Stretch Blow Nozzle Valve Layout for Low Dead Space Airflow
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Solution Overview
Problem
Existing methods for manufacturing containers from thermally conditioned preforms require high volumes of compressed air, leading to high energy consumption and inefficient production processes.
Innovation Solution
A device with a blow nozzle, stretching rod, and axially movable blow-air valves arranged in an annular configuration, minimizing dead space volume and optimizing compressed air usage through reduced distances and sealed fluid paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If compressed air is supplied in large volumes for pre-blow, intermediate, and main blow pressure stages, then the preform can be expanded into a container, but energy consumption increases
Solution Approach 1:
The patent implements a nested valve structure where a first blow air valve and a second blow air valve are arranged concentrically, with the first valve positioned inside the second valve. This nesting arrangement allows both valves to control compressed air flow through different pathways to the blow nozzle, enabling multi-stage pressure control (pre-blow, intermediate, main blow) while minimizing dead space volume. The compact nested configuration reduces the overall space required for valve assembly, thereby reducing the volume of compressed air needed for pressure build-up and release.
Solution Approach 2:
The patent transitions from a conventional linear or side-by-side valve arrangement to a concentric/circular arrangement where valves are positioned radially around the blow nozzle opening. This dimensional reorganization places the valve seats closer to the blow nozzle opening in a radial configuration, significantly reducing the dead space volume between the valves and the blow nozzle. The circular arrangement allows compressed air to be supplied from multiple radial directions, improving pressure control efficiency while minimizing the volume of air required.
2Speed
If compressed air is supplied through conventional valve arrangements, then pressure stages can be applied, but dead space volume increases leading to slower pressure build-up and release
Solution Approach 1:
The nested concentric valve arrangement minimizes dead space volume by positioning the first blow air valve inside the second blow air valve, both with their seats adjacent to the blow nozzle opening. This compact configuration eliminates large volumes of trapped air that would otherwise slow down pressure build-up and release. The nested structure ensures that compressed air can be rapidly supplied and vented through short pathways, enabling faster pressure transitions.
Solution Approach 2:
By arranging the valve seats in a radial configuration around the blow nozzle opening rather than in a linear sequence, the patent reduces the distance compressed air must travel to reach the preform. This dimensional optimization places the valve seats as close as possible to the blow nozzle opening in all radial directions, minimizing dead space volume and enabling rapid pressure build-up and release for increased production speed.
3Productivity
If compressed air is guided outside the die around the outer circumference, then the preform can be expanded, but the distance from air supply to preform increases reducing efficiency
Solution Approach 1:
The patent repositions the compressed air supply from an external circumferential path to an internal radial path through the hollow die. The blow nozzle is positioned inside the die with its opening facing the preform, and compressed air is supplied radially from the blow nozzle opening directly to the preform surface. This dimensional change from external to internal air supply dramatically reduces the distance the air must travel, improving pressure transmission efficiency and enabling faster production cycles.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces dead space volume, enabling more efficient energy use, faster pressure build-up and release, and increased production output.
Implementation Method 1
a blow nozzle (1) for blowing compressed air into a preform (80) for forming the preform (80) into a container
Implementation Method 2
a sealing surface is arranged between the first air valve and the second air valve on at least one of these two air valves, which, when these two air valves are in contact, blocks a fluid flow path for a fluid flow, in particular for a gas flow
Data Source
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AI summary
The invention relates to a device and a method for producing containers from thermally conditioned preforms and a stretch blow molding machine. The device comprises a blow nozzle (1) for blowing compressed air into a preform (80) for forming the preform (80) into a container (90), wherein the blow nozzle (1) has a blow nozzle opening (2). Furthermore, the device comprises a stretching rod (50) for stretching the preform (80) and a valve block (10) with several blow air valves (21, 22, 23) that are axially movable within the valve block (10) and that are at least partially annular in shape. At least two of the blow air valves surround the stretching rod (50) at least partially annularly, wherein the several blow air valves (21, 22, 23) comprise a first blow air valve (21) and a second blow air valve (22).Between the first blow-air valve (21) and the second blow-air valve (22), a sealing surface (22c) is arranged on at least one of these two blow-air valves (21, 22). When these two blow-air valves (21, 22) are in contact, this sealing surface blocks the fluid flow path between these two blow-air valves (21, 22) and towards the blow-out nozzle opening (2) by means of a sealing effect. The first blow-air valve (21) is arranged at least partially inside the second blow-air valve (22) in a radial direction (R) that is orthogonal to the longitudinal axis (A).