Food-Contact Transparent Blender Jars and Juice Extractor Collection Bowls

INEOS Styrolution Absolan SAN 2300 is processed as a transparent styrene-acrylonitrile copolymer for direct food-contact appliance parts, specifically blender jars, juice extractor collection bowls and spice-grinder lids. The material is selected where the application requires repeat contact with citrus juices, diluted acetic acid from fruit preserves or coffee oils at temperatures below 80 °C. Under such conditions, general-purpose polystyrene develops environmental stress cracking, whereas SAN maintains stress-crack resistance because the acrylonitrile comonomer raises intermolecular dipole density and reduces fatty-acid absorption. Tensile modulus for this flow class is commonly reported in the 3300–3900 MPa range under ISO 527-2, and the melt volume-flow rate is calibrated in the 20–30 cm³/10 min band under ISO 1133-1:2022 at 220 °C/10 kg; the exact batch value must be taken from the certificate of analysis before mold filling simulation is run. The optical requirement for a blender jar is normally a luminous transmittance above 88% at 2.0 mm thickness according to ISO 13468-2, with haze held below 2.0% by ASTM D1003-21. These values are tightened when the part is combined with a metal blade base because insert-induced stress in the SAN wall can raise haze and reduce impact strength.

Processing on production-scale reciprocating-screw injection molding machines requires desiccant drying. The granulate is dried at 80 °C for 2–4 h to residual moisture below 0.05 wt%, with hopper airflow dew point at −25 °C or lower; if ambient relative humidity exceeds 60%, the residence time is extended to 4 h and the return-air temperature is monitored because moisture in SAN causes splay marks and weakens knit lines near the blade insert. A screw with an L/D ratio of 20:1–25:1 and compression ratio of 2.0:1–2.5:1 is used. Melt temperature is kept at 220–250 °C; mold temperature is controlled at 40–60 °C. The hold-pressure profile is applied in two stages: 60–80 MPa for 1.5–2.5 s, then 35–50 MPa for 4–6 s, to compensate for volumetric shrinkage without overpacking the gate area. Back pressure is set at 3–7 MPa and screw surface speed at 50–100 rpm. When a multicavity tool is used for a 1.0 L bowl, the clamp force requirement is typically 4–6 t per cavity; hot-runner valve gates are preferred, but if a cold runner is used, the sprue and runner should be polished below 0.4 µm Ra to avoid gate blush. Residence time above 280 °C must not exceed 5 min, because thermal degradation releases acrylonitrile and styrene volatiles and shifts the melt color to yellow.

Regrind use for food-contact parts is limited to 15 wt% for non-optical components such as opaque bases, and to 5 wt% or less for high-clarity jars. Regrind must be screened to remove metal shavings from blade insert overmolding and re-dried under the same dew point conditions. If color is added, only food-contact masterbatch with a carrier resin compatible with SAN is used at 0.5–2.0 wt%; pigment concentrates based on polystyrene can be dispersed without severe haze rise, but the final formulation must still be tested under the end-use food simulant because some organic pigments can release extractives under acidic conditions. Mold release agents are eliminated for food-contact articles; if ejection is insufficient, the tool texture in the bottom region is changed to a micro-roughness of 0.8–1.2 µm Ra instead of adding external lubricants. Compliance is verified against FDA 21 CFR 177.1040 for styrene-acrylonitrile copolymers, Commission Regulation (EU) No 10/2011 with an overall migration limit of 10 mg/dm², and the relevant national provisions such as LFGB in Germany. The finished blender jar or juice extractor bowl is not suitable for microwave use, steam sterilization above 85 °C, or contact with undiluted citrus terpenes at elevated temperature; these boundaries must be communicated to downstream users.

For thin-wall fragrance caps, lip gloss barrels and airless pump shells, the same SAN 2300 polymer is molded without food-contact assumptions, but with stricter gate and surface requirements. In this segment, wall thickness drops to 0.7–1.2 mm, and the flow-length-to-wall ratio frequently exceeds 120:1. The melt is therefore processed at the upper temperature band, 235–255 °C, with mold temperature raised to 50–70 °C to improve replication of mirror-polished cavity surfaces. Injection velocity at the melt front is controlled to 250–400 mm/s, and the fill time for a 0.8 mm closure is typically 0.15–0.35 s. Gate diameter is set to 0.8–1.2 mm for a pinpoint gate, or an edge gate thickness of 60–70% of the wall section; valve-gated hot-runner systems with sequential opening are used for cylindrical caps to move the weld line away from the visible shoulder. Hold pressure is applied at 50–70 MPa for 0.8–1.8 s, followed by cooling time of 6–10 s depending on wall thickness. The part is ejected when surface temperature falls below the Vicat softening point of approximately 101 °C so that the sealing bead does not distort under ejection forces.

Additive loadings in cosmetic packaging are kept at 0.2–1.0 wt% for process aids and 0.3–0.8 wt% for UV stabilizer concentrate if the closure must remain colorless under retail lighting. Fragrance perfume components are often dissolved in ethanol or volatile silicones; the converter is expected to screen each new formulation for environmental stress cracking using a constant-strain jig and candidate perfume surrogate under ISO 22088-3. Crosshatch adhesion tests for vacuum metallization or pad printing are conducted under ISO 2409, and the substrate must show surface tension above 36 dyn/cm after corona or flame treatment if lacquered; if the surface is metallized, outgassing must be below 0.1% by loss on drying, because volatile styrene and acrylonitrile residues can cause adhesion failure.

Compliance is handled under EU 94/62/EC for packaging and packaging waste, where the sum of lead, cadmium, mercury and hexavalent chromium is limited to 100 mg/kg, and under REACH Regulation (EC) No 1907/2006 for substances of very high concern. The finished airless pump shell or cap is subject to dimensional stability verification at 45 °C and 75% RH for 48 h; axial shrinkage greater than 0.3% at the cap inner diameter can cause loosening of the pump fitment and is rejected. Closure torque is not tested on the material alone, but the molded thread geometry must retain torque after three closures at 21 °C; if thread stripping occurs below the specified assembly torque, the gate vestige must be reduced to 0.05 mm maximum height and the thread root radius increased.

Compliance Matrix for Selected SAN 2300 Downstream Segments

What Changes Below 0.6 mm Wall Thickness in Copier Paper-Tray Windows?

Office equipment components such as copier paper-tray windows, label holder strips and scanner document guides are molded with wall thicknesses between 0.4 mm and 0.8 mm to reduce mass and cycle time. Below 0.6 mm, the melt-flow length of SAN 2300 becomes highly sensitive to mold temperature and gate design. The polymer is processed at 245–260 °C with a mold temperature of 60–80 °C to maintain high flow-front mobility; if the mold temperature falls below 50 °C, the flow front freezes before the part is fully packed, producing ripple marks and reduced weld-line strength. The gate is designed as a full-width fan gate or film gate of 0.3–0.5 mm depth, and the gate land is kept shorter than 1.0 mm to limit pressure drop. Injection pressure at transfer is typically 90–130 MPa, and the fill time is controlled at 0.05–0.12 s because low-speed fill in thin sections produces visible hesitation marks. After filling, hold pressure is set to 70–90 MPa for 0.5–1.0 s; longer hold time in sub-0.6 mm sections does not improve packing because gate freeze-off occurs early.

The critical control parameter in this segment is warpage caused by anisotropic in-plane orientation. Thin flat windows are measured after 48 h at 23 °C/50% RH against a flatness specification of 0.20 mm per 100 mm length. Because the grade is amorphous, shrinkage is relatively isotropic, but high melt temperature and thin wall increase frozen-in orientation parallel to flow; this is corrected by reducing melt temperature to 240 °C and increasing mold temperature to 75 °C, or by adding a static mixer in the melt stream to equalize temperature before entering the cavity. If an antistatic performance is required for paper dust resistance, a non-blooming antistatic additive concentrate is added at 1.0–2.0 wt%; surface resistivity is then measured under IEC 62631-3-2, with acceptance typically below 10¹² Ω. The material grade itself is rated UL 94 HB at 1.5 mm; it is not selected for live electrical components or for enclosures requiring V-2 or better because halogenated flame retardants are not incorporated. The finished part is evaluated for dimensional stability using ISO 291 standard atmospheres and is not used where continuous service temperature exceeds 80 °C because creep modulus declines.

Compliance for office equipment is maintained through Directive 2011/65/EU as amended, REACH, and the EU 94/62/EC packaging provisions if the window ships as a spare part with packaging. No food-contact declaration is required, but the converter must verify that added antistatic additives do not migrate to the surface in visually objectionable amounts; migration is assessed by wipe test after 72 h at 40 °C. End products include copier paper-tray windows, document handler covers, scanner guide frames and point-of-sale ticket rail windows. The material is not used for exterior copier bezels where a high-gloss black finish must withstand harsh cleaning agents, because chlorinated hydrocarbon cleaners can soften SAN surfaces.

In bench-top diagnostic instrumentation, clear housings for readers, cuvette racks and disposable sample-tray covers are injection molded from SAN 2300 in a controlled production environment, with the explicit boundary that the grade is not a dedicated medical resin and is not selected for implants or prolonged mucosal contact. The processing window is narrowed to 220–245 °C melt temperature and 40–60 °C mold temperature to limit thermal degradation products that could become extractables. Drying is performed at 80 °C for 3–4 h to residual moisture below 0.05 wt%. The tool is dedicated or cleaned of non-medical lubricants, and no external mold release is used. If ejection is difficult, a medical-grade silicone internal mold release is pre-compounded at 0.1–0.3 wt%, but the final extractables profile must still be measured according to ISO 10993-12. The molded parts are packed in low-lint bags, and particle contamination is controlled in an ISO 14644-1 Class 8 or cleaner area during assembly.

Biocompatibility testing is not inferred from the polymer type alone. Where the part is classified as a limited-contact housing for a diagnostic instrument, cytotoxicity testing under ISO 10993-5 is performed on the finished article, not on virgin granulate. A submission also includes an extractables screening by gas chromatography-mass spectrometry after extraction with polar and non-polar solvents. The converter must verify that the residual acrylonitrile monomer and total volatile organic content are below the thresholds agreed with the device sponsor; published data for this specific configuration are limited, so batch-specific analytical work is required before a medical device file can be completed. The material is stable to short contact with isopropanol and dilute aqueous buffers, but aggressive disinfectants containing quaternary ammonium compounds or strong surfactants may cause surface crazing when applied repeatedly at temperatures above 50 °C.

Sterilization with ethylene oxide is preferred over gamma irradiation because SAN yellows under gamma doses used for terminal sterilization; at 25 kGy, the transparent wall typically shows measurable yellowing, and impact strength can fall because of chain scission. If gamma is unavoidable, the product team must define a color shift acceptance criterion, such as ΔYI ≤3.0 under ASTM E313, and test every lot after the actual dose map. The finished diagnostic housing or cuvette rack is not suitable for autoclaving, steam sterilization, or use in contact with lipids. This limitation is recorded on the internal component drawing so that downstream designers do not substitute the material into a reusable sterilizable device without revalidation.

When SAN 2300 Is Selected for Injection-Molded Control Dials in White Goods

Rotary control dials, push-button surrounds and selector panels for washing machines, dryers and dishwashers are molded from SAN 2300 when the part is not exposed to continuous service temperatures above 70–80 °C and when the design requires a hard, scratch-resistant surface with high gloss. The melt is colored in opaque white, black or neutral grey at masterbatch loadings of 1.0–3.0 wt%; black formulations based on carbon black are normally dispersed without significant changes to viscosity, but the addition of heavy filler concentrates above 5 wt% is avoided because mold deposit and gate wear increase. The material is processed at 230–250 °C melt temperature and 50–70 °C mold temperature. Back pressure is set to 5–10 MPa to homogenize the colorant, and the screw surface speed is reduced to 40–80 rpm to limit frictional heat and color streaking. Because the dial includes a central core or metal spring insert, the insert is preheated to 80–100 °C before overmolding, and the plastic wall around the insert is kept above 1.5 mm to reduce hoop stress.

Dimensional stability is measured on finished dials after 48 h at 23 °C/50% RH using ISO 291. The inner bore tolerance for a control shaft is held to ±0.05 mm; this is achieved by using a post-mold cooling fixture for 10–15 s after ejection, because the part continues to shrink by 0.3–0.5%. For clipped or ultrasonically welded components, the weld horn amplitude and down speed are qualified on the actual grade; excessive ultrasonic energy at the joint melts the surface too fast and creates weld flash that is visible on the outer face. The part is checked for surface scratch resistance using a pencil hardness test according to ISO 15184; the target is typically H or harder after molding, but this depends on pigmentation and mold polish. If a soft-touch clear coat is applied, the substrate must pass a crosshatch adhesion test under ISO 2409 and a solvent rub test with isopropanol after 24 h.

The white goods segment is governed by IEC 60335-1 for household appliances when the material is evaluated as part of a complete control panel. The material is not selected for parts that support current-carrying contacts or that are located adjacent to resistance heating elements; it is not a fire-resistant grade. Ball-pressure tests under IEC 60695-10-2 are performed on the component at the maximum service temperature claimed by the appliance producer. The end product is a high-gloss control dial or button surround that is resistant to common household detergent sprays but not to hot steam, and this boundary must be reflected in the appliance service manual.

For writing instruments such as transparent ink-converter reservoirs, mechanical-pencil barrels and technical drawing templates, SAN 2300 is injection molded with wall sections of 0.8–1.5 mm. The material selection is based on clarity, low moisture absorption relative to cellulosics and nylon, and resistance to common glycol-based fountain pen inks and alcohol-based marking inks. The melt is processed at 210–230 °C to avoid yellowing, with mold temperature at 40–55 °C. The core pin defining the ink bore is cooled separately and held straight under clamp force; a slight taper of 0.5–1.0° and release ejection are required. Hold pressure is low, 35–50 MPa, because excess packing of a thin transparent tube causes gate stress and circumferential cracking when the brass cartridge is press-fitted. Additives are usually absent; if color is required, only transparent soluble dyes at 0.05–0.3 wt% are used, because pigment dispersions reduce light transmission and cause haze in a thin wall.

Dimensional checks include inner diameter consistency and roundness control to ±0.03 mm. The finished barrel is tested for ink compatibility by immersion in the customer’s standard blue and black inks at 40 °C for 72 h; surface cracking, clouding or catastrophic brittle fracture after flexure indicates environmental stress cracking. The product is used only with inks based on water, glycols and lower alcohols; ketone-based and strongly aromatic solvents are excluded because they soften the SAN barrel. The article is assessed under REACH and, when marketed as a children’s stationery item, under EN 71-3 for migration of specific elements; the finished writing instrument must also comply with the dimensional and functional requirements of its closure system, but no food-contact certification is required. The high-gloss barrel is packed immediately after cooling in a humidity-controlled environment below 60% RH to prevent moisture condensation on the polished core surface.