Injection moulding of transparent drinkware and food-serving articles from Chimei KIBISAN SAN PN-138H is specified around a narrow plasticating window to avoid yellowing caused by residence time. The high-flow rheology of the grade permits filling of 1.2 mm sidewalls in multi-cavity tools, but melt temperature must be held between 200–240 °C. Pre-drying at 80 °C for 2–4 h is required when storage humidity exceeds 60 % RH; wet resin produces surface splay and lowers tensile elongation at weld lines. Mould temperature between 40 °C and 70 °C balances surface gloss against sink formation. Back pressure is kept between 50 bar and 100 bar hydraulic, and screw rotation speed is reduced below 80 min⁻¹ to avoid shear heating in the compression zone. Injection velocity is profiled: a slow first stage through the sprue and runner, a rapid fill stage for the cavity, and a decelerated final 15–20 mm travel to avoid jetting at the gate. Terminal parts include tumblers, pitchers, salad bowls, and storage containers. Food-contact status is evaluated under 21 CFR 177.1040 for the copolymer and Commission Regulation (EU) No 10/2011 for EU market release, but migration testing with the intended food simulant is mandatory because colour concentrates and processing aids can shift overall migration. Continuous use with boiling water is outside the operational envelope. Stress cracking may develop in dishwashers operating above 75 °C. Tensile property checks under ASTM D638-14 at 23 °C are used to confirm that reground material does not reduce elongation at break below the lot-specific baseline. Notched Izod impact remains the limiting mechanical factor under ASTM D256; the grade is not a drop-in replacement for impact-modified ABS in this application.

When PN-138H Replaces ABS in Cosmetic Jar Closures

Clarity and chemical resistance in primary cosmetic packaging create a different acceptance matrix than food-contact moulding. PN-138H is converted into thick-wall jar closures, cream jar bodies, compact cases, and lipstick sleeves where transparency and scratch resistance are aesthetic requirements. Unlike ABS, the SAN copolymer does not require an opaque rubber phase, so wall sections up to 3.5 mm retain light transmission above 88 % under ASTM D1003 at 3 mm thickness; actual values depend on tool polish and processing. Thick-wall filling requires a two-stage holding pressure profile: an initial 600–800 bar packing pressure for 3–5 s, followed by a lower 300–400 bar holding phase for the remaining cooling time. Mould temperature is raised to 60–80 °C in closures with large planar surfaces to reduce internal stress and to delay stress cracking when the closure is exposed to cream bases. The main technical risk is environmental stress cracking caused by esters, essential oils, and ethanol-containing formulations. Compatibility is assessed by exposing moulded closures to the finished formulation at 40 °C for 72 h under a fixed strain of 0.5 %; visible crazing or a loss of gloss below 85 GU under ASTM D523 is treated as a rejection criterion. Hot stamping and metallized inner cups are processed at 150–180 °C for 0.5–1.0 s, which is below the distortion range of the grade. In-house scrap is limited to 15 wt% in cosmetic outer shells unless the lot-specific MFR under ISO 1133-1:2022 remains within ±10 % of virgin resin. Compliance for cosmetic packaging rests on the general safety framework of Regulation (EC) No 1223/2009 for the finished cosmetic article and on REACH Article 33 for SVHC communication. A direct food-contact declaration is not assigned unless migration testing under EU 10/2011 has been completed.

Hydraulic pressure decay testing is used when PN-138H is selected for transparent filter sumps and water-treatment housings instead of opaque engineering thermoplastics. The component is moulded with a uniform wall section of 3.0–4.5 mm to provide hoop strength under cyclic pressure. Mould fill is carried out with a sequential valve-gated hot runner; direct centre gating avoids visible knit lines at the threaded neck. A two-stage injection velocity profile reduces jetting: the first 20–30 mm of screw stroke is run at 15–25 mm/s, followed by a fast fill at 60–100 mm/s and a final deceleration to 10–15 mm/s before transfer to holding pressure. Holding pressure is maintained at 500–700 bar for 8–12 s, and cooling time is extended by 20–30 % relative to 2 mm wall sections to prevent vacuum voids at the thread root. After moulding, the transparent sump is tested under NSF/ANSI 61 for drinking-water contact and under a hydrostatic pressure of 1.5 times the rated service pressure for 15 min; any leakage, visible crazing, or thread-diameter deformation greater than 0.5 % is nonconforming. The grade is suitable for intermittent exposure to municipal chlorinated water at pH 6.5–8.5. Continuous contact with oxidizers above 5 mg/L free chlorine or elevated temperature above 50 °C can embrittle the sealing surface. Threaded inserts and O-ring grooves are machined with a radius of at least 0.8 mm to reduce notch sensitivity. Terminal parts include filter housings, sight glasses, and water trap bowls. Published data for this specific configuration is limited; burst-pressure capability must be confirmed by the converter using the actual thread geometry and closure torque.

What Limits Cycle Time in 48-Cavity Pen Barrel Tooling?

In multi-cavity stationery and office-product moulding, the controlling cycle-time factor is gate freeze and part ejection, not melt plastication. PN-138H is used in pen barrels, transparent rulers, document trays, and desk-accessory housings. The high-flow grade allows filling of 0.8–1.5 mm wall sections across 32–48 cavities from a valve-gated hot runner. Melt temperature is set at 210–230 °C in the manifold and 230–245 °C at the nozzle, with a variation of less than ±3 °C measured by nozzle thermocouple. The valve pins open in a staggered sequence: inner cavities first, then outer cavities after 0.3–0.5 s. This balances cavity pressure and prevents short shots at the end of the manifold. Injection velocity is set to a peak of 80–120 mm/s, and switchover is made by cavity pressure at 600–800 bar rather than by screw position. Holding pressure is held for 2–4 s, and the tool is cooled with water at 10–15 °C to freeze thin-walled pen barrels without sink. Industrially reported cycle times for similar high-flow SAN grades are 12–18 s for 2 mm nominal wall sections in 48-cavity tools, but published data for this specific configuration is limited. Ejection uses 8–16 pneumatic ejection stages with a stroke of 5–10 mm to prevent part distortion. Optical acceptance for transparent rulers is checked under ASTM D1003; haze above 1.5 % at 2 mm is rejected. Edge-gate vestiges are trimmed to below 0.1 mm for writing instruments. Compliance for stationery is limited to REACH Annex XVII and EN 71-3 when the articles are marketed as general consumer goods. The grade does not carry a specific toy declaration unless migration of restricted elements is confirmed on the final article.

Assigning the Grade to Small-Appliance Light Lenses

Assigning PN-138H to small-appliance light lenses and control knobs requires evaluation of thermal service under the appliance standard rather than only optical clarity. The material provides high surface hardness and transmission in 1.5–2.5 mm lens sections, and it can be polished to SPI A-1 finish with a diamond compound below 3 µm. Mould temperature is maintained at 60–80 °C, and the cooling circuit is balanced to hold a temperature difference across the lens of less than 5 °C; uneven cooling produces uneven birefringence visible under polarized light. Melt temperature is held at 220–240 °C, and the nozzle is equipped with a shut-off tip to avoid drool. The main limiting property is heat deflection: continuous service above 75 °C under load is not recommended for general-purpose SAN grades, and appliances with incandescent bulbs in direct contact require a heat shield or a different material. For LED-based indicator lenses, the heat load is lower and the material is acceptable when the lens temperature remains below 60 °C. Flammability is evaluated under IEC 60695-11-10 and is typically HB at 1.5 mm or 3.0 mm; higher ratings require flame-retardant grades and are outside the standard property set. Impact resistance is verified under IEC 60068-2-75 spring hammer or IEC 60335-1 clause 21.1 for mechanical strength. Ultraviolet exposure is a known boundary: prolonged outdoor light or UVC from disinfection lamps yellows the SAN surface, so the grade is specified only for indoor light diffusion. Terminal components include control knobs, LED diffusers, and refrigerator shelf supports. Compliance for EU electrical and electronic articles is confirmed under RoHS Directive 2011/65/EU Annex II and REACH; EN 60335-1 governs end-product safety.

Battery Case Assembly and Solvent-Bonded Joint Integrity

Transparent battery cases and non-invasive diagnostic housings are converted from PN-138H where the end-user must visually inspect cell orientation and leakage. The material is selected for resistance to alkaline electrolytes and for dimensional stability in snap-fit and solvent-bonded assemblies. Moulding is performed with a melt temperature of 210–230 °C, and the tool is maintained at 50–70 °C to reduce moulded-in stress at clip attachments. Clip arms are gated from the thickest section, and the melt is injected at moderate velocity of 30–60 mm/s to avoid shear heating in the narrow clip root. Solvent bonding is carried out with methyl ethyl ketone or a styrene-acrylonitrile solvent blend applied at 0.5–1.0 mL/m of joint length; the joint is fixtured for 2–5 h at 23 °C before leak testing. A destructive peel test under ASTM D3167 is used to verify that solvent-bonded seams exceed 20 N/25 mm; lower values indicate inadequate surface preparation or residual mould release. Battery leakage testing is performed with 1M KOH on the assembled case for 24 h at 45 °C; blistering, stress cracking, or loss of transparency above 5 % under ASTM D1003 is nonconforming. The operational temperature boundary is 50 °C continuous and 65 °C peak for alkaline battery compartments. Lithium-ion cell housings that rise above 70 °C during charging or thermal runaway testing are outside the grade’s recommended scope. Compliance is verified under IEC 62133-2 for battery system construction, RoHS Directive 2011/65/EU, and UL 94 HB at the final wall thickness. Terminal parts include alkaline battery holders, transparent case shells for portable instruments, and diagnostic cuvette adapters.

Laboratory and diagnostic housings impose a different requirement profile based on short-cycle exposure to reagents and repeated sterilization. PN-138H is used for cuvette adapters, microplate support frames, and non-sterile diagnostic instrument covers where transparency and dimensional accuracy are required. The melt is processed at 215–235 °C, and the tool surface is specified as high-gloss chrome-plated steel with a surface finish below Ra 0.05 µm. Drying is mandatory at 80 °C for 3–4 h with a desiccant dryer dew point below -30 °C. The shot is filled with a profiled velocity between 40–80 mm/s, and switchover is completed by screw position at 3–5 mm before the cushion. Holding pressure is maintained at 400–600 bar for 2–4 s to stabilize micro-features such as optical windows and snap-fit ribs. Chemical exposure is limited to short-term contact with dilute acids, bases, and alcohols at room temperature. Continuous immersion in strong solvents, ketones, or esters is incompatible. Sterilization is limited to gamma irradiation at doses below 25 kGy or ethylene oxide at 50–55 °C; steam autoclave cycles above 121 °C cause distortion and are excluded. Dimensional acceptance is checked under ISO 16012 for linear dimensions on moulded parts. Optical transmission is verified under ASTM D1003 after sterilization. Compliance is governed by RoHS Directive 2011/65/EU, REACH, and instrument-specific biocompatibility evaluation under ISO 10993-1 when skin or tissue contact is intended.