Chi Mei KIBISAN SAN PN-127L150 is a styrene-acrylonitrile copolymer pellet supplied as a high-flow, general-purpose injection-moulding grade within the KIBISAN SAN product series. The PN-127L150 designation places the material in the lubricated high-flow segment of the portfolio, with a nominal melt flow index of 15 g/10 min when tested at 200°C/5 kg under ASTM D1238. Because the resin is amorphous, it transmits visible light with a luminous transmittance near 90% and a haze level near 1.5% on a 3 mm plaque per ASTM D1003. Density is reported at 1.06 g/cm³ per ISO 1183-1:2019, and the material exhibits the characteristic styrene-acrylonitrile balance of surface hardness, dimensional stability, and resistance to aliphatic hydrocarbons, dilute acids, detergents, and vegetable oil. Published data for this specific configuration is limited to supplier bulletins and distributor data sheets; all values are screening data and must be replaced by lot-specific certificates of analysis for production qualification.

The polymer is primarily intended for injection moulding of transparent thin-wall parts, including cosmetic packaging, water filter housings, refrigerator shelf edging, mixer bowls, blender jars, and appliance indicator lenses. In melt processing, the high-flow classification reduces injection pressure and permits shorter holding-pressure times, but it also narrows the impact and elongation envelope relative to lower-flow SAN grades; the property trade-off is quantified by tensile strain at break under ISO 527-2:2012 and notched Izod impact under ISO 180/A. Because the grade does not contain a rubber phase, it is not a direct substitute for opaque ABS in snap-fit or high-impact structural parts. The product can be considered where transparency and chemical resistance matter more than low-temperature impact.

What separates PN-127L150 from lower-flow KIBISAN grades and general-purpose polystyrene?

The grade is differentiated from lower-flow KIBISAN SAN products such as PN-117C and PN-127L100 primarily by melt viscosity and molecular-weight-dependent mechanical properties. A lower-viscosity melt reduces filling pressure and improves shearing of fine features, but it also reduces notched impact and tensile elongation at break. The selection is therefore a balance between mouldability and toughness. When measured on the same tool, the higher melt-flow material can reduce peak injection pressure by approximately 5 MPa to 15 MPa relative to a low-flow SAN grade for a 1 mm wall transparent housing, depending on gate size and shear rate; published data for this specific configuration is limited, so this range should be confirmed with spiral-flow studies or cavity-pressure sensors on the production tool.

Against general-purpose polystyrene, PN-127L150 offers higher heat deflection temperature and better resistance to detergent stress cracking and hydrophobic foodstuffs. It requires a barrel temperature that is typically 20°C to 30°C higher than crystal polystyrene because the acrylonitrile comonomer raises the melt viscosity and glass-transition temperature. Against poly(methyl methacrylate), the SAN grade has lower density by approximately 0.12 g/cm³, lower water absorption, and better resistance to alcohol-water mixtures and surfactants, but inferior ultraviolet stability and surface hardness. In any replacement programme, accelerated weathering under ISO 4892-2 and constant-strain chemical exposure under ISO 22088-2:2006 should be completed before deleting acrylic.

Against acrylonitrile-butadiene-styrene, PN-127L150 is transparent and has a higher modulus but much lower notched Izod impact. Unfilled ABS grades commonly exceed 15 kJ/m² at 23°C under ISO 180/A, whereas unfilled SAN grades are typically below 3 kJ/m². This distinction governs product design: snap-fit lugs, living hinges, and threaded bosses with flank interference must be derated for SAN to avoid stress cracking, and prototypes should be tested at the lowest expected use temperature, typically -10°C to 0°C for freezer-contact parts.

Moisture control is the first processing boundary because styrene-acrylonitrile pellets can pick up sufficient surface moisture in humid warehouses to cause splay in transparent sections. When the material has been stored in an open gaylord at relative humidity above 60% or at temperatures below dew point, a desiccant dryer set at 80°C for 2 h to 4 h is required. The target residual moisture should be below 0.05% by weight; halogen moisture analysers calibrated to 0.01% resolution are suitable for in-line verification. Over-drying at 90°C for more than 6 h can cause slight yellowing because the styrenic backbone is susceptible to thermo-oxidative discolouration; yellowness index measured under ASTM E313 should remain below 2.0 on a 2 mm plaque during acceptable processing.

The barrel should use a general-purpose screw with 20:1 to 24:1 L/D and compression ratio between 2.0:1 and 2.5:1. A feed-zone temperature of 190°C, compression-zone temperatures of 210°C to 220°C, and a nozzle temperature of 220°C to 230°C are typical, with a melt-temperature limit of 240°C. At melt temperatures above 250°C, chain scission accelerates, visible colour shifts appear, and volatile emission increases; the residence time should not exceed 5 min when the barrel is above 230°C. On a production-scale injection moulder with a 100 t clamp force, viscosity drift is monitored through hydraulic pressure at a constant fill speed; a deviation greater than 5% from the start-up baseline warrants checking dryer dew point, regrind ratio, or barrel temperature calibration.

Mould temperature should be held between 40°C and 70°C. The lower bound reduces cycle time but can freeze weld lines and reduce surface gloss; the upper bound improves weld-line strength and micro-texture replication but extends cooling. For thin-wall sections below 1.0 mm, the mould should be set to 60°C to 70°C and injection velocity should be increased until jetting or gate blush appears. Vent depths for SAN are typically 0.02 mm to 0.03 mm; inadequate venting causes burn marks and mould staining. Because the grade is high-flow, flash can occur at parting-line clearances above 0.03 mm, so the clamping system and mould alignment must be verified with pressure-sensitive film before production.

Regrind use is possible up to 20% by mass in transparent applications when the regrind is clean, dust-free, and free of foreign polymer. Polypropylene, polyethylene, and EVA are immiscible with SAN; contamination at even 1% can produce visible haze, weld-line splitting, and delamination. Colour masterbatches should use a styrenic carrier; polyolefin or EVA carriers should be avoided. In black or opaque parts, higher regrind levels may be acceptable if melt-flow index and Izod impact are retested per ASTM D1238 and ISO 180/A, but the burden of establishing lot consistency lies with the moulder.

When transparent chemical resistance justifies replacement of acrylic or ABS

In cosmetic packaging, personal-care pump bodies, blender jars, water filter housings, and refrigerator crisper trays, PN-127L150 is evaluated where the part must tolerate intermittent contact with alcohol-water mixtures, surfactants, vegetable oil, or dilute fruit acids without stress whitening. Chemical compatibility is not universal. Constant-strain exposure to acetone, methyl ethyl ketone, ethyl acetate, toluene, xylene, or chlorinated hydrocarbons produces crazing and rapid loss of mechanical integrity in SAN. The substitution of acrylic by SAN should be supported by constant-strain testing under ISO 22088-2:2006 in the final product geometry and with the intended packaging medium, because moulded-in residual stress can shift the stress-cracking threshold below the value obtained on unstressed plaques.

Food-contact status is not automatic for the pellet. For the United States, the final article should be evaluated under 21 CFR 177.1040 for acrylonitrile-styrene copolymers, including restrictions on residual acrylonitrile monomer and total non-volatile extractives under the intended food-simulant and use temperature. In the European Union, Regulation EU No 10/2011 applies, with specific migration limits for styrene and acrylonitrile and a documented declaration of compliance for the final article. Published data for this specific configuration is limited for hot-fill or microwave conditions above 70°C; migration testing under the exact time-temperature profile is mandatory before commercial release.

Water filtration housings and clear appliance reservoirs benefit from SAN’s water absorption, typically near 0.2% after 24 h immersion per ISO 62. This value is lower than many polycarbonate grades and contributes to reduced warp after washing cycles, but it does not eliminate the need for mould-flow-balance validation. In a production mould with hot runners, the gate-freeze time for a 2 mm wall is short, and process engineers should use pressure-drop studies and short-shot series to verify that the high-flow grade does not flash at parting-line gaps above 0.03 mm. The high-flow characteristic also permits reduced packing pressure, but sink marks must still be controlled by gate geometry and cooling-channel placement.

Optical quality is controlled by melt-temperature uniformity, pigment dispersion, regrind quality, and mould polish. Cavities for transparent parts should be polished to SPI A-1 or equivalent; gate blush and jetting are the most common optical defects in transparent SAN injection moulding. Haze values below 2% at 3 mm wall under ASTM D1003 are achievable when processing conditions are balanced; thermal history and mould fouling raise haze over extended runs. Yellowness index under ASTM E313 on a 2 mm plaque should be monitored every 2 h during long runs to detect degradation before it is visible in the part. Pigmented transparent colours require a styrenic compounded carrier and a let-down ratio that maintains the required colour coordinates under CIE 1976 L*a*b* colour space.

Mould shrinkage is commonly reported in the range 0.2% to 0.6% per ASTM D955, with lower values in the flow direction and higher values across flow in unreinforced SAN. Shrinkage anisotropy must be considered in cylindrical water filter housings and rectangular containers because warpage increases with gate layout, wall thickness, and mould-temperature asymmetry. The glass-transition temperature is below 110°C; ejection with a cavity-surface temperature above 95°C can cause sink marks and dimensional drift after cooling. Cooling-time calculations should use a thermal diffusivity appropriate for amorphous SAN and a cavity-surface temperature measured by an inserted thermocouple rather than the water manifold temperature.

On twin-shot or over-moulded assemblies, styrene-acrylonitrile is compatible with styrenic thermoplastic elastomers but not with olefinic TPEs; trials with olefinic TPEs fail by interfacial delamination. For ultrasonic welding, the high modulus and relatively low impact of SAN favour shear-joint geometry with positive interference rather than energy-director geometries. Weld strength should be verified by burst testing or tensile testing per ISO 527-2:2012 on the final assembly, because notched Izod data alone does not predict weld performance. For hot-plate welding, platen temperature in the range 240°C to 260°C is typical, but published data for this specific grade in welding applications is limited and preliminary weld trials are required.

Application Validation, Regulatory Compliance, and Boundary Conditions

Regulatory compliance for the pellet is typically evaluated against RoHS 2011/65/EU for lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers below the maximum concentration values; and against REACH Regulation (EC) No 1907/2006 for substances of very high concern on the candidate list. The supplier’s declaration must be maintained with the material batch, and the final article may require additional compliance documentation if flame retardants, pigments, or other additives are added downstream. Published data for this specific configuration is limited for some packaging-specific requirements; the moulder must obtain the latest regulatory statement from the resin supplier before use in children’s articles or medical-device housings.

Material handling and processing safety requires local exhaust ventilation at the moulding machine because trace styrene and acrylonitrile monomers can be released during melt processing. Occupational exposure limits for styrene and acrylonitrile must be checked against national regulations; the resin supplier’s safety data sheet contains the relevant hazard statements. Spilled pellets should be swept to prevent slipping, and fines should be collected with a non-sparking vacuum because dust clouds can form ignitable atmospheres. Waste material can be mechanically recycled when clean and source-separated, but it is not biodegradable and should not be disposed of in uncontrolled composting or landfill without local permit review.

In application validation, part qualification should include dimensional stability under environmental cycling, chemical resistance under the intended service fluid, and impact testing at the minimum service temperature. The high-flow nature of PN-127L150 supports thin-wall transparency and shorter cycles, but it also demands tighter control of parting-line tolerances, regrind quality, and melt residence time. These boundary conditions define the usable processing window more than the nominal property data alone.