Polyacetal Sliding Member Composition for Extrusion Dimensional Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The use of polyacetal resin in sliding members for transport devices, such as conveyor rails, is challenging due to shrinkage during extrusion forming, which makes it difficult to adjust dimensions and requires additional cutting processes, increasing the number of work processes.
Innovation Solution
A resin composition comprising polyacetal resin, a metal salt of fatty acid containing calcium and/or magnesium, and a fatty acid ester, with a specific mass ratio of these components, is used to create a sliding member that can be profile section extrusion formed, maintaining excellent wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyacetal resin is used for sliding members in transport devices, then wear resistance is improved, but dimensional control during extrusion forming deteriorates due to shrinkage
Solution Approach 1:
The invention changes the chemical composition parameters of the resin by adding specific additives (metal salts of fatty acids and fatty acid esters) to the polyacetal resin. This modification alters the shrinkage characteristics during extrusion forming, enabling dimensional control while maintaining wear resistance. The additive composition is precisely controlled within specific ratio ranges to achieve the desired balance between wear resistance and dimensional stability.
Solution Approach 2:
The invention creates a composite resin material by combining polyacetal resin with metal salts of fatty acids and fatty acid esters. This composite formulation integrates the wear resistance of polyacetal with the dimensional stability provided by the additive system, resolving the contradiction between these two properties during extrusion forming.
2Ease of manufacture
If profile section extrusion forming is used for conveyor rails, then manufacturing complexity is reduced, but dimensional accuracy deteriorates due to polyacetal shrinkage
Solution Approach 1:
By modifying the resin composition parameters (adding metal salts of fatty acids and fatty acid esters in specific ratios), the invention changes the shrinkage behavior during extrusion. This enables profile section extrusion forming to be performed with acceptable dimensional accuracy, making the simplified manufacturing process viable for conveyor rail production.
3Manufacturing precision
If additional cutting processes are used to compensate for shrinkage, then dimensional accuracy is improved, but productivity deteriorates due to increased work processes
Solution Approach 1:
The invention performs preliminary action by incorporating shrinkage control additives into the resin composition before extrusion. This pre-preparation of the material properties eliminates the need for subsequent cutting processes to correct dimensional inaccuracies, thereby maintaining productivity while achieving dimensional accuracy.
Solution Approach 2:
The invention extracts the problematic shrinkage characteristic from the polyacetal resin by adding modifiers that counteract or control the shrinkage. This removes the need for corrective cutting operations, streamlining the manufacturing process.
Data Source
AI summary
To provide a sliding member for transport devices that has excellent wear resistance and can be subjected to profile section forming, and a resin composition. The sliding member for transport devices, formed from a resin composition contains (A) a polyacetal resin, wherein a cross-sectional area of a wear groove is 1,000 µm2 or less when a JIS K7139 multipurpose test specimen type A1 formed from the resin composition and an S45C pin are subjected to reciprocating sliding 40,000 times at a moving speed of 6,000 mm/min, a load of 500 g, and a one-way moving distance of 20 mm, and the melt volume flow rate of the polyacetal resin as measured according to JIS K7210-1 is 1.0 to 5.0 cm3/10 min.