Bada AG BADAFLEX® SEBS-Comp. UL TPE-S 40A FR01 is a styrenic block copolymer compound classified under ISO 18064:2022 as a TPE-S grade. The designation distinguishes it from olefinic TPE-O, vulcanised TPE-V, and urethane TPE-U materials because the elastomeric phase is derived from hydrogenated styrenic block copolymers. The product name carries three operational identifiers: a nominal hardness of 40 Shore A, a UL-recognised flame-retardant package, and an SEBS compounding base. The suffix FR01 designates the manufacturer’s first flame-retardant formulation in this hardness series; it does not identify filler loading or a single UL 94 classification.

The SEBS backbone consists of polystyrene end blocks and a hydrogenated poly(ethylene/butylene) midblock. Hydrogenation removes most carbon-carbon double bonds from the midblock, which improves oxidative stability and raises continuous service temperature relative to unsaturated SBS compounds. The microphase-separated polystyrene domains act as physical crosslinks below the glass transition temperature of polystyrene. Above melt temperature, the physical crosslinks disengage and the compound can be processed on conventional thermoplastic equipment.

From a compounding perspective, the flame-retardant package in the UL TPE-S 40A FR01 forms a dispersed phase within the SEBS matrix. This second phase modifies melt rheology, density, surface gloss, and combustion behaviour. Compared with a non-flame-retardant SEBS compound of similar hardness, the FR01 grade should be expected to exhibit a narrower processing window and higher melt viscosity at equivalent shear rates. The UL recognition path also implies that the formulation has passed standardised vertical burn testing at defined thicknesses; that result is specific to grade, colour, and specimen thickness rather than a universal material property.

How Does This Grade Differ from Non-FR SEBS and Alternative Thermoplastic Elastomers?

Compared with a general-purpose SEBS TPE-S compound of 40 Shore A, the UL TPE-S 40A FR01 is differentiated primarily by its combustion-resistance package. Non-FR SEBS grades are frequently unclassified or HB under UL 94. The FR01 designation indicates that vertical burn test data exist for specific wall sections, allowing the compound to be referenced in electrical and electronic device certification workflows. The flame-retardant additives may reduce tensile strength and elongation compared with an unfilled grade of equal hardness; product-specific tensile data should be obtained from the manufacturer before load-bearing design.

Against a flame-retardant TPU grade of similar hardness, the SEBS-based TPE-S compound tends to show lower density and better hydrolytic stability but lower abrasion resistance when measured under ISO 4649 and lower resistance to nonpolar oils. Against a PP/EPDM TPV, the SEBS grade generally processes at lower melt temperature and provides lower high-temperature compression set but may offer better surface aesthetics and lower density. These comparisons are chemistry-level differences and do not replace direct product testing on the finished part.

Specification alignment requires separation of product-specific published values from generic literature values for SEBS compounds of similar hardness. The nominal hardness of 40 Shore A is tested according to DIN ISO 48-4:2021 or ASTM D2240-15(2021). Hardness alone does not capture the effect of the flame-retardant package on tensile modulus, elongation at break, or compression set. A test method matrix for initial material verification is provided below.

When Application Geometry Requires V-0 Performance at Thin Walls

The vertical burn classification under UL 94 is evaluated on defined specimen thicknesses. A V-0 classification at 3.0 mm does not automatically extend to 1.5 mm or 0.8 mm sections. The UL Yellow Card for BADAFLEX® SEBS-Comp. UL TPE-S 40A FR01 should be consulted to identify the minimum thickness at which V-0, V-1, or V-2 performance is listed. For connectors, cable glands, and battery housing seals with wall sections below 1.5 mm, the design must be verified at the as-moulded thickness because material selection at 3.0 mm can mask thin-wall performance limits.

During vertical burn testing, flame-retardant SEBS compounds may exhibit flaming drips, afterglow, or wicking along mineral fillers. The UL-recognised FR01 formulation is expected to balance char formation against melt flow so that dripping does not invalidate the vertical burn classification. Pigments can also shift UL 94 results; black and white colourants may alter heat absorption, char morphology, and ignition time. Therefore, a natural-grade classification does not automatically cover colour-matched production compounds. If the end-use colour is not listed on the UL Yellow Card, additional testing may be required.

The suffix FR01 does not provide information about halogen content. Halogen-free status must be separately confirmed through the manufacturer’s regulatory datasheet. UL 94 addresses flame spread and dripping on vertical specimens; it does not measure heat release rate, smoke density, or combustion gas composition. Where those parameters are relevant, cone calorimetry under ISO 5660-1:2019 or glow-wire testing under IEC 60695-2-11:2021 is required.

On production-scale injection moulding equipment, SEBS-based TPE-S grades with Shore A hardness around 40 are processed in the melt temperature range of 170 to 220 °C. Barrel zone temperatures should increase from rear to nozzle, but the front zone should not exceed 220 °C for extended residence times because thermal breakdown of the styrenic endblocks and flame-retardant additives can generate hard spots, flow lines, and reduced UL 94 performance. A general-purpose screw with an L/D ratio of 20:1 to 25:1 and low-to-medium shear geometry is preferred over high-shear barrier screws; high shear can raise melt temperature locally and degrade the SEBS midblock.

Pre-drying is recommended when storage humidity has exceeded 60 % RH. Typical drying conditions for SEBS and polar flame-retardant additives are 60 to 80 °C for 2 to 4 h in a desiccant dryer. Insufficient drying can produce surface streaks and splay. Mould temperatures of 20 to 50 °C are generally suitable, with higher mould temperatures improving weld line strength but extending cycle time. On extrusion lines, a 24:1 to 30:1 L/D single-screw extruder with a melt pump can be used for profiles and tubing; melt temperature should be kept below the upper processing limit to avoid pre-crosslinking and gel formation.

Flame-retardant SEBS compounds can generate plate-out on polished mould surfaces when low-molecular-weight FR additives migrate under sustained high mould temperatures. Mould maintenance intervals may need to be shortened compared with non-FR TPE-S production. Screw recovery speed and back pressure should be set conservatively until melt viscosity is known for the specific batch; batch-to-batch variation in SEBS feedstock can shift melt viscosity by approximately 10 to 15 % in industrial compounding, requiring adjustment of barrel temperatures or injection speed.

Reported application contexts for UL-listed SEBS TPE-S compounds include cable grommets, electrical connector bodies, strain-relief components, battery pack gaskets, appliance damping elements, and protective covers where flame retardance and elastomeric recovery are required. In these parts, the TPE-S designation indicates that no vulcanisation step is required after moulding; the styrenic block copolymer provides rubber-like elasticity through physical crosslinks. UL recognition reduces the need for end-product flame testing only to the extent that final part geometry, colour, and thickness match the yellow card conditions.

Regulatory documentation should be requested for RoHS Directive 2011/65/EU and REACH Regulation EC 1907/2006; the flame-retardant package may contain substances subject to reporting or exemption. The UL Yellow Card does not imply RoHS compliance or REACH compliance. A documentation matrix for initial regulatory assessment is provided below.

Operational boundaries are defined by solvent exposure and the chemical resistance of the SEBS matrix. Continuous contact with aromatic hydrocarbons, chlorinated solvents, strong acids, and high-aniline-point oils can cause swelling, softening, and loss of dimensional stability. For sealing applications involving service fluids, immersion testing under ISO 1817:2015 is required. Published data for this specific FR01 formulation under all fluid classes is limited. The material is not a direct substitute for high-temperature silicone elastomers or fluorocarbon elastomers. It should not be specified for continuous service above the thermal limits of the SEBS polystyrene endblock network without confirmation of compression set, hardness retention, and flame-retardant migration stability. When joining to polyamide, polycarbonate, or other polar substrates, mechanical interlocks or adhesives are generally necessary because SEBS-based compounds do not develop strong inherent polar adhesion.