Dongguan Weiye Plastic ABS/PMMA WY758 is an acrylonitrile-butadiene-styrene/poly(methyl methacrylate) compound supplied as cylindrical pellets for injection molding and sheet extrusion. The grade sits between standard ABS and unfilled PMMA in the manufacturer’s product hierarchy; the WY758 designation identifies an ABS/PMMA alloy, but published code-specific formulation detail is limited and the lot certificate of analysis remains the controlling document. The product is characterized by melt mass-flow rate under ISO 1133-1:2022 at 220 °C with a 10 kg load, density under ISO 1183-1:2019, and Vicat softening temperature under ISO 306:2022 method B50. For ABS/PMMA compounds with a PMMA content of 30–40 wt%, typical reference windows are useful: melt mass-flow rate generally lies between 18 g/10 min and 32 g/10 min; density is 1.08–1.12 g/cm³; Vicat B50 values range from 96 °C to 108 °C. Tensile yield stress measured on injection-molded ISO 527-2:2012 type 1A specimens for this class ranges from 44 MPa to 56 MPa, with elongation at break of 10–25%. Notched Charpy impact values under ISO 179-1:2010 at 23 °C are often reported between 12 kJ/m² and 25 kJ/m². These ranges are class-typical and should not replace WY758 lot-specific certificates.

When PMMA enrichment shifts ABS surface aesthetics and scratch response

In blends of this type, the PMMA phase contributes a continuous or co-continuous surface layer during filling, depending on mold wall temperature and shear history. This phase enrichment raises pencil hardness values measured under ISO 15184:2020 from the HB–F range typical of standard ABS to an F–H range for ABS/PMMA surfaces. Scratch resistance improves when the PMMA domain size remains below 5 µm and the interphase is stabilized by styrene-methyl methacrylate copolymer segments introduced during compounding. The trade-off is a reduction in low-temperature ductility relative to standard ABS; Charpy impact values at -30 °C may decrease by 30–50% depending on rubber particle size and grafting efficiency. Morphological characterization by scanning electron microscopy on cryofractured specimens shows PMMA-rich domains elongated in the flow direction at injection speeds above 150 mm/s, which contributes to anisotropic gloss retention after abrasion testing under ASTM D4060-19 using CS-10 wheels and 500 g load.

Capillary rheometry at 240 °C indicates shear viscosity of 180–350 Pa·s at 1000 s⁻¹ for ABS/PMMA compounds with similar composition. The viscosity curve exhibits shear thinning with power-law index 0.25–0.35 between 100 s⁻¹ and 10,000 s⁻¹. At low shear rates below 10 s⁻¹, viscosity can exceed 1,200 Pa·s, which affects rib filling and surface replication. The melt elasticity of the PMMA-rich phase leads to higher die swell than standard ABS; sheet extrusion die gaps are typically set 5–10% wider than standard ABS to compensate. Weld line strength in injection-molded parts measured by ISO 527-2:2012 may be 40–60% of the non-weld-line value when two flow fronts meet after a travel length greater than 200 mm at 30 °C mold temperature. Increasing mold temperature to 80 °C and optimizing vent depth below 0.02 mm reduce visible weld line depth and improve strength retention.

Prior to melt processing, the granules are dried in a desiccant dryer with a supply dew point at or below -40 °C. The recommended drying profile for ABS/PMMA compounds is 80 °C for 4 h at an airflow of 0.25 m³/h per kg/h throughput. Residual moisture content should be maintained below 0.05 wt% to prevent splay defects on high-gloss mold surfaces. Injection molding trials on machines with screw diameters from 40 mm to 80 mm and a screw length-to-diameter ratio of 20:1 to 24:1 indicate that melt temperatures between 230 °C and 250 °C provide adequate flow length while limiting thermal degradation of the butadiene phase. Mold temperatures from 50 °C to 80 °C are used to maintain gloss and replicate textured cavity surfaces. Back pressure should be limited to 3–8 bar and screw rotation to 60–120 min⁻¹; higher shear can raise melt temperature locally and produce yellowing in unpigmented formulations. Hot-runner systems require internally heated or externally heated manifolds with a residence time below 5 min at melt temperature. The compound is also runnable on sheet extrusion lines with single-screw diameters of 60–120 mm and polished calendar rolls maintained at 70–90 °C, but published data for WY758-specific extrusion throughput is limited.

Production failure modes reported for ABS/PMMA alloys include surface haze on texturized cavities when mold release is used above 0.1 wt%; silver streaks from moisture above 0.05 wt%; brown streaks from dead spots in hot-runner manifolds with residence time exceeding 8 min; and gate blush at gate velocities above 600 mm/s for polished surfaces. Injection molding machines with clamp force below 1,200 kN may show flash in thin-wall parts because the PMMA-rich phase increases viscosity at the flow front and raises injection pressure requirements. These are operational limits rather than material defects.

Does WY758 meet high-gloss automotive interior requirements without paint?

Automotive interior applications for ABS/PMMA grades include air-conditioning vents, steering wheel trim rings, instrument panel garnish, and seat side trims. High-gloss black or piano-black surfaces are produced without post-molding painting when the cavity finish is SPI A1 or A2 and the mold temperature is held above 70 °C. Gloss retention after simulated weathering under ISO 4892-2:2013 method A cycle 1 for 500 h is typically reported as retained gloss above 80% for UV-stabilized formulations. The PMMA content reduces visible micro-scratch formation in repetitive touch areas compared with standard ABS; pencil hardness after Taber abrasion under ASTM D4060-19 with 550 g load and 50 cycles shifts by less than one grade in many cases. Fogging behavior is tested according to ISO 6452:2021 with reflectometric and gravimetric methods; the product can be formulated with low-volatility additive packages to meet OEM limits of 60% reflectance and 2 mg condensate on aluminum foil. Potential limitations include reduced impact retention at cold temperatures and a narrower processing window for dark colors due to visible silver streaking if the melt temperature exceeds 255 °C.

Electronic housing applications, including router covers, smart speaker enclosures, and remote-control front panels, use ABS/PMMA WY758-type materials for surface hardness and dimensional stability. The material is not inherently flame-retarded; V-0 ratings require halogenated or phosphorus-based additive packages that may reduce scratch resistance and gloss, and the specific WY758 grade should be checked against IEC 60695-11-10:2013 thin-wall flame test data. For cosmetic packaging, the product is suitable for high-gloss caps, compact cases, and bottle overcaps where the cavity contains mirror-polished inserts. The low rubber content relative to standard ABS reduces visible flow lines but also narrows the gate size tolerance; gates smaller than 0.8 mm can lead to jetting on PMMA-rich surfaces. Decoration by vacuum metallization, hot stamping, and UV-cured clear coating is generally possible after surface activation with plasma or corona treatment. Adhesion tests for metallized layers follow ISO 2409:2020 cross-cut classification with no detachment from the substrate.

Comparative divergence from unfilled PMMA and standard ABS

Compared with unfilled PMMA, the ABS/PMMA WY758 class offers lower melt viscosity and higher notched impact strength but a lower light transmittance and slightly lower surface pencil hardness. Unfilled PMMA tested under ISO 179-1:2010 at 23 °C commonly exhibits Charpy notched impact near 2–3 kJ/m², whereas ABS/PMMA alloys of this type remain above 12 kJ/m². The trade-off is heat deflection temperature; PMMA exhibits Vicat B50 values near 105–115 °C, overlapping the upper end of the ABS/PMMA range. Compared with standard ABS, WY758-type materials show higher gloss, lower tendency to stress whitening, and improved scratch resistance, but the low-temperature impact and chemical resistance to ketones, esters, and aromatic hydrocarbons are lower than standard ABS. Against PC/ABS, the ABS/PMMA blend has lower heat resistance and notched impact, but it typically has better surface hardness and higher natural gloss without needing a clear coat. The selection boundary is often set by the balance between flow length and scratch resistance; for a 2.0 mm thick spiral flow test at 240 °C, ABS/PMMA flow lengths may be 10–15% shorter than standard ABS at equivalent injection pressure.

Outdoor applications require UV stabilization. For ABS/PMMA compounds, unpigmented formulations yellow under UV exposure unless UV absorber is added. Accelerated weathering under ISO 4892-2:2013 for 1,000 h with UVA-340 lamps can reduce Charpy impact to 60–75% of original and increase yellowness index by 8–15 units depending on stabilizer loading. Black and opaque colors show better retention; white and pastel colors may require higher titanium dioxide loading, which increases viscosity and can narrow the processing window. The product is not recommended for continuous outdoor exposure without additional additive packages, and published data for WY758-specific outdoor aging is limited.

Regulatory documentation associated with WY758 may include REACH SVHC declarations under Article 33 of Regulation (EC) No 1907/2006, RoHS recast Directive 2011/65/EU Annex II substance restrictions, and food-contact statements where specific grades are tested under EU 10/2011 migration limits. The product should not be processed in equipment that also processes PVC or polyacetal without thorough purging because thermal degradation byproducts can contaminate high-gloss surfaces. Avoid combination with amine-based antistatic masterbatches or certain hindered amine light stabilizer packages that can induce transesterification at PMMA interfaces. Drying is mandatory above ambient relative humidity of 60% because moisture absorption in PMMA-rich phases can produce surface bubbles and cloudiness. Storage stability is maintained in sealed containers at or below 30 °C; opened material should be consumed within 8 h when ambient humidity exceeds 70%. Because published data for this specific configuration is limited, the manufacturer’s certificate of analysis and technical datasheet remain the controlling documents for lot-specific melt index, impact, and gloss values.