Multi-layer PVC Hose with Reinforcement for Kink Resistance
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Solution Overview
Problem
Flexible garden hoses often kink when bent, leading to restricted fluid flow and inconvenience, as existing solutions either increase weight and cost or fail to maintain a cylindrical shape under compressive forces.
Innovation Solution
A multi-layer hose construction using a PVC compound with specific gravity and K value ranges, combined with a spiraled or braided reinforcement layer, allows for a smaller bend radius without kinking, maintaining a circular cross-section and enhanced burst strength, making the hose lighter, easier to handle, and more economical.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a thicker (heavier) hose construction is used to improve kink resistance and burst strength, then strength and kink resistance are improved, but the hose becomes heavier, more expensive, and more difficult to handle
Solution Approach 1:
The hose employs a composite construction with multiple layers including an inner tube layer, reinforcement layer, and outer jacket layer made from different materials (PVC compounds with specific gravities and K values). This composite structure achieves superior burst strength and kink resistance without requiring increased overall thickness, thereby maintaining light weight and ease of handling.
Solution Approach 2:
Different layers of the hose are assigned specific material properties optimized for their functions: the inner tube layer uses PVC compound with specific gravity 1.15-1.25 and K value 75-85 for flexibility and kink resistance; the reinforcement layer provides structural strength; the outer jacket layer uses PVC compound with specific gravity 1.10-1.20 and K value 65-75 for durability. This localized optimization achieves high performance without uniform thickness increase.
2Reliability
If a thicker (heavier) hose construction is used to improve kink resistance, then kink resistance is improved, but the hose becomes more expensive and difficult to coil
Solution Approach 1:
The invention specifies precise parameter ranges for the PVC compounds used in different layers: specific gravity 1.10-1.20 for the outer jacket and 1.15-1.25 for the inner tube, with K values of 65-75 and 75-85 respectively. These controlled parameter changes optimize the balance between kink resistance, flexibility, and manufacturability without requiring complex construction.
3Ease of operation
If the hose is made lighter and thinner, then ease of handling and manufacturing cost are improved, but burst strength and kink resistance deteriorate
Solution Approach 1:
The multi-layer composite construction with reinforcement layer embedded between PVC compound layers provides high burst strength in a thin-walled design. The specific gravity and K value specifications for each layer ensure optimal material properties that deliver strength without excessive thickness, maintaining light weight and ease of handling.
Data Source
AI summary
Multilayer hose construction and hose formulation provide a surprising combination of physical properties and enhanced performance, more specifically providing improved kink resistance and burst strength. The garden hose comprises an extruded composite tube including core and jacket layers of a polyvinyl chloride (PVC) compound and an intermediate reinforcement layer having interstices through which the core and jacket layers are bonded, the PVC compound comprising: 100 PPH (parts in weight per hundred parts of resin) of PVC resin; and 45-75 PPH of plasticizer. The PVC compound has a K value in a range of 79-85 measured according to standard ISO1628-2 and a specific gravity in a range of 1.17-1.23 measured according to standard ASTM D792. The composite tube has a bend radius of less than 3 inch and the composite tube has a minimum burst pressure of 500 psi measured according to standard ISO 1402:2009.