PS-Trinseo STYRON 678D
PS-Trinseo STYRON 678D is an optical-grade general purpose polystyrene (GPPS) engineered by Trinseo, prized for its exceptional glass-like clarity, high heat resistance, and balanced melt moldability. Featuring a density of 1.04 g/cm³ and a stable melt flow rate of 10 g/10 min, this grade is universally specified for thin-walled containers, jewel boxes, and diagnostic labware. Jucheng Precision, under ISO 9001 and ISO 13485 frameworks, excels in processing STYRON 678D to avoid optical stress marks. Supported by our 25+ in-house five-axis CNC machines and cleanroom facilities, we implement low-stress tool paths to prevent brittle cracking during part ejection.
Trinseo STYRON 678D Physical and Optical Properties
STYRON™ 678D is a prime general purpose polystyrene (GPPS) resin engineered by Trinseo to deliver glass-like clarity, high thermal stability, and low-stress moldability:
| Optical & Structural Property | STYRON 678D Typical Value | Engineering Molding Advantage |
|---|---|---|
| Optical Clarity | Glass-Like High Light Transmission | Provides absolute transparency and high gloss directly from polished core cavities, ideal for medical diagnostics and optical lenses. |
| Heat Resistance | Vicat Softening Temperature 97.2°C | Maintains rigid structural geometry under moderate thermal stress. Excellent for display cases and food service packaging. |
| Food Safety | FDA 21 CFR 177.1640 Compliant | Ensures complete compliance for contact with food and household consumables, featuring ultra-low volatile outgassing. |
Process Compatibility for STYRON 678D
With a Melt Flow Rate of 10 g/10 min, STYRON 678D flows smoothly to support thin-walled, high-volume injection molding runs:
| Process Category | Molding Strategy & Application Details |
|---|---|
| Standard & Optical Molding | Excellent. Fully optimized for high-transparency medical petri dishes, lab cuvettes, cosmetic display jars, and compact disc jewel cases. |
| Thin-Wall Packaging | Excellent. Stable flow behaviors at low melt temperatures allow rapid, high-pressure injection into thin-walled disposable cutlery and clear tumblers. |
| Co-Extrusion Cap Coating | Good. Highly compatible with other easy-flowing polymers to provide a protective, high-gloss clear outer barrier on structural components. |
PS-Trinseo STYRON 678D Tooling & Brittle Fracture Prevention Guide
STYRON 678D is an amorphous resin offering extremely low shrinkage, but its brittle nature (Tensile Strain 1-3%) requires meticulous mold design and process care:
- Brittle Fracture & Ejection Design: Because GPPS has negligible elongation, parts can crack easily around sharp corners during mold release. Jucheng’s tooling division machines generous draft angles (minimum 1.5° to 2°) and implements broad, strategically positioned ejector pins to distribute demolding forces evenly.
- Mirror-Surface Mold Polishing: Any microscopic tool mark on core or cavity surfaces will scatter light and compromise optical clarity. We use S136 stainless steel mold cavity blocks, mirror-polished to a pristine finish, to ensure maximum light transmission.
- Thermal and Pressure Profiles: Processing melt temperatures are kept at 199°C–249°C (390°F to 480°F). Mold temperatures are managed between 17°C and 65°C (63°F–149°F) using pressurized temperature controllers. Slower injection and low holding pressures are applied to avoid residual stresses.
- Low Isotropic Shrinkage: STYRON 678D exhibits extremely low shrinkage (typically 0.3% to 0.6%). This amorphous behavior enables us to hold extremely tight dimensional tolerances for stackable diagnostic labware.
Key Application Fields for PS-Trinseo STYRON 678D
- Medical Diagnostics & Labware (ISO 13485): Crystal-clear petri dishes, laboratory test tubes, microplates, transparent cuvettes, and pipette cassettes.
- Cosmetic & Consumer Packaging: Luxury thick-walled cosmetic jars, transparent covers, CD/DVD jewel cases, and retail display organizers.
- Thin-Walled Housewares: Disposable plastic cutlery, clear party tumblers, storage canisters, and high-gloss rigid desk organizers.
Properties
| Density | 1.04 g/cm³ |
| Melt Mass-Flow Rate (MFR) (200°C/5.0kg) | 10.0 g/10 min |
| Tensile Strength | 37.2 MPa |
| Tensile Elongation at Break | 1.0 - 3.0 % |
| Flexural Strength | 57.9 MPa |
| Flexural Modulus | 3,378 MPa |
| Izod Impact Strength (Notched) | 21.4 J/m |
| Rockwell Hardness (L-Scale) | 107 - |
| Vicat Softening Point | 97.2 °C |
| Deflection Temperature Under Load (DTUL @ 66 psi) | 86.1 °C |
| Linear Mold Shrinkage | 0.3 - 0.6 % |
| Flammability Rating (1.6mm) | UL 94 HB - |
| Maximum Part Size | 800 x 600 mm |
| Minimum Part Size | 1 x 1 mm |