Bada AG BADAFLEX® SEBS-Comp. TPE-S 60A 5002LD FR H UV is a styrenic block-copolymer thermoplastic elastomer compound classified as TPE-S, based on a SEBS matrix, with a nominal hardness of 60 Shore A, a halogen-free flame-retardant package, and ultraviolet stabilization for light-exposed flexible components. The 5002LD FR H UV suffix is an internal Bada AG grade identifier and should be read against the manufacturer’s technical data sheet rather than inferred from generic TPE-S nomenclature. The material is supplied as fully compounded pellets and does not require vulcanization or dynamic crosslinking before final part production. This characteristic separates it from thermoset EPDM and from dynamically vulcanized TPV grades, although the flame-retardant additives used in halogen-free SEBS compounds can raise melt viscosity, density, and processing torque relative to non-filled SEBS. Because the exact additive composition of 5002LD FR H UV is proprietary, design validation should be performed against the manufacturer’s lot certificate. Published data for this specific configuration is limited beyond the Bada AG certificate; mechanical and flame-retardant performance should therefore be verified on production-scale test specimens rather than by analogy with non-FR 60A TPE-S data.

On a production compounding line, moisture control is the first processing boundary. For mineral-hydroxide flame-retardant systems, pre-drying is recommended at 70–80 °C for 2–4 h in a desiccant dryer when pellets have been stored at relative humidity above 60%. Residual moisture above 0.03% by weight can produce surging, surface porosity, and reduced tensile elongation. On a 40:1 L/D co-rotating twin-screw extruder, a barrel profile of 160–210 °C is class-typical for SEBS-based halogen-free FR compounds, but melt temperature may exceed the setpoint by 8–12 °C at screw speeds above 300 min⁻¹ because of filler-induced shear heating. In injection moulding, a medium-shear screw with a compression ratio of 2:1 to 2.5:1 and a non-return valve clearance of 0.03–0.05 mm is commonly used to reduce dead spots. Prolonged residence time above 220 °C can shift natural colour and reduce flame-retardant consistency, particularly in hot-runner systems with inadequate thermal uniformity.

What Distinguishes the Halogen-Free Flame-Retardant Package from Non-FR SEBS Grades?

In standard SEBS compounds, hardness is controlled primarily by the ratio of polystyrene end-blocks to the oil-extended ethylene-butylene mid-block. In halogen-free FR SEBS, the flame-retardant package is typically built around mineral hydroxide fillers such as magnesium dihydrate or aluminium trihydrate, often combined with phosphorus–nitrogen synergists. The loading required to achieve UL 94 V-0 at 3.0 mm in a flexible 60A matrix generally raises compound density into the 1.05–1.20 g cm⁻³ range, compared with approximately 0.89–0.93 g cm⁻³ for unfilled SEBS. This density shift changes part weight and cost per cubic metre. Mechanical properties also shift: tensile strength may remain in the 5–9 MPa range, while ultimate elongation often falls from above 600% in unfilled 60A SEBS to 350–550% in the FR-modified compound. The UV package adds light stabilizers and, in coloured grades, selected pigments to slow surface chalking and property loss. The interaction between mineral FR particles and UV stabilizers can produce a matte surface and slightly higher yellowness index in natural grades; therefore outdoor colour retention should be validated by ISO 4892-2 rather than inferred from the UV designation alone.

Mechanical Property, Density, and Ignition-Resistance Boundary Values

The following matrix lists class-typical values for a halogen-free flame-retardant 60 Shore A TPE-S. These are not lot-specific acceptance criteria for 5002LD FR H UV and must not be used for final part certification without the Bada AG certificate and production trial data.

Compression set at elevated temperature is a critical boundary for sealing applications. At 70 °C, halogen-free FR SEBS grades often show higher set than unfilled SEBS or TPV, which can lead to seal leakage after thermal cycling if the part is designed only for room-temperature recovery. Final validation should include compression-set measurement at the upper service temperature and, where applicable, a thermal cycling sequence based on the actual mating-component thermal expansion.

The Processing Window Narrows at the Interface of Flame Retardancy and 60 Shore A Softness

The transition from low-hardness SEBS to an FR-modified 60A compound narrows the operating envelope because the flame-retardant filler raises melt viscosity while the oil-loaded soft phase reduces melt strength. Nozzle melt temperatures above 220 °C or cumulative residence times beyond 10 min can cause stabilizer decomposition, colour drift, and inconsistent flame-retardant performance. Injection velocities should be adjusted to avoid shear rates above 20 000 s⁻¹ in thin gates, because high shear heating can locally exceed the stabilizer package limit. Mould temperatures of 30–50 °C are typical for this class; higher temperatures may improve knit-line appearance but extend cycle time and increase platelet-out on vent faces. Venting depth should be limited to 0.01–0.02 mm to allow moisture and volatile escape without creating flash. If a hot runner is used, thermal uniformity better than ±5 °C across nozzles is recommended because cold zones can create partially filled parts and flame-retardant inhomogeneity.

Components typically specified under this material class include cable bushings used in outdoor power equipment, connector strain reliefs in charging cables, grommets for enclosures requiring flame retardancy, and flexible boot seals exposed to natural sunlight. The combination of 60 Shore A hardness and a halogen-free FR package is especially relevant where assembly requires push-fit flexibility but the end-use environment imposes glow-wire or needle-flame requirements. In cable jacketing, extrusion of this TPE-S may replace flexible PVC when the application specifies reduced acid-gas generation or reduced smoke density. The material should be validated for stress-cracking resistance in contact with polycarbonate or ABS enclosures because oil-loaded SEBS compounds can exhibit low-molecular-weight migration; published data for this specific 5002LD FR H UV configuration is limited, so a chemical compatibility test according to ISO 22088-3 or a manufacturer-specified bent-strip method is required for load-bearing snap-fit assemblies.

When Replacement of Flexible PVC Is Evaluated Against Smoke Acidity and UV Cracking

Flexible PVC jacket compounds often contain phthalate plasticizers and a chlorinated polymer backbone; under fire, PVC can release hydrogen chloride and dense visible smoke. Halogen-free FR TPE-S compounds are designed to reduce corrosive gas release, but smoke density is not automatically low. Specific IEC 61034 smoke-density and IEC 60754-2 acidity tests are required before substituting PVC in enclosed or transit applications. In comparison with a TPV of similar hardness, the 60A SEBS-based TPE-S typically shows lower compression-set resistance but easier colour matching, lower processing torque, and regrind reprocessability without a crosslinked rubber domain. Compared with polyester or polyether TPU, the SEBS compound generally has lower tensile strength and abrasion resistance but lower density and greater softness at the same Shore A hardness. Compared with non-FR SEBS of equivalent hardness, the flame-retardant grade is denser and usually has reduced elongation. The material choice is therefore driven by the combination of UL 94 V-0, outdoor UV resistance, and the need for a non-vulcanized thermoplastic feedstock.

Material compliance in this product class is commonly assessed under RoHS Directive 2011/65/EU for restricted substances and REACH Regulation (EC) No 1907/2006 candidate-list SVHC obligations. If halogen restrictions apply to the final cable assembly, the halogen-free designation should be verified by IEC 60754-1 or EN 50642 rather than assumed from the grade label. Comparative tracking index and hot-wire ignition performance may be assessed by IEC 60112 and IEC 60695-2-12 for insulating parts. Avoid unapproved peroxide or reactive co-agent additions because residual radicals can consume the UV stabilizer and shift the flame-retardant result. Operational limits include avoidance of continuous immersion in strongly polar solvents or esters unless validated by ISO 1817; for 60A SEBS compounds, maximum continuous service temperature is often below 90 °C in air, but final part qualification must account for mechanical load, UV dose, and FR additive ageing.