Air-Permeable Mandrel Segments for Elastomer Hollow Body Vulcanization
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Solution Overview
Problem
Existing methods for producing shaped hollow bodies from elastomeric material, such as vulcanization, are limited by the number of parts that can be produced per process due to the internal pressure requirements of the vulcanization press, restricting output.
Innovation Solution
A method involving mandrels with air-permeable and airtight segments, where blanks are pushed onto the mandrels, subjected to pressure and temperature in an autoclave, and then vulcanized, allowing for multiple hollow bodies to be produced simultaneously, with adjustable pressure and air flow to balance process forces and facilitate easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a vulcanization press is used to produce hollow bodies, then the parts can be vulcanized with the required internal pressure, but the number of parts that can be produced simultaneously is limited by the clamping force of the press
Solution Approach 1:
The system divides the production process into multiple independent mandrels, each capable of holding and vulcanizing multiple hollow bodies simultaneously. This segmentation allows parallel processing across multiple mandrels in the autoclave, dramatically increasing the number of parts produced per cycle without requiring proportional increases in clamping force for each individual part.
Solution Approach 2:
The mandrel serves as an intermediary tool that transfers the vulcanization pressure uniformly to multiple hollow bodies. The mandrel's air-permeable wall allows pressure transmission while maintaining the necessary form-fitting connection, enabling multiple parts to be vulcanized simultaneously without directly applying clamping force to each part individually.
2Manufacturing precision
If air-permeable wall areas are used in the mandrel, then air can be forced through to create form-fitting connection, but the wall structure becomes more complex
Solution Approach 1:
The mandrel wall is designed with different properties in different locations: air-permeable areas where air flow is needed for pressure transmission and form-fitting connection, and airtight areas where structural integrity and pressure containment are required. This localized differentiation of wall properties allows the mandrel to achieve precise form-fitting connection without requiring complete complexity throughout the entire structure.
Solution Approach 2:
The air-permeable wall areas utilize porous or sintered materials that allow controlled air flow while maintaining structural strength. These porous sections enable the necessary air pressure transmission to create form-fitting connection between the blank and mandrel, achieving manufacturing precision without requiring complex active control mechanisms.
3Productivity
If multiple hollow bodies are produced per vulcanization process, then output increases, but the coordination of process forces and air flow becomes more difficult
Solution Approach 1:
The mandrel is designed as a multi-functional component that simultaneously performs several functions: holding multiple hollow bodies, transmitting air pressure uniformly, providing form-fitting connection through air-permeable walls, and facilitating easy removal through air cushion creation. This multi-functionality consolidates what would otherwise require multiple separate systems into a single coordinated tool, making process parameter coordination more manageable.
Solution Approach 2:
The system incorporates pressure equalization elements that provide feedback control for air pressure distribution across the mandrel. This feedback mechanism automatically adjusts air flow to maintain balanced process forces across multiple hollow bodies, simplifying the coordination of process parameters despite producing multiple parts simultaneously.
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
Enables the production of multiple hollow bodies per vulcanization process, improving output efficiency and allowing for precise control of process parameters, including air permeability and material viscosity, while simplifying the removal of finished products from the mandrels.
Implementation Method 1
Applying pressure and temperature to the autoclave, whereby air that is trapped between the blanks and the mandrels is forced through the areas of airtight wall into the respective air chamber
Implementation Method 2
Applying pressure and temperature to the autoclave, whereby air that is trapped between the blanks and the mandrels is forced through the areas of airtight wall into the respective air chamber, thereby vulcanizing the blanks
Implementation Method 3
pressurizing the air chambers of the mandrels, thereby allowing air to pass through the air-permeable wall areas from the air chambers between the mandrels and the finished vulcanized hollow bodies, forming an air cushion between the mandrels and the hollow bodies
Data Source
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AI summary
The invention relates to a method for producing a molded hollow body (17) made of an elastomer material. The aim of the invention is to provide a method for producing the aforementioned hollow bodies (17), said method allowing a higher output. This is achieved in that the method has at least the following steps, namely: a) pushing a prefabricated blank (9) onto a respective mandrel (1), wherein the mandrel (1) has at least one region with a wall (5) which is designed to be permeable to air, and each mandrel (1) has at least one air chamber (7) which is operatively connected to the at least one region of the air-permeable wall (5), b) introducing the mandrels (1) with plugged-on blanks (9) into a known autoclave, c1) applying pressure and heat to the autoclave, wherein air (10) which is enclosed between the blanks (9) and the mandrels (1) is pressed through the regions of an air-tight wall (5) into the respective air chamber (7), in the process vulcanizing the blanks (9), d) relieving and cooling the autoclave, e) removing the mandrels (1) with completely vulcanized and molded hollow bodies (17), and f2) detaching the hollow bodies (8) from the mandrels (1). The mandrels (1) are composed of segments of air-tight walls (6) and air-permeable walls (5) in the axial direction.