Food grade epoxy is a type of epoxy resin that meets the standards of the Food and Drug Administration (FDA) for indirect food contact. This means that the epoxy resin can be used in applications where it may come into contact with food, such as in food processing equipment, packaging, utensils, and containers. However, the epoxy resin itself is not edible and should not be ingested.
Food grade epoxy has many advantages over other types of materials, such as metals, plastics, and ceramics, for food processing applications. Some of these advantages are:
- Chemical resistance: Food grade epoxy can resist a wide range of chemicals, such as acids, bases, solvents, oils, fats, and detergents, that are commonly used in food processing and cleaning. This makes food grade epoxy suitable for applications where the material may be exposed to harsh chemical environments, such as in food storage tanks, pipes, valves, pumps, and mixers.
- Thermal stability: Food grade epoxy can withstand high temperatures up to 450°F and low temperatures down to -60°F. This makes food grade epoxy suitable for applications where the material may be exposed to extreme temperature fluctuations, such as in baking ovens, refrigerators, freezers, and microwaves.
- Mechanical strength: Food grade epoxy has high tensile strength, tensile modulus, and compressive strength, which means that it can resist deformation, cracking, and breaking under stress. This makes food grade epoxy suitable for applications where the material may be subjected to mechanical forces, such as in cutting boards, knives, spoons, and forks.
- Electrical insulation: Food grade epoxy has high electrical resistivity and dielectric constant, which means that it can prevent electric currents and electromagnetic fields from passing through. This makes food grade epoxy suitable for applications where the material may be exposed to electrical hazards, such as in electric motors, sensors, and switches.
- Optical clarity: Food grade epoxy can be cured to form a clear and transparent material, which allows the visibility of the food or the product inside. This makes food grade epoxy suitable for applications where the material may be used for aesthetic or functional purposes, such as in food containers, jars, bottles, and cups.
The following table summarizes some of the properties and applications of food grade epoxy:
| Property | Value | Application |
|---|---|---|
| Chemical resistance | Resists acids, bases, solvents, oils, fats, and detergents | Food storage tanks, pipes, valves, pumps, and mixers |
| Thermal stability | Withstands temperatures from -60°F to 450°F | Baking ovens, refrigerators, freezers, and microwaves |
| Mechanical strength | Has high tensile strength, tensile modulus, and compressive strength | Cutting boards, knives, spoons, and forks |
| Electrical insulation | Has high electrical resistivity and dielectric constant | Electric motors, sensors, and switches |
| Optical clarity | Can be cured to form a clear and transparent material | Food containers, jars, bottles, and cups |
One example of a food grade epoxy product is Master Bond EP42HT-2FG Black, which is a two-component, moderate heat-cured epoxy system that offers enhanced chemical resistance. It complies with the FDA 21 CFR 175.105 requirement for indirect food contact and can be used in food processing applications and assembly. It has a relatively long working life of 105 to 150 minutes for 100 grams of the mixed material at 75°F. It cures optically opaque and has a high glass transition temperature of 145°C to 150°C. It has a high tensile strength of 11,000 to 12,000 psi at room temperature and a tensile modulus of 400,000 to 450,000 psi. It is electrically insulative with a volume resistivity greater than 10^14 ohm-cm and a dielectric constant of 4.6 at 60 Hz at room temperature.
