Chimei KIBISAN SAN PN-117 L100 FG is a rigid, amorphous styrene-acrylonitrile copolymer supplied in cylindrical pellet form for injection moulding and sheet extrusion. The material is specified where transparency, surface hardness, food-contact clarity, and resistance to staining by beverages, edible oils, and household detergents are required. The FG suffix denotes a food-contact grade; the designation does not itself confer regulatory approval but identifies the neat resin as suitable for food-contact evaluation under the appropriate end-use test regime. Lot-specific certificates of analysis and migration test reports remain the responsibility of the converter or brand owner, because processing aids, regrind, colourants, and mould-release lubricants can alter final compliance.

Published datasheet values for the PN-117 L100 FG grade include a melt-flow rate of 2.8 g/10 min at 200°C under 5.0 kg load by ASTM D1238, a density of 1.06 g/cm³ by ASTM D792, and a tensile yield strength of approximately 68 MPa by ASTM D638. Flexural modulus is approximately 3.3 GPa by ASTM D790, and notched Izod impact at 23°C is 16.7 J/m by ASTM D256. Light transmittance at 3.0 mm thickness is 90% with haze of 1.0% under ASTM D1003. These are typical values only and should not be used as release specifications.

Material Constitution and the Regulatory Meaning of the FG Suffix

The base polymer is an acrylonitrile-styrene copolymer. The exact acrylonitrile comonomer content of PN-117 L100 FG is not separately published in the public datasheet; industrial SAN resins in this viscosity class typically lie between 24 wt% and 32 wt% acrylonitrile. The FG suffix indicates that the neat resin is intended for food-contact applications. In the United States, acrylonitrile copolymers used in food-contact articles may be evaluated under 21 CFR 177.1040; in the European Union, the finished article is typically assessed under Regulation (EU) No 10/2011 for overall migration and specific migration of acrylonitrile and styrene. For a finished article falling under Regulation (EU) No 10/2011, the overall migration limit is 10 mg/dm² for most food-contact applications and 60 mg/kg for food simulants intended for infants and young children, but the applicable reduction factors and test conditions depend on the final food category. Published data for high-temperature fatty-food contact above 100°C with this specific FG formulation is limited, and converters should not assume compliance for retort, microwave, or hot-fill conditions above the resin’s heat deflection temperature without additional migration testing.

The grade is not classified as impact-modified. Its comonomer sequence distribution produces a rigid amorphous structure with a glass transition temperature high enough to provide dimensional stability under low stress, but continuous load-bearing service above approximately 80–85°C can produce creep and stress relaxation. Published post-irradiation colour data for this exact FG grade is limited; gamma sterilisation may induce yellowing at dose levels commonly used for dry food-contact articles, and validation must be performed on moulded parts rather than pellets. Steam autoclave cycles above 100°C are not recommended because dimensional relaxation and surface haze may occur.

Properties in the table are generated on dry-as-moulded or annealed specimens at 23°C and 50% RH. The annealed HDT value of 100°C is not a continuous service temperature; it is a short-term deflection point under a 1.82 MPa flexural load. The Vicat softening point of 110°C is similarly a short-term surface indentation index. Long-term load-bearing applications should maintain wall stresses below approximately 10–15 MPa if ambient temperature can exceed 40°C, although published creep-rupture data for this specific FG grade is limited.

How Does the Resin Respond Under Standardised Thermal and Mechanical Loading?

Under tensile loading, failure occurs with 3.0% elongation at break, which classifies the resin as a rigid glassy polymer with low ductility. The high flexural modulus of 3.3 GPa provides stiffness but also concentrates stress at sharp radii, gate vestiges, and internal weld lines. In notched Izod testing at 23°C, the value of 16.7 J/m places the material below impact-modified grades such as ABS; at -20°C the impact resistance typically falls further, although the exact low-temperature value for the FG-modified lot is not published. Consequently, parts designed from PN-117 L100 FG should use generous radii of at least 1.0 mm at corners, avoid deep undercuts, and place gates away from high residual stress regions.

Thermal expansion is typical of amorphous styrenic resins; the coefficient of linear thermal expansion is on the order of 6–8 × 10^-5 /°C, which is higher than that of aluminum and steel. Differential thermal expansion in metal-insert moulded components can generate cracking when ambient temperature cycles exceed 50°C. Post-mould annealing of machined or solvent-wiped parts at 70°C for 1–2 h reduces moulded-in stress and improves resistance to environmental stress crazing by alcohol-based cleaning agents.

Chemical resistance of the resin is moderate against aliphatic hydrocarbons, aqueous acids, alkalis, and common household detergents. Continuous immersion in ketones, esters, chlorinated hydrocarbons, aromatic hydrocarbons, or hot concentrated oxidising acids is not recommended. Alcohols such as methanol and ethanol can initiate environmental stress crazing in regions of high moulded-in stress; flame polishing or solvent polishing should therefore not be used on stressed parts. Food-contact articles intended for fatty foods above 60°C should undergo specific migration testing for acrylonitrile and styrene monomers, because diffusion coefficients are temperature-dependent and extraction into oil simulants increases with contact temperature and time.

Injection Moulding, Sheet Extrusion, and Re-Grind Boundaries

Before melt processing, pellets should be dried in dehumidified air at 80°C for 2–4 h to a final moisture content below 0.05% by mass. Storage outside sealed moisture-barrier packaging at relative humidity above 60% requires re-drying before extrusion. Barrel temperature settings can start at 180°C in the rear zone and increase to 220–230°C at the nozzle; melt temperature should be maintained at 220–240°C. Residence time above 240°C should not exceed 5 min, because prolonged residence can generate yellowing, gel specks, and a downward drift in melt viscosity due to chain scission. A screw with L/D ratio between 20:1 and 24:1 and compression ratio of 2.0:1–3.0:1 is suitable for homogeneous plastication.

On production-scale injection moulding machines with clamp force from 800 kN to 3,000 kN, the material is typically processed with a shot size of 30–70% of barrel capacity. Cushion control is critical; a cushion below 2 mm can reduce hold pressure transfer and increase sink marks, while cushion above 8 mm extends residence time and can cause yellowing. Gate freeze should be established by weight-versus-hold-time studies rather than fixed timers, because hot-runner and cold-runner systems differ in gate cooling rate.

Mould temperature should be held at 40–70°C to balance surface gloss and cycle time. Higher mould temperatures improve surface finish and reduce residual stress but increase cooling time and may increase cycle time by 15–20% compared with 30°C mould conditions. Injection velocity should be moderate to avoid jetting; a gate diameter or thickness of at least 50% of the nominal wall is recommended. Packing pressure of 60–80 MPa and hold time of 5–10 s per 2.5 mm of wall thickness minimise sink marks and dimensional variation. Batch-to-batch variance in melt viscosity is normally controlled by the manufacturer, but converters should track first-stage filling time as an early indicator of lot changes.

For sheet extrusion, die temperature should be set between 230°C and 250°C. Roll stack temperatures from 80°C to 100°C are used to obtain high gloss; lower roll temperatures reduce haze but increase orientation. Edge trim and start-up sheet can be re-ground at levels up to 20 wt% provided the regrind is dried and free of foreign polymers. PVC contamination must be avoided because thermal degradation of PVC liberates hydrogen chloride and can produce black specks and surface pitting. Acetal contamination is also incompatible and should be excluded from the recycling stream.

When Impact Strength Is Secondary, This SAN Grade Offers a Distinct Property Envelope

Compared with general-purpose polystyrene, PN-117 L100 FG raises heat deflection temperature by approximately 15–25°C and improves resistance to edible oils, weak acids, and stress crazing, while maintaining a comparable transparent appearance. The tensile yield strength of SAN is approximately 68 MPa, compared with 40–50 MPa for GPPS; however the SAN resin remains brittle in thick sections. Compared with general-purpose ABS, the SAN grade is transparent and harder but has notched Izod impact about an order of magnitude lower. ABS should be selected when repeated impact, snap-fit assembly, or ductile failure is required. The FG suffix adds a food-contact evaluation dimension that standard GPPS and general-purpose ABS grades may not carry.

Class ranges in the following table are representative published ranges for unfilled general-purpose grades and are not specification values for the FG product.

Operational boundaries for this resin include the avoidance of continuous load-bearing service above approximately 80°C, avoidance of ketone- or ester-based cleaning solvents, and exclusion of PVC and acetal contamination from the recycling stream. The grade is not recommended for hot-fill packaging above 90°C unless the package is geometrically stable under the fill pressure and the food-contact layer is migration-tested at the upper fill temperature. Published data for retortable food-contact packaging based on this specific FG grade is limited; converters should not extrapolate from typical SAN steam-sterilisation data without part-level validation.