JPS597014A - Method of sealing end of thermoplastic resin corrugated card-board - Google Patents

Abstract

PURPOSE:To prevent water from going into the corrugated card-board made of thermoplastic resin, by forcing a heated blade having a specified shape to the corrugated card-board so that the resin is softened and melted to form a film to the cut end of the corrugated card-board thereby sealing quickly the cut end. CONSTITUTION:For example, the blade 2 with a slant 4 inclined relatively to the sheet surface of corrugated card-board 1 is heated and driven down toward the corrugated card-board 1 of a thermoplastic resin placed on a platen 3 so that the tip of the blade 2 is forced on the sheet surface, and as the blade 2 is forced into the partly softened and melted corrugated card-board 1, a softened, melted film 6 of the thermoplastic resin is formed along each side of the slant 4 of the blade 2. When the blade 2 is lowered until the tip 7 reaches the undersurface of the corrugated card-board 1, the corrugated card-board 1 is cut into corrugate card-board pieces 8, 9, and each of the cut ends is sealed by a softened and melted film 6 that extends from the surface sheet 1a and the undersurface sheet 1b. Finally the softened and melted film is cooled and solidified to complete the sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sealing the edges of thermoplastic corrugated cardboard.

Plastic cardboard is lighter than paper cardboard.
It has become widely used in various applications due to its water and oil resistance. However, plastic cardboard (hereinafter simply referred to as cardboard) generally has a structure in which a corrugated plastic sheet or a plastic sheet with many protrusions is sandwiched and glued between two sheets, or two sheets. Since the intermediate wall is integrally provided between the two sheets, it is easy for rainwater or washing water to enter the inside of the cardboard from the edge of the cardboard, i.e., between the two sheets, and it is difficult to prevent the corrugated cardboard from entering. It is extremely difficult to completely drain water that has entered the interior. As a result, there have been reports that moisture evaporates from cardboard boxes stored in export containers over a long period of time, causing rust on mechanical parts inside the containers.

This invention has been made in view of the above two points, and provides a sealing method that quickly seals the edges of a cardboard made of thermoplastic resin and reliably prevents water from entering the inside of the cardboard. This is what I am trying to do.

However, this invention heats a knife provided with an inclined surface that is inclined with respect to the sheet surface of the thermoplastic resin corrugated board.
Push the cutlery into the cardboard by feeding it in a direction approximately perpendicular to the sheet surface, and then press the thermoplastic material along the inclined surface from the front sheet to the back sheet of the cardboard. A heat++J plastic resin step yJ? characterized by forming a softened molten film of resin, and cooling and solidifying the softened molten film. - A method for sealing the end of a wall.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2).

In the figure, the cardboard 1 is made of heat + tJ plastic resin such as polypropylene or polyethylene.
A partition wall 1e is integrally provided between 1a11b by extrusion molding. 2 is a straight bar-shaped knife that is heated by a built-in electric heater (not shown), etc.
It is supported by an air cylinder or the like so as to be able to move in two directions "in a direction substantially perpendicular to two surfaces" of the surface plate 8. An inclined surface 4.4 is formed at the lower end of the cutter 2.

First, as shown in FIGS. 1(a) and 2, the cardboard 1 is placed on the surface plate 3'' so that the longitudinal direction of the partition wall IC is perpendicular to the longitudinal direction of the cutter 2. At this time, cardboard l
It is preferable to place an asbestos sheet or other cushioning material 5 under the. Next, the blade 2 is heated and driven downward to push the tip against the cardboard 1.

For example, in the case of a polypropylene special pole, the heating temperature of the cutter is preferably about 180 to 200°C. The cardboard l is heated by the cutter 2 and locally softens and melts, and as the cutter 2 penetrates into the cardboard L, the H-sized cardboard is removed by the cutter 2 and is softened and melted, as shown in Fig. 1 (b).
As shown in FIG. 3, a softened molten film 6 is formed along the l1ri fr·1 4 of the cutter. If the cutter 2 is further lowered and pressed until the tip 7 of the cutter almost reaches the bottom surface of the corrugated pole l as shown in FIG. 6 and the corrugated board 1 is cut into two corrugated boards 8.9. The time from the start of contact of the blade 2 to the cardboard 1 to the completion of cutting is approximately 3 seconds, 6 seconds, and 10 seconds for the temperature of the blade 2 and each part of the cardboard, respectively. Remove the knife 2'1,
As shown in FIG. 1(d), when the corrugated board 8.9 is separated from the cutter 2 and allowed to cool, the softened molten film 6 solidifies in a few seconds, completing the sealing between the sheets 1-1a1111.

1, J-, In the embodiment described above, a case was described in which a sealing end oriented perpendicularly to the partition wall 1c of the cardboard was obtained. It is also possible to obtain a sealed edge oriented in the direction of .It is also possible to obtain a sealed edge oriented in the direction of . can also be sealed in the same manner as above.

Furthermore, in the above embodiment, two corrugated boards 8 and 9 are obtained whose ends are sealed with a single culm, but if it is necessary to seal only the end of one corrugated board, as shown in Fig. 3, A knife 2 having an inclined surface 4 on only one side may be used.

In the embodiment shown in FIG. 4, the end 11 of the cardboard l that needs to be sealed is placed directly under the tip 7 of the cutter 2, and the cutter 2 is heated in the same manner as described above. In this case, since the cardboard 1 is not cut, unnecessary edges are not produced and it is economical.The same effect as this embodiment can be obtained by the embodiment shown in FIG. )
It will be done. In this case, two pieces of pre-cut cardboard 12.
13 with their ends abutted, and then nut so that I4 is directly below the tip 7 of the blade 2, -
The edges of two pieces of cardboard can be sealed using a culm.

FIG. 6 shows still another embodiment of the present invention, in which the end ICI of the corrugated board l is aligned with the end 15 of the surface plate 3, and
A cutter 2 is used which cuts the tip 7 at a position deviated outward from the end surface 15 of the surface plate, and the inclined surface 4 of the cutter 2 is aligned with the cushion material 5.
Alternatively, a softened molten film is formed on the end of the cardboard 1 to seal it by pressing down the cutter until it almost touches the surface plate 3 (if no cushioning material is used).

The case where one side of the cardboard is sealed has been described above, but by selecting the shape of the cutter 2, for example, if the cutter 2 is made into a rectangular frame shape, it is also possible to seal all four sides of the cardboard at the same time. If you use a blade that is curved in the longitudinal direction, you can obtain a curved seal edge (fusion cutting).If you also want to seal, it is recommended to seal the entire circumference at the same time using a blade that is bent to match the developed shape. Ru. FIG. 7 to FIG. 9 show an example of this, and as shown in FIG. 7, a continuous seal end 21 is formed around the entire circumference of an A-shaped expanded cardboard box material 20 made of thermoplastic resin. If a blade 22 with an inclined surface 4 bent along the periphery of the moon 20 is used, the flap 23
．． This makes it possible to seal the notches 25 between the flaps 24 and the edges of each flap.

- As explained above, according to the present invention, the edges of the cardboard can be quickly sealed by a simple process of pressing a heated knife against the cardboard, ensuring that water does not enter the inside of the cardboard. This prevents rusting of metal parts due to the release of moisture from cardboard boxes used for various types of packaging.

[Brief explanation of the drawing]

Figures 1 (a) to (d) are explanatory diagrams of a seal culm showing an embodiment of the present invention, Figure 2 is a sectional view taken along line A-- in Figure 1 (a), and Figures 3 to 6 are 1(A), FIG. 7 is a plan view of the main parts of cardboard and cutlery showing still another embodiment of the present invention, and FIG. 8 is a diagram corresponding to FIG. The sectional view taken along line H-13 in the figure and Figure 9 are the same.
It is a sectional view taken along the line CC. ■...Cardboard, lit...C1..., l IJ...
Sheet, 2... Cutler, 4... Inclined surface, 6... Softening and melting tip, 7... Tip, 20... A shaped cardboard box development period, 21... Seal end, 22...Knife. Applicant: Toyota Corrugated Box Industry Co., Ltd. Agent: R. Inui (Figure 6)

Claims (1)

[Claims] Heat a cutlery provided with an inclined surface inclined to the sheet surface of the plastic resin corrugated board, and press the cutter into the corrugated board described in 2. A: A softened molten film of the thermal IJ plastic resin is formed along the inclined surface from the front sheet to the back sheet of the corrugated board, and the softened molten film is cooled and solidified. Heat +, +J method for sealing the edges of plastic resin cardboard.