US 12,233,587 B2
Coextrusion die for manufacturing multilayer tubular preforms made from thermoplastic plastic
Felix Schulte, Langenberg (DE)
Assigned to BBM Maschinenbau Und Vertriebs GmbH, Langenberg (DE)
Filed by BBM Maschinenbau und Vertriebs GmbH, Langenberg (DE)
Filed on Feb. 21, 2023, as Appl. No. 18/112,222.
Claims priority of application No. 10 2022 104 059.3 (DE), filed on Feb. 21, 2022.
Prior Publication US 2023/0264406 A1, Aug. 24, 2023
Int. Cl. B29C 48/335 (2019.01); B29C 48/09 (2019.01); B29C 48/21 (2019.01)
CPC B29C 48/3366 (2019.02) [B29C 48/09 (2019.02); B29C 48/21 (2019.02)] 11 Claims
OG exemplary drawing
 
1. A coextrusion die for manufacturing a multilayer, coextruded, tubular preform made from thermoplastic plastic, the coextrusion die comprising:
at least one storage cylinder element having an inner storage space;
at least one spindle;
an annular storage space being formed between the spindle and the storage cylinder element, which opens into an output ring channel; and
at least one extrusion head that is axially displaceable with respect to the storage cylinder element and includes a ring piston, in which at least two heart distributor elements are coaxially arrangement; and
a flow channel being formed between the ring piston and the adjacent heart distributor element as well as between each of two heart distributor elements, which widens from an inlet opening to a ring channel from where it transitions into a cylindrical ring channel as a frustoconical ring channel,
wherein the distributor ring channel has an upper vertex arranged at the inlet opening from which one branch of the distributor ring channel extends on each side of the heart distributor element, and
wherein the distributor ring channel descends with respect to a diametric plane in a direction of a lower vertex, which is situated in the frustoconical ring channel and at which the two branches of the distributor ring channel join together.