ArcBiox™ BGF30-B1 is an impact-modified long glass fiber polylactic acid compound supplied as 12 mm cylindrical pellets in which continuous glass fiber bundles are aligned parallel to the pellet axis. The product nomenclature encodes the reinforcement: BGF30 denotes a nominal glass fiber content of 30 wt%, and the B1 suffix identifies the impact-modifier package. The compound is built on a semicrystalline PLA carrier. Differential scanning calorimetry at 10 K/min under nitrogen shows a glass transition onset between 58°C and 62°C. Density determined according to ISO 1183-1:2019 is 1.41 g/cm³ to 1.48 g/cm³. Melt volume-flow rate measured according to ISO 1133-1:2022 at 210°C with 2.16 kg is 15 cm³/10 min to 25 cm³/10 min. The product is packaged in sealed foil-lined boxes at a moisture content below 250 ppm. This datasheet profile is intended for structural injection-molded parts that require higher notched impact energy than unmodified PLA or short-glass PLA while retaining a bio-based polymer matrix.

The reinforcing architecture differs from short-glass PLA in the fiber length distribution after molding. Short-glass compounds produced by melt mixing typically reach a number-average fiber length below 0.4 mm after pelletization and injection molding. Long-glass pellets such as BGF30-B1 are produced by a pultrusion wet-out process in which the thermoplastic melt is drawn onto continuous glass roving before cutting. This preserves a mean fiber length of 1.2 mm to 2.0 mm in molded parts when a low-shear screw and adequately sized gates are used. The longer fiber network increases load transfer efficiency and reduces strain at break in a direction-dependent manner. At the same 30 wt% glass content, long-glass PLA compounds generally show higher tensile modulus and notched Charpy impact energy than short-glass PLA, but they also exhibit higher flow-direction versus cross-flow property anisotropy. The fiber length distribution should be measured on burned-off coupons by microscopy after solvent digestion or ashing to verify that the molder has not reduced the reinforcement to short-fiber dimensions.

What Distinguishes Long Glass Fiber Reinforcement from Short Glass Fiber and Unmodified PLA?

Unmodified PLA fails under notched impact by brittle crack initiation at the notch tip, with notched Charpy impact energy under ISO 179-1/1eA:2023 at 23°C typically between 2 kJ/m² and 4 kJ/m². A short glass fiber PLA compound with 30 wt% reinforcement raises the notched Charpy value to 7 kJ/m² to 12 kJ/m², but the fracture surface still shows limited fiber pullout. In BGF30-B1, the long glass fiber phase maintains load transfer over a larger fracture process zone. At 23°C, the notched Charpy impact energy from ISO 179-1/1eA specimens machined from an 4 mm injection-molded plaque is 22 kJ/m² to 30 kJ/m². At -20°C, the value falls to 12 kJ/m² to 18 kJ/m². The impact modifier contributes to this behavior by forming discrete low-modulus domains that initiate multiple craze or shear-band events in the PLA matrix. Without the impact modifier, an unmodified long-glass PLA compound may retain a high flexural modulus but can still show a notched Charpy value below 15 kJ/m² at room temperature. The combined system therefore shifts the material response away from purely brittle fracture while retaining the stiffness benefit of the long fiber.

Moisture control is a processing boundary, not a secondary recommendation. PLA hydrolyzes rapidly in the melt when the water content exceeds 250 ppm. At a plant ambient condition of 60% RH or higher, pellet exposed to room air for more than 10 min can exceed this limit. Pre-drying is performed at 80°C for 4 h in a desiccant dryer with a dew point of -30°C or lower and a drying air flow of 3.7 m³/h per kg/h of polymer throughput. The hopper must be sealed and blanketed with dried air. Return of predried material to open storage is not acceptable. Machine operators using a moisture analyzer should verify the hopper inlet moisture is below 200 ppm before startup. Failure to dry the product produces hydrolysis-induced chain scission, visible silver streaking, reduced glass fiber wet-out, and a loss of notched Charpy impact energy of 30% or more relative to dry-as-molded specimens.

The Impact Modification Package Moves Notched Charpy Failure Out of the Brittle Region

The impact-modifier phase in BGF30-B1 is dispersed as a secondary polymeric phase within the PLA matrix. Under flexural loading according to ISO 178:2025 at 2 mm/min, the compound displays a departure from linear stress–strain behavior before maximum load, indicating ductile deformation contributions that are absent in unmodified PLA. The tensile stress–strain curve measured according to ISO 527-2:2016 on 1A specimens shows a tensile strength of 95 MPa to 115 MPa and a tensile modulus of 9.0 GPa to 11.0 GPa. The notched Charpy impact energy at 23°C is 22 kJ/m² to 30 kJ/m². The presence of the impact modifier lowers the heat distortion temperature relative to an unmodified long-glass PLA by roughly 5°C to 10°C at 1.8 MPa because the modifier contributes a low-modulus phase. The measurable HDT-A value under ISO 75-2:2013 method A is 105°C to 130°C depending on mold temperature and crystallization. The impact modification also improves knit-line toughness to a limited extent but does not remove the weld-line weakness caused by long fibers.

Injection molding trials on a 1,000 kN clamp force machine with a general-purpose screw of 22:1 L/D and 2.0:1 compression ratio produced excessive fiber breakage and uneven glass distribution in bosses and thin ribs. A low-shear screw with 20:1 L/D and 1.8:1 compression ratio is preferred. Barrel temperatures from feed throat to nozzle are set at 175°C, 185°C, 190°C, 190°C, 195°C. The melt temperature after a stable shot is kept below 205°C. Residence time is limited to 5 min; longer residence produces lactide, reduces melt viscosity, and causes a sharp loss in impact. Back pressure is controlled between 0.5 MPa and 1.0 MPa. Screw surface speed is maintained below 0.3 m/s. Injection pressure is 80 MPa to 120 MPa hydraulic, and holding pressure is 60 MPa to 90 MPa. The mold temperature is set from 25°C to 60°C for thin-walled parts; heated molds at 80°C to 100°C are used where elevated HDT and crystallinity are necessary, but cycle time increases accordingly.

Rheological characterization by parallel plate at 200°C reveals a pronounced shear-thinning response. At an angular frequency of 1 rad/s, complex viscosity is 1,800 Pa·s to 2,500 Pa·s; at 100 rad/s, it falls to 180 Pa·s to 260 Pa·s. This is higher than short-glass PLA and neat PLA because the long fibers create a yield-like network at low shear. Spiral flow length in a 2.0 mm cavity at 190°C is 220 mm to 260 mm at 80 MPa injection pressure, compared to 320 mm to 360 mm for a short-glass PLA. The lower spiral flow length means that thin-wall sections below 1.5 mm require shorter flow paths or additional gates. Capillary rheometry according to ISO 11443:2021 at 200°C gives a shear viscosity at 1,000 s⁻¹ of 120 Pa·s to 180 Pa·s. The processing window is bounded by upper temperature to avoid PLA degradation and lower temperature to avoid gate freeze-off.

Gate Freeze-Off, Weld Line Strength, and Mold Design Inputs

Long glass fiber compounds have higher molten viscosity and more elastic entrance flow than neat PLA. For a nominal wall thickness of 2.5 mm, the gate diameter should be 1.5 mm to 2.0 mm. Edge gates with a land length of 0.8 mm to 1.0 mm allow fiber transfer without excessive shear. Pinpoint gates below 1.2 mm produce fiber accumulation at the gate entrance and surface delamination. Weld-line strength is a primary limitation. In double-spiral mold testing, weld-line tensile strength under ISO 527-2:2016 is 45% to 60% of the no-weld-line value. Short-glass PLA usually retains 70% to 80%. The loss occurs because long fibers orient parallel to the flow front and do not cross the weld line into the opposing front. Increasing mold temperature to 80°C can improve knit-line strength by 5% to 10%, but the effect is limited. Parts with multiple gates should be analyzed for weld-line location; ribs and bosses should be placed to avoid weld lines on load-bearing surfaces. Sharp corners reduce mean fiber length by 15% to 25%, so generous corner radii are required.

Table 1 compares representative dry-as-molded property ranges for neat PLA, short glass PLA at 30 wt% loading, and ArcBiox™ BGF30-B1. The values for BGF30-B1 are product datasheet ranges; end-user qualification is required for design allowables.

Controlling Shrinkage Anisotropy and Warpage in Long Fiber PLA Molding

The shrinkage behavior of BGF30-B1 is anisotropic because the long fibers align with melt flow. On a 150 mm × 100 mm × 2.5 mm plaque molded with a single edge gate, shrinkage after 48 h at 23°C and 50% RH according to ISO 294-4:2018 is 0.3% to 0.5% in the flow direction and 0.6% to 1.0% in the cross-flow direction. Neat PLA shows more uniform shrinkage but often higher magnitude. The differential shrinkage causes out-of-plane warpage in large flat parts, particularly when ribs or bosses are asymmetric. Mold filling with sequential valve gates can reorient flow fronts and reduce distortion. A mold temperature of 80°C reduces molded-in stress but increases cycle time. When the application requires close tolerances, a post-mold crystallization anneal at 90°C to 100°C for 1 h to 2 h stabilizes dimensions after machining. Dimensional inspection should be performed only after conditioning because PLA absorbs moisture over time.

Quality control of molded parts includes fiber length analysis by solvent digestion or burn-off followed by optical microscopy. A representative specimen is ashed at 600°C for 2 h, and the remaining glass is dispersed for image analysis. The weighted average fiber length after injection molding should be above 1.0 mm. If the value falls below 0.8 mm, the molder has either over-sheared the melt or used undersized gates. The fiber length distribution is also monitored for fines content below 10% by number. This testing is not part of routine incoming inspection but is useful for first article qualification and process troubleshooting.

When BGF30-B1 Replaces Fossil-Based Engineering Resins in Non-Halogenated Housings

ArcBiox™ BGF30-B1 is considered in enclosure applications only when the design requirements include a bio-based polymer matrix and a lower density than glass-filled PC/ABS. The tensile modulus of 9.0 GPa to 11.0 GPa is higher than many unreinforced PC/ABS grades, but the strain at break is lower. Multi-axial impact is a critical limitation. Instrumented puncture tests on 2.0 mm plaques using a 20 mm hemispherical striker at 2.2 m/s may absorb 3 J to 5 J; a general-purpose PC/ABS at the same thickness can exceed 15 J. The comparison is not a direct substitution. Enclosure designs using BGF30-B1 should increase corner radii, ribbed side-wall sections, or boss thickness to move failure away from snap-fit features. At sub-zero temperatures, the impact modifier retains some ductility, but the glass fiber network still undergoes fiber pullout and localized delamination. Published multi-axial impact data for this exact product configuration is limited; end-product drop testing according to IEC 60068-2-31:2008 or the relevant product standard is mandatory before application release.

The PLA carrier is derived from lactic acid feedstock that can be certified for bio-based carbon content under ASTM D6866-24. The compound does not contain halogenated flame retardants or phthalate plasticizers. Electrical and electronic housings must be assessed against the RoHS Directive 2011/65/EU Annex II restricted substances; the glass fiber and impact modifier components require a supplier material declaration. No regulatory clearance is implied under FDA 21 CFR 177.1520 for food-contact use because the reinforcement and impact-modifier system have to be evaluated for migration in the finished article under the intended conditions of use. Under REACH Regulation 1907/2006, the product is a mixture and requires a safety data sheet when handled in an industrial setting. Grinding or machining of long glass fiber PLA generates respirable particulates; local exhaust ventilation and dust capture are required to prevent fiber dust accumulation in the workplace.