JPS6054867B2 - Cardboard forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming corrugated cardboard used as interior material for vehicles, ships, houses, etc.

Corrugated cardboard interior material is made by molding a thermoformable corrugated cardboard base material into a predetermined shape and attaching a decorative skin material to the surface as necessary, and is highly rigid, heat-retaining, and lightweight. . FIG. 1 shows an example of a corrugated hole base material used for molding. The corrugated board base material 1 has a thermoplastic resin film 4 between a sheet-like liner 2 and a corrugated core 3. A plurality of small through holes 2a and 4a are provided in the liner 2 and the resin film 4, respectively, and are used as air escape holes during molding.

Such a corrugated cardboard base material 1 is set between an upper mold 6 and a lower mold 7 that are heated by high temperature fluid flowing in pipes 16 and 17 of a heat press device 5 as shown in FIG. 2, and hot pressed. After molding into a predetermined shape, a skin material is attached to the surface to form an interior material. Figure 3 shows the conventional cardboard forming process, in which the thick cardboard base material 1 is
After being pressed to the regular thickness tl in the process, in a second process a skin material 8 of 2 thickness made of tricot, PVC sheet, etc. is attached to obtain an interior material 9 of a predetermined thickness. . However, according to such a conventional corrugated board forming method, the air existing inside the corrugated board base material 1 cannot escape to the outside in the first step of heat pressing, and the formed corrugated board has local parts as shown in FIG. This may result in expansion and convexity.

This phenomenon is noticeable when the humidity is high, such as during the rainy season. That is, as the humidity increases, the moisture content of the liner 2 and core 3 that make up the corrugated board base material 1 increases, and the water content increases from approximately 120°C to 14°C.
1 or 2 circles between the upper and lower molds 6 and 7 heated to 0°C?
During the holding heat forming process, water contained in the corrugated board base material 1 turns into water vapor, and after the upper die is lifted, the water vapor inhibits adhesion between the liner 2 and the core 3, resulting in the formation of convex portions.

In this heat forming process, internal air and water vapor escape through the small through holes 2a and 4a of the liner 2 and resin film 4 in a direction perpendicular to the liner 2, and also bounce through internal gaps and flow parallel to the liner 2. I try to run away in the direction, but
The upper and lower surfaces of the liner 2 are in close contact with the upper die 6 and the lower die 7, and the small through holes 2
a, 4a to block the flow in the direction perpendicular to the liner 2, and at the same time, the liner 2 and the core 3 are also brought into close contact;
The flow in the direction perpendicular to the central waveform is also blocked, creating a portion where the internal air and water vapor have nowhere to escape.

FIG. 5 shows the occurrence of convex portions 10 in a molded ceiling 11 for an automobile molded by a conventional molding method. This invention was made in view of the above points, and after forming the corrugated cardboard molded product to a thickness thicker than the normal thickness in the first step of heat forming, it is formed to the normal thickness in the second step. The aim is to provide a new method for molding corrugated board that eliminates the drawbacks of the above.

Embodiments of the present invention will be described below with reference to FIGS. 6 and 7 of the accompanying drawings. The same parts as in the conventional example shown in FIGS. 2 and 3 are designated by the same reference numerals. Therefore, the explanation of that part will be omitted. The corrugated board forming method according to the present invention is as follows.
Thickness T, as shown in the figure.

The corrugated cardboard base material 1 is heated to a thickness T3 (T3=t1+α) that is α thicker than the regular thickness t1 of the molded product in the first step of heat pressing.
After that, in the second step, the board is formed to the regular thickness ζ, and the skin material 8 of the board thickness is attached to make the entire board to the predetermined thickness t.
get. T here. =5.5Wn. ．． t1=2Tn1t
When 2=3, α=1.5Wr1n1 or T
3=3.57177! It has become clear from various experiments that if α is less than that, water vapor can escape from the end of the corrugated board 1 and the occurrence of protrusions can be eliminated, and if α is less than that, the escape of water vapor is insufficient. . Therefore,
In order to form such a corrugated board using a heat press machine as shown in FIG. .57r$
The gap may be increased by l, and the second step may be made similar to the conventional gap. FIG. 7 shows an example of a molded plate thickness adjustment mechanism in a heat press device 6 for carrying out the above-mentioned molding method. The thickness of the first spacer sub 12, which was inserted in multiple places between the two, was 1.577177! Apply the shim 13 and perform the first step of heat pressing, and then. The second spacer block 15 moves forward and backward by the cylinder 14 as in the conventional case.
Move it forward to the left and perform the second step of heat pressing.

In other words, the gap between the upper die 6 and the lower die 7 is increased by 1.5 TfrIn from the conventional one in the first step, and the gap between the corrugated cardboard base material 1
is molded 1.5Tmm thicker than the regular thickness of the corrugated cardboard molded product.

Further, the height difference β between the upper surface of the second spacer block 15 and the lower surface of the contact surface 6b of the upper mold 6 is determined by the thickness 3wn of the skin material 8.
If it is set to 1.5 wn (α) smaller than 1.5 ugliness, the final thickness of the corrugated board base material 1 will be 2 wm in the second step, and the total thickness of the interior material 9 will be 5T11 m.

As described above, according to the present invention, the first heat breather
In the process, the cardboard molded product is formed to be thicker than the standard board thickness, and in the second process it is molded to the standard board thickness, so even if the cardboard base material contains a large amount of moisture during the rainy season, etc. In the first step of thermoforming, the water vapor generated inside the corrugated board material can escape laterally through the gap between the liner and the core, and the adhesion between the liner and the core is not hindered by the water vapor. do not have.

In addition, in the second step, the corrugated cardboard base material that has been bonded in the first step can be easily pressed to the regular thickness, and has the excellent effect of completely preventing the occurrence of wrinkles and the like.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the structure of a corrugated board base material, Fig. 2 is a partially sectional front view of a heat press device used for forming corrugated board, and Fig. 3 is a process diagram showing a conventional corrugated board forming method. , a shows the state of the cardboard base material before processing, b shows the state after the first step, and c shows the molded product after the second step. FIG. 4 is a sectional view of a molded product showing a convex portion produced by a conventional molding method, and FIG. 5 is a perspective view of a molded ceiling draw product for an automobile molded by a conventional molding method. 6th
The figure is a process diagram showing the corrugated board molding method according to the present invention.
A shows the state of the corrugated cardboard base material before processing, b shows the state after the first step, and c shows the molded product after the second step. 7th
The figure is a cross-sectional view of a molded board thickness adjustment mechanism in a heat press device for carrying out the cardboard molding method according to this invention. 1... Corrugated cardboard base material, 2... Liner, 3... Core, 4... Resin film, 5... Heat press device. , 6... upper mold, 7... lower mold, 8... skin material, 9...
...Interior material, 10...Protrusion, 11...
・Automotive molded ceiling draw product.

Claims (1)

[Claims] 1. A first step of forming a corrugated cardboard base material with a thermoplastic resin film interposed between a liner and a core to a thickness greater than the regular thickness of the molded product using a heat press; A method for molding corrugated board, comprising a second step of molding a corrugated board base material to the above-mentioned regular thickness.