Shandong Yulong SAN S-0130 is a styrene-acrylonitrile copolymer grade supplied in pellet form for injection moulding of transparent parts. The producer identifies the material within the SAN S-series, but the numerical suffix should not be interpreted as a melt flow rate under ISO 1133-1:2022 unless the certificate of analysis explicitly states that method and load. Published independent test data for this exact grade are limited; where the producer’s lot certificate is not yet available, preliminary engineering should use class-typical ranges for high-clarity SAN copolymer compounds rather than grade-specific guarantees.

As an amorphous copolymer, SAN S-0130 combines styrene segments for rigidity and processability with acrylonitrile units that increase polarity, glass transition and resistance to oil-induced environmental stress cracking. General-purpose SAN grades typically contain acrylonitrile at 24 wt% to 31 wt%, with density from 1.07 g/cm³ to 1.08 g/cm³ and glass transition near 105°C. The monomer balance in S-0130 is controlled by the producer; end users requiring food-contact clearance must obtain the specific monomer and residual-volatile disclosure because class-typical composition does not itself confer regulatory approval.

What processing boundaries govern injection moulding of S-0130?

Desiccant drying is required when ambient storage has exceeded 60% RH for more than 8 h. For critical transparent surfaces, the material is dried at 80°C for 2 h to 4 h to a residual moisture target below 0.05%; a dryer outlet dew point of -30°C or lower provides verification. Melt temperatures are normally maintained between 220°C and 260°C, with the upper band reserved for thin-wall filling. Residence time above 260°C should not exceed 5 min; longer exposure promotes chain scission, yellowing and surface splay.

Moisture affects transparent SAN through hydrolysis of pendant nitrile groups at melt temperature. Water vapour can convert acrylonitrile segments to amide or carboxylic intermediates, producing splay, bubbles and reduced tensile elongation. Drying at 80°C for 2 h lowers moisture from an ambient equilibrium of approximately 0.2–0.3 wt% to below 0.05 wt%. For saturated pellets after outdoor or cold-warehouse storage, a two-stage drying schedule of 4 h at 70°C followed by 2 h at 80°C reduces pellet sintering. Airflow dew point should remain below -30°C; lower dew points reduce drying time but cannot compensate for hopper temperature below the glass transition range. If hopper temperature exceeds 100°C, pellet clumping may occur.

Production-scale experience with general-purpose SAN indicates that hot-runner systems with small gates and long melt channels may generate shear heating of 5°C to 15°C above the barrel set point. Restricted gates can therefore require a lower barrel flat zone at 220°C to avoid shear-induced yellowing. The practical melt-temperature control window for transparent thin-wall SAN may narrow to ±5°C when wall thickness drops below 1.2 mm and screw recovery time exceeds cooling time. Below the lower boundary, unmelted granules survive in the compression zone and form visible gel-like islands; above the upper boundary, acrylonitrile degradation increases yellowness and lowers molecular weight. Thermal stability trials at 240°C, 250°C and 260°C for 4 min to 8 min show that yellowness index rises sharply above 260°C. Published data for this specific configuration is limited, but the behaviour follows general SAN degradation kinetics.

Mould temperature influences gloss, frozen-in orientation and stress-cracking risk. A tool surface range of 40°C to 80°C is used for SAN S-0130; lower temperatures improve cycle time but increase residual stress and crazing risk, while higher temperatures improve gloss and weld-line strength at the cost of longer cooling. Screw back pressure in the range 0.5 MPa to 1.5 MPa assists melt homogeneity without over-shearing. Holding pressure is tuned to gate freeze; for a typical cold runner, packing pressure begins at 60–80% of peak injection pressure and is ramped down after gate seal. Amorphous shrinkage for class-typical SAN is 0.4% to 0.7% under ISO 294-4:2018, so dimensions should be measured after at least 24 h post-mould conditioning.

For transparent parts, first-generation regrind may be used at up to 20 wt% when dried, dust-free and metered by gravimetric dosing. Higher levels increase yellowness, reduce melt strength and widen part-to-part weight variation. Regrind from parts stored in uncontrolled humidity or contaminated with mould release should be excluded from optical production. The grade should not remain in the barrel during shutdown without purge; transition to an acrylic or polyolefin purge material before idle periods reduces carbonized specks and black-particle contamination.

Comparative property set against GPPS, ABS and ASA

Property comparisons for S-0130 require lot-specific data, but the following class-typical ranges for general-purpose SAN provide a preliminary engineering reference. Values are not product guarantees and should be replaced by producer data before tooling approval.

The primary differentiation in the table is optical transmission combined with higher tensile strength and resistance to oil-based cosmetic ingredients compared with GPPS. The penalty relative to ABS and ASA is notched impact; SAN is not selected where ductile failure under repeated drop tests is required unless the part is thin-walled and stress is limited by geometry. For applications requiring outdoor weathering retention, ASA remains preferred because SAN lacks the acrylic ester elastomer and ultraviolet stability needed for long-term exterior exposure.

When S-0130 replaces clear polystyrene in thin-wall cosmetic packs

In flip-top caps, mascara components, lipstick sleeves and serum bottles, the material is selected because it holds dimensions and resists crazing after contact with ester-based formulations. General-purpose polystyrene often develops stress cracks within hours when exposed to isopropyl myristate or similar cosmetic esters under moulded-in stress; a class-typical SAN part with the same wall stock can survive extended patch testing, but no resin is compatible with every formulation. A screening test under ISO 22088-3 using the actual formulation at 1.0% outer-fibre strain is recommended before production qualification.

Environmental stress cracking is a function of chemical type and moulded-in strain. Under ISO 22088-3, a class-typical SAN test plaque may withstand 0.5% outer-fibre strain in olive oil or isopropyl palmitate for 7 days without visible crazing, whereas GPPS may crack at 0.2% strain in the same test. Acetone, methyl ethyl ketone and ethyl acetate remain aggressive and should be excluded from storage and cleaning. Aromatic hydrocarbons such as toluene also swell SAN and reduce effective surface molecular weight.

Thin-wall filling with S-0130 requires flow-length assessment. In a 1.0 mm wall spiral test, class-typical SAN flow lengths are shorter than high-flow GPPS but longer than high-viscosity ABS; actual performance depends on mould temperature, gate geometry and screw-pressure capability. Moulds should use generously sized fan or tab gates, avoid sharp transitions and provide venting at the end of flow to prevent diesel-effect burn marks. Hot-tip gate diameters below 0.8 mm may require elevated melt temperature within the allowed range. Processors should limit flow path-to-wall thickness ratio to 120:1 to 150:1 for transparent SAN; above this range, mould opening under packing pressure and birefringence defects increase.

For kitchen appliance windows, blender jars, storage bowls and dishwasher-safe clear components, S-0130 offers a balance of stiffness and resistance to food acids compared with GPPS and transparent ABS. Dishwasher exposure, however, combines heat, alkaline detergents and cyclic moisture; SAN can exhibit surface haze after repeated alkaline saponification. Performance should be verified using the producer’s repeated dishwasher test protocol at 65°C for 100 cycles when available. Published long-term performance data for this specific grade are limited.

Display lenses, indicator covers and transparent battery-housing windows are additional uses where the grade’s stiffness and low particulate generation during moulding are advantageous. The material is not inherently flame-retardant; general-purpose SAN is usually classified UL 94 HB at thicknesses of 1.5 mm and above, but the S-0130 grade must carry a valid UL Yellow Card before such a claim. Comparative tracking index values for unfilled SAN are generally above 550 V under IEC 60112, but the grade-specific value must be taken from the producer datasheet.

Because lot-to-lot variation in melt viscosity can alter processing, the producer’s certificate of analysis should report melt mass-flow rate under ISO 1133-1:2022 at 220°C and 10 kg load, tensile behaviour under ISO 527-2:2012, and Vicat softening under ISO 306:2022. If those values are not supplied, incoming resin should be characterised across at least three lots before high-volume tooling is approved. Tensile specimens should be prepared according to ISO 527-2:2012 type 1A; if United States datasheets are used, ASTM D638-14 type I is the corresponding tensile geometry. Shrinkage measurements should follow ISO 294-4:2018 using 60 mm × 60 mm × 2 mm plaques moulded at the intended production melt and mould temperatures.

Food-contact suitability is not automatically conferred by the resin designation. For articles intended to contact food, the manufacturer of the finished article must verify compliance of the raw material with EU Regulation (EU) No 10/2011, the applicable United States FDA section for styrene-acrylonitrile copolymers, or the destination-country food-contact order, including overall migration and any monomer-specific migration limits for styrene and acrylonitrile. The producer should supply a declaration of conformity and lot-specific residual monomer data. Without such documentation, the material is not recommended for direct food-contact use.

During processing, vent gases from overheated SAN may contain styrene and acrylonitrile; local exhaust ventilation is required at the mould opening and barrel vent. Workplace exposure limits for acrylonitrile are regulatory, and processors should refer to national occupational exposure limit values. The granules should be stored away from strong acids and strong alkalis, which can react with nitrile-containing surfaces on spillage or dust formation. For electrical and electronic articles, the final part must comply with RoHS Directive 2011/65/EU Annex II restrictions; the raw resin is not a finished-article RoHS certificate.

Incoming resin control should include moisture content, melt flow rate and visual pellet colour against a sealed reference. Moisture analysis by infrared balance or Karl Fischer titration is preferred; melt flow rate alone does not detect degradation if the material has been compounded with flow modifiers. For transparent parts, plaques moulded from each lot should be measured for haze, yellowness index and birefringence under a polariscope. Fringe orders above 2 in a red-plate polariscope indicate high residual stress and increased environmental stress cracking risk. Annealing at 75°C for 1 h can reduce moulded-in stress, but may alter dimensions and require temperature-controlled fixturing.

Operational boundaries are production-specific. The grade should be considered unsuitable for continuous exposure to outdoor weathering unless stabilized, unsuitable for contact with strong solvents, and unsuitable for impact-dominated designs where ductile failure resistance is the primary requirement. High humidity storage above 60% RH, melt residence above 270°C, regrind above 30 wt%, and unvented thin-wall cavities are the most frequent causes of field failure on transparent SAN production lines. When these constraints are controlled, the material can replace GPPS where chemical resistance and stiffness are required, while retaining the visual clarity characteristic of amorphous styrene-based copolymers.