Knowde Enhanced TDS
Identification & Functionality
- Type of Material
- F-40
Features & Benefits
- Product Information
They are made up of sand and clay, usually bentonite, which gives the mixture cohesion and plasticity, rendering it easier to mold and making it strong enough to keep the shape of the pattern after it is removed and while the molten material is poured into the mold. The proportion of bentonites in the mixture varies between 5% and 10%. Sodium or calcium bentonite is used, depending on the kind of use intended for the mold. Sodium bentonite is used when higher temperatures are involved, because it is more stable than calcium bentonite at high temperatures. They are often used in steel, ductile iron and malleable iron foundry, and to a lesser degree in the range of non-ferrous metals. On the other hand, calcium bentonite is more suitable for making molds with more complex shapes and is used mainly in non-ferrous metals foundry. The increasing cost of raw materials is forcing foundries to recover as much sand mixture as possible for reuse, although this does not usually affect the demand for bentonite significantly. Recycling is favored by the use of natural sodium bentonites, as they possess a high thermal stability.
Applications & Uses
- Application Rate
The percentage of bentonite added to the molding sand varies acording to the molding system (manual or high productivity) and the type of piece to be cast. It is usually between 2% and 10%.
Properties
- Typical Properties
| Value | Units | Test Method / Conditions | |
| Moisture | max. 13.5 | % | — |
| PH | 6-9 | — | — |
| Swelling Capacity | min. 40 | ml | — |
| Methylene Blue Absorption | min. 50 | ml | — |
| GREEN COMPRESSION STRENGTH | min. 11 | N/CM2 | — |
| WET TENSILE STRENGTH | min. 0.30 | N/CM2 | — |
| COMPACTABILITY | 47 +- 1 | % | — |
Technical Details & Test Data
- Chemical Composition And Average Chemical Analysis
Chemical Composition: Hydrated silicate with general formula (Na, CA); (Mg, Al)2 (OH)2Si4O19.11H2O, containing quartz, feldspar, and gypsum impurities.
Average Chemical Analysis
COMPOUND CONTENT SIO2 (gr/100gr) 62.2 AL2O3 (gr/100gr) 16.35 Fe2O3 (gr/100gr) 4.09 TiO2 (gr/100gr) 0.65 P2O5 (gr/100gr) 0.06 MnO (gr/100gr) 0.03 CaO (gr/100gr) 0.63 MgO (gr/100gr) 3.26 Na2O (gr/100gr) 2.38 K2O (gr/100gr) 32 SO3 (gr/100gr) 0.20 PPC a 1000 ºC (gr/100gr) 9.82 - Specifications
TYPE OF BENTONITE F-40
High swelling, high dispersibility bentonite, suitable for green sand molding, with high thermal stability, ideal for obtaining cast pieces with no flaws on their surfaces due to its high wet tensile strength.
Packaging & Availability
- AVAILABLE IN
25 Kg bags, palletized, fastened with hoops and waterproofed with 200 micron heat shrink wrap, and 1000Kg BIG BAG.