Toray Industries ABS 700-SG5 is a high-flow, high-gloss acrylonitrile-butadiene-styrene injection-moulding grade within the TOYOLAC 700 series. The numeric 700 designation denotes the high-fluidity segment of the Toray ABS portfolio, while the SG5 suffix identifies a surface-gloss-optimised variant. The product is supplied as natural or pigmented pellets for thin-wall, high-appearance parts. The polymer architecture consists of a continuous styrene-acrylonitrile matrix and a dispersed polybutadiene rubber phase; the SG5 grade uses a controlled rubber morphology to reduce surface haze while retaining the viscosity reduction of the 700-series base. Published property data for this grade are summarised in the table below.

What separates ABS 700-SG5 from impact-modified and heat-resistant TOYOLAC grades?

Relative to a general-purpose impact grade such as TOYOLAC 100, ABS 700-SG5 shifts the property balance toward melt fluidity and surface distinctness while trading away notched impact. An impact-modified 100-series grade may show notched Charpy values above 20 kJ/m² at 23°C, whereas 700-SG5 typically falls in the 8–13 kJ/m² range to ISO 179-1/1eA. The fluidity difference is reflected in melt volume-flow rate: the high-flow 700-SG5 generally moves at least 10–15 cm³/10 min higher than medium-flow grades at 220°C/10 kg. Against a heat-resistant 500-series TOYOLAC, 700-SG5 provides lower filling pressure and better gloss retention but has a lower heat distortion ceiling and is unsuitable for sustained load above 85–92°C. Compared with a mid-range PC/ABS blend, the ABS grade shows lower notched impact at sub-zero temperatures and a lower continuous use temperature, but it offers lower melt temperature demand and better suitability for conventional ABS electroplating etch chemistries. The selection between these products should be made on the basis of the actual part thermal requirement and the applicable OEM impact specification, not surface gloss alone.

Drying before melt processing is mandatory for high-gloss ABS surfaces. A desiccant-bed dryer with dew point below -40°C and return-air monitoring is recommended. Residual moisture above 0.05 wt% hydrolyses the SAN phase at processing temperatures, producing splay, silver streaks, and gloss loss at the gate. The material is typically dried for 3–4 h at 80–90°C; under high ambient absolute humidity or in bulk containers stored below 10°C, drying should be extended to 6 h. Hopper-dryer residence time should not exceed 8 h at maximum temperature, because over-drying can cause pellet clumping and additive migration. Residual moisture should be verified with an absolute moisture analyser, not by visual inspection.

Melt temperature settings from rear to nozzle of 210°C to 240–250°C are typical. The melt temperature limit for continuous operation is 260°C. Above 260°C, polybutadiene degradation accelerates, causing yellowing, black specks, and a permanent loss of surface gloss. A 20:1 to 25:1 L/D single-flight or barrier screw with a low compression ratio is preferred. Back pressure should be maintained at 0.5–1.5 MPa and screw speed at 30–60 rpm for a 40 mm diameter screw. Hot-runner systems should use valve gates rather than open gates where possible; melt residence time above 8–10 min at 240°C in an internally heated torpedo can produce gate-area gloss rings and colour shift. Mould temperature should be held at 50–80°C, with gloss-critical surfaces requiring 65–80°C. A mould temperature above 85°C adds cycle time without proportional gloss improvement. Shot weight should be 40–80% of barrel capacity; larger residence volumes increase the risk of degradation, while smaller shots make holding pressure harder to control.

Within the recommended melt-temperature range, the optimum surface-gloss window is typically ±5°C around the established set point. A reduction of 10°C promotes flow marks and incomplete replication; an increase of 10°C risks jetting and yellowing. The high-flow grade exhibits pseudo-plastic shear-thinning; no single melt flow value characterises injection behaviour. Flow simulation should use a shear-rate-dependent Cross-WLF viscosity model. The melt volume-flow rate value alone is insufficient for direct-gated thin-wall tool design.

When direct-gated bezels are moulded at reduced clamp force

In large flat glossy parts such as television front bezels, air-conditioner fascia, or appliance display frames, the processing window for ABS 700-SG5 is narrower than the full datasheet range because the gloss response is sensitive to cavity-surface temperature at the end of fill. If the cavity surface falls below 50°C, the 60° gloss value to ISO 2813 can drop by more than 5 GU. Flow marks and tiger stripes occur when the flow-front velocity changes abruptly at ribs, bosses, or thickness steps. Injection velocity should be profiled to maintain a constant flow-front speed of 100–200 mm/s in the initial filling phase and reduced to 40–80 mm/s during the last 10% of fill. Holding pressure of 60–80% of peak injection pressure is applied for 4–8 s for a 2.0 mm wall, with gate seal confirmed by weight stability across 50 consecutive shots. When the same part is transferred to a lower-clamp-force machine, the shot-to-barrel capacity ratio should remain above 30% and below 80%; ratios below 30% can extend melt residence time and produce degradation. If gloss is inconsistent around the gate, the gate diameter should be increased or the melt temperature reduced by 5–10°C; raising the mould temperature alone will not correct shear-induced gloss loss at the gate. Hot-runner valve-gated systems show better gloss retention than tip-gated systems because they reduce shear at the gate.

For high-gloss surface moulds, cooling-circuit spacing should be less than 50 mm and the distance from the cavity surface should be 10–12 mm to maintain a surface temperature differential below 5°C across the part. Conventional cooling layouts with wide spacings create local temperature differences that appear as gloss banding. In thin-wall consumer electronics housings with snap-fit features, the lower notched impact of 700-SG5 should be considered at the design stage. Snap-finger roots should have radii of at least 0.5 mm, and assembly should avoid strain rates that exceed the material capability at 10°C. If a drop specification of 0.5 m onto concrete at -20°C is required, an impact-modified ABS grade or a PC/ABS blend is normally specified to the applicable OEM drop procedure.

Electroplating Etch and Plating Adhesion Boundaries

An additional application segment is electroplating of automotive and sanitary fittings. ABS 700-SG5 can accept a conventional chromic acid/sulfuric acid etch followed by electroless nickel or copper and decorative chromium electroplating. The high-gloss substrate reduces polishing requirements, but the high-flow grade has a lower rubber content than high-impact electroplating ABS, so etching conditions are more critical. In a typical ABS plating line, etch immersion at 60–65°C in a solution containing 350–400 g/L chromic acid and 20–30% sulfuric acid is used for 6–10 min. Adhesion should be measured by peel testing to ASTM B533 or the applicable automotive OEM standard; values below 0.5 kN/m generally indicate insufficient microporous etch. If the etchant bath temperature falls below 55°C, the etch rate becomes too low and peel failure occurs at the plating interface. Published data for this specific configuration is limited; production validation on the actual part geometry is required.

The grade is not recommended for continuous service above 80°C under mechanical load. Unfilled ABS of the 700-SG5 class is not inherently flame-retardant; the standard unfilled material typically achieves a UL 94 HB rating at 1.5 mm and 3.0 mm, but the specific yellow card must be confirmed by colour and lot. The resin should not be compounded with amine-based heat stabilisers, which accelerate SAN yellowing, or with PVC residues, which release HCl and corrode hot runners. Halogenated flame-retardant additives can cause plate-out and loss of gloss. Recyclate content above 20 wt% is not recommended for appearance parts unless the regrind is clean, dry, and validated for gloss and colour. If UV exposure is required, an ASA or AES grade should be specified because the polybutadiene phase in ABS undergoes photo-oxidation and significant impact loss under UV.

In high-gloss white goods control panels, ABS 700-SG5 is typically moulded in 2.0–2.5 mm wall thickness with a melt temperature of 240°C and a mould temperature of 70°C. The resulting surface can be painted, screen-printed, or left as moulded. Mould release agents should be avoided because they migrate to the surface and create adhesion failure of subsequent coatings. If ejection is difficult, a dry-air pneumatic ejection system with static elimination is preferred. Batch-to-batch colour variation for natural resin should be specified as ΔYI < 0.5 units to ASTM E313 when the moulded surface is visible. The material is compatible with ultrasonic welding and heat staking, but welding parameters must be retuned for its high flow: excessive collapse distance can produce flash at the joint line.