JPH0123794Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a plastic blow-molded product that has a beautiful portion from which burrs have been removed and has excellent appearance characteristics.

In general, blow molded products made by sandwiching thermoplastic plastic material between split molds and blow molding require removing burrs generated at the mold parting line. However, as shown in FIG. 1, the conventional blow molded product 11 is
When removing the burr 17 generated on the parting line 12 with a knife or the like, it is easy to remove the wall surfaces 13 and 14 formed by the mold cavity surface near the parting line 12. The cut surface 16 was formed in a wavy shape and had poor appearance characteristics. In particular, when one wall surface 13 is formed with a slightly uneven surface such as grain or engraving, the convex portion of the slightly uneven surface located near the parting line 12 is cut, and the cut surface 16 and the other wall surface 1 are cut.
The gloss and texture were significantly different from those of No. 3 and No. 14, and the appearance characteristics were inferior.

The present invention overcomes the above drawbacks.

An embodiment of the present invention will be described below based on the drawings. 1. A thermoplastic material such as polyethylene, polypropylene, polystyrene, polyamide, vinyl chloride, ethylene-vinyl acetate copolymer, ABS, etc. is sandwiched in a split mold. This is a plastic blow molded product made by blow molding, and 2 is a parting line that corresponds to the mold mating surface when it is sandwiched between split molds. Further, a slightly uneven surface 3 such as a textured pattern, an embossed pattern, a carving, etc. is formed on one wall using the parting line 2 as a boundary line,
A smooth surface 4 is formed on the other wall. Incidentally, the slightly uneven surface 3 and the smooth surface 4 are molded on the mold cavity surface. By forming a stepped portion 5 on the parting line 2 so that the slightly uneven surface 3 is lower than the smooth surface 4, the cut surface 6 from which the burr 7 has been removed is formed on a straight line.

In the present invention, as described above, the stepped portion 5 is formed at the mold parting line 2 where the burr 7 occurs, so when cutting off the burr 7 with a knife or the like, the wall surfaces 3 and 4 near the parting line 2 are also not damaged. Without regular cutting, the cut surface 6 from which burrs 7 have been removed is minimally thin and formed on a straight line and is beautiful, making it possible to obtain a plastic blow-molded product 1 with excellent appearance characteristics. In particular, when the slightly uneven surface 3 is formed on one wall with the parting line 2 of the blow molded product 1 as the boundary line, there is no fear that the convex portions of the slightly uneven surface 3 will be cut as in the conventional case, and the slightly uneven surface 3
It is possible to accurately form the outline of

Furthermore, the plastic blow-molded product 1 according to the present invention refers to molded products obtained by blow molding such as chairs, benches, tanks, hollow double-walled containers, housing members for automobiles, furniture, general equipment, plate-shaped members, etc. This is a general term for the present invention, and the present invention can be implemented even with a general blow molded product that does not have a slightly uneven surface.

FIG. 3 shows an example in which the present invention is applied to the main body of a chair, in which the front surface 3 of the chair main body 1, which is a blow-molded plastic product, has a slightly uneven surface, and the back surface 4 has a smooth surface.

As mentioned above, in blow-molded products made by sandwiching thermoplastic material between split molds and blow molding, the mold parting line is formed by sandwiching the thermoplastic material to be molded between the molds. Burrs were generated on the cut surface, and the appearance of the cut surface, which was the remains of the removed burrs, was sometimes impaired. Particularly in the case of blow-molded products in which a slightly uneven surface is formed near the parting line, the cut surface of the parting line becomes irregularly wavy due to the convex parts of the slightly uneven surface being cut, and the cut surface This had the disadvantage that the gloss and texture of the wall surface were significantly different from those of other wall surfaces, impairing the appearance characteristics of the blow-molded product.

However, in the present invention, a slightly uneven surface is formed on one wall and a smooth surface is formed on the other wall, with the mold parting line where burrs occur as a boundary line, and the parting is performed so that the slightly uneven surface is lower than the smooth surface. Since the stepped portion is formed on the line, the cut surface is formed on a straight line without cutting to the protruding convex portion of the slightly uneven surface. Therefore, the cut surface is formed in a minimally thin and straight line and is beautiful, making it possible to obtain a plastic blow-molded product with excellent appearance characteristics.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view of the main part of a conventional plastic blow molded product, FIG. 2 is a cross-sectional perspective view of the main part of the plastic blow molded product of the present invention, and FIG. 3 is a cross-sectional perspective view of the main part of the plastic blow molded product of the present invention. It is an overall perspective view showing an example implemented in a chair body. 1: Plastic blow molded product, 2: Parting line, 5: Step portion, 6: Cutting surface.

Claims (1)

[Scope of utility model registration request] In blow molded products made by sandwiching thermoplastic plastic material between split molds and blow molding,
A slightly uneven surface is formed on one wall and a smooth surface is formed on the other wall with the mold parting line where burrs occur as a boundary line, and a step is formed on the parting line so that the slightly uneven surface is lower than the smooth surface. A plastic blow molded product featuring: