MoS₂-Filled PTFE Seal — why this filler for this component
MoS₂ filling suits a seal that has to survive a chemically demanding fluid but still resist the scuffing that destroys an unfilled lip. Because molybdenum disulphide is used at only around 5%, the compound keeps most of PTFE’s chemical breadth while gaining a noticeably harder sealing face.
Where MoS₂-Filled PTFE Seal is used
Against a glass-filled seal
MoS₂ keeps far more of PTFE’s chemical resistance and does not abrade the counterface, but glass is markedly better at holding sealing force against creep. Choose MoS₂ when chemistry and surface durability lead; choose glass when relaxation is the failure you are seeing.
The lip wears slowly and evenly. Loss of interference, rather than scoring or extrusion, is the usual end of life.
Key properties
Compound
MoS₂-filled PTFE, typically around 5% molybdenum disulphide
Duty
chemically demanding sealing where an unfilled lip scuffs
How it behaves here
The filler hardens the surface layer and acts as a solid lubricant, so the lip beds in with less initial wear and holds its profile better than unfilled PTFE. Chemically the compound behaves much like plain PTFE, which is the reason to choose it over a structural filler.
Where it does not belong
It adds little to extrusion resistance or creep resistance. Where the seal is failing because it is being forced into a clearance or relaxing over time, MoS₂ is not the fix and a glass- or bronze-filled grade is.
Specifications
| Property | Value |
|---|---|
| Compound | MoS₂-filled PTFE, typically around 5% molybdenum disulphide |
| Duty | Chemically demanding sealing, moderate load |
| Form supplied | Machined to seal drawing |
| Governing factor | Surface hardness with near-virgin chemical resistance |
| Counterface | Tolerant of moderate finishes |
| Not suitable for | High extrusion or sustained creep loading |
Manufacturing process
Compression moulded from roughly 5% MoS₂ compound, sintered, then machined to the seal drawing.
Material selection notes
The filler hardens the surface layer and acts as a solid lubricant, so the lip beds in with less initial wear and holds its profile better than unfilled PTFE. Chemically the compound behaves much like plain PTFE, which is the reason to choose it over a structural filler.
How to specify your order
Against a glass-filled seal: MoS₂ keeps far more of PTFE’s chemical resistance and does not abrade the counterface, but glass is markedly better at holding sealing force against creep. Choose MoS₂ when chemistry and surface durability lead; choose glass when relaxation is the failure you are seeing.
Quality checks and inspection
Dimensions are verified on CMM against your drawing. Filler content and sintered density are checked per ASTM D792, with tensile and elongation per ASTM D4894. A mill test certificate stating the lot, filler content and measured values ships with the order.
Ordering and export documentation
Standard PTFE seal practice applies. Because the compound is close to virgin PTFE in stiffness, it conforms readily and is forgiving of a counterface that is not perfectly finished.
Export packing and lead time
HEMSUN is a DGFT IEC registered exporter (Government of India). Commercial invoice, packing list and certificate of origin accompany international despatch.
Storage and handling
The lip wears slowly and evenly. Loss of interference, rather than scoring or extrusion, is the usual end of life.
Compliance & Standards
HEMSUN is a DGFT IEC registered exporter (Government of India). Filler content and sintered density are verified per ASTM D792 on each batch, with tensile and elongation checked per ASTM D4894.
Frequently Asked Questions
What MoS₂-Filled PTFE Seal options does HEMSUN manufacture?
MoS₂ filling suits a seal that has to survive a chemically demanding fluid but still resist the scuffing that destroys an unfilled lip. Because molybdenum disulphide is used at only around 5%, the compound keeps most of…
Can you supply MoS₂-Filled PTFE Seal for OEM and export orders?
Yes. We support prototype lots, recurring OEM programmes, and export packing with material certificates and dimensional inspection reports on request. Typical RFQ response is within one business day when drawings are complete.
How do I request a quote for MoS₂-Filled PTFE Seal?
Send material grade, dimensions or drawing, quantity, application media, and operating temperature/pressure via https://hemsun.com/contact. Our engineering team confirms manufacturability, lead time, and pricing.
