What is Excellent PS Pellets?

Excellent PS pellets are high-grade granular polystyrene raw materials that comply with strict industrial specifications. They deliver superior performance in appearance, processing stability, mechanical strength, heat resistance, material purity, and batch-to-batch consistency.

These pellets are widely supplied in standard and high-impact polystyrene grades, including GPPS (General Purpose Polystyrene) and HIPS (High Impact Polystyrene). Their key benefit lies in supporting reliable mass production while maintaining uniform product quality, making them ideal for high-end applications such as premium packaging, electronic components, optical products, and more.

Based on specific end-use requirements, excellent PS pellets are categorized into multiple specialized types: packaging-grade PS, transparent PS for containers, electronic-grade PS, PS for insulation components, clear PS for toys, general-purpose PS for daily necessities, and food-grade PS pellets.

Advantages

Premium appearance with uniform pellet shape, free from black specks, impurities, and color variations, delivering a smooth and high-quality surface for finished products.

Ultra-high material purity with low residual monomers, minimal ash content, and low moisture levels, fully compliant with food-contact regulations and clean production standards.

Stable processing performance with narrow melt index (MI) consistency between batches, excellent melt flow, high production yield, and reduced processing waste.

Excellent mechanical and thermal properties, including high rigidity, strong dimensional stability, exceptional optical clarity (for GPPS), and enhanced impact resistance (for HIPS).

Consistent batch-to-batch quality reduces frequent machine adjustments and ensures reliable performance in mass production.

Strong compatibility with functional modifications such as flame retardant and antistatic treatments, as well as secondary processes including printing and electroplating.

Lower overall production costs thanks to high first-pass yield and reduced rejection and rework rates.

Common types of Excellent PS Pellets are divided into GPPS and HIPS, and the following is their detailed information.

Excellent PS pellets, including both GPPS and HIPS grades, deliver consistent physical, mechanical, thermal, electrical and processing properties to support reliable production for high-end applications. Below are the typical technical properties tested under international standards.
Physical Properties
Density: Tested in accordance with ISO 1183 at 23℃, typically ranging from 1.04–1.05 g/cm³ for GPPS and 1.03–1.06 g/cm³ for HIPS
Water Absorption (24h): Per ISO 62 at 23℃ immersion, ≤0.04% for GPPS and ≤0.08% for HIPS
Refractive Index: Measured by ASTM D542 at 23℃, 1.59–1.60 for GPPS (not applicable for HIPS)
Molding Shrinkage Rate: According to ISO 294-4 under injection molding, 0.4–0.7% for GPPS and 0.4–0.6% for HIPS
Mechanical Properties
Tensile Strength: ISO 527-2 at 23℃, 5 mm/min, 30–44 MPa for GPPS and 28–32 MPa for HIPS
Tensile Modulus: ISO 527-2 at 23℃, 1 mm/min, 2300–4100 MPa for GPPS and 1900–2400 MPa for HIPS
Elongation at Break: ISO 527-2 at 23℃, 5 mm/min, 1.6–1.8% for GPPS and 38–55% for HIPS
Notched Izod Impact Strength: ISO 180 at 23℃ (4mm specimen), approximately 11–19 J/m for GPPS and 45–110 J/m for HIPS
Rockwell Hardness (M Scale): ASTM D785 at 23℃, 60–90 for GPPS and 55–85 for HIPS
Thermal Properties
Heat Deflection Temperature (0.45MPa): ISO 75-2/B at a heating rate of 50℃/h, 89–90℃ for GPPS and 85–90℃ for HIPS
Heat Deflection Temperature (1.8MPa): ISO 75-2/A at a heating rate of 50℃/h, 80℃ for GPPS and 75–80℃ for HIPS
Vicat Softening Point: ISO 306 under 10N load and 50℃/h heating rate, 90–101℃ for GPPS and 84–101℃ for HIPS
Thermal Conductivity: ASTM D5930 at 23℃, 0.10–0.14 W/(m·K) for GPPS and 0.13–0.22 W/(m·K) for HIPS
Electrical Properties
Volume Resistivity: IEC 60093 at 23℃ (dry condition), >10¹⁶ Ω·cm for GPPS and >10¹⁴ Ω·cm for HIPS
Dielectric Strength: IEC 60243 at 23℃, 20 kV/mm for GPPS and 18 kV/mm for HIPS
Dielectric Constant: IEC 60250 at 1MHz and 23℃, 2.4–3.1 for GPPS and 2.5–3.2 for HIPS
Processing Properties
Melt Flow Index (MI): ISO 1133 at 200℃, 5kg load, 3.3–9.0 g/10min for GPPS and 3.7–5.5 g/10min for HIPS
Processing Temperature Range: Recommended injection molding temperature is 190–240℃ for both GPPS and HIPS
Other Properties
Limiting Oxygen Index (LOI): ISO 4589-2 at 23℃, 18–19% for both GPPS and HIPS
With stable performance and reliable batch consistency, Excellent PS Pellets (High-Quality Polystyrene Pellets) have been widely used in high-end packaging, electronics, food containers, optical parts, home appliances, toys and daily necessities.