Chemical Compound

This is a resol type phenolic resin with two part system, used for the large size iron and steel casting for machines  and automotive industries. The first part is the resin and the second part is catalyst in liquid form.The shelf life of the resin is 2 months while the shelf life of the catalyst is 6 months.

No-bake process is economical because it is a cold cured system and application of extra heat is not required.They cured rapidly even at 5º C to  produce distinctively brilliant red sand colour.

One of the greatest advantages of this technique is the capability of varying the curing time/setting time by varying the catalyst addition rates, which varies 40% to 100% on the basis of resin. No-bake is suitable for the casting of large pieces of gray-cast iron and cast steel for machine and vehicle construction.

Nitrogen free fast setting Phenolic resins were introduced later on . A compromise between removal time, casting performance and price is achieved by the combination of three resin components – PF, UF and FA. This is used for cores and moulds of gray and ductile cast iron steel and non-ferrous light and heavy metal castings.

Resin addition is maintained between 1.2 to 2% and 65 to 85% PTSA solution is used @ 40 to 100% on resin, depending on the curing rate/setting time.

A typical formulation for no-bake sand:

Dry Silica Sand                                   100 pts.
65% Catalyst                                         0.6 pts.
PF/FA Resin                                        1.2 pts.
Iron Oxide                                           0 to 1 pts.