Outdoor automotive trim components moulded from FCFC TAIRILAC® ASA WG1700 are specified where unpainted surfaces must retain colour, gloss, and impact integrity after repeated UV exposure and winter thermal cycling. The compliance framework for this downstream sector includes SAE J2527 exterior xenon-arc weathering, supplementary method A of ISO 4892-2:2013 at 0.55 W/m² irradiance at 340 nm, and notched Charpy impact determined according to ISO 179-1:2023 at -30°C to simulate low-temperature embrittlement failure modes observed on commercial vehicle exterior trim. The formulation addition ratio on production lines is held at 85–95 wt% WG1700 base resin, 2–5 wt% ASA-matrix UV/light-stabiliser masterbatch, 1–4 wt% colour concentrate, and 0–15 wt% dried regrind recovered from cold-runner waste; regrind fractions above 20 wt% have been associated with a weld-line Charpy impact reduction exceeding 15% and yellowness index drift of 1.5–2.5 ΔYI after 1500 h xenon ageing. The downstream shaping process is high-pressure injection moulding on clamping units sized at 4–6 kN/cm² of projected area, using hardened mould steel with VDI 12–18 cavity polish, valve-gated hot-runner sequencing to move knit lines into non-appearance regions, and desiccant drying to a dew point below -40°C before moulding. Barrel set-points are maintained at 240–260°C, mould temperature at 60–80°C, pack pressure at 60–80 MPa for 1.5–3.0 s, and residual moisture below 0.02% to prevent silver streaking on large mirror-housing surfaces. Terminal finished product types include non-painted exterior mirror housings, radiator grille frames, A-pillar cowl covers, and rear spoiler trim for light commercial vehicles.

Why Does Capstock Layer Thickness Control Colour Retention in PVC Window Profiles Above 0.35 mm?

Window and door profile coextruders that specify WG1700 as the exterior capstock do so where the PVC substrate alone cannot meet long-term colour-fastness requirements under northern-latitude UV exposure. Finished building profiles are validated under EN 12608-1 for dimensional stability and impact behaviour, while capstock weathering is evaluated by ISO 4892-2:2013 cycle 6 with colour shift measured against the CIE Lab scale; typical acceptance criteria for traffic-white capstock are ΔE ≤1.2 after 4000 h and grey scale rating ≥4 per ISO 105-A02. The addition ratio in this downstream sector is expressed as layer thickness rather than batch formulation: the ASA capstock constitutes 8–15% of the total profile wall thickness, typically 0.25–0.45 mm over a 2.5–3.0 mm PVC substrate, and the capstock compound is run at 100 wt% WG1700 with 1–2 wt% dry colour concentrate for non-white surfaces. The production process is a single-screw vented coextrusion line with 30:1 L/D screw geometry, barrel set-points of 210–230°C, and die temperature held at 200–215°C; line operators report melt fracture on the capstock surface when the melt falls below 205°C at the die lip, corrected by raising the final die zone 5–8°C and reducing screw speed from 45 rpm to 35 rpm without changing the die gap. Calibration is performed in vacuum sizing tanks with water temperature staged from 15–20°C to control thermal contraction and prevent capstock delamination at the sharp corners of sash profiles. Terminal finished product types include window main profiles, door outer sashes, soffit boards, fascia cladding, and exterior corner trim for low-maintenance residential and light-commercial building envelopes.

Solar Junction Box Warpage Control During Ultrasonic Welding

Photovoltaic system enclosures impose a competing requirement: the WG1700 housing must be thin enough to dissipate heat from bypass diodes yet rigid enough to maintain dimensional sealing after ultrasonic welding of the lid. The compliance references for a WG1700 junction box include IEC 62790 for PV junction enclosures, IEC 60529 with an IP65 ingress-protection rating after thermal cycling, and UL 746C f1 recognition for ultraviolet water exposure; end-product glow-wire testing to IEC 60695-2-11 at 650°C is sometimes required by inverter assemblers even though WG1700 is not marketed as a flame-retardant compound, and published data for flame-retardant compounded WG1700 is limited. The formulation addition ratio for unfilled outdoor junction enclosures is 100 wt% WG1700 with 0–10 wt% closed-loop regrind, and no reinforcing filler because glass fibre increases post-weld warpage anisotropy and reduces gate-area dimensional repeatability. The downstream production process uses an electric injection moulding machine with 120–160 t clamp force for a four-cavity tool, melt temperature 240–255°C, mould temperature 65–75°C, and a low-compression screw with 20:1 L/D to minimise shear heating. Holding pressure is profiled at 55–70 MPa for 6–10 s, followed by mould-cooling water at 40°C until part ejection below 75°C, which reduces corner lift that otherwise produces fail-open gaps in IP-rated enclosures. Ultrasonic welding of the cover is performed at 20 kHz with 0.9–1.4 s weld time, 200–350 N trigger force, and horn amplitude limited to 28–35 µm peak-to-peak; horn amplitude above 40 µm has produced microcracks adjacent to the energy director during field trials. Terminal finished product types include solar combiner boxes, PV junction enclosures, microinverter lids, and outdoor DC disconnect housings.

Telecom and outdoor power distribution housings impose different processing constraints than solar junction boxes because deep-draw rectangular enclosures with integrated cable knockouts create multiple knit lines at core-pin junctions and gate weld points. The applicable standards are IEC 62208 for empty enclosures, EN 62262 IK08 impact resistance for vandal-prone installations, and UL 746C f1 for outdoor UV and water exposure. The formulation addition ratio is maintained at 88–95 wt% WG1700, 3–6 wt% ASA-compatible UV stabiliser masterbatch, 1–3 wt% carbon-black concentrate, and 5–12 wt% internally recovered regrind; regrind loading above 15 wt% has been shown to depress notched Izod impact at -20°C below 4 kJ/m² when measured on gate-adjacent specimens, so it is prohibited for enclosures with side-wall knockouts. The downstream manufacturing process is injection moulding on a 350–450 t clamping unit with sequential valve gating, using valve delay timings of 0.3–0.8 s to shift the knit line away from the cable-entry membrane. Barrel temperature is set at 230–255°C and mould temperature at 50–70°C; chemical-etch grain depth of 25–40 µm is used on external faces, requiring vent gaps of 0.02 mm along the parting line to eliminate gas-burn marks at the end of fill. Batch-to-batch variation in melt flow rate above ±10% requires switchover-point adjustment because packing response changes by 3–5% in thin-wall boss sections. Terminal finished product types include 5G small-cell enclosure shells, outdoor power distribution boxes, telecom cable splice housings, and smart-meter outer covers for subtropical and coastal installations.

When Air-Conditioner Outdoor Unit Grilles Are Moulded with Sequential Valve Gating

In split air-conditioner production, outdoor unit discharge grilles and front panels moulded from WG1700 are evaluated under IEC 60335-2-40 for electrical safety of the finished appliance and ISO 4892-2:2013 for long-term weatherability; OEM specifications commonly require colour shift ΔE ≤2.0 after 2000 h xenon exposure and retained tensile elongation at break ≥50% per ISO 527-2:2012 type 1A specimens. The formulation addition ratio for large grilles is 80–90 wt% base resin, 2–4 wt% UV masterbatch, 1–3 wt% grey pigment concentrate, and 5–15 wt% regrind that has passed a 0.02% moisture-content check after drying. The production process uses a 650–850 t hydraulic injection moulding machine with sequential valve-gated hot runners to fill the 900–1100 mm long flow path without creating surface flow lines behind the louvre ribs. Melt temperature is controlled at 235–255°C, mould temperature at 55–75°C, and injection speed is profiled from 40 mm/s at the gate to 120 mm/s across the central louvre field to prevent hesitation marks on textured surfaces. A production bottleneck exists at the flow-front meeting zone around V-shaped discharge louvers: if packing pressure is not maintained at 50–65 MPa for at least 8 s, sink marks deeper than 0.02 mm form on the outward-facing cosmetic surface and lead to visual rejection under assembly-line lighting. Moulders also document that resin lot-to-lot variation in yellow index above 0.8 ΔYI shifts final part colour outside the OEM grey-scale tolerance band without re-matching the pigment concentrate ratio. Terminal finished product types include outdoor unit front panels, discharge grilles, side intake louvres, and condensate drain covers for residential and light-commercial air-conditioning systems.

High-Gloss Garden Equipment Housings Without Post-Mould Painting

For ride-on mower and garden equipment housings, WG1700 is selected where high-gloss unpainted surfaces must resist direct sunlight, fuel splash, and mechanical abrasion from grass debris while avoiding secondary painting operations that add volatile organic compound emissions. The relevant compliance indicators include ISO 4892-2:2013 weatherability testing, flexural modulus retention measured per ISO 178:2019, and surface gloss quantified at 60° geometry according to ISO 2813; production-validated panels typically retain 85–92 GU after 1000 h xenon ageing when the moulding process is configured for gloss and the regrind fraction is restricted. The formulation addition ratio is 2–5 wt% UV stabiliser masterbatch, 0.5–2 wt% internal mould-release additive, 3–7 wt% custom colour concentrate, and 5–10 wt% regrind; regrind loading above 10 wt% has produced visible gloss reduction on large flat hood surfaces because minor chain scission alters melt-surface replication against the polished cavity. The downstream production process is rapid heat cycle moulding on electric injection machines with variothermal mould inserts heated to 100–120°C during the fill phase and cooled to 60°C before ejection, which eliminates flow marks without the use of solvent-based primer or post-mould clearcoat. Polished cavity surfaces are specified at VDI 8–12, with melt temperature set at 240–255°C and fill speed kept below 80 mm/s in the first 20 mm of flow to avoid jetting from sub-gates into the visible hood surface. Field failure data from commercial mower assembly lines indicate that cracking at trapped-moisture voids occurs when material is processed without re-drying after storage at ambient relative humidity above 60% for more than 48 h. Terminal finished product types include garden tractor hoods, string-trimmer motor housings, pool-pump lids, spa cabinet panels, and walk-behind mower engine shrouds.