Toray Industries Toyolac 100G-20 is a 20 wt% glass-fibre-reinforced acrylonitrile-butadiene-styrene injection-moulding compound. The model designation denotes a Toyolac 100-series ABS matrix modified with short glass fibres; the numerical suffix after the G indicates a nominal fibre loading of 20%. The grade is supplied as cylindrical pellets and is specified for injection moulding. Its primary technical differentiator is the rise in tensile and flexural modulus relative to unfilled Toyolac 100, combined with lower mould shrinkage and a higher heat deflection temperature. In exchange, notched impact strength decreases and the melt becomes more abrasive to screws, barrels, and check rings. The product is specified where rigid structural housings, brackets, frames, and motor mounts require thinner wall sections than an unfilled ABS can sustain under load.

Published datasheet values for Toyolac 100G-20 are generated on ISO-conditioned specimens; lot-specific certification should be requested before design. The following table restates typical values from manufacturers' published data, not absolute design limits.

How Should the ISO Data Be Interpreted for Anisotropic Glass-Fibre Mouldings?

Because the glass fibres align with the melt flow front, tensile modulus, mould shrinkage, and coefficient of thermal expansion are anisotropic. Flow-direction tensile modulus typically exceeds transverse-direction tensile modulus; the magnitude of the difference depends on gate type, part thickness, and filling speed. Published data for this specific configuration is limited, so design validation should include transverse-direction specimens cut from the same gate geometry intended for production, and ISO 294-1 should govern the injection-moulded plaque preparation.

Processing Latitudes, Screw Wear, and Drying Requirements for Glass-Fibre-Filled ABS

Pre-drying is mandatory, not optional, because the glass-fibre sizing layer and the ABS matrix absorb ambient moisture. The resin should be dried at 80–90 °C for 3–4 h in a dehumidifying dryer with a dew point of -30 °C or lower, to a residual moisture content below 0.05 wt%. In high-humidity production environments above 60 % RH, a simple hopper dryer with no desiccant bed is insufficient and frequently produces splay, increased viscosity variation, and reduced tensile strength at the gate.

The melt temperature window is 240–270 °C. Sustained barrel temperatures above 280 °C drive degradation of the butadiene rubber phase and fibre-matrix coupling agent, causing brown discoloration, acrid volatiles, and a measurable loss of Charpy notched impact. Production-scale experience on toggle-clamp injection moulding machines with general-purpose 20:1 L/D screws indicates that barrel residence times beyond 15 min at 260 °C produce visible surface delamination and enlarged glass-fibre patterns at weld lines. When interruptions exceed this window, the barrel should be purged with a suitable purging compound, not with unreinforced ABS.

Mould temperature should be held between 60 °C and 80 °C for parts requiring maximum dimensional stability, although cycle-time-driven processes sometimes use 40–50 °C mould surfaces; the lower surface temperature increases free-grain appearance, moulded-in stress, and post-mould warpage. Injection velocity is selected in the moderate-to-high range to prevent premature freezing at thin sections, but excessive velocity produces gate jetting and increases fibre orientation differences between the skin and core. Back pressure of 5–10 bar hydraulic is commonly used to ensure glass-fibre dispersion without excessive fibre breakage, which reduces tensile modulus and increases batch instability. The screw should have a compression ratio between 2.2 and 2.8, a non-return valve with hard-facing, and a bimetallic barrel to resist the erosive wear caused by short glass fibres; component replacement intervals are shorter than for unfilled Toyolac grades.

Clamp force requirements are 0.4–0.6 t/cm² of projected area for typical technical mouldings, which is comparable to other glass-filled ABS compounds but higher than for high-flow unfilled ABS because the higher melt viscosity requires higher injection pressure. Hot-runner systems should use open-flow tips with no dead spots, as the glass fibres cause stagnant resin to degrade and generate black specks. The melt flow rate of 5–12 g/10 min at 220 °C/10 kg indicates that the grade is stiffer in the melt than high-flow unfilled ABS. When thin-walled sections drop below 1.0 mm, short shots can occur unless injection velocity and melt temperature are adjusted upward within the processing window. In practice, the effective flow path-to-thickness ratio for a 20 wt% glass-fibre grade is lower than for unfilled ABS because the fibres increase shear viscosity and freeze-off speed. Tool designs that push the flow ratio beyond 120:1 should be validated by mould filling simulation and pressure-drop measurement; where the ratio is exceeded, a second gate or a widened runner is preferable to raising melt temperature into the degradation range.

When regrind is used, the ratio should not exceed 20 wt% in technical parts because repeated shear on the glass fibres shortens the mean fibre length and reduces tensile modulus. Closed-loop regrind systems often show greater batch-to-batch viscosity variation; the granulate should be dried under the same conditions as virgin pellets.

When Dimensional Stability Requirements Rule Out Unreinforced Grades

Relative to unreinforced Toyolac 100, Toyolac 100G-20 increases tensile modulus from approximately 2.2–2.5 GPa to 6.5–7.5 GPa and reduces mould shrinkage from 0.4–0.6 % to 0.1–0.3 %. These differences permit thinner wall sections and tighter part dimensions in load-bearing housings without moving to polycarbonate or PBT. The penalty is notched impact sensitivity: the Charpy notched impact of the unfilled grade is typically 18–25 kJ/m², while the 20 wt% glass-fibre grade falls to 7–10 kJ/m². Therefore the material is unsuitable where a dropping weight or low-temperature impact event is the controlling failure mode.

Compared with Toyolac 100G-30, the 20 wt% grade provides lower stiffness, but also less moulded-in warp due to its lower fibre-fraction-induced anisotropy. When tooling is designed for tight flatness tolerances, the 20% grade often represents a compromise between stiffness and post-mould dimensional stability; when stiffness dominates, the 30% grade is preferred but requires more careful gate balancing. Against an unfilled high-impact Toyolac 250 grade, the stiffness and heat-deflection temperature differentials are larger, but the low-temperature impact toughness of the high-impact grade is not approached. Selection between the two depends on whether the part is governed by a stiffness-critical creep-limit or an impact-critical energy-absorption requirement; the two failure criteria produce mutually exclusive property targets in many housing designs.

Compared with a 20 wt% glass-fibre-reinforced PBT, Toyolac 100G-20 offers lower density and reduced moisture-driven hydrolysis risk, but lower continuous-use temperature and lower solvent resistance. Compared with a 20 wt% glass-fibre-reinforced polycarbonate, it has broadly similar modulus but higher melt flow and lower impact strength. These comparisons position the grade as an intermediate-cost structural ABS for indoor technical components.

In motor housings, sensor brackets, office-equipment chassis, and automotive interior supports, the grade is specified where a component is clamped at fastening points and creep under continuous load would cause unfilled ABS to lose torque retention. Glass-fibre reinforcement reduces creep strain under a sustained tensile load; ISO 899-1 tensile creep testing is used for design validation, though published multi-point creep curves for this specific grade are limited. For parts exposed to hot air flow above 90 °C under load, a heat-resistant ABS or PBT/PPA should be evaluated, because the HDT of 105–112 °C at 1.82 MPa is a short-term thermal index, not a continuous-use temperature.

Chemical incompatibility must be considered when specifying Toyolac 100G-20. ABS is softened or stress-cracked by ketones, esters, chlorinated hydrocarbons, and aromatic solvents; contact with solvent-bearing adhesives, paints, or cleaning agents should be validated under service strain. Unreinforced and glass-fibre-reinforced ABS grades are not generally suitable for continuous exposure to strong acids or alkaline solutions at elevated temperature. No FDA 21 CFR 177.1020 clearance should be assumed for this glass-fibre-reinforced grade; if food-contact certification is required, a specific food-contact ABS grade or a migration study under the intended end-use conditions is necessary. The UL94 rating for the unfilled matrix at 1.5 mm is typically HB; flame-retardant performance is not a design feature of this product.

When weld lines are inevitable, their location should be shifted away from load-bearing geometry. Glass-fibre orientation at knit lines disrupts continuity, and the local tensile elongation may be substantially lower than the bulk value. Flow simulation should be used to place gates so that weld lines form in low-stress regions; actual weld-line strength should be confirmed on production-scale tools because published data for weld-line tensile strength of Toyolac 100G-20 is limited.