Hose Extrusion Mandrel Composite Core for Flexibility and Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hose extrusion mandrels face challenges with flexibility and wear issues as hose diameters increase, leading to reduced flexibility and high tolerance problems, along with issues like 'snake skin' and pinhole formation, which hinder efficient mass production of larger hoses.
Innovation Solution
A hose extrusion mandrel with a solid thermoplastic core covered by a rubber compound layer, allowing for increased flexibility and preventing 'snake skin' and pinhole issues, enabling larger diameters and longer hose production while maintaining tolerance and ease of winding on a reel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a solid thermoplastic mandrel is used for extruding hoses, then the mandrel maintains dimensional stability and tolerance, but the mandrel becomes too stiff for hoses with outer diameters of size -20 SAE and above
Solution Approach 1:
The mandrel is constructed as a composite structure with a solid thermoplastic core providing dimensional stability and a rubber compound outer layer providing flexibility. This composite design allows the mandrel to maintain manufacturing precision while achieving the necessary flexibility for larger hose diameters through reel winding.
2Ease of operation
If a rubber mandrel is used to increase flexibility, then the mandrel can be wound on a reel, but the mandrel wears quickly and has high tolerance for bigger outer diameters
Solution Approach 1:
The composite structure assigns different functions to each material layer: the rubber compound outer layer provides flexibility and wear resistance, while the solid thermoplastic core maintains dimensional stability and manufacturing precision throughout the mandrel's service life.
Solution Approach 2:
Different regions of the mandrel have different material properties optimized for their specific functions: the outer surface layer is made of rubber compound for flexibility and contact with the hose, while the inner core is solid thermoplastic for maintaining overall shape and dimensional accuracy.
3Ease of operation
If a thermoplastic flexible mandrel is used for smaller hose diameters, then the mandrel provides sufficient flexibility, but a residual film called 'snake skin' is left on the mandrel after extrusion
Solution Approach 1:
The rubber compound outer layer of the composite mandrel prevents snake skin formation during extrusion, while the solid thermoplastic core maintains the structural integrity needed for flexibility. This combination eliminates the harmful residual film issue while preserving the flexibility benefits.
4Stability of the object's composition
If a non flexible mandrel is used for hoses with outer diameters of size -20 SAE and above, then the mandrel maintains structural stability, but the length of hose that can be manufactured is limited
Solution Approach 1:
The composite mandrel structure enables the production of longer hose lengths by providing the flexibility needed for reel winding while maintaining structural stability through the solid thermoplastic core, thereby increasing productivity without sacrificing compositional stability.
Data Source
AI summary
A hose extrusion mandrel for manufacturing rubber hoses includes: a solid thermoplastic, elongate core; and a rubber compound outer layer covering a surface of the elongate core. A ratio between a diameter of the core and a thickness of the rubber compound layer may be between 8 and 11.