JPH1130035A - Plastic mold for concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate troubles of sticking hard thin plates to the surface and the reverse of an expanded material and to reduce cost therewith by a method wherein an expanded layer is formed by extrusion molding at the core part and skin layers each in an appropriate thickness are formed at surface layers, being integral with the core part. SOLUTION: A plastic mold 1 for concrete made up by extrusion molding has an expanded layer 2 at its core part. Surface layers are formed of skin layers 3 each in an appropriate thickness. The expanded layer 2 is partitioned with a honeycomb-shaped skin layer 4 that is connected at both its ends to the skin layers 3. Polypropylene and polyethylene are suitable as resin for forming the mold 1. As the expanded layer 2 is put between the skin layers that harden first, the mold 1 hardly deforms and becomes excellent in separability with its surfaces being smooth. Therefore, sticking of thin plates becomes unnecessary and a highly durable plastic mold for concrete that is equipped with desired rigidity, strength and separability can be obtained at low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic concrete template, and more particularly, to forming a skin layer, which is hardened to an appropriate thickness, on the surface of a template in which the inside is formed into a foam layer during extrusion molding of the template. It is the feature that it did.

[0002]

2. Description of the Related Art Conventionally, a plastic concrete template using a foam has a thin plate having a thickness of, for example, 2.0 to 2.5 mm on the front and back of a foam formed into a plate having a thickness of 10 mm. A plastic plate such as a urethane plate or a polypropylene plate is adhered to impart rigidity, strength, and releasability of the template.

[0003]

According to the conventional template in which another hard thin plate is bonded to the front and back of the template once formed as described above, the bonding requires a lot of time and costs. There were disadvantages. From the above, the problem to be solved by the present invention is to eliminate the trouble of attaching a hard thin plate to the front and back of the foam, and to reduce the cost of this type of template without reducing the rigidity, strength and releasability. Is to be able to

[0004]

In order to solve the above-mentioned problems, the present invention forms a foamed layer on a core by extrusion molding and integrally forms a skin layer of an appropriate thickness on a surface layer. A plastic concrete template is provided.

In the template of the present invention constructed as described above, a skin layer having an appropriate thickness is formed on the surface layer at the same time as the formation of the foam layer, so that it is not necessary to attach a thin plate later. This saves time and costs, and makes it possible to manufacture a highly durable plastic concrete template.
The present invention has solved the above-mentioned problems as described above.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 denotes a plastic concrete template obtained by extrusion molding. The template 1 has a foam layer 2 in a core portion as shown in the figure, and a surface layer portion is formed of a skin layer 3 having an appropriate thickness. The foam layer 2 is partitioned by a honeycomb-shaped skin layer 4 having both ends connected to the skin layer 3 as shown in the figure.

The resin used for the template 1 is polypropylene,
Polyethylene is preferable, and for example, a recycled resin such as a discarded PET bottle can be used. The boundaries between the foam layer 2 and the skin layer 3 and the honeycomb-shaped skin layer 4 are indicated by the upper lines for convenience of illustration, but are not actually formed so clearly.

[0008] The thickness of the template 1 is 12 to 15 mm, similarly to a normal concrete panel, and the thickness of the skin layer 3 is 2.0 to 2.5 mm. In addition, the molding method of the template 1 will be described. A resin set to a foaming ratio of 1.5 is extruded to a thickness of 5 mm, and is continuously connected to a die. By introducing and passing through a cooling mold provided with a gap corresponding to the thickness, the surface in contact with the mold is rapidly cooled to form a skin layer 3 having a predetermined thickness.

The template 1 obtained as described above has a specific gravity of 0.9 to 0.7, and has very little distortion due to the foam layer 2 being sandwiched between the skin layers 3 that cures first on both sides.
The surface is smooth and excellent in releasability.

In the present invention, the honeycomb-shaped skin layer 4
Although it is not indispensable to provide the die, by providing the die with a honeycomb-shaped extrusion port along the transverse direction, a more rigid template can be obtained even with the same thickness.

In practicing the present invention, changing the thickness of the template 1 or the thickness of the skin layer 3 or changing the type, blending, foaming ratio, etc. of the resin are optional according to the gist of the present invention. It is.

[0012]

According to the present invention in which a skin layer having an appropriate thickness is integrally formed around a foam layer at the time of molding as described above, it is not necessary to attach a thin plate, and desired rigidity, strength and strength can be obtained. An extremely durable plastic concrete template having releasability can be obtained at low cost.
The present invention has extremely excellent effects as described above.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention.

[Description of sign]

 Reference Signs List 1 template 2 foam layer 3 skin layer 4 honeycomb-shaped skin layer

Claims (2)

[Claims] 1. A plastic concrete template in which a foam layer is formed on a core portion by extrusion molding and a skin layer having an appropriate thickness is integrally formed on a surface layer portion. 2. The plastic concrete template according to claim 1, wherein a honeycomb-shaped skin layer having both ends continuous with the skin layer is integrally formed in the foam layer.