China Lost Foam Casting Foundry
Simis Lost Foam Casting Foundry
Lost Foam Casting Factory Introduction
SIMIS Lost Foam Casting Foundry is a modern facility specializing in the production of medium and large precision castings using advanced Lost Foam Casting (EPC – Evaporative Pattern Casting) technology. The foundry integrates EPS pattern making, coating and drying, molding, vacuum pouring, cleaning, and precision machining, providing a complete one-stop casting solution from design to finished products.
No parting lines, no cores, and unrestricted design freedom for complex shapes
Excellent dimensional accuracy and surface finish (Ra 6.3–12.5 μm)
Reduced machining allowance and improved material utilization
Clean production environment and high automation level
Ideal for complex, medium- and large-sized castings in batch production
Casting Weight Range: 5 kg – 5,000 kg
Maximum Dimensions: approx. 2.5 m × 2.0 m × 1.8 m
Pouring Method: Vacuum pouring (-0.03 to -0.05 MPa)
Sand Treatment: Fully automatic dry sand circulation system (cooling, sieving, dust removal, storage)
EPS Pattern Production: High-precision EPS/EPMMA pattern line (automatic molding, steam pre-expanding, vacuum cooling)
OEM Custom Lost Foam Casting Parts
Simis Lost Foam Casting Process
Lost Foam Casting process overview
Lost Foam Casting is a precision casting process that makes a mold of expandable foam plastic (such as polystyrene) in the same shape as the casting, assembles it, coats it with a high-temperature resistant coating, buries it in dry sand after drying, and then when pouring molten metal, the foam mold vaporizes and disappears due to heat, allowing the molten metal to fill the mold in place and finally solidify into shape. The Lost Foam Casting process has the advantages of high casting dimensional accuracy, good surface quality, reduced processing allowance and production cost, and is suitable for casting complex parts made of aluminum alloy, gray cast iron, ductile iron and steel.
1. Model making
Use expandable foam plastics such as polystyrene (EPS) to make a foam model with the same shape as the final casting through thermoforming, mold forming or extrusion.
In addition, the surface of the foam model needs to be carefully polished and trimmed by CNC machining, laser engraving, etc. to ensure that the model size is accurate and meets the design requirements and the surface quality requirements of the casting.
2. Apply high temperature resistant coating
A layer of high temperature refractory coating needs to be applied on the surface of the foam model. The main components of the coating usually include high temperature resistant sand, adhesive and water.
The coating process usually uses spraying, brushing or dipping to ensure that the coating is evenly covered on the surface of the foam model.
The coating is cured and has sufficient strength by natural drying or hot air drying.
3. Model embedding and sand mold making
The foam model coated with coating is placed in dry sand, and the sand is usually dry sand without binder.
Through vibration or compaction, the sand is tightly wrapped around the model to form a sand mold.
4. Model baking and mold preheating
Before pouring, the foam model needs to be properly baked to improve the strength of the coating and avoid the impact caused by rapid gasification when the molten metal is poured.
The sand mold should be preheated. Preheating the sand mold helps to improve the fluidity of the molten metal, reduce thermal shock, and effectively avoid surface defects of lost foam castings.
5. Melting metal and pouring
According to the material requirements of the casting, select suitable metals (such as aluminum alloy, cast iron, steel, etc.) for melting.
The molten metal is injected into the sand mold through the pouring system (such as gate, riser, etc.). Since the model is a foam plastic, when the temperature of the molten metal reaches a certain level, the foam will quickly gasify and disappear to form a cavity. The molten metal fills the cavity and finally solidifies and forms.
6. Cooling and demolding of castings
After the molten metal fills the model, it needs to wait for it to cool naturally. The metal will solidify during the cooling process and gradually form a casting.
After the metal is completely cooled, open the sand mold, remove the sand shell and take out the casting. Since the foam model is completely vaporized and disappears, there is no need for traditional mold removal.
7. Casting cleaning and post-processing
After the lost foam casting is taken out of the sand mold, the surface needs to be cleaned, and the residual sand shell and coating are removed by shot blasting, sand blasting or mechanical cleaning.
Post-processing: The casting may require finishing, such as grinding, cutting, heat treatment, etc., to ensure that the casting meets the size, tolerance and mechanical property requirements.
Available Materials for Simis Lost Foam Casting Foundry
What metal parts can be cast in Simis lost foam casting factory？
Lost foam casting is a near-net-shape sand casting process that uses expendable foam patterns to form complex geometries without traditional parting lines or cores. By embedding the foam pattern in unbonded sand and vaporizing it during metal pouring, the process enables the replication of intricate internal cavities and integrated structures that are difficult or costly to achieve with conventional sand molding. Due to its reliance on gas evacuation through the sand bed and coating system, lost foam casting is best suited for materials with good fluidity and moderate sensitivity to gas-related defects. Lost foam casting process is primarily applied to gray iron, ductile iron, selected low-alloy irons, aluminum alloys, particularly for large, complex components produced in medium to high volumes.
| Material Category | Why It Is Suitable for Lost Foam Casting | Simis Lost foam casting Foundry Typical Applications | Simis Lost foam casting Foundry Common Grades |
| Gray Iron | Excellent fluidity and low shrinkage behavior allow gray iron to compensate for the foam pattern vaporization process. Its tolerance to gas evolution and solidification stresses makes it one of the most stable and widely used materials in lost foam casting | Engine blocks, cylinder heads, machine housings, crankcases, large structural frames | ASTM A48 Class 30/35/40, EN-GJL-250, EN-GJL-300 |
| Ductile Iron | With controlled spheroidization and proper coating permeability, ductile iron can be reliably produced using lost foam casting. The process enables complex internal geometries while maintaining mechanical performance, though stricter process control is required than for gray iron | Crankshafts, suspension components, pump bodies, hydraulic components | ASTM A536 65-45-12, 80-55-06, EN-GJS-500-7 |
| Low-Alloy Cast Iron | Low alloy additions enhance strength or wear resistance while preserving acceptable castability. Lost foam casting allows integrated designs and reduced machining for large or complex low-alloy iron components when gas evacuation and feeding are carefully managed | Automotive structural parts, machinery housings, wear-resistant components | EN-GJL / EN-GJS (alloyed grades) |
| Aluminum Alloys | Low melting temperature and good fluidity make aluminum alloys well suited for lost foam casting. The process supports thin walls and complex internal features, enabling lightweight designs and reduced machining in high-volume production | Engine blocks, transmission housings, structural brackets | ASTM A356, A319, EN AC-42100 |
