JPS5836525Y2 - plastic cardboard - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in a plastic corrugated board made by welding liners to both sides of a core which has a number of protrusions formed on one side of the sheet using, for example, an embossing roll.

Conventional plastic cardboard of this type has individual air chambers defined by protrusions (hereinafter referred to as embossed portions), so when heat-processed, for example by vacuum forming, the air chambers in the embossed portions are The embossed portion bulges due to thermal expansion of air (see FIG. 4), and this bulge remains even after molding, resulting in a poor appearance.

The purpose of this invention is to provide a plastic corrugated board with a good appearance that eliminates the above drawbacks, and examples thereof will be described below with reference to the drawings.

In the figure, 1 is a plastic core with cylindrical protrusions 2 extending vertically and horizontally over the entire surface of the sheet, and each protrusion 2
are arranged in parallel in the horizontal direction at appropriate intervals, and in the vertical direction so that adjacent rows are alternately shifted by half a pitch.

Projections 3 are also formed between the projections in each row, and when the liner 4 is welded to the back surface, the projections become communication holes that connect the embossed portions defined by the projections 2, and the communication hole covers or embossments. By opening to the outside air at the edge of the cardboard, all the embossed parts are communicated with the outside air.

It is necessary that the height of the protrusion is at least one time, preferably one time, the thickness of the core, or less than ±, preferably less than 2, the thickness of the projection 2, and the width is also preferably about the same.

If the height of the protrusions is too low, it will be difficult to form the protrusions, and if the height is too high, the compressive strength of the corrugated board will be poor.

However, according to the present invention, even if the air in the embossed part is heated and expanded during thermal processing, the expanded air is discharged to the outside through the communication hole, thereby preventing the embossed part from bulging and improving the appearance. You can get good plastic cardboard.

In the above embodiment, the protrusions are formed between the protrusions in the horizontal direction, but they may be formed between the protrusions in the vertical or diagonal direction, or between two sets of protrusions. .

Since the plastic corrugated board of the present invention has a good appearance after vacuum forming, a skin material such as nonwoven fabric, woven fabric, or synthetic leather is laminated, or urethane foam, polyethylene foam, polypropylene foam, etc. is used between the skin material and the skin material. After being thermoformed into a predetermined shape as a panel of laminated cushioning materials, it can be suitably used as an automobile ceiling material or other interior material.

[Brief explanation of drawings]

Figure 1 is a plan view of the plastic cardboard according to the present invention;
FIG. 2 is a partially enlarged perspective view, FIG. 3 is a sectional view taken along the line A--A in FIG. 1, and FIG. 4 is a sectional view of the embossed portion in the conventional example. 1...Central core, 2...Protrusion, 3...
・Protrusion, 4, 5・・・Liner

Claims (1)

[Scope of utility model registration request] In a plastic corrugated board made by welding a liner to both sides of a center core with vertical and horizontal protrusions formed over the entire surface of the sheet, the embossed part defined by the protrusions is at least two pairs of other embossed parts above. A plastic corrugated board characterized in that the protrusions are communicated with each other through communication holes formed by protrusions provided between the protrusions, and further communicated with outside air through the communication hole cover or an opening at the edge of the corrugated board of the embossed portion.