CORE: -
Cores are also painted according to the type, in either water base or thinner base, paint prepared by mixing graphite ready mix paste or powder in water or thinner as the case may be and then spray paints.
A2) Oil Sand Cores: -
Generally water base graphite paints are as spray-painted and the torched or heated in the oven at a temperate of 105oC for proper drying.
B2) CO2 Sodium Silicate Cores:
Here the cores are essentially painted with in inner base painted prepare as mentioned in b1 and then ignited for proper drying.
C2) NO BAKE SYSTEM CORE:
Here the painting can be water base or spirit base graphite prepared as mentioned in A1 or B1 and then as spay painted – torched or ignited as the case may be.
D2) SHELL CORE: -
These are generally painted in water base Zircon mix paints, prepared in the same way as graphite paints but is important that these cores are dried completely after painting.
However in the all above cases, the moulds and cores are ensured for proper drying, if necessary torching before after core setting. |
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CORE OIL SAND
Here the sand is mixed with Core Oil & Dextrin according to the type of cores which the baked in core oven with a maximum temperature of 250*c to 280oc. The percentage of Core Oil & Dextrine also varies from 1% to 2%. Hare the sand and Dextrine are mixed first and then Core Oil is mixed with if mean while, core boxes cleaned thoroughly and checked before farthing up the sand mix for core making. After checking the core box sand the fixed and tightened by hand, using fingers if necessary for intricate portions and the entire core is rammed properly and then leveled. It is now placed on a core plate upside down and the core box stripped from the core, which is then sent for baking & painting. |
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