Indian core oil, since 1967, manufactures various types of foundry chemicals. When cores and molds are produced without baking or heating, it is known as no bake process. Dry sand is mixed with liquid or powder catalyst and then mixed with binder. This sand mix must be used as soon as possible. Otherwise with the passage of time there will be deterioration in tensile strength and compaction of sand resulting in various defects like metal penetration, scabbing etc. Work time/ strip time ratio depends on resin accelerators, temperature of sand, moisture and humidity. Setting time can be varied from a few minutes to several hours. This process reduces, pollution and also saves energy. No bake resins are of different types, which are as follows:
