On production-scale injection moulding lines for transparent appliance parts, LyondellBasell Hiloy SAN 242 is processed at melt temperatures of 210°C to 240°C, with mould surface temperatures maintained at 40°C to 70°C to balance flow length against frozen-in orientation. Converters running refrigerator crisper drawers and blender jars on hydraulic presses with clamp forces from 1,800 kN to 2,500 kN and screw L/D ratios of 20:1 to 24:1 observe that shot mass variability rises when the melt cushion falls below 3 mm; this condition prolongs residence time in the compression zone and accelerates yellowing of the acrylonitrile segment. Drying prior to moulding is set at 80°C for 2 h to 4 h when ambient relative humidity exceeds 60%, because free moisture above 0.08 wt% generates splay and weld-line haze measurable under ASTM D1003-13. For food-contact appliance parts, the compound is evaluated against FDA 21 CFR 181.32 for acrylonitrile copolymers and Commission Regulation (EU) No 10/2011, with overall migration determined according to the food simulant and declared contact ratio. The formulation is typically 100 wt% virgin SAN 242; where a tinted refrigerator drawer is specified, a styrene-based colour masterbatch is added at 0.5 wt% to 2.0 wt%, and total non-resin additives are held below 3.0 wt% because higher loadings reduce notched Izod impact strength when tested under ASTM D256-10(2018). Amine-based mould release agents and basic additives are excluded; residual amines at the moulding surface can accelerate nitrile hydrolysis at processing temperatures, producing colour drift and surface haze. Terminal products produced in this application segment include refrigerator crisper trays, transparent blender jars, food-processor bowls, mixer lids, and small-appliance measuring cups.

Because low haze and resistance to ethanol, isopropyl myristate, and common cosmetic ester systems are specified for rigid cosmetic packaging, SAN 242 is injection moulded into jar bodies and overcaps using melt temperatures between 215°C and 235°C. The cavity must be polished to SPI A-2 or better to achieve surface gloss above 85 GU at 60° when measured under ASTM D2457-13; lower polish levels produce micro-flow marks that become visible after secondary decoration. Compliance for rigid packaging placed on the EU market requires conformity to Regulation (EC) No 1223/2009 for the finished cosmetic product, while the plastic material itself is assessed for substances of concern under REACH and, where reusable contact is claimed, Regulation (EU) No 10/2011. The addition level for colour and effect masterbatches is between 1.0 wt% and 3.0 wt%; for transparent components, no filler or impact modifier is used because the refractive index mismatch between styrenic matrix and conventional impact modifiers raises haze above 3.0% at 2 mm path length. Processing uses a two-plate, hot-runner multi-cavity tool with sequential valve gating; shot size and hold pressure are set to prevent gate blush, with hold pressures from 40 MPa to 60 MPa maintained until the gate freezes. Terminal product types include cream jars, cosmetic caps, compact bases, lipstick tubes, mascara overcaps, and fragrance caps.

Extractables Control Determines Diagnostic Consumable Rejection Rates

The conversion of Hiloy SAN 242 into cuvettes and diagnostic sample cups is governed less by melt flow than by surface quality, wettability, and low extractables in the presence of assay buffers and alcohol-based reagents. Injection moulding is conducted in an ISO Class 7 cleanroom or local laminar-flow enclosure, with melt temperatures constrained to 210°C to 230°C and mould temperatures of 35°C to 50°C to reduce condensed-phase volatile deposition on cavity surfaces. The relevant compliance pathway for primary laboratory consumables is not a single resin certificate; the converter must qualify the finished component under ISO 10993-12:2021 for sample preparation and extractables, ISO 10993-5:2009 for cytotoxicity, and USP <661> for plastic packaging where applicable. Published grade-specific extractables data for SAN 242 in diagnostic reagent environments are limited; therefore, the burden of test data falls on the converter’s validated protocol. Formulation is kept at 100 wt% virgin resin with no internal release additive and no external silicone mould spray, because surface silicone migration changes reagent contact angle and meniscus geometry in optical cells. Cold-runner, two-plate tools with wedge gates are standard; hot-runner systems with exposed resin pools are avoided unless the manifold can be purged within 10 min at no more than 230°C, above which the resin fraction begins to develop free styrene and acrylonitrile decomposition products detectable as UV-absorbing extractables. Terminal outputs are spectrophotometer cuvettes, petri dishes, reagent reservoirs, sample transfer cups, and centrifuge tube outer sleeves.

Where transparency without polycarbonate cost is specified in water treatment sump housings, SAN 242 is moulded as unfilled resin, but the housing must survive cyclic hydraulic pressure without stress cracking. Potable water contact compliance is demonstrated under NSF/ANSI 61 for health effects and, where aesthetic clarity is marketed, NSF/ANSI 42 for particulate and turbidity reduction components; EU submissions rely on Regulation (EU) No 10/2011 with food-contact testing conducted in 10% ethanol and 3% acetic acid simulants for the intended service temperature. The formulation is 100 wt% SAN 242; no glass fibre is used because the resulting haze exceeds 30% at 2 mm thickness, and no elastomer impact modifier is added above 2.0 wt% because phase separation under high shear creates annular flow marks around the bowl threads. Moulders select compression screws with L/D 18:1 to 22:1 and back pressures of 3 MPa to 7 MPa to homogenise the melt without excessive shear heating; injection speed is profiled to maintain a flow-front velocity of 80 mm/s to 120 mm/s through the thread and sealing face. The process conflict is that high hold pressure can improve seal flatness but raises moulded-in stress at the thread roots; typical holding pressure is capped at 50 MPa, and stress relaxation is checked by annealing a sample at 70°C for 1 h and measuring diametric change. Terminal parts include clear overhead filter bowls, sediment sumps, flow-regulator windows, and pressure-differential gauge covers.

What Limits Injection Speed in Thin-Wall Houseware Articles?

In thin-wall transparent housewares such as storage trays and food containers, the limiting factor is not plastication but the balance between mould filling and shear-induced degradation of the acrylonitrile segment. At wall thicknesses from 0.8 mm to 1.2 mm, flow-length-to-wall-thickness ratios exceeding 120:1 require melt temperatures at the upper end of the SAN processing window, 230°C to 240°C, and injection velocities from 70 mm/s to 110 mm/s; above 110 mm/s, shear rates at the gate can exceed 10⁵ s⁻¹, causing melt fracture and visible surface defects at the gate area. Process engineers use ISO 1133-1:2022 melt mass-flow rate data to establish lot-to-lot consistency but then verify filling in a spiral-flow tool with a 2 mm cavity depth, because spiral-flow length correlates inversely with mould fill pressure. Compliance for food storage trays is established under FDA 21 CFR 181.32 and Regulation (EU) No 10/2011, with the converter completing migration testing using food simulants matched to the declared contact temperature and time. The formulation is 100 wt% SAN 242 for maximum transparency; if multicavity release is insufficient, 0.1 wt% to 0.3 wt% of a saturated fatty acid release agent is added, but levels above 0.5 wt% produce plate-out on polished cores and should be avoided. Production tools are high-cavitation two-plate moulds with full hot-runner systems and valve pin sequencing; hold pressure is kept at 25 MPa to 40 MPa for 0.5 s to 1.2 s to reduce post-mould shrinkage variation without introducing gate blush. Terminal outputs include food storage boxes, refrigerator organisers, serving trays, cup racks, and modular drawer inserts.

Writing Instrument Barrel Moulding and Solvent Compatibility

Writing instrument barrels, transparent rulers, and correction-tape bodies made from SAN 242 are produced by injection moulding with melt temperatures of 210°C to 230°C and mould temperatures of 30°C to 50°C. The critical requirement is resistance to inks, marking solvents, and cleaners; compatibility is assessed by immersion testing in ethanol and methyl ethyl ketone according to ASTM D543-20, with the component inspected for cracking after 24 h at 23°C. Regulatory compliance for the European market is mainly under REACH and, when the article is intended for children’s use, EN 71-3:2019+A1:2021 migration limits; the resin supplier’s safety data sheet and food-contact status are not sufficient for children’s categories. Formulation is normally 100 wt% virgin resin; only masterbatches with a styrene-based carrier are used, at 0.5 wt% to 2.5 wt%, because incompatible polyolefin carriers create visible delamination streaks at high shear during filling. Production tooling uses small-diameter gates with reverse taper to reduce gate vestige on pen barrels; screw L/D is 20:1 and back pressure is limited to 2 MPa to 5 MPa to maintain melt homogeneity without excessive residence. Terminal product types include ballpoint pen barrels, rollerball pen bodies, mechanical pencil barrels, transparent rulers, geometry instruments, and correction-tape casings.