Twin-screw injection moulding machines with clamp forces between 1,800 kN and 2,600 kN are regularly used to convert KUMHO® ASA ASAG5115 into exterior mirror housing shells, A-pillar garnish covers, and cowl grille sections. The pellets are pre-dried in desiccant dryers at 80 °C for 3 h to 4 h or until residual moisture is ≤0.05 wt% measured by ISO 15512:2019. The direct formulation for this exterior trim segment is 100 parts by weight KUMHO® ASA ASAG5115 as the thermoplastic matrix, 1–2 parts by weight color masterbatch, and 0.1–0.3 parts by weight internal lubricant; the pre-stabilized ASA grade does not require additional hindered amine light stabilizer for most black or dark grey systems. Melt temperature at the injection nozzle is held between 245 °C and 260 °C, mould surface temperature is kept at 70–90 °C, and hydraulic hold pressure is set between 60 MPa and 90 MPa depending on runner length and gate freeze time. Production-scale failure modes concentrate at the mirror fold boss weld line, where melt fronts rejoin after flowing around the mounting hole; insufficient packing pressure at this location creates subsurface knit-line porosity that reduces notched Izod impact energy under ISO 180:2023/1A by more than 20 % relative to the as-moulded flow-path region. To minimize the effect, processors use sequential valve gating or raise melt temperature to 255 °C, provided barrel residence time remains below 4 min to avoid surface yellowing and gloss shift at 60° specular gloss per ISO 2813. Compliance for this segment is assessed by SAE J2527 or ISO 4892-2:2013 Method A, typically at 0.51–0.55 W/m² irradiance at 340 nm and black panel temperature 65±3 °C; automotive exterior specifications often require ΔE ≤2.0 after 1,000 h and no visible cracking after 1,500 h. Final product types include outside mirror shells, cowl vent grilles, B-pillar appliqués, tailgate handle covers, and roof rail closures.

Why Do Coextruders Cap PVC Window Lineals With 0.3 mm–0.8 mm ASA Layer?

KUMHO® ASA ASAG5115 is used as a coextruded capstock over rigid PVC window lineals, door sashes, mullions, and fascia panels where the substrate provides sectional stiffness and the ASA cap provides gloss retention and color stability. The addition ratio in the capstock is 100 parts by weight KUMHO® ASA ASAG5115, 2–4 parts high-dispersion inorganic pigment concentrate, 1–2 parts acrylic processing aid, and 0.5–1.5 parts oxidized polyethylene or paraffin lubricant. In profile production, the capstock layer is maintained between 0.3 mm and 0.8 mm, which corresponds to approximately 8–15 wt% of total lineal weight for a 60 mm class window frame. The downstream process uses a main 54 mm or 65 mm counter-rotating conical twin-screw extruder for rigid PVC and a 35 mm single-screw coextruder with a 30:1 L/D barrier screw for the ASA cap. ASA melt temperature is kept between 220 °C and 240 °C at the die lips, while the PVC melt enters the die at 185–195 °C. The temperature mismatch creates a viscosity differential that is managed by limiting the cap layer thickness and by maintaining the capstock pressure drop across the coextrusion die land below 8 MPa. A process conflict appears when the ASA melt is raised above 245 °C to reduce viscosity: residence times above 5 min accelerate localized PVC degradation at the die joint, producing hydrogen chloride gas that corrodes chromed die lips and generates plate-out on the profile surface. Therefore, operators avoid prolonged residence and purge the ASA extruder with acrylic-based purge compound after shutdown. Ketone-based or chlorinated solvent purge compounds are not used on ASA hot melt lines because they attack the styrene-acrylonitrile phase. Compliance governing this application includes DIN EN 513:1999 for artificial weathering of PVC-U window profiles and ISO 4892-2:2013 for accelerated weathering, with grey-scale change assessed under ISO 105-A02. Dark brown, black, and mid-green capstock specifications generally require ΔE ≤3.0 after 2,000 h xenon arc exposure with no cracking or capstock delamination. End products are coextruded window lineals, door jambs, fence profiles, and exterior fascia trim.

Profile class	Capstock thickness	Capstock weight fraction	Weathering acceptance
Window sash and main lineal	0.4–0.8 mm	10–15 wt%	DIN EN 513:1999, 2,000 h, ΔE ≤3.0
Door frame and mullion	0.3–0.6 mm	8–12 wt%	ISO 4892-2:2013, 1,500 h, no cracking
Fence profile and fascia trim	0.25–0.5 mm	5–10 wt%	ISO 4892-2:2013, 1,000 h, ΔE ≤3.5

For outdoor HVAC control boxes and irrigation controllers, KUMHO® ASA ASAG5115 is moulded at 100 parts by weight with 1–2 parts UV-stabilized black masterbatch and up to 20 wt% regrind; injection processing on 800–1,600 kN presses at 240–255 °C melt and 50–70 °C mould temperature is standard for 2.5–4.0 mm wall sections. Compliance is verified under UL 94 HB at 3.0 mm thickness per IEC 60695-11-10:2013, with enclosure cycling from −40 °C to +85 °C within assembly-level NEMA 250 type 3R testing where specified; this grade is not suitable for live-contact insulation or UL 94 V-0 internal parts. Finished parts include outdoor HVAC control enclosures, pump control boxes, and irrigation controller covers.

Garden Power Equipment Housing Weatherability After 1,500 h Xenon Arc Exposure

Qualification of lawn tractor hoods, ride-on mower side panels, portable generator covers, and snow thrower chutes moulded from KUMHO® ASA ASAG5115 is usually driven by xenon arc exposure under ISO 4892-2:2013 cycle 1 at 0.51 W/m², 340 nm, and black panel temperature 65±3 °C. The formulation is 100 parts by weight KUMHO® ASA ASAG5115, 2–4 parts by weight carbon black masterbatch for solar opacity, and 0.2–0.5 parts by weight processing aid. Addition of carbon black above 4 parts by weight creates a measurable cliff edge in mechanical performance: the low-temperature notched impact value under ISO 180:2023/1A at −20 °C falls below the design margin, and the melt viscosity at 260 °C increases by more than 8 % relative to natural resin. The specific retained impact value depends on the masterbatch carrier resin and processing history; published data for this exact formulation are limited. Consequently, dark grey and black garden equipment parts are moulded with concentrates designed specifically for ASA rather than general polyolefin masterbatches, because the latter may introduce incompatible carrier resins. Injection processing uses melt temperature 245–260 °C, mould temperature 50–80 °C, and a medium-to-fast injection profile; slow filling across large flat hood surfaces causes flow hesitation lines that become more visible after 500 h of outdoor exposure. Weathering acceptance for this segment commonly requires ΔE ≤2.5 after 1,500 h, gloss retention above 50 % at 60° under ISO 2813, and no surface cracking. Final product types include lawn tractor hoods, mower fender decks, portable generator covers, snow thrower discharge chutes, and garden shredder covers.

When ASAG5115 Replaces Painted ABS in RV Exterior Trim and Hatch Frames

When painted ABS is replaced by KUMHO® ASA ASAG5115 in RV refrigerator vent bases, furnace access doors, and baggage hatch frames, the formulation is 100 parts by weight neat ASA plus 1–2 parts black or grey color masterbatch; no paint layer is applied, eliminating coating adhesion loss after thermal cycling. Injection moulding is performed on 1,000–2,000 kN vertical or horizontal presses with melt temperature between 230 °C and 250 °C and mould temperature 60–80 °C. Grained surfaces in the range VDI 3400 27–33 are used to reduce visible scratch damage and to hide minor flow lines on large flat areas. The primary process bottleneck occurs at deep drawn bosses for gas strut mounts and latch cams; processors increase wall thickness from 3.0 mm to 4.5 mm or use gas-assist to prevent sink marks and short shots without increasing cycle time beyond 35 s. Compliance for exterior exposure uses SAE J2527 at 0.51 W/m², 340 nm, with 1,000 h exposure and no visible cracking after 500 h of thermal cycling from −30 °C to +80 °C. ASA generally delivers lower high-gloss surface quality than painted ABS; this limitation is accepted in grained RV trim. Finished products include RV hatch frames, refrigerator vent bases, access door liners, and drip rail covers.On single-screw sheet extrusion lines with 35:1 L/D barrier screws, KUMHO® ASA ASAG5115 is converted at 0.8–6.0 mm gauge for subsequent thermoforming into agricultural cab roof shells, light vehicle roof pods, golf cart dash panels, and marine bridge console covers. The sheet formulation is 100 parts by weight KUMHO® ASA ASAG5115, 2–3 parts by weight color masterbatch, and 0.3–0.8 parts by weight external lubricant. Melt temperature at the flat die is controlled between 230 °C and 250 °C, and roll stack temperatures are set from 75 °C to 95 °C to prevent surface hazing and die lines. Thermoforming is performed at sheet surface temperatures of 150–180 °C using plug-assisted vacuum or pressure forming. Above 180 °C, sheet sag reduces wall-thickness uniformity in deep-draw areas below 25 % of nominal thickness, so infrared pyrometers and zoned quartz heaters are used to hold surface temperature within ±5 °C. Compliance is assessed by ISO 4892-2:2013 for 1,000–2,000 h exterior weathering and by ISO 6603-2 multi-axial puncture impact on formed parts. Published multiaxial impact data for ASAG5115 at the 2.0 mm and 4.0 mm formed gauge in this specific application are limited; production lot validation therefore includes direct puncture testing on formed reference specimens. Final parts include agricultural cab roof shells, golf cart dash panels, light vehicle roof pods, and marine bridge console covers.