Elevator Cord Polymer Jacket Flame Retardant Nanoscale Filler
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Solution Overview
Problem
Elongated flexible assemblies, such as elevator load bearing members and conveyor belts, face challenges in maintaining flame resistance while maintaining flexibility and desired surface characteristics, as existing flame retardants are not compatible with the requirements of these applications.
Innovation Solution
A polymer jacket with a nanoscale filler, specifically polyhedral oligomeric silsesquioxane, is chemically bonded to a matrix phase, combined with halogen-free melamine-based intumescent or phosphate flame retardants, to create a flame-resistant material that inhibits fire spread by forming a char surface and diluting oxygen, without compromising flexibility or compatibility with the assembly components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional flame retardants are added to the polymer jacket material, then flame resistance is improved, but flexibility and surface characteristics deteriorate
Solution Approach 1:
The patent changes the chemical parameters of the flame retardant by using a silane-modified polyurethane composition with specific functional groups (alkoxysilane groups) that react to form a crosslinked network. This chemical modification allows the flame retardant to integrate molecularly with the polymer matrix, maintaining flexibility while achieving flame resistance through chemical bonding rather than physical addition.
Solution Approach 2:
The patent creates a composite material system where silane-modified polyurethane components form an integrated flame-retardant network within the polymer jacket. The silane groups react with the polyurethane chains to create a composite structure at the molecular level, combining flame retardancy with the mechanical properties of the base polymer without the need for separate additive phases that would compromise flexibility.
2Reliability
If conventional flame retardants are added to the polymer jacket material, then flame resistance is improved, but compatibility with assembly components deteriorates
Solution Approach 1:
The patent modifies the chemical parameters of the flame retardant system by using silane groups that can form covalent bonds with the polyurethane matrix and potentially with metal surface oxides. This chemical adaptation allows the flame retardant to be compatible with various assembly components including metal cords and other polymer elements, as the silane chemistry provides a universal bonding interface.
3Reliability
If flame retardant additives are incorporated into the polymer material, then flame resistance is improved, but the complexity of material formulation increases
Solution Approach 1:
The patent merges the flame retardant function with the base polyurethane polymer by incorporating silane-modified components directly into the polymer formulation. Instead of adding separate flame retardant additives, the silane groups are integrated into the polymer chains during synthesis, creating a unified material system where the flame retardant and structural polymer are chemically combined, thereby reducing formulation complexity.
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
The solution effectively renders the jacket material flame-resistant, maintaining flexibility and compatibility with the assembly components, providing a char barrier to prevent fire spread and maintaining mechanical properties, while being easy to incorporate into the polymer material.
Implementation Method 1
a nanoscale filler chemically bonded to a matrix phase
Implementation Method 2
inhibits fire spread by forming a char surface and diluting oxygen
Data Source
Figure 1~3
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AI summary
A load bearing assembly (26) for an elevator system (20) includng at least one elongated tension member (32) and a jacket (34) covering at least some of the at least one tension member. The jacket (34) comprises a polymer material (64, 68); and a flame retardant (62) which is a filled polymer having a nanoscale filler, the flame retardant nanoscale filler comprising a polyhedral oligomeric silsequioxane.