When API Megol AM SEBS-Comp. SV/P is evaluated for two-shot injection moulding over a 20% talc-filled polypropylene core, the processing window is set by the melt tack of the oil-extended styrenic block copolymer and the cooling behaviour of the hard segment. Grade-specific Shore hardness and melt-volume rate data should be taken from the supplier’s current technical datasheet; the parameters below are representative for oil-extended SEBS/PP compounds of this hardness band. Rear-zone barrel temperatures are normally maintained at 190–230 °C, with the nozzle held at 210–230 °C. The first-shot PP core is cooled to a mould temperature of 20–45 °C. Pre-drying is fixed at 75–80 °C for 2 h in a closed-loop desiccant dryer, and the drying time is extended to 4 h when ambient relative humidity exceeds 60 %. The overmould layer commonly represents 28–38 % of total part mass, with wall stock between 0.8 mm and 2.5 mm. Direct tab gates of 1.0–1.5 mm diameter are used rather than pin gates because high shear at the gate can cause melt fracture at the surface. Packing pressure of 30–50 MPa for 0.5–1.2 s after fill reduces interfacial sink and delamination on the PP boundary. On a 150-ton multi-shot press, cycle time is dominated by cooling of the TPE soft segment; a 3 mm-thick overmould layer reaches ejection temperature in 18–24 s. Handheld power tools, manual pruners, razor handles, and children’s toothbrush grips are typical terminal parts. Adhesion to untreated HDPE is weaker than to PP unless the substrate is flame-treated to a minimum wetting tension of 38 mN/m measured according to DIN 53364. Regulatory documentation for these consumer articles normally requires compliance screening under REACH Annex XVII, RoHS 2011/65/EU clause 4 substance restrictions, and EN 71-3 element migration limits where the part is marketed for children under three years.

What Limits Post-Sterilization Compression Set in Peristaltic Pump Tubing?

Extrusion of peristaltic pump tube from this SEBS compound is performed on a vacuum-vented single-screw extruder with an L/D ratio of 24:1 and a compression ratio of 2.5:1. Barrel temperature is ramped from 165 °C in the feed zone to 200–220 °C at the head. Tubing dimensions for infusion and dialysis pump segments are typically inner diameter 1.6–3.2 mm and wall thickness 0.8–1.2 mm, with a wall-to-ID ratio below 0.5 to maintain dynamic occlusivity. After extrusion, the tubing is annealed at 60 °C for 4 h to relax orientation and reduce residual bowing before cutting. Compression set measured under ISO 815-1:2019 at 70 °C for 22 h is normally below 35 % for an SEBS/PP-type compound in this hardness class. The material is used in peristaltic pump segments for enteral feeding, water-borne dialysis circuits, and portable infusion pumps, where occlusion is calibrated to 15–20 % of tube height and pump head speed is between 20 rpm and 80 rpm. Sterilization tolerance remains the limiting operational boundary. Gamma irradiation at 25–50 kGy generally causes a measurable yellowing shift and slight hardening due to secondary crosslinking in the PP hard phase. Autoclave exposure at 121 °C is not recommended beyond a limited number of supported cycles because continuous service temperatures above 100 °C can cause gross dimensional distortion. Ethylene oxide sterilization at 55 °C with a 6:1 gas dilution is commonly selected for sealed tube sets. Biocompatibility documentation must include ISO 10993-5 cytotoxicity with a result of grade 0 or 1, ISO 10993-10 sensitization and irritation evaluation, and USP <88> Class VI systemic toxicity and implantation data where indirect blood contact is possible. Amine-containing mould-release agents and lubricants must be avoided because residual surface amines can migrate into pump fluid paths and interfere with endotoxin tests.

When Charge-Cable Jackets Must Meet EN 50620 Low-Smoke Performance

Halogen-free flame-retardant SEBS compounds of this type are specified for AC and DC electric vehicle charging cable jackets only when the base compound is modified with a hydrated mineral FR package. Magnesium hydroxide content in the range of 40–65 wt % and an ATH co-agent at 5–15 wt % are typical for low-smoke, zero-halogen cable formulations. The filled compound is extrusion-jacketed onto stranded copper at barrel temperatures from 170 °C to 210 °C; exceeding 210 °C will decompose the hydrate fillers and create microvoids that reduce elongation at break under IEC 60811-501. Extrusion is run on a 45–90 mm single-screw line with an L/D ratio of 24:1 to 30:1 and a compression ratio of 2.0:1 to 2.5:1. A breaker plate with screen pack is used to stabilise head pressure, but the back pressure should not exceed 35 MPa at the adapter. Jacket wall thickness for EV charging cable is typically 1.0–1.8 mm, with a cable outer diameter between 8 mm and 20 mm. Pre-drying at 70 °C for 4 h is essential because the hydrate filler is hygroscopic. Compliance testing must cover flame spread under IEC 60332-1-2, halogen acid gas under IEC 60754-1 with HCl equivalent below 0.5 %, smoke density under IEC 61034-2 with light transmittance not less than 60 %, and pH and conductivity under IEC 60754-2 with pH not below 4.3 and conductivity not above 10 µS/mm. Terminal parts include EVSE charge cables, energy storage system harnesses, and industrial robot dress packs. Sulfur- or amine-based heat stabilizers must not be combined with the halogen-free FR package because these additives can accelerate thermo-oxidative decomposition of the SEBS mid-block during high-temperature jacketing.

Sheet and profile extrusion for thin-walled food-storage lids and reusable drinking-spout seals uses a barrier screw with an L/D ratio of 28:1 and a static melt mixer at the adapter. Barrel temperatures are set between 180 °C and 220 °C, with die temperature held at 205 °C to avoid melt fracture at draw-down ratios above 1.5:1. Edge trim and start-up sheet are reintroduced as regrind at a maximum addition level of 20 wt %; at higher addition levels the Shore A hardness can increase by 2–4 points after repeated heat history. End products are limited to repeated-use kitchen storage closures, freezer-safe bowls, and cold beverage spouts. The compound must be certified under EU 10/2011 with overall migration below 10 mg/dm² for food contact, and for the US market under 21 CFR 177.1810 for styrenic block copolymers. Migration testing follows EN 1186-1 and EN 13130-1 using simulants A, C, and D2. This application band is not suitable for oven or microwave reheating above 100 °C.

Interior Skin Lamination and 60° Grazing Angle Low-Gloss Trims

Cast sheet made from this SEBS compound is laminated to a foamed polypropylene or ABS support for door panel armrests, console bin lids, and sun visor cover skins. The sheet is extruded at 190–215 °C through a coat-hanger die to a thickness of 0.5–1.2 mm, then embossed with a grain depth of 20–40 µm to reduce gloss and obscure flow lines. Low-gloss readings at a 60° grazing angle are specified below 2.0 according to ASTM D523-14 for matte interior surfaces. The compound bonds to the PP foam layer under heat lamination at 140–160 °C and 0.2–0.4 MPa pressure for 20–40 s. The ratio of decorative skin to foam core is typically 1:3 to 1:5 in thickness, which keeps panel weight below all-PVC constructions. Flammability testing under ISO 3795 or FMVSS 302 is required for passenger vehicles, with a horizontal burn rate below 100 mm/min in most OEM standards. Fogging according to VDA 275 is generally specified at condensate below 5 mg, and odour per VDA 270 should be grade 3.0 or lower. Soft-touch skins used in sun visors must also survive ageing at 90 °C for 500 h without surface tack or colour shift greater than 2 Delta E units. The main processing defect in sheet lamination is pre-stretch of the SEBS skin during feed into the lamination nip; edge clamping and low-friction rollers are used to keep pre-stretch below 3 % because greater deformation produces gloss variation across the grain pattern.

Pneumatic sealing elements in automated cleanroom handling equipment are machined from extruded preforms rather than direct-moulded to avoid gate vestige contamination on the sealing lip. The compound is first extruded into round bar stock of 12–25 mm diameter, then water-bath cooled. The bars are cut into blanks and compression moulded at 190–210 °C under 10–15 MPa for 4–6 min. Vacuum cups manufactured from this material operate at −0.08 MPa and resist mushroom deformation when the cup lip thickness is maintained at 0.6–0.8 mm. Compression set resistance at 23 °C is normally below 20 %; at 70 °C the value moves above 35 %, so elevated-temperature pneumatic duty is not recommended. The material utilisation in this compression-moulding route is 70–80 % because of flash loss at the parting line. End products are suction cups for wafer handling wands, sealing bellows in laminar-flow isolators, and docking buffers on AGV charging stations. Continuous exposure to methyl ethyl ketone, toluene, or other strong aromatic and ketone solvents must be avoided because they attack the oil-extended SEBS matrix; this application band is restricted to air, water, and diluted alcohol cleaning media. Cleanroom compatibility documentation is usually limited to particle emission and surface cleanability rather than full outgassing certification because published data for this specific configuration is limited.