Special adhesives for lost foam casting are bonding materials specifically designed for the lost foam casting process. According to their application, they are divided into foam pattern bonding adhesives and coating binders. Their primary function is to ensure proper pattern assembly and stable coating performance.
Special adhesives for lost foam casting are available in various types. The following are common categories and representative products:
1. Foam Pattern Bonding Adhesives (for Pattern Assembly)
(1)Water-Based Cold Adhesives (PVA / Acrylic Emulsions)
These adhesives bond at ambient temperature without corroding EPS foam patterns. They feature low gas generation, flexible adhesive layers that are easy to cut, fast positioning, and high bonding strength, making them suitable for batch assembly of complex foam patterns.
(2)Hot-Melt Glue Sticks
Hot-melt adhesives provide instant bonding and rapid positioning upon heating. They do not corrode foam patterns or increase carbon content, making them suitable for fast assembly and temporary fixation.
(3)Two-Component Fast-Curing Adhesives (Epoxy / Acrylic)
These adhesives offer extremely fast curing and high bonding strength, making them suitable for precise positioning of foam patterns in small-batch, high-accuracy applications.
2. Coating Binders (for Coating Formation)
(1)Organic Binders (PVA / CMC / Starch)
These binders provide strong bonding strength at room temperature and improve coating hang-on properties. They decompose at high temperatures with low gas evolution, are water-based and environmentally friendly, and are suitable for various water-based coatings.
(2)Inorganic Binders (Bentonite / Silica Sol / Sodium Silicate)
Inorganic binders offer high sintering strength at elevated temperatures, strong resistance to molten metal erosion, and excellent anti-burn-on performance. With good compatibility with refractory aggregates, they are suitable for high-temperature applications such as cast iron and cast steel.
(3)Composite Binders (Organic + Inorganic)
Composite binders balance room-temperature adhesion and high-temperature performance. The resulting coatings are easy to peel off after pouring, making them suitable for batch production of castings made from various materials.