초록 ▼

The invention relates to a cutting mill for the comminution of runners, injection moulding parts, blown moulding parts and so forth in operation of a synthetic material processing machine. Waste or reject parts becoming available should, if possible, be led back again to the process cycle of the mac

The invention relates to a cutting mill for the comminution of runners, injection moulding parts, blown moulding parts and so forth in operation of a synthetic material processing machine. Waste or reject parts becoming available should, if possible, be led back again to the process cycle of the machine after comminution to granulated size for use as a regenerate. For this purpose one makes use of a cutting mill having a cylindrical driven rotor mounted in a housing, over the periphery of which rotor a plurality of adjacently positioned cutting element groups are arranged, which cooperate with at least one stationary blade provided in the housing, wherein a sieve for filtering of the comminuted material extends over a part of the boundary of the rotor. The cutting mill provides an additional means for gripping and precomminution in front of the stationary blade, considered in the input direction, and is characterized in that the rotor rotates with a relatively low rotational speed of below 500 Rpm, preferably approximately 100 Rpm. The additional means is preferably constructed from a cylindrical carrier with guide surfaces and a plurality of guide plates preferably equally spaced along the length of the housing, wherein these guide plates preferably lie in planes at right angles to the axis of the rotor.

대표청구항 ▼

1. A cutting mill for the comminution of synthetic material bodies such as runners, injection moulding parts, blown moulding parts and the like comprising: a housing; a cylindrical rotor mounted for rotation in the housing; a plurality of mutually spaced cutting element groups arranged on the periph

1. A cutting mill for the comminution of synthetic material bodies such as runners, injection moulding parts, blown moulding parts and the like comprising: a housing; a cylindrical rotor mounted for rotation in the housing; a plurality of mutually spaced cutting element groups arranged on the periphery of said rotor said cutting element groups comprising knives having knife edges substantially parallel with the axis of the rotor; at least one stationary blade, having a cutting edge substantially parallel with the axis of the rotor, and provided in the housing for cooperation with the knives of the cutting element groups; a sieve for filtering of the comminuted material extending over a part of the periphery of the rotor; means for gripping and precomminution of the material bodies before the stationary blade in an entry direction, said means including a plurality of guide plates, each guide plate having a narrow, generally curved lower input edge, each of the lower input edges extending from an area in proximity to the cutting edge of the stationary blade a substantialy distance along the periphery of the rotor and outside a peripheral path defined by the knife edges of the cutting elements of the rotor, the lower input edges being generally arcuately disposed with respect to the path defined by the knife edges of the cutting elements of the rotor, the guide plates being disposed substantially orthogonally to the knife edges and the axis of the rotor; and drive means for driving the rotor with a rotational speed of below 500 R.P.M. 2. A cutting mill according to claim 1, wherein said drive means is arranged to drive the rotor at a rotational speed of 100 R.P.M. 3. A cutting mill according to claim 1, wherein said rotor carries from three to five adjacent cutting element groups in the form of knife blades secured on the rotor, wherein each individual group consists of from 2 to 4 knife blades and neighboring cutting element groups are mutually staggered at an angle such that they provide an equidistant cutting sequence of the rotating knife blades in respect of the stationary blade. 4. A cutting mill according to claim 1, wherein said means for gripping and precomminution comprises a plurality of guide plates including said lower input edges. 5. A cutting mill according to claim 4, wherein at least one central pair of guide plates converges slightly in the direction of the stationary blade. 6. A cutting mill according to claim 4, wherein said guide plates are evenly distributed along the length of said housing. 7. A cutting mill according to claim 4 wherein said means for gripping and precomminution further comprises: a tubular carrier; and guide surfaces supported by said carrier. 8. A cutting mill according to claim 7 wherein said guide plates are supported by said carrier. 9. A cutting mill according to claim 4 wherein the number of guide plates is at most equal to the number of cutting element groups on the rotor. 10. A cutting mill according to claim 4 wherein said lower input edges of the guide plates are formed to converge towards the rotor up to the cutting edge of the stationary blade. 11. A cutting mill according to claim 4 wherein additionally an upper edge of each guide plate passes in the upper region of an edge of the housing first of all downwardly across a gently curving region, then forms a tooth with said lower input edge in the neighborhood of the cutting blade path, the lower input edge then entering a region where the distance between the lower input edge and the rotor initially widens and then narrows again up to the cutting edge of the stationary blade. 12. A cutting mill according to claim 4 for the comminution of blown moulding parts and the like, wherein said lower input edges are serrated adjacent the rotor, wherein serrations of said serrated edges are directed towards an edge of the stationary blade to enhance gripping of said material bodies. 13. A cutting mill according to claim 1, wherein the cylinder of the rotor is flattened between neighbouring knives of every cutting element group and is there provided with ribs. 14. A cutting mill according to claim, wherein bores in the sieve provide both on the side facing the rotor and on the side directed away from the rotor widened portions for gripping.