Foundry Bentonite for Green Sand Moulding
Bentonite is an essential ingredient in foundry molding sands, providing the binding strength needed to form stable, precise molds for iron, steel, and non-ferrous metal castings. Its natural binding and thermal durability make it the backbone of green sand systems used in modern foundries.
Why Foundries Choose VARAN® as a Sand Binder
A 5% addition rate of VARAN® is enough to bond green sand systems that hold shape through pour, cool and shakeout — without the scabbing, veining or burn-on defects that undersized bentonite bonds leave behind. For iron and steel foundries, bond quality determines scrap rate more than any other single input.
VARAN® is Amrfeo’s activated sodium bentonite, processed by a 100% clay extrusion method for foundry-grade purity, and engineered for green sand moulding across high-pressure moulding (HPM) lines, jobbing foundries and hand-moulding operations. It delivers a minimum wet tensile strength of 0.22 N/cm² at a simple 5% addition on new sand — among the highest in the industry.
1
High Wet Tensile Strength
Strong green bond at lower addition rates, reducing bentonite consumption per tonne of sand mix.
2
Thermal Bond Durability
Resists breakdown under repeated heat cycling, extending usable sand-system life.
3
Consistent Compactability Control
Stable mould hardness across automated lines, minimising rejects from under- or over-ramming.
4
Low Dead-Clay Buildup
100% clay extrusion avoids the inert fillers that accumulate as dead clay in recirculating sand systems.
5
Fine, Uniform Mesh Grading
Rapid, even dispersion through mullers and sand mixers.
6
Batch-Consistent Supply
Bond strength, swelling index and moisture held within tight tolerance shipment to shipment.
VARAN® Technical Profile
Free Swelling Volume
28–30 ml
Montmorillonite (MBA) value
380 mg/gm
Moisture content
12% max
pH
9–10
Wet Tensile Strength
0.22 N/cm² min
Wet tensile strength at 5% addition on new sand. Figures represent standard product performance — download the TDS for the full technical profile.
Processed for Export-Grade Consistency
VARAN® is processed from Amrfeo’s own Kutch, Gujarat bentonite reserves under ISO 9001:2015 quality systems, with Star Export House-backed logistics from Mundra and Kandla ports. For foundries and bentonite distributors sourcing bond material internationally — particularly across East and Southeast Asia — that means a traceable, activation-controlled supply chain rather than a variable commodity spot-buy.
Frequently Asked Questions
VARAN® is an activated sodium bentonite binder used in green sand moulding for iron and steel foundries, including high-pressure moulding lines, jobbing foundries and hand-moulding operations.
Typically 5% by weight of sand mix, depending on sand base, casting type and moulding method.
Yes. Its particle size and activation profile support fast dispersion and stable compactability under the short mixing cycles typical of automated HPM lines.
The 100% clay extrusion processing limits dead-clay buildup, helping recirculating sand systems maintain active bond percentage across more reuse cycles.
In Bhuj, Gujarat, India, from Amrfeo’s own bentonite reserves, under ISO 9001:2015 certification, and exported globally through Mundra and Kandla ports.
Tell us the metal cast, moulding line and monthly sand volume. Replies usually within one working day.