The purpose of the present invention is to make it possible to shorten the time required for a burr removal step and make it difficult for the burrs to detach from a sheet member in a step for removing the burrs together with the sheet member. For removal, by making the burrs to adhere to a pliable sheet member such as paper or nonwoven fabric that has been incorporated beforehand in the molding die and stripping the sheet member from the molding die, the burrs are removed together with the sheet member. The present invention is characterized in that in order to make it difficult for the burrs to detach from the sheet member during the stripping, a radiused shape with an arc-shaped cross-section is formed by the molding die on the areas surrounding the sections where the burrs adhere to the sheet member.

Method and apparatus for injection moulding of plastic materials using at least one nozzle with an obturator including a stem having a through hole and displaceable transversely with respect to the nozzle between a closing position and an opening position wherein the through hole opens communication between the nozzle and the flow path towards the mould. When the obturator is arranged in the closing position following injection, the through hole remains in communication with the cavity of the mould and a residual core made of plastic material present in the through hole remains joined to a residual core made of plastic material in the flow path and it is removed together with it.

A cutting station includes a plurality of actuator driven cutting blades for separating seals which have been formed as a mat of connected individual seals. The cutting station also includes a plurality of actuator driven pins which bear against and break away a runner portion of the mat thus freeing the individual seals.

A cutting station includes a plurality of actuator driven cutting blades for separating seals which have been formed as a mat of connected individual seals. The cutting station also includes a plurality of actuator driven pins which bear against and break away a runner portion of the mat thus freeing the individual seals.

An injection molding apparatus includes: a mold including a fixed mold and a movable mold facing the fixed mold, and that has a cavity defined by the fixed and movable molds and a runner communicating with the cavity; a mold clamping unit moves the movable mold with respect to the fixed mold; an injection unit injects a molding material into the cavity through the runner; a cutting mechanism at the mold includes a cutter projecting to the runner; a drive unit provided on the mold that drives the cutting mechanism; and a control unit controlling the injection unit, the mold clamping unit, and the drive unit. The control unit controls the injection unit to inject the molding material into the cavity, and then controls the drive unit to cause the cutter to project to the runner, thereby cutting the molding material hardened in the runner.

An injection molding apparatus includes: a mold including a fixed mold and a movable mold facing the fixed mold, and that has a cavity defined by the fixed and movable molds and a runner communicating with the cavity; a mold clamping unit moves the movable mold with respect to the fixed mold; an injection unit injects a molding material into the cavity through the runner; a cutting mechanism at the mold includes a cutter projecting to the runner; a drive unit provided on the mold that drives the cutting mechanism; and a control unit controlling the injection unit, the mold clamping unit, and the drive unit. The control unit controls the injection unit to inject the molding material into the cavity, and then controls the drive unit to cause the cutter to project to the runner, thereby cutting the molding material hardened in the runner.

The rolling bearing seal includes a core metal and rubber adhered to the core metal by vulcanization. The rubber includes: a seal lip portion having, over the entire circumference in the circumferential direction, a plurality of projections that extend inward in the radial direction from the inner diameter side of the core metal, and slides on a seal sliding surface of an inner ring of a rolling bearing; and an attachment portion that is attached to an outer ring of the rolling bearing. A compression vulcanization molding mold includes a female mold and a male mold. The female mold has a guide portion for positioning the core metal and a rugged shape forming the projections on the seal lip portion. The male mold has an inner-diameter-side burr groove and an outer-diameter-side burr groove and the shape of a radially outermost portion of the inner-diameter-side burr groove is formed in a circle.

The rolling bearing seal includes a core metal and rubber adhered to the core metal by vulcanization. The rubber includes: a seal lip portion having, over the entire circumference in the circumferential direction, a plurality of projections that extend inward in the radial direction from the inner diameter side of the core metal, and slides on a seal sliding surface of an inner ring of a rolling bearing; and an attachment portion that is attached to an outer ring of the rolling bearing. A compression vulcanization molding mold includes a female mold and a male mold. The female mold has a guide portion for positioning the core metal and a rugged shape forming the projections on the seal lip portion. The male mold has an inner-diameter-side burr groove and an outer-diameter-side burr groove and the shape of a radially outermost portion of the inner-diameter-side burr groove is formed in a circle.

An injection mould comprises first and second relatively movable mould halves defining at least one mould cavity between them, a first of the halves having a sprue through which moulding material is injected, a runner leading from the sprue to at least one gate into the or each mould cavity. The mould is characterised in that, when the mould halves are engaged one with the other, an insert projects from one mould half into a corresponding recess in the other mould half at a position corresponding to the or each gate into the mould cavity, the insert having a cutting groove extending therealong opening into an end face of the insert, the end face being in communication with the sprue and the opposite end of the groove being in communication with the gate, the groove thereby constituting at least a part of the runner, the groove extending at an acute angle to the relative direction of movement of the mould halves whereby, as the mould halves are separated, a cutting edge of the groove travels across the gate to shear the material in the gate.

An injection mould comprises first and second relatively movable mould halves defining at least one mould cavity between them, a first of the halves having a sprue through which moulding material is injected, a runner leading from the sprue to at least one gate into the or each mould cavity. The mould is characterised in that, when the mould halves are engaged one with the other, an insert projects from one mould half into a corresponding recess in the other mould half at a position corresponding to the or each gate into the mould cavity, the insert having a cutting groove extending therealong opening into an end face of the insert, the end face being in communication with the sprue and the opposite end of the groove being in communication with the gate, the groove thereby constituting at least a part of the runner, the groove extending at an acute angle to the relative direction of movement of the mould halves whereby, as the mould halves are separated, a cutting edge of the groove travels across the gate to shear the material in the gate.