Transparent kitchen appliance subcomponents are injection-moulded from Chimei KIBISAN SAN PN-117H L150 FG, a styrene-acrylonitrile copolymer with food-contact compliance declarations, on a reciprocating screw machine having a barrel L/D ratio of 20:1–24:1 and a compression ratio of 2.5:1–3.0:1. Pellets exposed to ambient relative humidity above 60% are dried in a desiccant dryer at 80 °C for 2–4 h until residual moisture falls below 0.1 wt%; failure to observe this threshold produces splay, surface haze, and partial surface depolymerisation at nozzle temperatures above 240 °C. The processing window at the upper temperature limit is no wider than ±5 °C; barrel residence time above 5 min oxidises residual styrene oligomers and shifts moulded part colour from water-white to yellow, with transmittance loss measurable under ASTM D1003-21. Melt volume-flow rate is confirmed according to ISO 1133-1:2022 using a 220 °C barrel and 10 kg load, with the lot-specific value taken from the certificate of analysis rather than a nominal datasheet. Formulation loading for these parts is 100 wt% virgin PN-117H L150 FG or 97.5–99.2 wt% with a SAN-compatible food-contact colour masterbatch; reprocessed sprues and runners are limited to ≤20 wt% of total feed because higher regrind ratios reduce luminous transmittance and increase yellowness under ASTM D1003-21 and ISO 11664-4. Barrel zone set points are 200–220 °C at the rear, 210–230 °C in the centre, 220–240 °C at the front, and 210–230 °C at the nozzle, with a mould temperature of 40–60 °C to balance cycle time against surface replication. Injection speed is profiled slow-to-fast across the first 60–70% of fill to prevent jetting; hold pressure is set at 50–70% of peak injection pressure with a screw cushion of 2–5 mm and back pressure of 5–15 bar. Compliance for food-contact appliance parts rests on FDA 21 CFR 177.1040, (EU) No 10/2011 at an overall migration limit of 10 mg/dm², GB 4806.7-2023, and NSF/ANSI 51 for materials used in food-zone equipment. Terminal moulded items include blender jars, coffee-machine water tanks, food-processor bowls, juice extractor containers, and clear lids that must tolerate dry-cycle dishwashing without stress whitening.

Why Does Regrind Ratio Dominate Food-Container Lot Consistency?

Rigid food storage containers and beverage dispenser reservoirs moulded from PN-117H L150 FG exhibit measurable lot-to-lot optical variation when post-industrial regrind exceeds a defined mass fraction. The critical control point is the thermal history accumulated by recycled SAN; each additional heat cycle increases the concentration of conjugated degradation products that absorb at 400–450 nm, lowering transmittance and shifting the yellow-blue colour coordinate. For thin-wall containers with wall thickness below 1.2 mm, the addition ratio is maintained at 80–100 wt% virgin PN-117H L150 FG with in-house runner regrind at 0–20 wt%; colour masterbatch is limited to 0.5–2.0 wt% to avoid excessive tint strength and migration-relevant colourant loadings under (EU) No 10/2011. Production is carried out on high-speed injection moulding machines with accumulator-assisted injection capable of fill times below 0.8 s; the mould is cooled at 10–25 °C for fast-cycling thin-wall food containers, while deeper beverage reservoirs use 35–45 °C to prevent gate blush. The manufacturing process is cold-runner injection moulding; hot-runner valve gates are used only when gate vestige height must remain below 0.02 mm to avoid lip contact surfaces on drinkware. Compliance standards include FDA 21 CFR 177.1040, (EU) No 10/2011 with overall migration testing according to EN 1186-1 and specific migration testing according to EN 13130-1, GB 4806.7-2023, and Japanese MHLW Notification No. 370 for food-contact synthetic resins. Terminal product types include nested refrigerator storage boxes, cereal dispenser canisters, beverage reservoirs for water dispensers, airtight lunch boxes, and transparent food pans.

Cosmetic Package Clarity and Migration Control in PN-117H L150 FG

With wall sections above 3 mm and a mirror-finish cavity surface, thick-wall cosmetic packaging moulded from PN-117H L150 FG follows a solidification profile that is slower than thin-wall food containers and places surface gloss as the primary acceptance criterion. The addition window for this application is 98.5–99.5 wt% virgin resin with 0.5–1.5 wt% cosmetic-grade colour masterbatch; external lubricants are restricted to 0.05–0.2 wt% of a food-contact-approved ester wax because excess lubricant migrates to the mould surface and deposits on mirror-polished cavities, reducing distinctness of image. Amine-based antistatic additives are excluded because they generate surface haze and can interact with fragrance components stored in the packaged formulation. Processing uses a mould temperature of 50–70 °C and a cavity surface finish of SPI A1–A2 to maximise gloss; cavity pressure is typically 700–900 bar, and the pack phase is maintained until gate freeze, which for a 4 mm wall can require 18–30 s cooling time. The downstream production process is conventional injection moulding; for airless pump bottles and cylindrical jars, a mould with an unscrewing core or collapsing core is used to create internal threads without secondary machining. Compliance for cosmetic packaging is dominated by REACH 1907/2006 and EU Regulation (EC) No 1223/2009, including traceability of packaging materials and absence of packaging-derived contamination; food-contact declarations may also be requested for dual-use jars, so FDA 21 CFR 177.1040 and (EU) No 10/2011 remain applicable. Terminal finished products include cream jars, airless pump housings, lipstick caps, compact powder cases, and brush handles.

Because point-of-use water treatment housings operate under continuous hydrostatic pressure and intermittent thermal disinfection, transparent filter bowls and sight glasses made from PN-117H L150 FG require a different risk assessment than dry food containers. Regrind is restricted to ≤10 wt% in pressure-bearing components, and masterbatch is omitted above 1.0 wt% because pigment agglomerates act as crack initiation sites in threaded zones. Moulding is performed with sequential valve-gated injection to shift weld lines from the thread root to a low-stress region; barrel temperatures are set at the upper end of the SAN window, 220–240 °C, and mould temperature at 60–80 °C to reduce residual hoop stress. Moulded threads and sealing faces are post-checked by polarised light for stress birefringence according to ASTM D4093-20, and components exhibiting visible fringe order greater than 2 are rejected. Compliance for water-contact use depends on FDA 21 CFR 177.1040, (EU) No 10/2011, and applicable final-part certifications such as NSF/ANSI 61 for water system components; published third-party cyclic pressure data for PN-117H L150 FG in this specific configuration are limited, so housing producers conduct component-level burst and thermal-cycling validation. Addition ratio for water-contact mouldings is 99.0–100 wt% virgin resin; antistatic and mould-release additives are avoided entirely in filter bowl closures. Terminal part types include clear filter sumps, sight glasses for reverse osmosis skids, ice-machine water reservoirs, and UV disinfection chamber sleeves.

When Refrigerator Interior Panels Are Converted from Polystyrene to SAN

Conversion of refrigerator interior panels from general-purpose polystyrene to PN-117H L150 FG is justified by improved resistance to stress cracking caused by vegetable oils, dairy fats, and citrus extracts. The replacement is not universal because SAN has a higher processing temperature than polystyrene; barrel set points must be raised by 20–30 °C relative to PS settings, and the mould temperature should be maintained at 40–60 °C to prevent surface flow lines on textured drawer fronts. The formulation addition ratio is 100 wt% virgin PN-117H L150 FG for transparent dairy compartment windows and 97.5–99.5 wt% with masterbatch for opaque or tinted crisper drawers; regrind is kept at ≤15 wt% because low-temperature impact performance declines with reprocessing. Production is split between injection moulding for drawers and extruded sheet followed by thermoforming for shallow trays and lids; sheet extrusion uses a single-screw extruder with L/D 28:1–32:1 and a polished three-roll stack set at 70–90 °C. Compliance for refrigerator interiors is anchored to FDA 21 CFR 177.1040 for food-contact surfaces, (EU) No 10/2011 for migration, and IEC 60335-1 for general appliance safety; chemical resistance is verified by applying a food-simulant stress-crack protocol based on ISO 22088-3. Terminal product types include crisper drawers, dairy compartment windows, meat-pan covers, bottle retainers, and freezer door inserts.

Transparent Housewares Requiring Repeated Dishwasher Exposure

For transparent housewares that pass through domestic dishwasher cycles, PN-117H L150 FG must be moulded with low residual stress and controlled regrind content because stress whitening becomes visible after 50 domestic dishwasher cycles at 65 °C under EN 12875-1 conditions. The addition ratio for these parts is 98.0–100 wt% virgin resin with 0–2.0 wt% masterbatch; regrind is limited to ≤20 wt% and is produced from trimmed sprues only, never from post-consumer scrap. Processing is injection moulding with a mould temperature of 45–65 °C to lower residual stress, and the holding pressure profile is extended until the gate freezes; mould-release agents are not added to the formulation, but ejected parts are allowed to cool uniformly on post-mould fixtures to prevent asymmetric shrinkage. Industry compliance and test standards include FDA 21 CFR 177.1040, (EU) No 10/2011, GB 4806.7-2023, and EN 12875-1 for mechanical dishwashing resistance of domestic articles. Terminal product types include salad spinner bowls and baskets, cake domes, cheese keeper covers, storage lids, and serving domes that must retain transparency after repeated alkali detergent exposure.