Polyurethane Rubber Roll Covering Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rolls used in papermaking machines face challenges with mechanical and thermal stress, leading to issues like cracking, embrittlement, and reduced performance due to existing rubber and polyurethane coverings, which lack adequate heat resistance and resilience.
Innovation Solution
A roll covering composed of a blend of millable polyurethane rubber and conventional rubber, with a specific weight proportion of 22% to 28% polyurethane rubber, combined with crosslinked nitrile and hydrogenated nitrile rubbers, and filled with inorganic materials, providing enhanced thermal stability and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rubber roll coverings are used to provide good mechanical properties, then mechanical strength and resilience are improved, but thermal stability deteriorates due to continuing vulcanization at high temperatures causing excessive hardening and embrittlement
Solution Approach 1:
The patent changes the chemical composition parameters of the roll covering by using a specific blend ratio of polyurethane rubber (22-28% by weight) and conventional rubber (72-78% by weight), and controlling the vulcanization degree to 5-20%. This parameter optimization prevents excessive hardening while maintaining mechanical strength at high temperatures.
Solution Approach 2:
The patent creates a composite material system by blending polyurethane rubber with conventional rubber (such as NBR or HNBR). This composite structure combines the advantages of both materials: polyurethane provides wear resistance and dimensional stability, while conventional rubber provides elasticity and mechanical strength, achieving both mechanical performance and thermal stability.
2Stability of the object's composition
If polyurethane roll coverings are used to improve dimensional stability, then resistance to swelling in liquid is improved, but mechanical resilience deteriorates due to lower resilience and inferior dynamic properties
Solution Approach 1:
The patent optimizes the polyurethane content to a specific range (22-28% by weight) rather than using high polyurethane content formulations. This parameter control ensures sufficient dimensional stability and swelling resistance while maintaining adequate mechanical resilience through the complementary rubber matrix.
Solution Approach 2:
The patent forms a composite material where polyurethane rubber provides dimensional stability and swelling resistance, while the conventional rubber matrix (72-78% by weight) provides mechanical resilience and dynamic properties. The synergistic combination resolves the contradiction between dimensional stability and mechanical resilience.
3Temperature
If the proportion of polyurethane rubber in the blend is increased to improve thermal properties, then heat resistance is improved, but mechanical properties deteriorate
Solution Approach 1:
The patent identifies and implements an optimal polyurethane content range (22-28% by weight) that balances thermal properties and mechanical properties. This parameter optimization ensures sufficient heat resistance for high-temperature applications while maintaining the mechanical strength provided by the conventional rubber majority phase.
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 significantly improves the roll's heat resistance and mechanical durability, extending its lifespan and reducing maintenance costs, while maintaining optimal performance in high-temperature applications.
Implementation Method 1
the roll covering obtained has particular thermal stability
Implementation Method 2
crosslinked nitrile and hydrogenated nitrile rubbers
Data Source
AI summary
A roll covering includes a functional layer formed of a polymer which is a blend of at least one rubber and one millable polyurethane rubber. The polymer includes from 65% by weight to 85% by weight of the at least one rubber and from 15% by weight to 35% by weight of the millable polyurethane rubber. A roll having the roll core, a method of using the roll and a combination of the roll and a heated drying cylinder are also provided.