All ABOUT CHILLED ROLLS!
Rolling mill roll manufacturers’ are spread across the country. Here in Punjab we have two main cities where chill rolls are made. Mandi Gobindgarh and Malerkotla are historically known for their chill roll industry. Last few years have seen a significant increase in soap making and flour mill plants implementations. Also manufacturers are using advanced German technology to provide high quality products to their customers. Let’s see in depth what are chill roll and its specification!
Construction of a Chill Roll
There are 2 main parts to a chilled roll: Barrel (Big cylinder in the middle) and Journal (small cylinders at sides).
Type of Chill Rolls
Steel Rolls (Alloy Cast & Alloy Steel Base)
Spheroidal Graphite Iron Rolls (Pearlitic & Aceicular)
Indefinite Chill Rolls
Clear Chill Rolls
Double Poured Rolls Steel Shaft fitted with Chill Rolls.
Hollow & Solid Rolls (for non-metallic applications).
Chilled Cast Iron
When grey cast iron is cooled very rapidly it becomes white/chilled cast iron . A chilled iron casting can be produced by adjusting the carbon composition of the white cast iron so that the normal cooling rate at the surface is just enough fast to produce white cast iron while the slower cooling rate below the surface will produce grey iron. The depth of chill decreases and the hardness of the chilled zone increases with increasing carbon content.
Chill rolls applications:
Rubber Mixing & Calendering
Seamless Tube Rolling
Solvent Extraction through Cracking & Flaking
Compound Mixing in Soap, Chocolate, Paint Industries etc.
Stem Flattening Machines for Tobacco Industries etc.
Sugar & Salt Milling
Chemical used to manufacture chill rolls:
Chromium is used to control the chill depth so to increase hardness and improve abrasion resistance.
Manganese isused for rust and corrosion prevention on steel.
Silicon is a graphitestabilizing element in cast iron
Phosphorus improves the wear resistance of the grey cast iron
Sulphur determines the machinability of a chill roll
Other chemicals are molybdenum, carbon and nickel
How to clean chill rolls?
Chilled rolls tend to have build-up and iron oxide after several usages so it is very important to have a constant roll maintenance program in place. The staff in the unit must all be trained to do the following tasks to maximize cast film and extrusion coating equipment performance and durability of the rolls. We recommend using a scientifically developed rust removing material for cleaning operations.
This is a partial schematic knowledge for whom is interested in mill plants; our main target was to cover the basics of chill rolls like how they are made, their applications, types of rolls and their maintenance process. When you are looking out for tube rolling companies, you should check their history, reputation and their availability of products.