Styrene-acrylonitrile copolymer grafted onto polybutadiene rubber particles forms the two-phase morphology of LG Chem ABS TF-100, a high-flow injection-moulding grade in the LG Chem ABS portfolio. The grade is opaque in natural form and is supplied as pellets for thin-wall electrical, electronic, and appliance components. The manufacturer’s specification sheet places melt mass-flow rate near 30 g/10 min under ISO 1133-1:2022 conditions of 220 °C and 10 kg. Low-flow extrusion ABS grades commonly measure 8–12 g/10 min under the same method. The difference alters pressure drop in thin-wall cavities: in a 1.2 mm wall section, a melt with 30 g/10 min typically requires 15–30% lower injection pressure than a 12 g/10 min melt, permitting higher cavitation on machines rated from 800 kN to 3,000 kN without increasing tool deflection.

Material Constitution and Structural Parameters for LG Chem ABS TF-100

Acrylonitrile content contributes resistance to hydrocarbon stress cracking, butadiene domains provide notched impact capacity, and styrene segments govern melt flow and gloss. Representative values from manufacturer literature include density 1.04 g/cm³ under ISO 1183-1, tensile stress at yield 45 MPa under ISO 527-2/1A, flexural modulus 2,450 MPa under ISO 178, and notched Izod impact 18 kJ/m² at 23 °C under ISO 180/A. Heat deflection temperature is 84 °C at 1.8 MPa under ISO 75-2/A, and Vicat softening temperature is approximately 94 °C under ISO 306/B50.

The inverse relation between melt flow and impact is visible when TF-100 is compared with general-purpose impact ABS. At equivalent wall thickness, the high-flow grade trades approximately 5–7 kJ/m² of room-temperature notched Izod impact for the ability to fill long flow paths. Published data for the precise rubber-particle size distribution and graft density in TF-100 is limited; however, the 6 kJ/m² notched Izod impact at −30 °C suggests a reduced capacity for shear-yield initiation in the rubber phase. The 84 °C HDT/A value restricts continuous-load applications above that threshold; for under-hood or heat-shield components, a high-heat ABS or PC/ABS grade is normally substituted.

Capillary rheometry under ISO 11443 at 220 °C places apparent viscosity near 350–450 Pa·s at 100 s⁻¹ and below 100 Pa·s at 1,000 s⁻¹. The power-law index between 100 s⁻¹ and 1,000 s⁻¹ is approximately 0.55–0.65, indicating strong shear thinning. This shear-thinning response is exploited in thin-wall moulding; however, when hot-runner gate shear rates exceed 1,000 s⁻¹, local melt temperature rise and splay at the gate become measurable.

How Does TF-100 Differ from General-Purpose Impact ABS During Injection Moulding?

Production-scale behaviour is governed by melt temperature and mould surface temperature. The manufacturer’s processing range is 190 °C to 240 °C melt temperature, with a rear-to-nozzle profile of 180 °C to 230 °C and mould temperature of 40 °C to 70 °C. On a 1,200 kN hydraulic injection-moulding machine with a 22:1 L/D screw, observed peak injection pressure for a 1.0 mm wall-thickness multi-cavity tool remains below 90 MPa, whereas a general-purpose impact grade with 12 g/10 min MFR may require 110–130 MPa to fill the same cavity. This pressure differential permits an increase in cavity count without increasing clamp force.

Knit-line strength is the main performance boundary. Melt fronts meeting around a core pin in a 1.2 mm wall section retain 40–60% of un-notched tensile strength when mould temperature is held at 40 °C. Raising mould temperature to 70 °C improves knit-line strength by 10–15% under ISO 527-2, but increases cycle time by 15–25 s depending on part mass. Production planners therefore select TF-100 where pressure drop to fill a thin rib is the limiting constraint rather than where impact is the limiting specification.

Drying, Residence-Time, and Incompatibility Boundaries

Moisture control is not optional. The SAN phase of TF-100 can reach 0.2 wt% or higher water content in high-humidity storage. Pre-drying in a desiccant dryer at 80 °C for 2–4 h to below 0.05 wt% prevents splay and surface gloss loss on textured mould surfaces. A dew-point of −40 °C or lower is required from the dryer air supply; ambient-air hopper dryers are insufficient when relative humidity exceeds 60%.

At melt temperatures above 250 °C, the polybutadiene phase undergoes thermal-oxidative degradation; visible yellowing begins after 5–8 min of static residence in a barrel at 270 °C. Residence time should be held below 5 min, and shot volume should be 50–80% of barrel capacity. Purging with PVC or acetal compounds is incompatible because phase separation and plate-out occur at the screw root; purging with PC or general-purpose ABS is preferred. The presence of certain amine-based antistatic additives in granulate blends can produce surface haze and reduced thermal stability during processing.

Compliance documentation for TF-100 typically addresses RoHS Directive 2011/65/EU, REACH Regulation EC 1907/2006, and flame class UL 94 HB at 1.5 mm. The grade is not formulated for food-contact use under FDA 21 CFR 177.1020 unless a specific food-contact approval letter is provided for the finished article. Migration testing under EU 10/2011 is not part of the standard commercial specification. Customers requiring a UL Yellow Card listing should verify the current edition for the exact minimum thickness and colour range.

When Flame-Retardant or Transparent Grades Are Required Instead of TF-100

TF-100 is not suitable for open-flame enclosure applications. Its UL 94 classification of HB at 1.5 mm is insufficient where IEC 62368-1:2023 or UL 746C require V-0 at 1.5 mm. In such applications, a halogenated flame-retardant ABS such as LG Chem AF-312 is substituted; the FR package typically raises density from 1.04 g/cm³ to 1.19–1.21 g/cm³ and reduces melt flow by 30–50%, requiring higher melt temperature and larger gates. The higher density also increases shot mass, which affects clamp tonnage calculations for multi-cavity tools.

Transparent ABS grades such as LG Chem TR-557 represent a fundamentally different morphology. Their butadiene particle size is reduced below the visible-light scattering threshold, yielding light transmittance near 88–90% at 3 mm thickness under ASTM D1003, but notched Izod impact drops to approximately 10–12 kJ/m² at 23 °C. TF-100 is opaque and retains higher notched impact; it should not be used where optical clarity is a specification. Conversely, transparent grades should not be used where high flow and higher impact are required, because their lower rubber content may cause brittle failure at thin-wall bosses.

The comparative ranges in the matrix below summarise class positioning; a single certificate of analysis may fall outside these ranges due to lot-to-lot variance and colourants.

Typical usage for TF-100 includes telephone and router housings, vacuum cleaner bodies, toy components, and office-automation chassis where wall thicknesses of 0.8–2.0 mm are combined with snap-fit latches and living hinges. On a 2,500 kN toggle-clamp injection machine with a 24-cavity hot-runner tool, shot-to-shot mass variation can be maintained below 0.2% when the melt cushion is held at 3–5 mm and switch-over position is set to 95% of fill volume. Dimensional shrinkage under ISO 294-4 is typically 0.4–0.6% in the flow direction and 0.5–0.7% transverse; these values must be compensated in tool steel design.

Surface appearance is controlled by melt temperature and injection velocity. For textured surfaces, an injection velocity of 100–200 mm/s at the melt front is recommended to replicate grain depth; below 60 mm/s, gloss and texture replication degrade. When hot-runner tips generate local shear above 1,000 s⁻¹, splay around gate locations may occur. This condition is addressed by enlarging gate diameter to 0.8–1.2 mm and lowering peak shear rate to below 500 s⁻¹.

Observed failure modes on production lines include short shots in rib sections below 0.6 mm, gate blush at high shear, and sink marks over bosses thicker than 2.5 mm. Short shots are corrected by raising melt temperature to 230–240 °C and increasing holding pressure, provided moisture content remains below 0.05 wt%. Sink marks require pack-time extension and gate-seal verification; if pack time is terminated before gate freeze, the part loses 0.1–0.3% of final mass and exhibits dimensional drift in post-mould inspection under ISO 294-4.