Polyoxymethylene Sliding Assembly With Silent Low-Friction Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tribological modifiers for polyoxymethylene polymers are often temperature-sensitive, leading to reduced effectiveness at high or low temperatures, and they fail to prevent noise generation during sliding contact between thermoplastic components, which is undesirable in consumer applications.
Innovation Solution
A polymer composition combining polyoxymethylene with ultrahigh molecular weight silicone, which maintains low friction properties and prevents noise over an extended temperature range by forming a polymer assembly with a dynamic coefficient of friction less than 0.08, even at high temperatures, and exhibits reduced wear track width.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional tribological modifiers are used in polyoxymethylene polymers, then friction is reduced at room temperature, but effectiveness is lost at high or low temperatures
Solution Approach 1:
The patent combines polyoxymethylene polymer with ultrahigh molecular weight silicone to create a composite material that achieves low friction across an extended temperature range. The silicone component (0.1-10% by weight) provides temperature-insensitive lubrication properties that complement the polyoxymethylene base polymer, resolving the temperature sensitivity issue of conventional single-material tribological modifiers.
2Force
If conventional tribological modifiers are used, then friction is reduced, but noise generation during sliding contact persists
Solution Approach 1:
The ultrahigh molecular weight silicone modified polyoxymethylene composition creates a composite material that simultaneously reduces friction and eliminates stick-slip noise. The silicone additive modifies the surface properties and friction characteristics of the polymer, enabling smooth, quiet operation during sliding contact between thermoplastic components.
3Strength
If high molecular weight polyolefins are used as tribological modifiers, then wear resistance is improved, but temperature sensitivity remains
Solution Approach 1:
The patent changes the molecular weight parameter of the silicone modifier to ultrahigh molecular weight, which provides superior wear resistance while maintaining temperature insensitivity. This parameter change in the modifier's molecular characteristics enables the composition to achieve both high wear resistance and broad temperature range effectiveness.
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 polymer composition achieves low friction and silent operation across a broad temperature range, significantly reducing wear and noise in applications where thermoplastic components slide against each other, enhancing the perceived quality and performance of consumer products.
Implementation Method 1
The first sliding member is made from a first polymer composition comprising a polyoxymethylene polymer combined with an ultrahigh molecular weight silicone. The second sliding member is made from a second polymer composition also containing a polyoxymethylene polymer combined with an ultrahigh molecular weight silicone. The ultrahigh molecular weight silicone can be present in the first polymer composition and the second polymer composition such that when the polymer compositions are tested against each other, the compositions exhibit a dynamic coefficient of friction of less than about 0.08
Data Source
AI summary
A tribologically modified polyoxymethylene polymer composition is disclosed. The polyoxymethylene polymer composition is comprised of a polyoxymethylene polymer and at least one tribological modifier. The tribological modifier may comprise an ultra-high molecular weight silicone having a kinematic viscosity of greater than 100,000 mm2s-1. When tested against itself, the composition of the present disclosure exhibits an extremely low dynamic coefficient of friction and produces no discernible noise over a very broad temperature range, such as from -20°C to 60°C.