Pellets Bakelite Phenolic Resin with Low Gas for Foundry Resin Coated Sands

Product description

Bakelite Phenolic resins pellets are synthetic polymers formed as condensation products of phenols and aldehydes by acid-catalyzed. In acid, the reaction forms novolac resins. These resins require a curing agent - often hexamethylenetetramine or hexa.They are not heat-sensitive. 

Pellets Bakeite Phenolic Resin for Foundry Resin Coated Sands

Process Method

Hot Coating
The washed and dried silica sand is heated to 120–150℃. The granulated phenolic novolak resin , with a melting point of around 80–100℃, is added to the mixer at 1–5% resin (based on sand and depending upon application). It melts and coats the grains of sand. The quantity of HMTA required for later curing of
the resin is then added as an aqueous solution (25–40% solids). Sufficient hexa solution to both cool the sand and deliver the correct amount of curative is added.The hexa level is 15–20% on the basis of resin, depending upon the desired properties. The cooling effect produced by the addition of the water solution prevents premature curing of the binder, although it is possible that some degree of cure occurs. Additives such as calcium stearate are incorporated during this stage of the coating operation.

Specification:

Packing&Storage

the package is paper-plastics bag in 25KGS each one
The storage life of this product is several months in a cool and dry place in original closed bags