Toray Industries ABS 700NC is supplied as a natural-colour, high-flow acrylonitrile-butadiene-styrene moulding grade within the Toyolac series. The grade is intended for injection moulding of thin-wall components where melt-flow length and cycle-time control outweigh the ductility retained by high-impact ABS grades. Melt mass-flow rate is commonly reported in the 20–25 g/10 min range at 220°C under 10 kg load following ISO 1133-1:2022. Density is typically in the 1.04–1.05 g/cm³ range under ISO 1183-1:2019. The natural-colour designation indicates that no pre-blended pigment system is present, allowing custom colour dosing, laser marking development, or visual inspection of weld lines and contamination. It also removes the thermal history associated with pigment compounding but requires the moulder to manage colour concentrate dispersion and lot-to-lot base colour. ABS 700NC is not supplied as a flame-retardant grade, and food-contact status is not assumed for this specific natural variant. The material is supplied as pellets and should be stored in sealed containers at 5–35°C and 20–80% RH. Opened packaging is re-sealable, but moisture ingress above 0.1 wt% must be corrected by desiccant drying before processing.

How Does ABS 700NC Occupy the Flow-Impact Gap Within the Toyolac Series?

The grade’s position is defined by the inverse relationship between melt flow and notched impact. General-purpose high-impact Toyolac grades with melt mass-flow rates below 10 g/10 min retain Charpy notched impact values of 25–35 kJ/m² at 23°C under ISO 179-1eA, but they require higher melt temperature and pressure to fill multi-cavity or thin-wall tools. ABS 700NC raises flow into the 20–25 g/10 min range while reducing Charpy notched impact to approximately 12–16 kJ/m². Heat deflection temperature under 1.8 MPa also decreases, typically to 78–85°C under ISO 75-2. Ultra-high-flow Toyolac grades achieve 30–40 g/10 min and are used in high-cavitation or very thin-wall articles, but they carry lower impact and lower thermal resistance. The 700NC designation therefore serves housings, structural enclosures, and similar parts with nominal wall thickness of 1.5–2.5 mm and moderate impact loads. Table 1 summarises the comparative positioning as representative ranges, not supplier specification limits.

Table 1. Comparative melt-flow and impact positioning of Toray ABS 700NC relative to other Toyolac categories.

For injection moulding conversion of ABS 700NC, drying is the first critical boundary. A desiccant dryer with dew point below -25°C is set to 80–85°C for 3–4 h. Moisture must be reduced below 0.1 wt% because residual water at melt temperatures above 220°C can produce splay, silver streaks, and loss of weld-line strength. On production lines with closed-hopper feed, hopper residence time should not exceed 2 h without conveying air purge to prevent moisture regain. When relative humidity in the moulding hall exceeds 60% RH, opened pellets should be dried immediately before loading rather than stored in open hoppers. Batch-to-batch moisture absorption is a recurring variable on production-scale machines; freshly opened bags should not be assumed dry. Regrind from sprues and runners may be used at 20–30 wt% if dried and size-controlled, but higher regrind fractions reduce impact strength and increase black-speck formation. Transitioning from PC/ABS to ABS 700NC should include purging with general-purpose ABS or high-viscosity polyethylene at low screw speed to remove residual blend layers from screw flights and check rings.

Injection Moulding Parameter Window and Weld-Line Management

The recommended barrel profile for ABS 700NC from feed to nozzle is typically 190–210°C, 200–220°C, 210–230°C, and 220–240°C. Mould temperature is held at 40–70°C; the lower half of this band improves cooling rate but may increase visible weld lines and reduce surface gloss. In multi-cavity tools, runner balancing should be verified with short-shot studies on the actual machine. Fill pressure should be set to the minimum needed to eliminate short shots; excessive packing pressure above 40–60 MPa specific pressure may increase gate blush and part-mass variation. Clamp force must be matched to projected area at 0.35–0.70 t/cm²; insufficient clamping allows flashing at the parting line with high-flow grades. Gate diameter is specified at 0.8–1.2 mm for direct side-gated housings. Edge gates smaller than 0.8 mm raise shear heating and can cause jetting. Vent depth is controlled at 0.02–0.03 mm to prevent burn marks and allow gas evacuation. In hot-runner applications, balanced flow channels and shear rates below 60,000 s⁻¹ are used to limit resin degradation, especially at the natural-colour surface where yellowing is more visible. Weld-line specimens show lower tensile yield under ISO 527-2 than virgin plaques; when ribs or bosses are placed near fill ends, gate sequencing or overflow wells should be considered.

Table 2. Representative property ranges reported for Toray ABS 700NC from public supplier literature and secondary datasheet aggregations. Values are not specification limits and must be confirmed against the manufacturer’s certificate of analysis for each batch.

In thin-wall consumer-electronics housings with nominal wall thickness of 1.6–2.2 mm, flow-length-to-wall-thickness ratios above 130:1 have been observed in production-scale trials when gate diameter is at least 0.8–1.2 mm and melt temperature is maintained above 230°C. The high melt flow reduces injection pressure and improves multi-cavity balancing, but it reduces melt strength. Sink marks over ribs are managed by limiting rib thickness to 50–60% of the adjacent wall. Because ABS is amorphous, mould shrinkage is low and no crystallisation plateau appears; dimensional stability after 24 h conditioning is reported in the 0.4–0.7% range under ISO 294-4. Warpage in large flat covers is controlled by gate placement, not by raising mould temperature beyond 70°C, because increased mould temperature slows solidification and raises cycle time. The natural colour permits optical inspection of contamination and flow-front hesitation lines before downstream painting. However, unpigmented ABS exposed to UV light loses surface appearance faster than carbon-black-loaded grades. For outdoor use, a UV-stabilised ABS or ASA should be selected instead; published data for this specific configuration is limited.

When a Non-Flame-Retardant Natural Grade Replaces PC/ABS in Electrical Enclosure Prototypes

In indoor electrical enclosure prototypes, ABS 700NC is considered only where UL 94 HB at 1.5 mm or 3.0 mm is sufficient. The grade carries no UL 94 V-0, V-1 or 5VA classification. Compared with PC/ABS, ABS 700NC has lower heat deflection temperature under 1.8 MPa and lower low-temperature multi-axial impact. However, its lower processing temperature reduces thermal stress on inserted brass or aluminium fittings, and its melt viscosity allows shorter injection cycles in multi-cavity tools. Compared with flame-retardant ABS grades, the natural grade avoids brominated or phosphorus-based additives that can raise density by 0.03–0.06 g/cm³ and reduce thermal stability during regrind exposure. The absence of flame-retardant additives also reduces mould deposit and plate-out on polished tool steels. Regulatory conformance is typically reported for RoHS recast 2011/65/EU and delegated directive (EU) 2015/863 with homogeneous-material limits below 0.1 wt% for lead, mercury, hexavalent chromium, PBB, PBDE, DEHP, BBP, DIBP and DBP. REACH candidate list obligations under Regulation (EC) 1907/2006 Article 33 require fresh written confirmation for each shipment because the SVHC list changes. ABS 700NC should not be used in direct contact with ketones, esters, chlorinated solvents or methanol because stress cracking can occur under moulded-in stress. It should not be combined with polycarbonate regrind unless the blend ratio and heat stabiliser package are controlled; otherwise stratified flow fronts and poor weld-line strength occur.