The governing constraint in profile extrusion is melt strength: once the profile leaves the die it is unsupported until it cools, and a compound that flows too freely will sag, draw down or lose the die's detail. That is why the 21 extrusion grades in this catalogue run a median melt flow of 7.5 g/10 min at 230°C against 73 for the injection grades.
Key takeaways
- Extrusion grades here span 0.6 - 32 g/10 min at 230C; the lower the figure, the better the profile holds its shape unsupported.
- Tall, thin-webbed or hollow profiles need the low end of that range.
- Every extrusion grade in this catalogue is SEBS-based, which suits the exterior applications extruded profiles often serve.
- TPE profiles can be corner-welded because the material re-melts - vulcanised rubber sections cannot.
- UV stabilisation is the starting point for any externally exposed profile, but service life still needs qualifying.
Melt strength and the unsupported span
Between the die face and the first cooling contact, an extruded profile is held up only by its own melt strength. A low melt flow index means high melt viscosity, which means the profile resists deforming under its own weight and under the draw of the haul-off.
The more demanding the geometry, the lower the melt flow you want. Tall vertical sections, thin connecting webs and hollow chambers are all cases where a high-flow compound will not hold the die profile.
| Grade | Hardness | MFI 230°C | Best suited to |
|---|---|---|---|
| FARRPRENE EU401A | 40 Shore A | 0.6 | The most viscous grade here - demanding unsupported geometry |
| FARRPRENE EF753AV | 75 Shore A | 0.93 | Firm profiles needing tight dimensional hold |
| FARRPRENE EF657A | 65 Shore A | 1.3 | Detailed sealing profiles |
| FARRPRENE EF455A | 45 Shore A | 1.5 | Soft compression seals |
| FARRPRENE EF651A | 65 Shore A | 1.6 | Weatherstrip and glass-run profiles |
| FARRPRENE EU400A | 40 Shore A | 1.8 | Soft translucent profiles and welts |
| FARRPRENE EF456A | 45 Shore A | 1.8 | Soft sealing profiles |
| FARRPRENE EF520DV | 52 Shore D | 2.7 | Rigid structural profiles |
| FARRPRENE EU502A | 50 Shore A | 3.6 | Translucent profiles, silky touch |
| FARRPRENE EF401DV | 40 Shore D | 5.5 | Rigid profiles and trim |
| FARRPRENE EF902AV | 90 Shore A | 7.5 | Firm profiles, 17.5 MPa tensile |
| FARRPRENE EF400DV | 40 Shore D | 8.1 | Rigid profiles, silky touch |
| FARRPRENE EF600AU | 60 Shore A | 8.2 | Sealing profiles, most heavily filled grade here |
| FARRPRENE EF653AU | 65 Shore A | 9.1 | Weatherstrip, UV stabilised |
| FARRPRENE EF820A | 82 Shore A | 9.5 | Firm trim sections |
| FARRPRENE EF656AU | 65 Shore A | 13 | Sealing profiles, >850% elongation |
| FARRPRENE EF551AU | 55 Shore A | 14 | Compression and expansion-joint seals |
| FARRPRENE EF457A | 45 Shore A | 17 | Soft profiles, higher flow |
| FARRPRENE EF501AU | 50 Shore A | 19 | Glazing and weather seals |
| FARRPRENE EF654AU | 65 Shore A | 23 | Complex dies needing more flow |
| FARRPRENE EF655A | 65 Shore A | 32 | Highest-flow extrusion grade here |
Hardness for sealing profiles
Compression seals generally use the softest compound that still recovers fully under the joint's working load. A softer seal fills an irregular gap at lower closure force and transmits less load into the mating parts. Glazing gaskets typically sit at 20 to 45 Shore A; window and door weather seals at 45 to 60; hard-wearing weatherstrip that wipes against a moving surface at 60 to 70.
Outdoor exposure
Extruded profiles disproportionately end up outdoors - glazing seals, weatherstrip, expansion joints. Two things matter. Every extrusion grade in this catalogue is SEBS-based, which is the right starting point because the hydrogenated backbone resists UV and oxidation far better than SBS. Beyond that, look for UV stabilisation: FARRPRENE EF457A, FARRPRENE EF501AU, FARRPRENE EF551AU, FARRPRENE EF600AU, FARRPRENE EF651A, FARRPRENE EF653AU, FARRPRENE EF654AU, FARRPRENE EF656AU, FARRPRENE EF657A, FARRPRENE EF753AV, FARRPRENE EF902AV and all three Shore D grades carry it.
Service life still depends on exposure, colour and section geometry, so qualify an outdoor profile against its actual duty cycle.
Corner welding and reprocessing
Because thermoplastic elastomers re-melt, extruded profiles can be heat-welded at corners and joints - something a vulcanised rubber section cannot do once cured. The same property means offcuts and start-up scrap can be reground and fed back, which is where the heat stabilisation on nearly every grade in this catalogue earns its place.
All values quoted are typical average values from a limited sample set, not a formal specification. Request the signed datasheet for current values.
Scope note. The guidance on this page is based on published mechanical properties - hardness, tensile strength, elongation, melt flow, specific gravity, base polymer and stabilisation. Food contact, skin contact, biocompatibility, flame retardancy, halogen-free formulation and electrical performance are not characterised in the public catalogue and require a separately qualified compound and testing. Contact us to qualify a grade against any of those.
Frequently Asked Questions
What melt flow index should a TPE extrusion grade have?
Low - typically below about 10 g/10 min at 230C for general profile work, and below 2 for tall or thin-webbed profiles that are unsupported for longer after the die. The extrusion grades in this catalogue run from 0.6 to 32 g/10 min with a median of 7.5.
Can TPE profiles be welded at the corners?
Yes. Thermoplastic elastomers re-melt, so extruded profiles can be heat-welded at corners and joints to form continuous frames. Vulcanised rubber sections cannot be welded once cured, which is one of the practical advantages of switching a sealing frame to TPE.
What hardness is used for extruded window and door seals?
Usually 45 to 60 Shore A. That band gives enough stiffness for an extruded lip to hold its shape and enough compliance to seal against the frame. Glazing gaskets go softer, typically 20 to 45 Shore A, so that closure force stays low.
Are TPE extrusion grades suitable for outdoor profiles?
The UV-stabilised SEBS-based grades are the correct starting point, and every extrusion grade in this range is SEBS-based. Real service life depends on exposure intensity, pigment and section thickness, so an outdoor profile should be qualified against its actual duty cycle rather than assumed from the datasheet.
Can I run an injection grade on an extrusion line?
It is generally the wrong choice. Injection grades are formulated for flow, not melt strength, so the profile tends to sag or draw down after the die and loses dimensional accuracy. If you need one compound across both processes, ask about a dual-process grade - IEU150A is the one qualified for both in this range.
Related guides
- TPE Melt Flow Index: Why Injection and Extrusion Grades Are Not Interchangeable
- UV and Heat Stabilised TPE: What the Callouts Mean
- Shore A vs Shore D TPE: When Your Part Needs to Be Rigid
- How to Choose a TPE Grade: A Specifier's Guide
About the FARRPRENE range
FARRPRENE is the thermoplastic elastomer (TPE) compound range of Farr Polychem FZCO, a polymer compounder based in Jebel Ali Free Zone, Dubai, United Arab Emirates, supplying the UAE, the wider MENA region and Europe. The range covers injection moulding and extrusion compounds from soft gel-like Shore A grades through rigid Shore D grades, in unfilled translucent and filled natural variants, colour-matchable to a customer reference, with free samples and technical datasheets available on request. Browse the full grade catalogue, see every grade side by side on the comparison table, or request a sample.
FARRPRENE GRADES
Grades commonly specified for industrial applications
| GRADE | HARDNESS | TENSILE (MPa) | TYPICAL USE |
|---|---|---|---|
| IEU150AInjection / Extrusion / Unfilled | 15 Shore A | 3 | Vibration-damping pads and soft mounts |
| IF752AInjection / Filled | 75 Shore A | 5.5 | Bushings, spacers and wear components |
| IF900AInjection / Filled | 90 Shore A | 5.5 | Hard bushings and near-rigid flexible parts |
Typical average values from a limited sample set; not a formal specification. Request the signed datasheet for current values.
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