Bada AG BADAFLEX® SEBS-Comp. TPE-S 85A 1522 is a hydrogenated styrene-ethylene/butylene-styrene block copolymer compound supplied for injection moulding and extrusion. The designation identifies a nominal hardness of 85 Shore A when tested under ISO 868 with a 15 s durometer reading, and a typical density of 0.89 g/cm³ obtained under ISO 1183-1. The 1522 suffix is an internal Bada AG formulation identifier linked to a specific melt-viscosity target, extender-oil level, and stabilizer package; it does not correspond to a single polymer CAS registry number. Unlike vulcanized rubber, the compound flows as a thermoplastic above its styrene-domain softening range and can be re-ground and reprocessed when the thermal history remains within the manufacturer’s specified window. The product is typically pelletized in natural, black, or custom-matched colour batches, and it is classified as a styrenic thermoplastic elastomer, TPE-S, rather than a crosslinked TPV.

Typical application areas include soft-touch grips, gaskets, seals, cable jackets, damping elements, and protective caps. Selection of 85A 1522 for any of these categories must be confirmed by part-specific testing, because a nominal 85 Shore A hardness does not by itself guarantee seal force retention, adhesion, abrasion performance, or long-term compression-set behaviour. The material is most frequently processed by injection moulding between 180 °C and 220 °C; extruded profiles require similar melt temperatures, but die design must account for die swell and the relaxation behaviour characteristic of block copolymers.

What Separates SEBS-Comp. TPE-S 85A 1522 from Non-Hydrogenated SBS and Ester-Based TPU?

At equal nominal hardness, the performance differences arise primarily from the saturated midblock and the block-copolymer morphology. A non-hydrogenated SBS contains unsaturated butadiene units that are susceptible to ozone attack and oxidative embrittlement; under ISO 1431 ozone exposure, SBS parts typically develop surface cracks sooner than SEBS parts. The hydrogenated ethylene-butylene midblock in 85A 1522 reduces the concentration of reactive carbon-carbon double bonds and raises thermal-oxidative resistance, making the material more appropriate for continuous exposure to warm air than SBS at the same 85 Shore A hardness. However, hydrogenation also reduces segmental polarity; consequently, adhesion to polar substrates and solvent resistance are lower than those of an ester-based TPU.

Compared with an 85 Shore A ester-based TPU, 85A 1522 has a density near 0.89 g/cm³, whereas TPU typically ranges from 1.10 g/cm³ to 1.24 g/cm³. The lower density yields a higher volume per kilogram, but tensile strength and abrasion resistance are generally lower than TPU. TPU ester linkages may hydrolyze in hot humid acidic environments, whereas the saturated SEBS midblock does not undergo the same hydrolysis mechanism. SEBS is therefore more stable in water, dilute acids, and dilute bases, but it swells in aliphatic hydrocarbons, aromatic hydrocarbons, and chlorinated solvents. The absence of vulcanization in 1522 permits re-melting of sprues, runners, and post-industrial scrap, while a crosslinked TPV cannot be reprocessed without measurable property loss.

Injection moulding of Bada AG BADAFLEX® SEBS-Comp. TPE-S 85A 1522 is normally performed with a general-purpose polyolefin screw having a compression ratio between 2.2:1 and 2.8:1. Barrel zone settings of 170 °C, 190 °C, 200 °C, and 210 °C from feed throat to nozzle are common starting points, with nozzle temperature controlled at 210 °C or lower. Melt temperature measured in the shot should remain below 230 °C for short residence cycles and below 220 °C for cycles longer than 60 s. Mould temperatures between 20 °C and 40 °C are used because lower mould temperatures may produce visible flow lines and weak weld lines, while higher mould temperatures increase cycle time and can cause sticking in deep-draw tools.

Injection and pack pressures are geometry-dependent. For thin-wall sections below 1.5 mm, filling pressures up to 800 bar are used, while pack pressure is typically 50% to 70% of the filling pressure. Gate freeze must occur during packing; insufficient packing produces sink marks in sections above 3 mm and anisotropic shrinkage in ribbed areas. Production-scale failure modes include gate stringing when nozzle temperature exceeds 220 °C, gas traps at ribs when vent depth is less than 0.02 mm, and gloss shifts caused by mould surface temperature drift of more than 5 °C. Batch-to-batch differences in melt-volume rate should be evaluated under ISO 1133-1 at 230 °C and 5 kg; a 10% deviation from the supplier’s reference value can alter fill pressure and should trigger processing adjustment.

Extrusion operations use a single-screw extruder with L/D ratio between 25:1 and 30:1 and a temperature profile from 175 °C to 210 °C. Screen packs are retained because unmelted particles or degraded gels can produce surface roughness in profiles and tubing. Melt strength at the die is lower than that of a high-molecular-weight TPV; therefore, cooling trough distance, water temperature, and line speed must be set to prevent draw-down and ovality in cross-sections. Water temperatures below 20 °C are common. Strand pelletizing is not recommended above 220 °C because block copolymer viscosity can shift and pellet surfaces may fuse. On co-rotating twin-screw compounding lines with L/D 40:1, barrel sections are typically set from 180 °C to 220 °C. Residence time above 220 °C should be kept below 90 s to avoid styrene-domain disruption and MVR drift.

Although SEBS is not hygroscopic in the same manner as polyamide or PET, surface moisture from condensation in cold storage can generate splay and surface defects during melt processing. Drying at 70 °C for 2 h in a desiccant dryer with a dew point below -30 °C is recommended when storage humidity exceeds 60% RH. Extended drying above 80 °C may cause pellet agglomeration and should be avoided.

The property values shown below are typical values from supplier documentation for Bada AG BADAFLEX® SEBS-Comp. TPE-S 85A 1522; they are not lot release limits and are not to be used for design without confirmation on production samples.

Compounding variables for 1522 include the ratio of styrenic end-block to ethylene-butylene midblock, the amount of paraffinic or white-oil extender, and the presence of a polypropylene modifier. These components are selected to achieve the 85 Shore A target without excessive surface oil exudation. If the extender content is too high, surface tack increases and pellet blocking can occur in silos; if too low, the compound becomes overly stiff for soft-touch applications. The polypropylene fraction raises upper service temperature and melt strength, but excessive polypropylene increases gloss and reduces low-temperature flexibility. Raw-material lot changes at the compounding stage can shift the melt-volume rate by 10% to 15%; incoming quality control should therefore compare MVR and volatiles against a retained reference batch rather than relying solely on hardness.

Thermal limits are defined by the styrenic domains at the upper end and by the ethylene-butylene segment glass transition at the lower end. The compound loses load-bearing stiffness above 90 °C to 100 °C; it is not a high-temperature elastomer such as silicone or FKM. Low-temperature embrittlement of SEBS compounds is typically below -50 °C, but grade-specific verification under ISO 812 or ASTM D2137 is required before low-temperature assembly or service.

Without a conductive modification, 85A 1522 is non-conductive. If surface or volume resistivity is required, a conductive SEBS formulation must be specified; the standard grade should not be used for electrostatically dissipative or ESD packaging without explicit surface-resistance data generated under IEC 62631-3-2. Pigment packages, especially carbon black, can alter electrical behaviour and must be captured in the final grade specification.

When 85A 1522 Replaces a Vulcanized TPV or a Plasticized PVC

The choice between 85A 1522 and a vulcanized TPV should be based on compression set at service temperature and the type of fluid contact. TPVs containing a crosslinked EPDM phase often show lower compression set at 70 °C, 100 °C, or 125 °C than SEBS compounds, but they may require higher melt temperatures and may be less predictable in two-shot adhesion to polycarbonate or ABS. 85A 1522 can be considered for static seals and gaskets operating below 90 °C in air, water, or dilute aqueous media. Dynamic seals under mineral-oil contact or continuous temperatures above 100 °C should be directed to a TPV, ACM, or HNBR unless the SEBS formulation has been specifically validated under ISO 1817 fluid-immersion testing. The absence of crosslinks lowers pressure-set resistance at elevated temperature but permits regrind inclusion at levels that many TPV processors cannot accept.

Compared with a plasticized PVC of similar Shore A hardness, 85A 1522 does not rely on fugitive phthalate plasticizers to achieve flexibility. This reduces the tendency for embrittlement caused by plasticizer migration and fogging in closed environments evaluated under DIN 75201 or similar condensation methods. The SEBS density is lower than that of a typical flexible PVC, and low-temperature stiffening occurs at a lower temperature than that of many plasticized PVC compounds. However, plasticized PVC may offer lower raw-material cost and higher polarity for certain joining and printing operations. PVC halogen content also introduces hydrochloric acid and dioxin formation risks in uncontrolled incineration, whereas the SEBS backbone is halogen-free subject to the additive and pigment package.

In overmoulding operations on polycarbonate, ABS, and PBT substrates, adhesion depends on substrate temperature and not solely on melt temperature. Infrared surface readings of 130 °C to 160 °C are required for consistent wetting; below 120 °C, bond strength shifts to mechanical interlock and is lower. Preheating of the insert by infrared or in-mould induction is used because of the low thermal conductivity of SEBS. Mould release agents containing silicone must be excluded from the substrate surface before overmoulding; residual silicones reduce adhesion below the acceptance limit of a 90° peel fixture or an ISO 813-adapted protocol for elastomer-to-rigid adhesion. For parts with living hinges, 85A 1522 is not substituted for polypropylene or polyethylene because SEBS has lower flex-fatigue resistance under repeated bending unless the design strain is kept below the material’s elastic recovery limit.

Regulatory status is formulation-specific. A standard industrial grade of Bada AG BADAFLEX® SEBS-Comp. TPE-S 85A 1522 may be supplied with a REACH SVHC declaration and a RoHS 2011/65/EU statement, but the end-user must request the declaration for the purchased lot because pigments, processing aids, and stabilizers vary with customer colour matches. Food-contact compliance is not automatic for an SEBS compound; FDA 21 CFR 177.2600 or EU 10/2011 migration testing must be completed on the final article and the exact grade. Medical applications require separate ISO 10993 evaluation by the finished-device manufacturer. These limitations are operational boundaries, not manufacturing defects.

Final acceptance should include hardness on a machined plaque under ISO 868, density under ISO 1183-1, and melt-volume rate under ISO 1133-1 for each batch. Tensile and elongation tests under ISO 37 are recommended after 1000 h heat aging at 100 °C to detect stabilizer depletion or poor dispersion. If parts are used outdoors, xenon-arc exposure under ISO 4892-2 with defined filter type, irradiance, humidity cycle, and test duration should be completed before lot approval.