HIPS 7350 ESCR is a high impact polystyrene grade with enhanced Environmental Stress Cracking Resistance (ESCR) compared to conventional high impact polystyrene. This grade is known for its excellent melt strength, making it highly suitable for deep-draw thermoforming. It is particularly designed for use in applications where low-temperature resistance is critical, such as frozen packaging and refrigerator components.
 
Key Features
Improved Stress Crack Resistance: Provides better performance in environments where stress cracking is a concern, especially at low temperatures.
Excellent Melt Strength: Facilitates deep-draw thermoforming, allowing for the creation of complex shapes and deep-drawn parts.
Food Contact Approval: Certified safe for contact with food, making it ideal for packaging oily foods and dairy products.
 
Applications
Sheet Extrusion: Used extensively for producing sheets that are further processed into various forms.
Refrigerator Components: Ideal for inner liners and door paneling in refrigerators.
Packaging for Oily Foods and Dairy Products: Specifically recommended for packaging applications that involve direct contact with food products that may degrade other materials.
 
Typical Properties
Melt Flow Index (200°C/5kg): 4 g/10 min (ASTM D-1238), indicating the flow characteristics of the material under heat.
Styrene Residual Monomer: Less than 500 ppm (CLG LABPSG004), ensuring low residual content for safety.
Vicat Softening Point: 93°C (ASTM D-1525), the temperature at which the polymer begins to soften under a specified load.
Tensile Stress at Yield: 18 MPa (ASTM D-638), indicating the stress at which the material begins to deform.
Tensile Stress at Break: 20 MPa (ASTM D-638), showing the material's maximum stress capacity before breaking.
Elongation at Break: 50% (ASTM D-638), indicating the flexibility of the material.
Tensile Modulus: 1600 MPa (ASTM D-638), reflecting the stiffness of the material.
Izod Impact Strength: 12 KJ/m2 (ISO 180/1A), demonstrating the material's resistance to impact at room temperature.
 
Conclusion
HIPS 7350 ESCR is engineered for applications that require high impact resistance and enhanced stress cracking resistance, making it an excellent choice for the packaging industry, particularly for frozen food and refrigeration applications. Its ability to withstand low temperatures and direct contact with food products ensures its versatility and utility in demanding packaging environments.