METHOD FOR MOULDING OF TOOTH-BRUSHES AND DEVICE FOR ITS REALIZATION Russian patent published in 2003 - IPC

FIELD: method for molding of tooth-brushes. SUBSTANCE: plasticized molding material is fed and injected under pressure into the cavity for molding. The pressure in the part of the cavity for molding determining the head section of the tooth-brush is additionally measured and controlled. Injection is stopped when the pressure inside the mentioned cavity attains the preset value, which is selected below the value of pressure at which the molding material leaks through the holes in the mould. Use is made of a mould with relatively movable parts in which at least one cavity for molding corresponding to the shape of the tooth-brush body is formed. One of the parts of the mould has a section determining the head part of tooth-brush with a great number of holes for partial insertion of the respective number of bundles of bristle in the mentioned part of the cavity for molding. The device has also a unit for plasticization of the material and feeding it under pressure into the cavity for molding, narrow feeding conduit, pressure transducer, valve and a control device. The feeding conduit connects the cavity for molding to the feeding unit. The pressure transducer is connected to the part of the cavity determining the head section of the tooth-brush. The valve is designed for shut-off of the feeding conduit in the direct proximity to the mentioned cavity. The control device is designed to control the valve depending on the pressure measured by the transducer inside the part of the cavity determining the head section of the tooth-brush. EFFECT: prevented leakage of material at molding. 9 cl, 3 dwg