Patent ID: 11925915
Assignee: MAAG AUTOMATIK GMBH
Field: Other special machines (Mechanical engineering)
Classification: CPC B | IPC B

Claim 15:
16. A squeezing roller granulator comprising
a squeezing roller pair including a toothed pressure roller and a toothed squeezing roller, in which teeth of the toothed pressure roller and the toothed squeezing roller have tooth flanks that are situated between a tooth root region and a tooth tip region;
both rollers of the squeezing roller pair have a helical gearing with helical gearing angle α between

arc tan πD/nB≤α≤5 arc tan πD/nB., where D is the outer diameter of the rollers, B is the width of the rollers, and n is the number of teeth distributed over the outer circumference of the rollers;
the tooth root region has an outer diameter that is smaller than an outer diameter of the tooth tip region;
the tooth tip region of at least one of the rollers of the squeezing roller pair has three squeezing zones including a middle squeezing zone, at least two of the three squeezing zones define different distances between the tooth tip regions of the squeezing roller pair with a minimum distance in the middle squeezing zone and wherein the tooth tip regions of the squeezing roller pair are situated opposite one another during a squeezing procedure such that the squeezing roller pair are synchronized; and
a contour of the tooth flanks and the tooth root region of the rollers of the squeezing roller pair defines a maximum cross-section of granulate cushions to be formed;
the granulate cushion has a length I of

I≤πD/n, 

where n is a number of teeth distributed over the outer circumference of the squeezing roller and D is the outer diameter of the squeezing roller, and has a width b of

b≤B/N, 

where B is the width of the squeezing roller and N is a number of parallel covering tubes with coextruded filler that are supplied to the squeezing roller, such that

N=2B/πd, 

where d is an outer diameter of the covering tube;
for the at least one of the rollers of the squeezing roller pair, the tooth root region extends from an end of a falling tooth flank to a beginning of a rising tooth flank and the tooth tip region extends from an end of the rising tooth flank to a beginning of the falling tooth flank;
the three squeezing zones of the tooth tip region have an incoming squeezing zone that is situated toward an infeed side, an outgoing squeezing zone that is situated toward an outflow side, and the middle squeezing zone, which is situated between the incoming and outgoing squeezing zones;
the incoming and outgoing squeezing zones of the teeth are delimited by the tooth flanks;
the outgoing squeezing zone is longer than the incoming squeezing zone;
the incoming squeezing zone defines a distance from the toothed pressure roller that decreases toward the middle squeezing zone; and
the outgoing squeezing zone defines a distance between the rollers of the squeezing roller pair that increases leading away from the middle squeezing zone;
wherein arrangement of the tooth tip regions of the squeezing roller pair causes the middle squeezing zone of the squeezing roller pair to create an intended breaking point seam between the granulate cushions;
the squeezing roller granulator configured to be fed a strand which is pre-filled with a filler material so that the contour of the squeezing roller granulator squeezes the pre-filled filler material of the strand into granulate cushions, the squeezing deforming the strand and its pre-filled filler material to match a shape of the contour.