JPH0623882A - Method for molding corrugated carboard - Google Patents

Abstract

PURPOSE:To permit the stretching of liner paper at the time of molding by a slit and to prevent the generation of wrinkles in the liner paper by superposing the liner paper on the surface of a corrugated cardboard base material to mold both of them and preforming a slit to the liner paper at a required place. CONSTITUTION:A corrugated cardboard base material B is constituted of a core 4 molded into a corrugated shape and the liners 6,7 bonded to both surfaces of the core through thermoplastic resin films 4,5. The corrugated cardboard base material B is molded under pressure and heating by a hot press device. In this case, liner paper C prepared separately is superposed on the surface of the corrugated cardboard base material B through a hot-melt adhesive S before molding. A slit 9 is preformed to the liner paper C at a place where wrinkles are easy to generate in a shape after molding of a drawing corresponding part. By this constitution, the stretching of the liner paper C at the time of molding is permitted by the slit 9 to prevent the generation of wrinkles. Further, the base material B is reinforced by the liner paper C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a molded corrugated board used as an interior material for automobiles, ships, houses and the like.

[0002]

2. Description of the Related Art Conventionally, as a ceiling interior material for an automobile or the like, there has been one in which a decorative skin material is laminated on the surface of a molded corrugated cardboard formed into a predetermined shape. To manufacture such an interior material, it is necessary to heat and pressurize the corrugated board base material alone or simultaneously with the skin material.

However, since the corrugated cardboard itself does not have elasticity, when the molded corrugated cardboard has a portion with a large curvature such as a deep-drawn portion, wrinkles or tears occur on the inner surface of the portion. Often occurs. If the molded corrugated board has such wrinkles or tears, they appear as traces on the surface of the skin material, impairing the external appearance, and reducing the commercial value.

Therefore, conventionally, as a measure against wrinkles and breakage of the molded corrugated board, slits are previously formed in a liner at a portion where wrinkles and the like are likely to occur in the shape after molding, such as an inner surface of a portion of the corrugated board corresponding to drawing. The slits allow the liner to stretch, so that wrinkles and tears do not occur as much as possible.

[0005]

However, according to the above conventional method, the liner already attached to the core of the corrugated board is peeled off once and a slit is made with a slitter or the like, and then the core is again attached. Since they had to be re-laminated again, the work was complicated, the productivity was poor, and the production cost was high.

In addition, a reinforcing piece is placed between the liner and the core when the liner once peeled is reattached to a place where reinforcement is required partially, but this work is also troublesome. Is.

The present invention has been made in view of the above problems of the prior art, and its purpose is to prevent the occurrence of wrinkles and tears, high productivity, low cost, and reinforcement material. It is to provide a method of forming corrugated cardboard that can be omitted.

[0008]

In order to achieve the above object, in the method for forming a corrugated board according to the present invention, a flat corrugated board substrate having liners bonded to both sides of a corrugated core through a thermoplastic resin film, A liner having slits formed in advance on the surface after molding, such as a portion corresponding to draw forming, where wrinkles or the like are likely to occur in the shape after molding, is pressed and heat-molded.

[0009]

In the corrugated board molding method configured as described above, like the conventional method, the elongation of the surface liner is allowed to some extent by the slit provided in the liner to prevent wrinkles and tears from occurring. Moreover, the strength is reinforced by the liner attached to the surface of the base material. Then, in molding, the work of peeling off the liner of the corrugated cardboard base material, making slits in it, and pasting it again to the core is omitted.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, A indicates a hot press device, and the heat press device A has a conventionally known structure and form consisting of a fixed lower mold 1 and a movable upper mold 2. Although not shown, both of these molds 1, The molding surface 2 is heated to a required molding temperature by a suitable heating means.

B is a flat corrugated cardboard base material press-molded by the hot press apparatus A. The corrugated cardboard base material B has a corrugated core 3 and a polyethylene film or the like on both sides of the core 3. As is well known in the art, one liner 6 is completely adhered to the center core 3 while the other liner is composed of the liners 6 and 7 which are laminated via the plastic resin films 4 and 5. In order to allow relative sliding between the liner 7 and the core 3 at the time of press molding, 7 is temporarily fixed to both sides only.

The corrugated board base material B is placed on the fixed lower mold 1 of the heat press device A with the liner 7 temporarily fixed to the core 3 as the upper surface, and the movable upper mold 2 is lowered to move both molds 1 together. It is formed by pressurizing and heating between the two. In the present invention, at this time, the liner paper C separately prepared on the corrugated board base material B is used.
Is placed and molded via a heat-soluble adhesive 8, and the liner paper C is attached to the surface of the corrugated board base material B.

The liner paper C to be bonded onto the corrugated board base material B is the same as the liners 6 and 7 of the corrugated board base material B, and is cut into the same size as the corrugated board base material B in advance, and then this is further cut. The slits 9 are appropriately formed with a slitter at a portion where wrinkles or the like are likely to occur in the shape after molding, such as a portion corresponding to draw forming when superposed on the corrugated board base material B.

The heat-soluble adhesive 8 is made of, for example, a polyolefin-based or polyamide-based hot melt film, and may be pre-laminated on the back surface of the liner paper C or the surface of the corrugated board base material B as shown in FIG. Alternatively, a film-sheet-shaped product may be placed on the corrugated board base material B at the time of molding.

Then, the flat corrugated board base material B is molded into a shape along the molding surface of the molds 1 and 2 by heating and pressurizing by the upper and lower molds 1 and 2 of the above-mentioned heat press device A, At this time, the softened and melted resin films 4 and 5 are cooled and solidified after demolding, so that a predetermined shape is maintained.

On the other hand, the liner paper C laminated on the corrugated board base material B is pressed to the surface of the corrugated board base material B at the same time when the corrugated board base material B is formed, and is heated by the adhesive 8 to melt it.
Following the surface of the corrugated board base material B, the surface is covered and bonded integrally. At this time, a tensile force acts on the liner paper C at the portion corresponding to the drawing by the above heating and pressure molding,
The expansion of the slit 9 allows the extension of the liner paper C, so that an unreasonable pulling force does not act on the draw-formed portion and wrinkles are avoided.

The molded corrugated cardboard D molded and demolded in this way has slits 9 which are opened in an expanded manner on the surface, but the depth of the slits 9 is equal to the thickness of the liner paper C. Since it is not too much, when a decorative skin material is pasted on the surface of the molded corrugated board, there is no possibility that slits will appear as traces on the skin material.

[0018]

[Effect] Since the present invention is configured as described above, the following effects can be obtained. (1). A liner paper prepared separately is placed on the surface of a corrugated board base material with an adhesive and is heated and pressure-molded. The liner paper is likely to have wrinkles in the shape after molding, such as a portion corresponding to drawing. Since a slit is provided in advance, even if a tensile force acts on the portion corresponding to the draw forming by heating and pressure forming, the expansion of the slit allows the liner paper to stretch, so that an unnecessary force is applied to the draw forming portion. It prevents wrinkles from being generated.

(2). Since the corrugated board base material is entirely reinforced by the liner paper attached to the surface, the conventional reinforcing material inserted and arranged between the core and liner of the corrugated board base material is no longer required. Therefore, it is not necessary to peel off the liner of the corrugated board base material, arrange the reinforcing material, and perform the work of attaching the liner again.

(3). Separately from the corrugated board base material, prepare liner paper with slits etc. in the required places beforehand with a slitter etc., overlay this liner paper on the corrugated board base material, heat and pressure mold it, Since the complicated work of peeling off the liner already attached to the corrugated board and making a slit and reattaching the liner to the core again is not performed, this is combined with the effect of (2) above. The productivity is greatly improved and the production cost is reduced as compared with the conventional method.

[Brief description of drawings]

FIG. 1 is an explanatory view of a corrugated board molding method showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a corrugated board base material and a liner paper separately in a state before molding.

FIG. 3 is a cross-sectional view of a product-molded corrugated board in a demolded state after molding, which is partially enlarged.

FIG. 4 is a perspective view of the molded cardboard.

[Explanation of symbols]

B Corrugated board substrate C Liner paper 3 Corrugated board substrate core 4,5 Thermoplastic resin film 6,7 Corrugated board liner 9 Slit

Claims (1)

[Claims] 1. A flat corrugated cardboard substrate having liners bonded to both sides of a corrugated core via thermoplastic resin films,
When heat-molding, a liner paper prepared separately is overlaid on the surface of the cardboard base material, which is to be the surface after molding, via a heat-soluble adhesive, and the liner paper is pre-molded such as a portion corresponding to drawing. A method for forming corrugated board, which comprises forming a slit in a location where wrinkles or the like are likely to occur in the shape.