Aclo Compounders Accutech SAN SAN930G10L is a glass-reinforced styrene-acrylonitrile copolymer compound supplied for injection moulding applications in which unfilled SAN lacks sufficient stiffness or dimensional stability. The grade designation identifies a 10 wt% glass-fibre loading in a SAN matrix; the suffix L is commonly associated with a lubricated modification intended to reduce injection pressure and improve mould release in thin-wall tools. Published data for this specific configuration is limited; therefore, the processing envelope and property expectations below are drawn from the general class of 10% short-glass SAN compounds and from characterisation methods defined by ISO and ASTM. Density for the glass-reinforced SAN class is typically 1.15 g/cm³ to 1.20 g/cm³ according to ISO 1183-1. Compared with unfilled SAN, the compound exhibits higher melt viscosity, lower mould shrinkage, and pronounced anisotropic contraction governed by fibre orientation.

Glass Fibre Reinforcement Level and Its Microstructural Consequences

At 10 wt% loading, the compound operates in the short-fibre reinforcement regime. Glass fibres act as a discontinuous rigid phase within the amorphous SAN matrix, and the residual fibre length after plastication controls the attainable modulus. For general-purpose short-glass SAN compounds, mean residual fibre length typically falls from 200 μm to 400 μm after injection moulding; values at the upper end require low screw shear and generous gate dimensions. Tensile modulus measured by ISO 527-2 in the partially aligned flow direction commonly ranges from 5.0 GPa to 6.5 GPa, while flexural modulus measured by ISO 178 is typically 5.5 GPa to 7.0 GPa. These compare with an unfilled SAN baseline near 3.6 GPa. The increase in stiffness is accompanied by a sharp reduction in tensile strain at break, often below 3%, and by a rise in notch sensitivity under ISO 180/A. Unnotched impact results may be less affected, but fibre ends create stress concentrations and should be considered in design of snap-fit arms and bosses.

Tensile strength under ISO 527-2 for the 10% glass-reinforced SAN class is generally between 65 MPa and 85 MPa, while flexural strength under ISO 178 is commonly 100 MPa to 130 MPa. These values are strongly dependent on fibre orientation: specimens cut perpendicular to the flow direction may fall 20% to 30% below flow-direction values. Creep modulus at 23 °C under continuous stress remains above 80% of initial modulus at 1,000 h for the class, but elevated temperature and high stress shift this retention downward. The amorphous SAN matrix does not exhibit the delayed crystallisation effects seen in glass-reinforced polypropylene and therefore shows more predictable long-term stiffness under isothermal conditions.

Relative to glass-reinforced ABS, SAN930G10L does not contain a polybutadiene rubber phase. The absence of that phase lowers low-temperature ductility and notched impact strength, but it also improves resistance to stress cracking in aliphatic hydrocarbons and some household oils. Relative to unfilled SAN, the glass-fibre modification increases heat deflection temperature measured under ISO 75-2, but the improvement is less than that obtained with crystalline resins because SAN remains amorphous. The practical advantage is therefore stiffness and creep resistance at moderate temperatures rather than an increase in continuous heat resistance. Another relevant comparison is with acrylonitrile-styrene-acrylate compounds at equivalent glass loading. ASA retains better ultraviolet resistance because the acrylate rubber is saturated, but SAN930G10L is positioned for indoor industrial components where UV exposure is intermittent. The acrylate rubber in ASA also provides higher notched impact strength at low temperature; however, the SAN matrix in SAN930G10L generally provides a stiffer, harder surface and better resistance to staining in some lubricant-rich environments. Outdoor suitability should be validated against ISO 4892-2 for accelerated weathering if required.

Drying and moulding parameters for the 10% glass-reinforced SAN class are constrained by the twin requirements of moisture removal and fibre-length preservation. The starting parameters in Table 1 are not product specifications but represent typical ranges used on production-scale reciprocating-screw injection moulding machines with a general-purpose SAN screw.

How Does the 10% Glass Fibre Loading Affect Shrinkage and Warpage Behaviour?

Glass-fibre orientation creates direction-dependent mould shrinkage. Flow-direction shrinkage in moulded plates of the 10% glass-reinforced SAN class is commonly 0.2% to 0.4%, while transverse shrinkage can reach 0.3% to 0.6%, depending on gate type, wall thickness, and mould temperature. This anisotropy is the primary source of warpage in flat covers and housing bases. Shrinkage should be determined according to ISO 294-4 after 24 h conditioning at 23 °C and 50% RH. Gate location should align the melt flow front with the longest axis of the part, and a fan or tab gate is preferred over a central pin gate to reduce radial fibre alignment. Weld lines in parts with multiple gates will show locally reduced tensile strength, typically 30% to 50% lower than the bulk value, because glass fibres do not bridge the weld line effectively. For this reason, structural load paths should be kept away from knit lines, or the gate configuration should be altered to move the weld line to a low-stress area.

Fibre-length retention is sensitive to screw geometry and non-return valve design. A general-purpose screw with an L/D ratio of 18:1 to 22:1 and a compression ratio of 2:1 to 2.5:1 is adequate for the 10% glass SAN class. Bi-metallic barrel and screw surfaces are recommended for extended campaigns because glass fibres are abrasive. The non-return valve should be of the ring type with generous flow passages; ball-check valves can create high shear zones that degrade the SAN matrix and shorten fibre length. Residence time at melt temperatures above 250 °C should not exceed 5 min, and the barrel temperature profile should avoid steep transitions exceeding 20 °C per zone. Processors report yellowing and occasional black specks when material is left in a hot barrel during interruptions; purging with a neutral viscosity polyolefin is standard practice before shutdown.

The melt behaviour of 10% glass-reinforced SAN is pseudoplastic. Melt volume-flow rate under ISO 1133-1 is not a reliable indicator of injection behaviour because the fibre phase orients during flow and causes shear-thinning. Spiral flow tests on production-scale tooling with 2.0 mm wall thickness show flow lengths 15% to 25% shorter than unfilled SAN under identical injection pressure. Therefore, nozzle, runner, and gate diameters should be enlarged by 10% to 20% relative to unfilled SAN, and cold slug wells should be generously dimensioned. Cavity filling simulation with fibre orientation models should be used for parts with wall thickness below 2.5 mm or flow length-to-thickness ratios above 150:1.

The grade is suited to injection-moulded housings, brackets, pump components, appliance structural parts, and electrical enclosures where dimensional accuracy is required under moderate mechanical load. Typical wall thickness is 1.5 mm to 4.0 mm. Thin-wall moulding below 1.2 mm is possible only with high mould temperature and fast injection velocity, and the fibre content increases the risk of flow hesitation and exposed glass at the melt front. The compound should be stored in sealed containers at temperatures below 30 °C; opened bags should be consumed within 4 h in humid environments or re-dried before moulding.

When SAN930G10L Replaces Unfilled SAN in Rigid Load-Bearing Components

Substitution of unfilled SAN by the 10% glass-reinforced grade allows a reduction in wall thickness while maintaining flexural stiffness, because stiffness rises more rapidly than density. The density penalty is limited to 0.05 g/cm³ to 0.10 g/cm³ relative to unfilled SAN. Design changes should compensate for the lower elongation at break: snap-fit deflection must be reduced or the snap arm lengthened, and sharp internal corners should be radiused because fibre-end stress concentrations magnify notch sensitivity. The material also exhibits lower post-mould shrinkage creep under sustained stress than unfilled SAN, which is relevant for threaded inserts and press-fit assemblies. However, direct replacement of polycarbonate is not recommended where impact loading below 0 °C is expected, because the SAN matrix remains brittle at low temperatures.

Glass-fibre filled SAN is abrasive. Tool steel selection should include hardened steel of at least 52 HRC for high-wear areas such as gates, runner turns, and ejector pin openings. Hard chrome or nickel plating is used on cores and cavities to extend tool life, but coating adhesion can be compromised at processing temperatures above 260 °C. Production-scale experience indicates that gate inserts may require replacement after 50,000 to 100,000 cycles in high-speed moulding, depending on glass content and injection velocity.

Moisture absorption of SAN is lower than polyamide or polycarbonate, but the glass fibre sizing can retain surface moisture. Bags left open in an uncontrolled moulding shop at 60% RH can absorb enough moisture to generate splay in 30 min to 60 min. A portable dew-point meter should be used to verify dryer performance; dew point below −20 °C is necessary, and dew point above −10 °C is unacceptable for thin-wall optical or textured surfaces. After drying, the material should be conveyed in closed dry-air lines to the machine throat to prevent moisture regain.

Regrind addition is permitted in many non-critical applications, but the glass fibre length decreases with each heat history. A maximum regrind level of 20% is recommended to limit tensile modulus loss and impact deterioration. When regrind is used, the proportion should be kept constant to avoid batch-to-batch viscosity variation. Fines generated during grinding should be screened through a 500 μm mesh because fines increase moisture uptake and burning risk. Documented production-scale experience indicates that modulus retention above 95% is achievable with 20% regrind, provided the material is dried and processing conditions are maintained.

Surface aesthetics of glass-reinforced SAN are different from unfilled SAN. Glass fibres may be visible as a matte texture or faint flow lines, especially at the melt front. Texturing of tool surfaces to a depth of 25 μm or greater reduces the visual impact of glass orientation. If painting or plating is required, adhesion tests should be performed because glass at the surface lowers the available SAN bonding area. Flame, corona, or plasma pre-treatment is often necessary; the appropriate test method is ISO 2409 cross-cut adhesion.

Quality-control documentation for SAN930G10L should reference the standardised test methods listed in Table 2. These methods support lot-to-lot comparison and international regulatory compliance documentation. Food-contact status is not inferred from this review and must be confirmed against the manufacturer’s current compliance declaration.

Chemical compatibility of the SAN matrix imposes defined operational limits. The compound is generally resistant to aliphatic hydrocarbons, dilute aqueous acids, and many household detergents, but it is attacked by ketones, esters, aromatic solvents, chlorinated solvents, and concentrated oxidising acids. Continuous immersion in acetone or methyl ethyl ketone causes stress crazing and catastrophic cracking under load; the relevant characterisation method is ISO 22088-2 for environmental stress cracking. In applications involving repeated exposure to ethanol or petroleum fuels, compatibility testing should be performed under load, because glass reinforcement reduces strain but does not eliminate stress-cracking sensitivity. The presence of glass fibres at the surface can accelerate moisture uptake along fibre-matrix interfaces, so outdoor parts should be evaluated for wet conditioning effects under ISO 62 before final approval.