JP2000158530A - Hollow synthetic resin plate and its edge face treating method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hollow synthetic resin plate with an edge face treated part, the surface shape of the thermally fused part of which is uniform, the finishing dimensions of a product, are stabilized, in which a warpage hardly develops, and pin holes are hard to be generated, which can be uniformly sealed without generation of sealing edges, excellent in safety, hygienic properties and beantifulness. SOLUTION: The web end part of a hollow synthetic resin plate 1 is thermally melted axially from its end edge with a forming hot plate 10 and, at the same time, a front wall end edge and a rear wall end edge are heated so as to bendingly form the front wall end edge and the rear wall end edge with forming plates 8 in order to wrap the melting part of the web so as to meltingly bond the front wall end edge and the rear wall end edge together, the edge face facing to the groove opening part between webs is seal formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow synthetic resin plate such as a case blank for forming a cardboard box made of synthetic resin, a method of treating an end face thereof, and an apparatus therefor.

[0002]

2. Description of the Related Art In recent years, instead of a conventional paper cardboard box,
As shown in FIG. 2 (a), a resin cardboard box formed of a case blank composed of a hollow synthetic resin plate 1 in which a plurality of webs 3 are integrally formed at equal intervals between a front wall 2 and a back wall 2 'is provided. It has been heavily used. These resin cardboard boxes are stronger than paper and can be used repeatedly as returnable boxes,
In addition, there is an advantage that cleaning and the like are easy and the device can be used repeatedly and cleanly for a long time. However, since the hollow synthetic resin plate has a large number of open grooves 4 whose end faces are opened in the web axial direction similarly to the conventional corrugated cardboard, foreign substances such as dirt are formed in the open grooves 4 in a repeated use process. However, there is a drawback that intrusion occurs. Therefore, in order to prevent intrusion of foreign matter, an end surface treatment for closing both ends of the opening groove is performed.

[0003] As a conventional end face treatment method, a method in which an end face of a hollow synthetic resin plate facing an opening groove is pressed from above and below by a hot plate and heat welded, or a method of welding by ultrasonic heat welding. It has been known. Further, the hollow synthetic resin plate is used not only for the case blank but also for various uses such as pats, and the end surface treatment is performed on the products in these uses as necessary by the same method as described above. . For example, in the case of a case blank, these end face treatments are performed in separate steps for each side of the flap facing the opening groove, the cut end, and the like.

[0004]

Among the above-mentioned conventional end-face treatment methods, the method of thermocompression bonding from above and below requires heating the inside and outside walls at an unnecessarily high temperature because the internal web must be thermally fused. There must be. Therefore, the front wall and the back wall are heated more than necessary to a part which does not directly participate in the end face sealing, and the webs are welded while being buckled in different directions with respect to the pressure bonding. The surface area and the shape of the part (1) are not uniform, and the finished dimensions of the product become unstable, and there is a disadvantage that warpage tends to occur. In addition, there are disadvantages such that the sealing of the end face becomes uneven, a pinhole is easily generated, and the sealing property is unstable. on the other hand,
The method of processing the end face by ultrasonic welding has a drawback that the processing speed is slow and the processing size is limited, and there is a drawback that a seal edge is easily formed on the processed end face. Furthermore, the end treatment of the case blank by the above-described method is liable to cause the blank to be warped because the heat-welded portion is non-uniform, and is a factor that hinders the improvement in productivity due to the number of steps performed. There is a problem.

The present invention has been made in view of the above-mentioned circumstances of the prior art, and has a uniform surface shape of a heat-welded portion, accurate and stable finished products, less occurrence of warpage, and a pin. Holes are not easily generated and can be sealed uniformly,
Further, to obtain a hollow synthetic resin plate having an end face treatment part excellent in safety, hygiene and aesthetics that does not generate a seal edge, and a method and an apparatus for treating the end face of a hollow synthetic resin sheet for obtaining the hollow synthetic resin sheet It is another object of the present invention to provide a case blank end face processing apparatus capable of processing a face blank in one step.

[0006]

The hollow synthetic resin plate of the present invention for solving the above-mentioned problems is a hollow synthetic resin plate in which a plurality of webs are integrally formed at equal intervals between a front wall and a back wall.
The edge of the web is melted in the axial direction from the edge, and the edge of the front wall and the edge of the back wall are bent so as to enclose the melted portion of the web, and the edge of the front wall and the edge of the back wall are welded to each other. The end face of the web facing the groove opening is formed by sealing. The end face other than the end face of the hollow synthetic resin plate facing the groove opening is formed by melting the outer web facing the end face over the axial length, and the front wall end and the back wall end are formed as described above. By bending so as to enclose the melted portion of the web and melting and joining the front wall edge and the back wall edge to each other, and processing the end surface into the same shape as the end surface facing the groove opening, the peripheral edge is It is possible to obtain a hollow synthetic resin plate whose end face has been treated in a uniform shape.

When the hollow synthetic resin plate is a case blank, at least the edge of the bottom wall flap and the edge of the top wall flap are sealed and molded as described above. The cut ends between the flaps are heated and pressed by a hot plate from above to seal them by heat welding.

In the method for treating the end surface of a hollow synthetic resin plate according to the present invention, the edge of the web is heated and melted in the axial direction from the edge by a forming hot plate, and the edges of the front and back walls are heated and melted. The wall opening and the back wall end are bent and formed so as to enclose the molten portion of the web by a forming plate, and the front wall and the back wall edge are fusion bonded to each other so that the groove opening between the webs faces each other. It is characterized in that the end face is formed by sealing.

The apparatus for treating an end face of a hollow synthetic resin plate according to the present invention further comprises a forming hot plate which heats and melts the end portion of the web in the axial direction from the edge to form a heat melting portion at the end portion of the web. A molding plate having a molding surface that bends the front wall end and the back wall end so as to enclose the heat-melted portion of the web end and that the front wall edge and the back wall edge are fusion-bonded to each other; It is characterized by comprising. The formed hot plate has a top portion formed in a triangular prism shape, and a vertex angle of 30 ° to 100 °.
Is more preferable, and a more preferable range is 50 °.
９０90 °.

In the apparatus for treating an end face of a case blank made of a hollow synthetic resin plate according to the present invention, the end of the web is heated and melted in the axial direction from the edge to form a heat-melted portion at the end of the web. A forming hot plate, and a forming mold surface for bending and forming the front wall end and the back wall end so as to enclose the heat-melted portion of the web end and melting and joining the front wall edge and the back wall edge to each other. Flap end face processing device comprising:
A cutting end face treatment device between flaps having a heating / pressing hot plate driven up and down, and a glue margin end treatment device having a heating / pressing hot plate driven up and down, wherein the end treatment device is a bottom wall of a case blank. It is characterized by being arranged corresponding to the flap end face, the cut end face between the flaps, and the glue margin end face, respectively.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows a method for treating an end face of a hollow synthetic resin plate according to an embodiment of the present invention. As shown in FIG. 2A, the hollow synthetic resin plate before the end face treatment has both end faces formed by webs 3 provided at equal intervals between the front wall 2 and the back wall 2 'corresponding to a liner of corrugated cardboard. Are formed integrally with a synthetic resin such as polypropylene or polycarbonate by extrusion molding. The hollow synthetic resin plate 1 is stamped and formed into an appropriate size depending on the product, and the end face of the open groove is processed as follows.

The end surface processing station includes a receiving plate 6 for receiving the hollow synthetic resin plate 1, a gauge plate 7 for positioning the end surface, a molding surface 11 for thermoforming the end surface from above and below,
A pair of forming plates 8, 8 ′ having a base plate 11 ′ and a holding plate 9 are arranged, and the forming hot plate 10 is formed so that the top thereof abuts against the web of the hollow synthetic resin plate at right angles from the side to the opening end surface. Are displaceably arranged. Formed plate 8, 8 '
The shape of the end face processing section 5 of the hollow synthetic resin plate is defined by the shape of the mold surface of the mold, and in this embodiment, the end face processing section 5
The mold surfaces 11 and 11 'are arranged such that the ends of the front wall 2 and the back wall 2' as shown in FIG. As shown in FIG. The base of the forming hot plate 10 is fixed to a heater 15, and the heater 15 is fixed to a tip of a rod 17 of a cylinder device 16 which is a heater displacement driving device. The cylinder device has a preset displacement amount and displacement speed. Is controlled by a control means (not shown) so as to be able to be displaced.

In the embodiment shown in the figures, the forming hot plate 10 has a triangular prism shape at the tip, and its vertex is set to a height exactly corresponding to the middle height position of the web 3. Melts the web in a triangular notch shape from the tip. The apex angle θ of the top of the forming hot plate can be any angle, but the front and back walls are securely joined to each other at the top edges, and the end surface treatment section is cleanly and uniformly sealed in the minimum range without generating pinholes. To 3
A range of 0 ° to 100 ° is desirable, and a more optimal range is 5 °.
0 ° to 90 °. If the apex angle is less than 30 °, the tip of the forming hot plate becomes too sharp, and the front and back walls of the hollow synthetic resin plate contact the triangular surface of the forming hot plate and soften by heating. And the melted portion of the web increases. On the other hand, if the apex angle is 100 ° or more, the depth of the melted portion of the web becomes too shallow, and it becomes difficult to form the end face treated portion.

The apparatus for treating an end face of a hollow synthetic resin plate of this embodiment is constructed as described above. In FIG. 1A, the hollow synthetic resin plate 1 is conveyed onto a receiving plate 6 by a suitable conveying means. The end face where the opening groove 4 is opened hits the gauge plate 7 descending to the gauge position, whereby the end face is positioned. Next, as the holding plate 9 descends, the hollow synthetic resin plate 1 is pressed and held at that position,
The gauge plate 7 rises. In this state, the cylinder device 16
Operates to displace the forming hot plate 10 previously heated to a predetermined temperature by the heater 15 to the hollow synthetic resin plate side, so that the leading end of the forming hot plate hits the middle portion of the web to melt the web from the middle portion. While the web is melted into a substantially triangular shape on the inclined side of the triangular prism-shaped forming hot plate, and the front and back walls contact the inclined side of the forming hot plate. The tip also softens (FIG. 1 (b)). The temperature of the forming hot plate is selected depending on the material of the hollow synthetic resin plate 1. In the case of polypropylene or polycarbonate, the temperature is preferably maintained at about 200 ° C to 240 ° C. Also, the forming hot plate 10 is shown in FIG.
In the state shown in (b), it is desirable to hold the resin for about 3 to 20 seconds until the resin in the end face treated portion melts and softens.

Then, at the same time as the hot platen 10 returns and retracts, the forming plates 8 and 8 'move up and down to pinch the hollow synthetic resin plate 1 and press-mold the molten portion. At that time, the front wall and the back wall are easily deformed because the web is melted in a triangular cross section, and the front wall edge and the back wall edge are joined at the intermediate thickness portion of the hollow synthetic resin plate, As shown in FIG. 2 (b), it is possible to obtain a smoothly arcuate end processed shape as shown in FIG. Note that FIG.
Reference numeral 18 in (b) denotes a molten portion of the web 3.

The shape of the end face processing section is not limited to that of the above-described embodiment, but may be any shape depending on the product. FIG. 3 shows one example. The end face processing portion 5a of the hollow synthetic resin plate 1a shown in FIG. 3 (a) is formed by changing the shape of the upper and lower mold surfaces so that the upper mold surface is curved and the lower mold surface is substantially horizontal. FIG. 3B shows an example in which the end face processing portion 5b of the hollow synthetic resin plate 1b shown in FIG.

FIGS. 4 and 5 show an embodiment in which the method and apparatus for treating the end face of a hollow synthetic resin plate are applied to an end face treating apparatus for a case blank formed of a hollow synthetic resin plate as shown in FIG. Is shown. In the case blank 20 of the present embodiment, a case is shown in which all the portions where the open ends of the open grooves are exposed are subjected to the end face processing, and the bottom wall flap edge 21, the upper wall flap edge 22, and both end faces 23 of the glue margin portion , 2
3 ', an end surface treatment of the cut edge portion 24 between the flaps is performed.
In the present embodiment, of the above-mentioned end face processing, the bottom wall flap edge 21 and the top wall flap edge 22 for which the most accurate end face processing is required are performed by the end face processing method in the above embodiment. The short end portion or the spot-like portion was processed by a simple heat welding method.

The case blank end face processing apparatus of the present embodiment includes a flap end face processing apparatus 30, a glue margin end face processing apparatus 45 in the same station corresponding to the shape of the case blank.
And a notch end face processing device 37 are respectively arranged,
All end face treatments are performed simultaneously in one step. FIG. 4 shows the flap end face processing apparatus 30 and the cut end face processing apparatus 37. In the figure, the same parts as those in the above embodiment are denoted by the same reference numerals, and detailed description will be omitted. The flap end face processing device 30 is constituted by the same technical means as in the above embodiment, but the gauge plate and the forming hot plate device are not shown. In the present embodiment, the forming plates 8, 8 'are fixed to the rod ends of the cylinder devices 33, 33' fixed to the main body frame 31 via appropriate brackets, and are driven up and down by the cylinder devices. Similarly, the holding plate 9 is also fixed to the tip of the rod of the cylinder device fixed to the main body frame 31, and presses and holds the case blank 20 with a constant pressure during the end face processing from the cylinder device.

Four sets of the flap end face processing apparatuses configured as described above are arranged along the transport path of the case blank, corresponding to the left and right flaps. Each of the forming plates 8 and 8 'of each flap end face processing device has a length corresponding to the length of each flap side.

The cut end face processing device 37 is for sealing the cut end located at the upper and lower ends of the corner after the case is assembled. A forming hot plate 39 having an inclined mold surface 38 is fixed to the heater 40. The heater is attached to the tip of the rod of the cylinder device 41, and is disposed above the cut end of the case blank so as to be able to be driven up and down so that the inclined mold surface 38 just hits the cut end. When the forming hot plate 39 heated to the predetermined temperature is lowered by the cylinder device 41, the inclined mold surface 38 comes into contact with the cut end surface 24 and the portion is melt-pressed in an inclined manner, thereby forming the cut end portion as shown in FIG. 24 can be heat-sealed and sealed in an inclined manner.

As shown in FIG. 5, the glue margin end face processing device 45 is configured such that a forming hot plate 47 having an inclined mold surface 46 is fixed to a heater 48, and the heater is attached to a rod end of a cylinder device 49. The mold surface 46 is disposed above both ends of the glue margin of the case blank so as to be able to be driven up and down by a cylinder device so as to contact the glue margin end surface. Note that 50
Is a pressing plate, which is attached to a rod of a cylinder device 49 together with a heater 48 via a bracket 51.
Reference numeral 52 denotes a spring for urging the holding plate 50 downward with respect to the bracket 51, whereby the glue margin can be pressed with a predetermined pressure during the end face processing operation. When the forming hot plate 47 heated to a predetermined temperature is lowered by the cylinder device 49, the inclined mold surface 46 hits the glue margin end face and melts and pressure-bonds the part in an inclined manner. Can be thermally welded and sealed in an inclined manner.

As shown in the above embodiment, the case blank end face processing apparatus according to the present invention has a flap end face processing apparatus in the same station corresponding to the shape of the case blank.
Since the glue margin end processing device and the cut end surface processing device are respectively arranged, the end surface processing of the case blank can be performed at a time, so that the production speed can be reduced from the conventional 20 c / s / H to 40 c / s / H. Thus, the productivity can be remarkably improved as compared with the related art. In addition, in the said embodiment, although the flap end surface processing apparatus is formed and arrange | positioned in the magnitude | size corresponding to each flap, one or more flap end surface processing apparatuses have several or all of the bottom wall or front wall flap edge part. The length of the formed plate and the formed hot plate may be formed and arranged so that the end surface treatment can be performed.

Although various embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made within the scope of the technical idea. For example, in the above embodiment, the end surface treatment of the end surface facing the opening groove is shown, but when the hollow synthetic resin plate is used as a single pad or the like, the end surface other than the end surface facing the groove opening portion is used. Also, by melting the outer web over the axial length in the same manner and treating the end face in the same manner as the end face facing the groove opening, the entire peripheral edge can be treated in a uniform shape, and the appearance can be improved. You can get a good putt. Also,
The end face treatment of the groove opening is not limited to the straight part, and the end face treatment of any shape such as a curved line or a diagonal line is possible by changing the thermoformed plate and the formed plate according to the shape. It is. In addition, the present invention can be suitably applied to the end face treatment of a hollow synthetic resin plate having a thickness of 3 to 7 mm,
The present invention is also applicable to the end face treatment of a hollow synthetic resin plate having a thickness larger than that.

[0024]

As described above, according to the first to eighth aspects of the present invention, the web is directly heated and melted into a predetermined shape. The edge of the back wall can be heat-welded, the surface shape of the end surface treatment is uniform, the finished dimensions of the product are stable, the occurrence of warpage is small, the pinholes are hardly generated, and the seal can be uniformly and reliably. Hollow synthetic resin plate with an end surface treatment part with excellent safety, hygiene and aesthetics that does not generate seal edges,
Then, a case blank made of the synthetic resin plate can be obtained.

According to the ninth aspect of the present invention, the flap end face processing device, the glue margin end face processing device, and the cut end face processing device are respectively arranged corresponding to the shape of the case blank. Can be performed, and productivity can be remarkably improved as compared with the related art. In addition, since the flap end face treatment is particularly performed by seal molding by the above-described method, the dimensional accuracy after the treatment is stable, and a case excellent in product dimensions can be obtained. Furthermore, since the heating and melting are performed at the minimum, a case blank in which the warpage of the blank and the generation of pinholes are extremely small can be obtained.

[Brief description of the drawings]

1 (a) to 1 (c) are schematic views showing an end face processing step of a hollow synthetic resin plate of the present invention.

FIG. 2A is a perspective view of a hollow synthetic resin plate before the end face processing, and FIG. 2B is a perspective view of the hollow synthetic resin plate after the end face processing.

FIGS. 3A and 3B are schematic views of hollow synthetic resin plates after end face treatment according to other embodiments.

FIG. 4 is a schematic diagram of a main part of a case blank edge processing apparatus according to an embodiment of the present invention.

FIG. 5 is a schematic view of another main part of the case blank end face processing apparatus according to the embodiment of the present invention.

FIG. 6 is a plan view of a case blank.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hollow synthetic resin board 2 Front wall 2 'back wall 3 Web 4 Opening groove 5 End surface processing part 7 Gauge plate 8, 8' Molding plate 9, 50 Holding plate 10, 29, 47
Forming hot plate 11, 11 'Forming die surface 15, 40, 4
Reference Signs List 8 heater 16, 33, 41, 49 cylinder device 20 case blank 30 flap end surface processing device 37 cut end surface processing device 45 glue margin end surface processing device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) B29L 24:00 31:60 (72) Inventor Shinichi Takahashi 841 Kozono, Ayase-shi, Kanagawa Toyo Unicon Corporation F-term (reference) 3E075 AA02 AA07 AA28 BA92 CA01 DD13 DD32 DD45 GA04 4F100 AK01A BA01 DB15A DC25A EC032 EC182 EH012 EJ172 EJ422 EK00 GB15 JK14 JL04 JL12 4F209 AC03 AD05 AD08 AG03 AG06 AG18 AG23 AK07 AM08 AG03 AG06 AG18 AG23 AK07 AM32 TA01 TA08 TC13 TC22 TD05 TH01 TH06 TH18 TJ30 TN07 TN87 TQ04 TQ10 4F213 AC03 AD05 AD08 AG03 AG06 AG18 AG23 AK07 AM32 WA09 WA54 WA72 WA83 WB01 WC02 WE06 WE16 WK01 WK03

Claims (9)

[Claims] 1. A hollow synthetic resin plate in which a plurality of webs are integrally formed at equal intervals between a front wall and a back wall, wherein the web ends are melted in the axial direction from the edges, and the front wall ends. And the back wall edge is bent so as to enclose the melted portion of the web, and the front wall edge and the back wall edge are welded to each other to seal the end face facing the groove opening between the webs. A hollow synthetic resin plate formed by molding. 2. The end surface of the hollow synthetic resin plate other than the end surface facing the groove opening is formed such that the outer web facing the end surface is melted over the length in the axial direction, and the front wall end and the back end are fused. The edge of the wall is bent so as to enclose the melted portion of the web, and the edge of the front wall and the edge of the back wall are melt-bonded to each other, and the edge is processed into the same shape as the edge facing the groove opening. The hollow synthetic resin plate according to claim 1. 3. The hollow body according to claim 1, wherein the hollow synthetic resin plate is a case blank, and the case blank has at least the bottom wall flap edge and the top wall flap edge formed by the seal molding. Synthetic resin plate. 4. The hollow synthetic resin plate according to claim 3, wherein both side ends of the margin portion of the case blank and a cut end between the flaps are heat-pressed from above and sealed by heat welding. 5. A method for treating an end face of a hollow synthetic resin plate in which a plurality of webs are integrally formed at equal intervals between a front wall and a back wall, wherein the web ends are axially moved from the edges by a forming hot plate. While heating and melting, the front wall end and the back wall end are heated, and the front wall end and the back wall end are bent and formed so as to enclose the melted portion of the web by a forming plate, and the front wall end is formed. An end face treatment method for a hollow synthetic resin plate, wherein the end faces of the webs facing the groove openings are sealed by melting and joining the back wall edges to each other. 6. The hollow synthetic resin plate is a case blank, and at least the bottom wall flap edge portion and the top wall flap edge portion are formed by the seal molding, and both side edges of a glue margin portion of the case blank. 6. The method according to claim 5, wherein the cut ends between the flaps are heat-sealed and sealed by a hot plate from above. 7. An end processing apparatus for a hollow synthetic resin plate in which a plurality of webs are integrally formed at equal intervals between a front wall and a back wall, wherein the web end is heated and melted from an edge to an axial direction. Forming a hot plate to form a heat-melted portion at the web end, and bending the front wall end and the back wall end so as to enclose the heat-melted portion of the web end; A molding plate having a molding die surface for melting and joining back wall edges to each other. 8. The apparatus for treating an end face of a hollow synthetic resin plate according to claim 7, wherein the forming hot plate has a top formed in a triangular prism shape, and a vertex angle in a range of 30 ° to 100 °. 9. An end processing apparatus for a case blank comprising a hollow synthetic resin plate in which a plurality of webs are integrally formed at equal intervals between a front wall and a back wall, wherein the web ends are axially moved from the edges. A forming hot plate that heats and fuses toward the web to form a heat melting portion at the web end; and a front wall end and a back wall end that are bent and formed so as to enclose the heat melting portion at the web end. A flap end surface treatment device comprising a molding plate having a molding die surface for melting and joining the wall edge and the back wall edge to each other, a notch end surface treatment device between flaps having a heating and pressing hot plate driven up and down, It consists of a glue margin end face treatment device having a heating / pressing hot plate that is driven up and down, and these end face treatment devices are respectively arranged corresponding to the bottom wall flap end face of the case blank, the cut end face between the flaps, and the glue margin end face. End of case blank characterized by the following Surface treatment equipment.