonding of the inclined surfaces of two thick corrugated core sheets and cold insulation due to the cavity (i.e., air layer) formed inside the corrugated core sheets, while also having high strength and high rigidity in the longitudinal and transverse directions due to the continuous corrugated structure inside the corrugated cardboard sheet.

[0018] According to the present invention, since adhesive application and drying devices are unnecessary, the device can be installed in a relatively small space, and installation costs are reduced, resulting in significant overall cost savings. Furthermore, double-core corrugated cardboard sheets can be continuously manufactured directly at a single station without passing through the single-facers and double-facers of the prior art.

[0019] According to the present invention, in addition to the four sheets of paper in the corrugated cardboard, an air-blocking function, a waterproof function, and a heat-blocking function can be additionally obtained by a total of eight layers of heat-adhesive material coated on each side of the four sheets of paper.

[0020] FIGS. 1(a) and FIGS. 1(b) are cross-sectional views illustrating a single facer and a double facer according to the prior art, respectively.

[0021] FIG. 2 is a cross-sectional view illustrating a manufacturing apparatus (100) for a high-strength double-core corrugated cardboard sheet according to one embodiment of the present invention.

[0022] FIG. 3(a) illustrates a cross-section of a first single-sided corrugated cardboard formed so that the peaks and valleys face downward by the manufacturing device of the present invention, FIG. 3(b) illustrates a cross-section of a second single-sided corrugated cardboard formed so that the peaks and valleys face upward by the manufacturing device of the present invention, FIG. 3(c) illustrates a cross-section of a double-core corrugated cardboard sheet in which the peaks and valleys of the first single-sided corrugated cardboard are fitted to correspond to the valleys and peaks of the second single-sided corrugated cardboard, and the corresponding peaks and valleys are heat-bonded to each other at the inclined surfaces (S) of the corresponding peaks and valleys, FIG. 3(d) illustrates a cross-section of a continuous corrugated structure formed inside the corrugated cardboard sheet, in which the peaks of the first single-sided corrugated cardboard, the heat-bonded inclined surfaces, and the peaks of the second single-sided corrugated cardboard are interconnected.

[0023] FIG. 4 is a process flow diagram of a method for manufacturing a high-strength double-core corrugated cardboard sheet according to one embodiment of the present invention.

[0024] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

[0025] FIG. 2 is a cross-sectional view illustrating a manufacturing apparatus (100) for a high-strength double-core corrugated cardboard sheet according to one embodiment of the present invention.

[0026] Referring to FIG. 2, the manufacturing apparatus (100) of a high-strength double-core corrugated cardboard sheet according to the present invention comprises: a first supply device (not shown) that supplies a first corrugated core sheet (101a) and a first surface liner (101b) from one side; a second supply device (not shown) that supplies a second corrugated core sheet (102a) and a second surface liner (102b) from the other side; a first roller (110a) and a second roller (110b) configured to rotate by interlocking with each other, wherein the first roller (110a) and the second roller (110b) are configured to heat-press the first corrugated core sheet (101a) supplied thereto so that the first corrugated core sheet (101a) is formed with creasing and bending of the crests and valleys at regular intervals. A first heat pressing part (120) configured to be formed with a flat surface and pressed in contact with the second roller (110b), wherein the first corrugated core (101a) having peaks and valleys formed thereon and the first surface liner (101b) supplied thereon are joined together to form a first single-sided corrugated board (101); and a third roller (130a) and a fourth roller (130b) configured to rotate by interlocking with peaks and valleys formed at regular intervals, wherein the third roller (130a) and the fourth roller (130b) are configured to heat press the second corrugated core supplied thereon so that peaks and valleys are formed at regular intervals and curves are formed thereon. A second heat pressing part (140) formed with a flat surface and configured to press in contact with the fourth roller (130b), wherein the second heat pressing part (140) forms a second corrugated core (102a) having peaks and valleys formed thereon and the supplied second surface liner (102b) are joined together to form a second single-sided corrugated board (102); and a heat joining part is configured such that the peaks and valleys of the first single-sided corrugated board (101) and the second single-sided corrugated board (102) face each other, and the valley on one side is inserted into the peak on the other side to form a heat joining on the inclined surface of the corresponding peaks and valleys.

[0027] In FIG. 2, the first heat compression part (120) and the second heat compression part (140) facing each other are configured to simultaneously perform the function of a heat bond. However, it should be noted that the heat bond may be implemented as a separate component (e.g., an additional pressure roller or a pressure belt). That is, the present invention should be interpreted to include not only embodiments in which the first heat compression part (120) and the second heat compression part (140) simultaneously perform the function of a heat bond, but also embodiments in which the heat bond is composed of a separate component.

[0028] The first corrugated core (101a) and the first surface liner (101b), and the second corrugated core (102a) and the second surface liner (102b) supplied by the first supply device and the second supply device are pre-coated with a heat bonding material on at least one side. Preferably, the heat bonding material is pre-coated on both sides of the first corrugated core (101a), the first surface liner (101b), the second corrugated core (102a), and the second surface liner (102b). More preferably, in addition to the heat bonding function, the heat bonding material additionally has an air blocking function, a waterproof function, and a heat blocking function, thereby allowing additional air blocking, waterproof function, and heat blocking function to be obtained by a total of eight layers of heat bonding material coated on each side of the four sheets of paper (i.e., the first corrugated core (101a), the first surface liner (101b), the second corrugated core (102a), and the second surface liner (102b)).

[0029] The manufacturing apparatus (100) according to the present invention adopts a method of bonding the first corrugated core (101a), the first surface liner (101b), the second corrugated core (102a), and the second surface liner (102b) by applying heat as needed to a heat bonding material pre-coated on at least one side thereof, so that a separate adhesive application device and an adhesive drying device are not required. Accordingly, the manufacturing apparatus (100) according to the present invention can be installed in a relatively small space, for example, in a single station, and the installation cost of the adhesive application device, etc. is also reduced, thereby achieving a significant overall cost reduction effect.

[0030] Referring to FIG. 2, the first heat pressing unit (120) rotates in contact with the second roller (110b) and forms a first single-sided corrugated board (101) by bonding a first surface liner (101b) to a first corrugated core sheet (101a) having peaks and valleys formed thereon. The second heat pressing unit (140) rotates in contact with the second roller (130b) and forms a second single-sided corrugated board (102) by bonding a second surface liner (102b) to a second corrugated core sheet (102a) having peaks and valleys formed thereon. At the same time, the first heat pressing unit (120) and the second heat pressing unit (140) heat-bond the first and second single-sided corrugated boards (101, 102) facing each other while pressing the valleys and peaks so that they correspond to each other, thereby forming a double-core corrugated board (103). That is, as the groove of the first single-sided corrugated cardboard (101) is inserted into the ridge of the second single-sided corrugated cardboard (102), thermal bonding is achieved at the slope (S) of the corresponding ridge and groove of the first single-sided corrugated cardboard (101) and the second single-sided corrugated cardboard (102).

[0031] Referring to FIG. 2, the invention further includes a guide section (150) positioned adjacent to the first heat pressing section (120) and the second heat pressing section (140) to guide the double-core corrugated cardboard (103) toward the discharge port. The guide section (150) may be configured to include a first rotating belt (150c) rotating through a pair of rollers (150a) on one side and a second rotating belt (150d) rotating through another pair of rollers (150b) on the opposite side. The guide section (150) functions to support or maintain the heat-bonded double-core corrugated cardboard (103) in its bonded state while cooling it (e.g., cooling to room temperature). FIG. 2 illustrates only one example of the guide section (150) that can be implemented in the present invention, and it is obvious that the present invention is not limited to the specific configuration of the guide section (150) described above. Accordingly, the guide portion (150) may be implemented in various configurations and arrangements by those skilled in the art.

[0032] FIG. 3(a) illustrates a cross-section of a first single-sided corrugated cardboard (101) formed such that the peaks and valleys face downward by the manufacturing device of the present invention. The sequential operation of the first roller (110a), the second roller (110b), and the first heat press (120) shown in FIG. 2 forms a first single-sided corrugated cardboard (101) by bonding a first surface liner (101b) to the first corrugated core (101a) in which peaks and valleys are formed.

[0033] FIG. 3(b) illustrates a cross-section of a second single-sided corrugated cardboard (102) formed such that the peaks and valleys face upward by the manufacturing device of the present invention. The sequential operation of the third roller (130a), the fourth roller (130b), and the second heat press (140) shown in FIG. 2 forms the second single-sided corrugated cardboard (102) by bonding a second surface liner (102b) to the second corrugated core (102a) in which the peaks and valleys are formed.

[0034] FIG. 3(c) illustrates a cross-section of a double corrugated cardboard sheet in which the ridges and valleys of the first single-sided corrugated cardboard (101) are fitted to correspond to the valleys and ridges of the second single-sided corrugated cardboard (102), and the corresponding ridges and valleys are heat-bonded to each other at the inclined surfaces (S).

[0035] That is, the heat bonding section is heated, for example, to 120 to 180 degrees, to melt the heat bonding material previously coated on the first corrugated core (101a) of the first single-sided corrugated board (101) and the second corrugated core (102a) of the second single-sided corrugated board (102), and to apply pressure so that the peaks and valleys of the first corrugated core (101a) and the second corrugated core (102a) are fitted together so that they correspond to each other. As a result, the first corrugated core (101a) and the second corrugated core (102a) are joined together at the inclined surfaces (S) of the corresponding peaks and valleys to form a double corrugated core corrugated board (103).

[0036] FIG. 3(d) illustrates a cross-section of a continuous corrugated structure formed inside a corrugated sheet by interconnecting the peaks of the first single-sided corrugated sheet (101), the heat-bonded inclined surface (S), and the peaks of the second single-sided corrugated sheet (102). FIG. 3(d) also illustrates a cavity (C) formed between corresponding peaks and valleys, for example, configured such that the upper width of the peaks of the first single-sided corrugated sheet (101) is greater than the lower width of the valleys of the second single-sided corrugated sheet (102).

[0037] That is, as shown in FIG. 3(d), a pair of facing single-sided corrugated cardboard sheets (101, 102) are heat-bonded at the inclined surfaces (S) of corresponding peaks and valleys, thereby providing a double-core corrugated cardboard that has high strength due to the bonding of the inclined surfaces of the two corrugated core sheets and cold insulation due to the cavity (i.e., air layer) formed inside the corrugated core sheets, while also having high strength and high rigidity in the longitudinal and transverse directions due to the continuous corrugated structure inside the corrugated cardboard sheet.

[0038] Another embodiment of the present invention provides a method for manufacturing a high-strength double-core corrugated cardboard sheet by the manufacturing apparatus of the present invention described above. Referring to FIG. 4, the manufacturing method comprises the steps of: coating a heat-bonding material on at least one surface of a first corrugated core sheet (101a), a first surface liner (101b), a second corrugated core sheet (102a), and a second surface liner (102b); supplying the first corrugated core sheet (101a) and the first surface liner (101b) from one side; supplying the second corrugated core sheet (102a) and the second surface liner (102b) from the other side; and applying heat to the heat-bonding material coated on the supplied first corrugated core sheet (101a) while applying pressure to form crests and valleys at regular intervals on the first corrugated core sheet (101a). The method is configured to include the step of forming a first single-sided corrugated board (101) by joining the first corrugated core sheet (101a) having the above-mentioned peaks and valleys and the supplied first surface liner (101b) together; the step of forming peaks and valleys at regular intervals on the second corrugated core sheet (102a) by applying heat and pressing a heat bonding material coated on the supplied second corrugated core sheet (102a); the step of forming a second single-sided corrugated board (102) by joining the second corrugated core sheet (102a) having the above-mentioned peaks and valleys and the supplied second surface liner (102b) together; and the step of inserting and fitting the peaks and valleys of the first single-sided corrugated board (101) so as to correspond to the valleys and peaks of the second single-sided corrugated board (102), respectively, so as to heat-bond them at the inclined surfaces (S) of the corresponding peaks and valleys.

[0039] Another embodiment of the present invention provides a high-strength double-core corrugated cardboard sheet composed of four sheets of paper laminated together. Two sheets of paper located on the outer surface of the high-strength double-core corrugated cardboard sheet each form a first surface liner (101b) and a second surface liner (102b) made of flat surfaces, and two sheets of paper located on the inner surface of the high-strength double-core corrugated cardboard sheet form a first corrugated core sheet (101a) formed by bending the ridges and valleys at regular intervals in a straight line, and a second corrugated core sheet (102a) formed by bending the ridges and valleys at regular intervals in a straight line, and the first corrugated core sheet (101a) and the second corrugated core sheet (102a) are inserted and fitted so that the ridges and valleys of the first corrugated core sheet (101a) correspond to the valleys and ridges of the second corrugated core sheet (102a), respectively, and are heat-bonded at the inclined surface (S) of the corresponding ridges and valleys. Accordingly, the peaks of the first corrugated core (101a), the heat-bonded inclined surface (S), and the peaks of the second corrugated core (102a) are interconnected to form a continuous corrugated structure inside the corrugated sheet.

[0040] Preferably, the height of the inclined surface (S) where the corresponding crests and valleys are joined is 30% to 70% of the valley depth on one side or the crest height on the other side of the double-core corrugated cardboard. If it is 30% or less, the joining surface at the inclined surface (S) is small, so the rigidity is weak, and if it is 70% or more, the overall thickness becomes too thin and the internal cavity is also small, making it inefficient. More preferably, the height of the inclined surface (S) where the corresponding crests and valleys are joined is 40% to 60% of the valley depth on one side or the crest height on the other side of the double-core corrugated cardboard.

[0041] Although the present invention has been described in detail above with reference to specific embodiments with reference to the drawings, the present invention is not limited to such specific structures. Those skilled in the art may make various modifications or changes to the present invention without departing from the technical spirit and scope of the present invention as described in the following claims.

Claims

1. As a manufacturing device for high-strength double-core corrugated cardboard sheets, A first supply device for supplying a first core sheet and a first surface liner from one side, wherein at least one side of the first core sheet and / or the first surface liner is coated with a heat bonding material; A second supply device that supplies a second core sheet and a second surface liner from the other side, wherein at least one side of the second core sheet and / or the second surface liner is coated with a heat bonding material; A first roller and a second roller configured to rotate by interlocking with each other, wherein the first roller and the second roller are configured to heat-press the first corrugated core supplied thereto so that the peaks and valleys are formed at regular intervals and curved. A first heat pressing part configured to form a first single-sided corrugated board by joining the first corrugated core sheet having the above-mentioned peaks and valleys and the supplied first surface liner together; A third roller and a fourth roller configured to rotate by interlocking with each other, wherein the third roller and the fourth roller are configured to heat-press the supplied second corrugated core so that the peaks and valleys are formed at regular intervals and folded. A second heat pressing unit configured to form a second single-sided corrugated board by joining the second corrugated core sheet having the above-mentioned peaks and valleys and the supplied second surface liner together; and A thermal bonding part in which the ridges and ridges of the first single-sided corrugated cardboard and the second single-sided corrugated cardboard face each other, and the ridge on one side is inserted and fitted into the ridge on the other side so as to be thermally bonded on the inclined surface of the corresponding ridge and ridge; A manufacturing apparatus for high-strength double-core corrugated cardboard sheets characterized by including 2. A manufacturing apparatus for high-strength double-core corrugated cardboard sheets according to claim 1, characterized in that the manufacturing apparatus is capable of producing double-core corrugated cardboard sheets at a single station without a separate adhesive application device and adhesive drying device.

3. An apparatus for manufacturing a high-strength double-core corrugated cardboard sheet according to claim 1, wherein the first heat pressing part and the second heat pressing part simultaneously perform the function of the heat bonding part, and the first heat pressing part and the second heat pressing part are arranged adjacent to each other and heat bond the peaks and valleys of the first single-sided corrugated cardboard and the second single-sided corrugated cardboard facing each other while applying corresponding pressure to form a double-core corrugated cardboard.

4. An apparatus for manufacturing a high-strength double-core corrugated cardboard sheet, characterized in that, in claim 1, the first heat pressing part and the second heat pressing part are composed of a heat pressing roller or a heat pressing belt.

5. An apparatus for manufacturing a high-strength double-core corrugated cardboard sheet according to claim 1, further comprising a guide portion disposed adjacent to the first heat pressing portion and the second heat pressing portion to guide the double-core corrugated cardboard toward the discharge port.

6. An apparatus for manufacturing a high-strength double-core corrugated cardboard sheet, wherein, in addition to the heat bonding function, the heat bonding material pre-coated on both sides of the first corrugated core sheet, the first surface liner, the second corrugated core sheet, and the second surface liner additionally has an air-blocking function, a waterproof function, and a heat-blocking function according to claim 1.

7. An apparatus for manufacturing a high-strength double-core corrugated cardboard sheet, characterized in that, in claim 1, the upper width of the peak is configured to be greater than the lower width of the valley, thereby forming a cavity between corresponding peaks and valleys.

8. A method for manufacturing a high-strength double-core corrugated cardboard sheet, A step of coating a heat bonding material on at least one surface of the first corrugated core, the first surface liner, and the second corrugated core and the second surface liner; A step of supplying the first corrugated core and the first surface liner from one side; A step of supplying the second corrugated core and the second surface liner from the other side; A step of applying heat and applying pressure to the heat-bonding material coated on the first corrugated core supplied above, thereby forming peaks and valleys at regular intervals on the first corrugated core; A step of forming a first single-sided corrugated cardboard by joining the first corrugated core sheet having the above-mentioned peaks and valleys and the first surface liner supplied thereto together; A step of applying heat and applying pressure to the heat-bonding material coated on the supplied second corrugated core to form peaks and valleys at regular intervals on the second corrugated core; A step of forming a second single-sided corrugated cardboard by joining the second corrugated core sheet having the above-mentioned peaks and valleys and the supplied second surface liner together; and A step of inserting and fitting the ridges and valleys of the first single-sided corrugated cardboard so as to correspond to the valleys and ridges of the second single-sided corrugated cardboard, respectively, and heat-bonding them on the inclined surfaces of the corresponding ridges and valleys; A method for manufacturing a high-strength double-core corrugated cardboard sheet characterized by including 9. A method for manufacturing a high-strength double-core corrugated cardboard sheet, characterized in that, in claim 8, the upper width of the peak is configured to be greater than the lower width of the valley, thereby forming a predetermined space between corresponding peaks and valleys.

10. A high-strength double-core corrugated cardboard sheet composed of four sheets of paper laminated together, Two sheets of paper located on the outer surface of the above-mentioned high-strength double-core corrugated cardboard sheet each form a first surface liner and a second surface liner made of flat surfaces, and The two sheets of paper located on the inner surface of the above-mentioned high-strength double-core corrugated cardboard sheet form a first corrugated core sheet that is curved in a straight shape so that ridges and valleys are wrinkled at regular intervals, and a second corrugated core sheet that is curved in a straight shape so that ridges and valleys are wrinkled at regular intervals. A high-strength double-core corrugated cardboard sheet characterized in that the first corrugated core and the second corrugated core are inserted and fitted such that the peaks and valleys of the first corrugated core correspond to the valleys and peaks of the second corrugated core, respectively, and are thermally bonded at the inclined surfaces of the corresponding peaks and valleys, thereby interconnecting the peaks of the first corrugated core, the thermally bonded inclined surfaces, and the peaks of the second corrugated core to form a continuous corrugated structure inside the corrugated cardboard sheet.

11. A high-strength double-core corrugated cardboard sheet according to claim 10, characterized in that the upper width of the peak is configured to be greater than the lower width of the valley, thereby forming a cavity between corresponding peaks and valleys.

12. A high-strength double-core corrugated cardboard sheet according to claim 10, characterized in that the height of the inclined surface where the corresponding peaks and valleys are joined is 30% to 70% of the valley depth on one side or the peak height on the other side of the double-core corrugated cardboard.

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