Lost foam casting

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.

Category：

Lost Foam Casting

Keyword：

Lost foam casting

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info@zj-castchem.com

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Details

1. Product Overview
STMMA is an advanced expandable copolymer resin bead engineered for precision lost foam casting.Composed of styrene-methyl methacrylate copolymer (Styrene:MMA=3:7) and n-pentane blowing agent, it significantly reduces carbon defects compared to traditional EPS foam. Designed for high-value castings including valves, pipe fittings, and machinery components in:
· Gray Iron
· Ductile Iron/Nodular Iron
· Low-Carbon Steel

2. Key Advantages

Feature	STMMA vs EPS	Benefit
Carbon Content	62%vs 93%	Reduces lustrous carbon defects by 60%+, Achieve 90%+casting yield
Gasification Temp	50C lower	Saves $50-$100/ton in energy costs
Residue Type	Liquid vs Tar	Cleaner decomposition,minimal surface contamination
Molecular Weight	220k vs 50-60k	Lower shrinkage for dimensional accuracy

3. Technical Specifications

3.1 Chemical & Physical Properties

Property	Method	Value	Unit
Chemical Composition	—	92%Styrene-co-MMA,8%n-pentane	—
Bead Size Distribution	Visual	See Section 3.2	mm
Volatile Content	JB/T11846-2014	7-9%	%
Moisture Content	JB/T11846-2014	<0.5%	%
Foaming Temperature	—	95-105	℃

3.2 Product Specifications

Product Code	Volatile Content	Carbon Increase	Bead Size(mm)	Pre-Expansion Density
STMMA-2#	≥7.0%	≤0.04%	0.65-0.85	19-21 g/L
STMMA-3#(A)	≥7.0%	≤0.04%	0.50-0.65	20-22 g/L
STMMA-3#	≥7.0%	≤0.04%	0.36-0.50	21-23 g/L
STMMA-3#(S)	≥7.0%	≤0.04%	0.33-0.35	23-26 g/L
STMMA-4#	≥7.0%	≤0.04%	0.25-0.33	23-26 g/L

4. Process Guidelines
4.1 Pre-Expansion
· Temperature: 95–105℃
· Pressure: 0.03–0.05 MPa
· Time: 40–60 seconds
· Target Density: Refer to Section 3.2

4.2 Aging
· Minimum Aging Period: 24 hours (ambient temperature-dependent)

5. Safety & Compliance
· Hazard Class: UN2211, Class 9
· Storage:
· Shelf Life: 3–6 months (original sealed packaging)
· Conditions: Cool (<15℃), dry, away from sunlight/alkali/acid
· Handling: Avoid ignition sources; ensure ventilation to prevent hydrocarbon vapor buildup.

6. Packaging & Logistics

Package Type	Net Weight	Gross Weight	Special Requirements
Steel Drum	125 kg	144 kg	Plastic liner for pentane retention

7. Why Choose STMMA？

· Proven Results: 0.04% max carbon increase post-pouring
· Industry Recognition: "Green Revolution" solution for casting defects
· Cost Efficiency: Energy savings up to $100/ton
· Global Compliance: Meets JB/T11846-2014 standards
· Achieve 90%+casting yield

Zhejiang Castchem New Material Co., Ltd, CN. 324002
Castchem markets this product through the following entities:
Castchem Hangzhou factory, Ltd
Castchem Quzhou factory, Ltd
For the contact details of Castchem, please visit www.zj-castchem.com or www.china-castchem.com
Contact Person: Eowyn Jiang
Inquiry: eowyn@zj-castchem.com
Technology consulting:+86-571-56396961
Tel:+86-17857651655
Before using a product sold by one of the Castchem family of companies, users should make their
independent determination that the product is suitable for the intended use and can be used safely and
legally.
SELLER MAKES ON WARRANTY; EXPRESS OR IMPLIED(INCLUDING AND WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE)OTHER THAN AS SEPARATELY AGREED
BETWEEN THE PARTIES IN WRITING.
Release Date: Feb 27, 2019