LG Chem Huizhou ABS HP181 is an injection-molding grade of acrylonitrile-butadiene-styrene copolymer produced at the Huizhou ABS complex in Guangdong Province, China. The grade is supplied as natural or pre-colored pellets and is characterized by a distributor-published melt volume-flow rate of 18 cm³/10 min at 220 °C under 10 kg load per ISO 1133-1:2022. Representative physical property sets from distributor datasheets list density at 1.04 g/cm³ per ISO 1183-1:2019, tensile stress at yield at 48 MPa per ISO 527-2:2012, tensile elongation at break at 20%, flexural modulus at 2,400 MPa per ISO 178:2019, and notched Izod impact at 18 kJ/m² at 23 °C per ISO 180/A:2023. The product is positioned for thin-wall injection-molded components with wall thickness from 1.0 mm to 2.5 mm, and is not intended for sheet extrusion or blow molding, where the low melt strength of this high-flow grade limits parison stability.

Pre-drying in a desiccant dryer at 80 °C for 2 h to 4 h is required to reduce pellet moisture below 0.05 wt%; ambient relative humidity above 60% can extend required drying time to 6 h. Residual moisture above 0.1 wt% produces silver streaking on the molded surface and reduces tensile strength by approximately 5% due to hydrolysis of the nitrile group at melt temperature. On a 20:1 L/D single-screw reciprocating injection machine, typical barrel settings from feed to nozzle are 210 °C, 220 °C, 230 °C, 220 °C with a nozzle of 220 °C; the melt temperature measured by an immersion probe should not exceed 250 °C. Mold temperature should be held between 40 °C and 80 °C. At mold temperatures below 40 °C, surface gloss measured at 60° per ISO 2813:2021 falls from approximately 90 GU to 70 GU, and knit-line notched impact can decrease by 15% to 25%. Screw tip injection pressure typically falls between 70 MPa and 110 MPa; back pressure should be maintained at 5 MPa to 10 MPa and screw surface speed at 0.2 m/s to 0.4 m/s. Melt residence time should be limited to 10 min at 240 °C; prolonged residence above 250 °C oxidizes the polybutadiene phase, shifts melt color to yellow, and reduces notched Izod impact by more than 30%.

How does HP181 differ from other ABS grades in the same production complex?

The primary differentiator is the balance between melt flow and impact resistance. HP181 is polymerized to a broader molecular weight distribution than HI121H, lowering viscosity at shear rates above 10² s⁻¹ while retaining sufficient rubber-phase grafting for impact performance. Distributor-published comparisons indicate melt volume-flow rate for HP181 at 18 cm³/10 min under 220 °C/10 kg is approximately 30% higher than HI121H and approximately 40% lower than HF-380. Notched Izod impact for HP181 is approximately 15% lower than HI121H and approximately 20% higher than HF-380 at 23 °C. Heat deflection temperature under 1.82 MPa per ISO 75-2:2013 is 88 °C, approximately 4 °C below HI121H and 3 °C above HF-380. Unlike flame-retardant ABS grades, HP181 contains no brominated flame retardants or antimony trioxide and therefore has lower plate-out on mold vents.

Flow simulation using Moldflow requires input of the Cross-WLF viscosity coefficients; published datasets for HP181 are available from material database releases and should be validated by spiral-flow testing. In a 25 mm diameter spiral mold with wall thickness 1.5 mm, HP181 typically reaches a flow length of 180 mm at 220 °C and 80 MPa injection pressure. Gate diameters should be 0.8 mm to 1.5 mm for thin-wall parts; direct gates below 0.5 mm cause premature freeze-off and increased molecular orientation. Rib thickness should not exceed 60% of adjacent wall to avoid sink marks. Mold shrinkage is anisotropic: 0.4% to 0.6% parallel to flow and 0.5% to 0.7% transverse to flow per ISO 294-4:2018.

Thermal deflection, moisture uptake, and dimensional tolerance in HP181

Equilibrium moisture absorption at 23 °C and 50% RH is approximately 0.2 wt% per ISO 62:2008; at 85 °C and 85% RH, moisture saturation increases to 0.6 wt%. Moisture uptake reduces heat deflection temperature by 2 °C to 4 °C and increases molded part weight by up to 0.3%. Linear thermal expansion coefficient is 70 × 10⁻⁶ K⁻¹ to 90 × 10⁻⁶ K⁻¹ parallel to flow per ISO 11359-2:2021; this makes tight-tolerance assemblies sensitive to temperature differences exceeding 30 °C. A part designed with a critical dimension of 50.00 mm can shift by 0.10 mm to 0.15 mm after molding due to shrinkage and moisture equilibration. Post-mold annealing at 70 °C for 2 h reduces residual stress but increases shrinkage by an additional 0.05%.

When environmental stress cracking and paint adhesion dictate material selection

ABS HP181 is susceptible to environmental stress cracking in the presence of ketones, esters, aromatic hydrocarbons, chlorinated solvents, and concentrated organic acids; the rubber phase swells and cracks under tensile strain above 0.5%. Testing under ISO 22088-3:2021 with 1% n-butyl acetate exposure at 23 °C typically produces visible crazing within 2 h for unstressed control specimens, but parts with high molded-in stress can fail within 15 min. Paint adhesion on HP181 is improved by surface treatment with a low-pressure air plasma or adhesion promoter after cleaning with isopropanol; direct painting without pretreatment yields a cross-cut adhesion rating of 2 to 3 per ISO 2409:2020, whereas plasma treatment raises the rating to 0 to 1.

Electrical and appliance applications include washing machine control panels, vacuum cleaner housings, rice cooker bases, and consumer electronics frames. UL 94 classification for natural HP181 at 1.5 mm is HB; end products requiring V-2, V-1, or V-0 must use flame-retardant ABS or ABS/PC formulations. Regulatory documentation supplied with Huizhou-produced HP181 includes RoHS Directive 2011/65/EU Annex II compliance and REACH SVHC concentration below 0.1 wt% per Article 33. The material is not recommended for continuous contact with hot water above 60 °C or for food-contact applications unless a specific food-contact letter is issued for the exact grade and color. In automotive interior trim, odor and fogging characteristics are controlled by the Huizhou plant’s devolatilization system; lot-to-lot total carbon emission from the pellet surface is typically below 50 µg/g per Volkswagen PV 3341 when tested on natural uncolored material. Published data for specific configurations involving laser marking, ultrasonic welding, or chrome plating is limited; qualification trials with production-scale tooling are required before locking process parameters.