US 12,403,644 B2
Apparatus and method for forming plastic preforms into plastic containers with adjustable throttle
Benedikt Hengl, Essing (DE); Andreas Brunner, Aufhausen (DE); Dieter Finger, Neutraubling (DE); Markus Kulzer, Zell (DE); Dominik Meier, Parsberg (DE); Thomas Gerstenberg, Regensburg (DE); Konrad Senn, Alteglofsheim (DE); Daniel Vogler, Neutraubling (DE); Thomas Hoellriegl, Teublitz (DE); Klaus Voth, Obertraubling (DE); and Christian Betz, Geigant (DE)
Assigned to KRONES AG, Neutraubling (DE)
Filed by KRONES AG, Neutraubling (DE)
Filed on Sep. 12, 2022, as Appl. No. 17/942,999.
Claims priority of application No. 10 2021 128 205.5 (DE), filed on Oct. 28, 2021.
Prior Publication US 2023/0134386 A1, May 4, 2023
Int. Cl. B29C 49/78 (2006.01); B29C 49/42 (2006.01)
CPC B29C 49/783 (2013.01) [B29C 49/4289 (2013.01); B29C 2049/7831 (2022.05); B29C 2049/7833 (2022.05)] 13 Claims
OG exemplary drawing
 
1. An apparatus for forming plastic preforms into plastic containers, having a forming device which has a plurality of forming stations which each have a blow mould within which the plastic preforms can be formed into the plastic containers, wherein the forming stations each have a stretching rod configured for stretching the plastic preform in its longitudinal direction and an application device configured for applying the plastic container with a flowable medium, wherein the forming device has at least four pressure reservoirs for the flowable medium, which each have predetermined pressures P1, Pi, P+, P2, wherein pressure Pi is smaller than pressure P+ and pressure P+ is smaller than pressure P2, and a valve block with at least five process valves V1, Vi, V+, V2, VEx, wherein the application device is configured to establish a fluid connection between the valve block and a mouth region of the plastic preform, to act upon the plastic preform with the pressurized flowable medium, and the process valves are configured to act upon the plastic preform with different pressures, wherein at least one process valve is configured to establish a connection between the plastic container and an environment,
wherein
at least one throttle is arranged between the pressure reservoir P1 and the process valve V1, the flow rate of which throttle is determined by an adjustable throttle cross-section, wherein the throttle cross-section is adjustable such that the throttle cross-section is larger than 28 mm2, and the at least one throttle is adjustable between at least two fixed positions, wherein the adjustment is producible by a rotatable cylinder with different passage bores,
wherein
the pressure P1 is a pre-blowing pressure, the pressures Pi and P+ are intermediate blowing pressures and the pressure P2 is a final blowing pressure, so that a valve block is provided which has an additional intermediate blowing stage and wherein the relief pressures PEx are used to apply a next lower pressure stage, and
wherein
the process valves VEx and V2 have small switching volumes and are each switched only once during the forming of the plastic container and the process valves V1, Vi and V+ are switched twice, once when the plastic container is applied with the corresponding pressure level and once during the associated recycling stage, so that the control volume for an entire process cycle is less than 60 ml.