Low Free Phenol Phenolic Resin Pellets with Low Gas for Foundry Resin Coated Sands

Product description

Novolac Phenolic resin (two-step) is produced by condensing a molar excess of phenol to formaldehyde in the presence of an acid catalyst. This produces a thermoplastic resin. To cure this resin, a hardening agent is used, HMTA (or hexa). Under heat and pressure, it yields ammonia and formaldehyde as methylene groups to cure the resin, hence the term “two-step,” because of the two formaldehyde additions. A novolak phenolic resin has an infinite shelf life under normal storage conditions.Cured phenolic resin provides the rigidity necessary to maintain structural integrity and dimensional stability even under severe conditions.

Characteristics

1. Bonding Strength

The primary use of phenolic resin is as a bonding agent. Phenolic resin effortlessly penetrates and adheres to

the structure of many organic and inorganic fillers and reinforcements, which makes it an ideal candidate for

various end uses.

2. High Temperature Performance

A key characteristic of thermoset phenolic resin is its ability to withstand high temperature under mechanical

load with minimal deformation or creep. In other words, cured phenolic resin provides the rigidity necessary to

maintain structural integrity and dimensional stability even under severe conditions.

3. Chemical Resistance

Phenolic resins accommodate the harsh exposure of severe chemical environments. The inherent nature of

phenolic resin provides an impervious shield to protect a variety of substrates from the corrosive effects of

chemicals. Laboratory tests confirm minimal degradation from many chemicals after prolonged exposure,

often at elevated temperatures.

4. Low Smoke and Toxicity

Burning phenolic resin typically generates hydrogen, hydrocarbons, water vapor, and carbon dioxide. Phenolic resin produces a relatively low amount of smoke at a relatively low level of toxicity.

5 .High Carbon and Char Yield

Phenolic resins demonstrate higher char yields than other plastic materials when exposed to temperatures

above their point of decomposition. In an inert atmosphere at high temperatures (600° - 2,000°F, 300 -

1,000°C), phenolic resin will convert to a structural carbon known as vitreous carbon. In many ways, this

material behaves similar to ceramic and may actually contribute to structural integrity when exposed to fire

situations.

Application

Novolac Phenolic Resin P1301 is recommended for Foundry Resin Coated Sands.Manufacturers using the shell molding process experience excellent dimensional accuracy, surface smoothness and high production rates using phenolic resin coated foundry sands. The shell molding process involves first creating mold cavities and cores by shaping sand coated with phenolic resin over a not metal form. Removed from the form and assembled, the mold and cores create the "negative" shape of the desired metal form. Hot metal is poured into the resin-sand mold and allowed to cool. Once hard, the excess resin-sand material is broken away revealing the metal part. Some recover the broken away sand for reuse. The careful selection of sand type, resin characteristics and coating method results in the desired mold and core properties such as strength, rigidity, flexibility, surface finish, part release and applicability to reuse.

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