SU958124A1 - Injection mould for shaping articles of polymeric material - Google Patents

Description

one

The invention relates to devices for the manufacture of products from polymeric materials.

A known mold for molding articles from a polymeric material, comprising upper and lower half-molds with conical guiding surfaces and formed on one of the floor (} garm groove, which is concentrated (Jummer cavity JQ and separated from it by a protrusion with a conical surface,. facing the groove fl.,

However, the sealing surfaces of a known mold quickly wear out due to high compressive forces, and the thickness of the abutment increases as the sealing surfaces wear.

Closest to the proposed 70 technical essence and the achieved effect is a press (|) Form for molding products from a polymeric material, containing upper and lower half-molds with conical guide surfaces, formed on the lower floor (} yurme a groove located concentrically forming cavity and separated from it by a protrusion with a sharp edge and a conical surface facing in c, the toron of the groove, and an additional protrusion made on the upper half-form with a conical surface C 2,

In the well-known mold, due to the pinching of the material on the interacting conical surfaces ffBfcTynoB, at the end of pressing in, a burr is formed, which reduces the quality of the products and necessitates their subsequent mechanical processing.

The purpose of the invention is to prevent the formation of burrs.

Claims (2)

To achieve this goal, in a mold for molding polymer products, comprising upper and lower half-molds with conical guiding surfaces, a groove formed on the lower half-mold, a groove concentrically forming the strip and separated from it by a protrusion with a sharp edge and a conical surface facing in the side of the groove, and an additional protrusion made on the half-form with a conical surface, the conical surfaces of the protrusions are made with different angles of inclination Eess-forms, the angle of inclination of the generatrix of the conical surface of the additional protrusion is made larger than the angle of inclination of the generatrix of the conical surface of the protrusion with a sharp sealing edge, and the line of intersection of the conic surfaces of the protrusions is located on the plane of the mold connector. The drawing shows the proposed mold, the cut. The mold contains upper 1 and lower 2 half-molds with conical guiding surfaces 3H. A lower groove is made on the lower semi-mold 2, the concentric forming cavity 5 is located. The groove is separated from the forming cavity 5 by a protrusion 6 with a sharp edge and a conical surface 7 ,, facing the side. grooves t. On the upper half-molds / Lf tt-1 Kl tftA LiMa OOnVLJDIit n r4LJ 1, an additional protrusion 8 with a conical surface 9 with different tilt angles forming the central axis of the mold was made. The angle of inclination of the generatrix of the conical surface 9 is greater than the angle с1 | 2 of the inclination of the generatrix of the conical surface 7 - The line of intersection of the conic surfaces 7 and 9 is located on the plane of the die connector. The mold works as follows. A polymeric material is loaded into the lower mold 2, for example rubber. Then a mold is placed in a vulcanization press and closed at a predetermined pressure. The centering of the half-molds, 1 and 2 is performed on conic surfaces. An excess of material flows out of the forming cavity 5 and fills the groove k. Due to the fact that surfaces 7 and 9 are made with different angles, the material does not become pinched in the groove, and at the end of the press-fit, the flap located in groove k is separated from the product located 9 in cavity 5 by means of a protrusion 8 and the sharp edges of the protrusion 6. After the time required for vulcanization, the mold is removed from the vulcanization press and opened to remove the finished product. Next, the mold cycle is repeated. The proposed mold ensures complete separation of the scrap from the product by eliminating pinching of the material along the conical surfaces of the protrusions. Since the conical protrusion surfaces of the protrusions have a line of contact with each other, rather than a plane, there is no need to precisely fit them to each other, and therefore, the manufacture of the mold is greatly simplified and its cost is reduced. DETAILED DESCRIPTION OF THE INVENTION A mold for molding articles from a polymeric material, comprising upper and lower half-molds with conical guiding surfaces, a groove formed on the lower half-shape, a concentrically forming cavity and separated from ltll44M riH jj "". "V." .. . .....- .. Have. It has a protrusion with a sharp edge and a conical surface facing the groove side, and an additional protrusion with a conical surface on the top half of the mold, characterized in that, in order to prevent formation of an oblo on the product, the conical surfaces of the protrusions are made with different angles of inclination to the central the mold axis, and the angle of inclination of the generatrix of the conical surface of the additional protrusion is made greater than the angle of inclination of the generatrix of the conic surface of the protrusion with a sharp sealing edge mkoy, and the line of intersection of the tapered surfaces of the projections disposed in the plane of the mold connector. Sources of information taken into account during the examination 1. USSR author's certificate, No. 1895 + 8, cl. B 29 C 1/00, B 29 And 5/22, 1965 2. USSR author's certificate No. 730577, class B 29 C 1/00, B 29 H “5/00, 1978 (prototype).