STMMA (American patent US 6770681B2) - Expandable co-polymer resin beads for lost foam casting

1. Product Description

The STMMA is an expandable Co-polymer resin beads developed for foamed patterns of lost foam casting process, it is co-polymerization reacted by liquid methyl methacrylate monomer and styrene monomer.

Compared with the EPS, STMMA carbon molecule content has been greatly reduced in order to eliminate carburization defects in the process of lost foam casting.

This formula Co-polymer product was designed for high-quality required valves, pipe fittings and machinery parts, especially made of gray iron, ductile iron and low-carbon steel.

2. Advantages of STMMA co-polymer:

• Reducing carbon defects of castings
  
• Reducing carburization defects on the surface of steel castings
  
• Reducing smoke carbon
  
• Improving the surface finish of castings
• Total carbon increase after pouring can be controlled to less than 0.04%.

3.Product Characteristics

• Chemical components: 92% Poly styrene-co-methyl methacrylate (Styrene: MMA=3:7), 8%n-pentane.
  
• Additives: n-Pentane (blowing agent), Organic Bromide, etc.
  
• Status: Co-polymer resin for lost foam casting
  
• Test Method used: JB/T11846-2014
  
• Features: Low-carbon content, low dissolution temperature, less residues.
  
• Appearance: Oyster white Spherical beads
  
• Typical Customer Applications: Gray iron, ductile iron/nodular iron, low-carbon steel.