Unpainted black automotive mirror housings moulded from LG Chem ASA LI913H are released on exterior trim platforms where secondary painting is deleted and long-term colour retention is assessed under Xenon-arc weathering to SAE J2527. The production blend typically contains 2.0 wt% to 3.0 wt% of a SAN-carrier carbon-black masterbatch, selected to bring final carbon-black loading above 0.2 wt% for UV opacity while limiting masterbatch concentration below 4.0 wt% to prevent gate blush and loss of melt elasticity. Resin is pre-dried in a desiccant dryer at 80 °C for 3–4 h until residual moisture is below 0.02 wt% by Karl Fischer check, because moisture above that level generates silver streaking and weakens weld lines in long-flow mirror shells. On a 22:1 L/D injection screw with a compression ratio of 2.2:1, the barrel profile is set from 220 °C at the feed section to 245 °C at the nozzle, with hot-runner manifold temperatures held at 235–250 °C. The melt temperature ceiling is normally 250 °C; excursions above 260 °C during prolonged hot-runner holds release degradation volatiles that produce surface splay at the valve-gate drop. Mould temperature is controlled at 40–60 °C with independently circulated water circuits to balance gloss on visible A-surfaces and minimize post-mould shrinkage differences. Injection velocity is profiled to fill the mirror shell through a sequential valve-gate pattern, and cavity pressure at gate freeze is held at 350–500 bar, with pack pressure stepped from approximately 60 % of peak injection pressure to 30–40 % over 1.5–2.5 s to control sink on bosses and rib intersections. Vent lands are cut to 0.015–0.025 mm at the parting line, and land length is kept under 1.0 mm because the high-flow grade flashes easily at the end of pack. Notched Charpy impact acceptance is often specified to ISO 179-1/1eA at both 23 °C and −30 °C, but published data for LI913H at the exact geometry of a mirror housing is limited; tool-specific validation coupons are therefore extracted from first-article mouldings. End products in this segment include exterior mirror housings, A-pillar finishers, cowl-vent grilles and antenna covers.

Why Outdoor Enclosure Moulders Lower Packing Pressure With LI913H

For outdoor junction-box and telecom-splice-closure moulders, post-mould geometry control defines the process window more than filling capacity, because thick walls from 2.5 mm to 4.0 mm retain heat and develop frozen-in strain when packing pressure is too aggressive. Regrind is limited to 25 wt% on production lines; above this level the melt viscosity shift becomes measurable by ISO 1133-1 and flash begins at the same clamp force that had previously sealed the tool. The grade is processed without additional impact modifier for general outdoor enclosures, and the dominant formulation variable is pigmentation: black or dark grey masterbatch is added at 2.0–3.0 wt%, while high-colour pastel grades require a UV-stabiliser masterbatch added at 1.0–1.5 wt%. Drying follows the same 80 °C desiccant profile to 0.02 wt% residual moisture, but the holding time may exceed 4 h in high-humidity coastal plants. Melt temperature is maintained at 230–245 °C, mould temperature at 45–60 °C, and pack pressure is deliberately reduced to 25–35 % of peak injection pressure for wall thicknesses above 3.0 mm; this lowers corner warpage at the expense of longer gate-seal time. Sequential valve gating is used on large access-box covers, while smaller junction boxes are filled through a single edge gate with a land length of 1.0–1.5 mm. Textured side walls require draft angles of 1.0–1.5 °, and ribs are dimensioned at 0.6 mm per 1.0 mm of nominal wall to avoid sink on the sealing face. When a UL 746C f1 weather-resistance listing is called out, the moulder must verify that the exact pigment concentration and minimum wall thickness match the UL file; black and dark grey are usually covered, but unpainted pastel grades are not automatically listed. UL 94 classification for unfilled ASA is typically UL 94 HB; if the enclosure calls for UL 94 V-0, LI913H alone is technically unsuitable because the grade does not contain a flame-retardant package. Empty enclosures are evaluated to IEC 62208 for mechanical performance, and IP65 gasket grooves are moulded with a flatness tolerance of ±0.1 mm over the sealing perimeter. End products include outdoor telecom access boxes, garden lighting driver housings, meter enclosures and solar combiner boxes.

In bright-colour garden furniture manufacturing, LG Chem ASA LI913H is specified over ABS for chair shells and table tops because the butadiene rubber phase in standard ABS embrittles under outdoor photo-oxidation, while the saturated acrylic ester elastomer in ASA retains a longer weathering window. Colour concentrates are added at 2.0–4.0 wt%, and the carrier must be ASA or SAN; polyethylene-based masterbatch above 0.1 wt% wax content reduces pigment dispersion and creates visible weld-line separation in armrest bosses. Pastel and light-grey grades receive an additional UV-absorber/HALS stabiliser masterbatch at 1.0–1.5 wt%, because translucent pastel wall sections permit deeper UV penetration than carbon-black-loaded parts. Pre-drying is run at 80 °C for 3–4 h, but air flow must be continuous because large chair shells consume resin slowly and hopper residence time can exceed 20 min. Melt temperature is set at 230–245 °C, and mould temperature is held at 40–60 °C to stabilise gloss across large visible surfaces. For deep-draw seat shells with wall thickness from 2.5 mm to 6.0 mm, injection-compression moulding with a compression stroke of 2–5 mm is preferred because it reduces residual orientation in the seat base and prevents sink above the leg attachment bosses. Weld lines at gate intersections are evaluated on production samples by notched Charpy impact to ISO 179-1/1eA, because impact failure in garden chairs usually initiates at the weld line behind the front leg mount. Exterior weathering acceptance for coloured parts is commonly assessed by ISO 4892-2 Xenon-arc exposure for 1500 h, with colour change limited to ΔE ≤3.0 and no cracking on a 10× visual inspection. End-use components include stackable chair shells, tabletop segments, contoured armrests and large planters.

Window and Roof Gable Vent Bases: Low-Temperature Notched Impact and Mould Shrinkage

When roof gable vent bases are specified for hail-prone regions, low-temperature ductility controls the regrind ceiling in LG Chem ASA LI913H. Wall sections in vent bases are usually 3.0–4.0 mm, with interconnecting ribs sized at 0.5–0.7 mm per 1.0 mm of nominal wall; thicker ribs lower cycle time but increase sink on the louvre-pivot surface. Mould shrinkage in this grade is anisotropic in unfilled parts, typically 0.4–0.6 % in flow direction and 0.5–0.7 % transverse depending on packing, so tool compensation is derived from plaques moulded at the same wall thickness rather than from datasheet ISO 294-4 values. Regrind is capped at 15 wt% for parts installed in hail-exposed roof sections, because reprocessing heat history shifts the ductile-to-brittle transition upward; production trials with regrind above 20 wt% showed more frequent failure in low-temperature bending tests, although published data for LI913H at these regrind fractions is limited. Melt temperature is run at 235–250 °C, mould temperature at 50–60 °C, and pack pressure is set high enough to freeze the gate, but not so high that the louvre-pivot holes become out-of-round. Low-temperature performance is assessed by notched and unnotched Charpy tests to ISO 179-1/1eA and ISO 179-1/1eU at −30 °C, supplemented by a production plant drop test from 1.0 m onto concrete at −20 °C for gable vent bases with integrated snap-fit louvre pins. The material is processed from black, grey or dark brown masterbatch at 2.0–3.0 wt%; bright white roof components are usually avoided because pigment loadings above 5.0 wt% reduce low-temperature impact and increase gate-area delamination risk. End products in this class include gable vent bases, roof louvre blades, soffit vent frames and attic ventilation baffles.

When Motorcycle Fairing Extensions Are Moulded Without Paint

Because painted ABS fairing extensions exhibit stone-chip delamination and UV fade at the mounting interface, some powersport programmes use unpainted dark-grey LI913H for low-stress side panels, blanking plates and meter surrounds. The moulding operation must balance high surface gloss against weld-line strength: melt temperature is held at 240–250 °C to reduce flow-line visibility, while mould temperature is raised to 60–70 °C for gloss, but pushing the mould above 75 °C increases cycle time without a measurable improvement in notched impact. Sequential valve gating is used to position weld lines away from mounting bosses and latch tabs; when this is not possible, the gate sequence is verified by short-shot study and Charpy bars cut from the affected area are tested to ISO 179-1/1eA. The colour package is a SAN-carrier black masterbatch at 2.0–3.0 wt%; regrind is limited to 20 wt% because higher regrind increases the melt flow, moves weld lines, and reduces the consistency of snap-fit retention in textured surfaces. Drying follows the standard 80 °C desiccant profile to below 0.02 wt% residual moisture, and nozzle temperature is kept at 245–250 °C with a shut-off nozzle to prevent drool when the injection unit retracts. The material is not recommended for fuel tank covers or components exposed to neat aromatic hydrocarbons, because styrenic copolymers can suffer environmental stress cracking in direct gasoline contact. Exterior weathering is evaluated by ISO 4892-2 Xenon-arc cycling with colour change limited to ΔE ≤1.5 for dark grey parts and no visible chalking at 3000 h. End-use mouldings include fairing side infill panels, meter covers, tail sections and side blanking plates.

Does Constant Gasket Compression Relax LI913H Sealing Bosses?

In outdoor PIR sensor housings and solar lantern covers, constant gasket compression is applied through self-tapping screws into moulded bosses, and this sustained load introduces creep that must be addressed in boss geometry rather than by material change alone. The housing wall is held at 2.0–2.5 mm, while the boss outer diameter is moulded at 2.0 × the screw nominal diameter and the boss hole is sized to 0.8 × the screw diameter to prevent splitting during thread forming. Regrind is capped at 20 wt% because higher levels shift melt viscosity enough to alter boss-hole diameter and thread-forming torque; production plants that exceed this limit report a wider torque band on automated screw-driving stations, although published data for the specific LI913H/regrind/boss combination is sparse. Where brass inserts are ultrasonically staked into sealing faces, the ultrasonic horn amplitude is set below 20 µm and the down speed is controlled at 30–50 mm/s to avoid melting the boss crown beyond the insert knurl. Mould temperature is kept at 50–65 °C, and packing pressure is tuned with cavity-pressure sensors to prevent sink on the gasket groove, which must remain flat within ±0.1 mm to pass an IP65 leak test to IEC 60529. Weathering certification for UL 746C f1 is colour- and thickness-dependent: black and dark grey parts in minimum 2.0 mm wall are typically fitted for outdoor UV exposure, but the UL file must be checked for each pigment package. Creep testing under gasket compression is often run internally at 60 °C for 1000 h with the seal compressed to 20–25 %; data for LI913H under those exact long-term compressive conditions is limited, so tooling revisions are released only after torque-retention and leak testing on aged assemblies. End products include PIR detector covers, solar path-light caps, camera mount housings and photocell enclosures.

Salt Fog, UV and Above-Deck Instrument Pod Geometry

Above-deck marine instrument pods and hatch latch covers use LG Chem ASA LI913H where the component is not continuously immersed, but is exposed to UV, salt spray and occasional wave splash. The geometry of these parts includes deep draw instrument pods with wall thickness from 3.0 mm to 5.0 mm; thick-section areas require a controlled pack profile to avoid internal voids that later become leak paths at gasket interfaces. Colour concentrates are used at 2.0–4.0 wt%, with black and dark grey preferred for maximum UV opacity; bright white pigments may require loading up to 5.0 wt%, which reduces flow in thin snap-fit regions and increases the risk of flow-line marking. Regrind is held at 20 wt% maximum, and marine plants dry the resin at 80 °C for 4 h with a dewpoint below −30 °C because humid coastal intake air raises residual moisture faster than centralised dryers can remove it. Melt temperature is set at 235–245 °C, mould temperature at 55–65 °C, and the tool is built with stainless steel cavity plates or corrosion-resistant coatings on ejector pins to prevent rust staining on textured surfaces. Weathering is checked by ISO 4892-2 Xenon-arc exposure for 2000 h, and salt-spray exposure may be assessed by ISO 9227 NSS for 720 h followed by visual inspection for blistering; published data for LI913H in this exact above-deck geometry is limited, so first-article parts are also installed on evaluation vessels before production release. The grade is not recommended for through-hull fittings or permanently submerged components because the long-term hydrolysis and fouling-abrasion boundary conditions exceed the optimisation window of an unfilled ASA resin. End-use parts include GPS/sounder pods, hatch latch covers, instrument bezels and above-deck cable entry shrouds.

In outdoor HVAC top-cover production, LG Chem ASA LI913H is moulded where the part must retain impact after long-term exposure to UV, rain splash and intermittent heat from condenser coils. The typical production blend uses 2.0–3.0 wt% carbon-black masterbatch; regrind is limited to 20 wt% because heat-cycled material at higher load levels increases viscosity variation and changes the fit of snap-fit air-deflector tabs. Drying is carried out at 80 °C for 3–4 h to below 0.02 wt% residual moisture before processing. Melt temperature is set at 235–245 °C, and mould temperature is controlled at 50–60 °C to balance cycle time against gloss retention on top surfaces. For multi-cavity fan-guard tools with wall thickness from 2.0 mm to 3.0 mm, hot-runner valve gates are preferred because the high-flow grade can otherwise produce gate stringing if the hot nozzle tip is overheated above 260 °C. Post-mould impact acceptance is tested by notched Charpy to ISO 179-1/1eA at 23 °C and −20 °C, and the UV ageing programme follows ISO 4892-2 for 1500 h with no cracking at 10× magnification. End-use components include condenser top covers, fan guard rings, wiring enclosures and compressor terminal shrouds.