VFI®-4286 85 D Polyurethane Casting Plastic

VFI®-4286 85 D Polyurethane Casting Plastic

VFI-4286 85 D Polyurethane Casting Plastic is a high-impact urethane plastic with high heat deflection and tensile strength. This material works well when vacuum-degassed and pressure-potted to provide a repeatable, uniform, void-free cast. It is a multi-faceted plastic capable of being used in rapid prototyping, production parts, and equipment housings for large part runs. VFI-4286 has a working time of 6 minutes. It is capable of passing UL 94 V-0 and can be used to make high-end, fire-retardant plastic parts for a variety of industries, including medical, automotive, and aerospace.

VFI-4286 85 D Polyurethane Casting Plastic from VFI is a high-impact urethane plastic with high heat deflection and tensile strength able to pass UL 94 V-0.

Features & Benefits

  • Usable in platinum-cured silicone, metal, or prototyping urethane molds
  • High heat deflection temperature (HDT) at 205°F (96.1°C @ 66 psi)
  • Neutral color for easy priming and top coat application
  • Excellent processing and demold times at 1-2 hours
  • Non-mercury based, TDI-free, MOCA-free, odorless polymer
  • Non-filled fire-retardant material

Instructions for Use:

Mold Preparation

Using release agents is recommended for any molding application to extend the life of the mold, and for prototyping urethane molds, it is a requirement. Heated molds or any mold over 120°F are not recommended because it will cause an uneven cure.

Casting Process

The B side (Poly) must be premixed once daily before each use. Be careful not to introduce extra moisture or air into the material. The A side (Iso) does not need to be mixed.

Prepare a container that is an appropriate size with at least 2/3 of head space for vacuum degassing. Pour the measured A side into the container, and promptly follow by pouring the measured B side into the same container. Mix the material until uniform by hand or power mixer. Mixing, vacuum degassing, and pouring must all be completed before the end of the pot life.

To create the necessary exotherm to fully cure the part, it cannot be poured less than a quarter inch thick at room temperature. If thinner pours are needed, you must elevate the mold and molding temperature to 115°F.

After an initial cure at room temperature for 16 hours, a heat cure at 150°F for 24 hours is recommended to achieve full physical properties. Physical properties at room temperature will be delayed until after 7 days and may not fully develop without post-curing in an oven.


*Always read the safety data sheet before working with chemicals 

Use chemicals only as directed and for their intended purpose. Do not dispose of chemicals down the drain. Most chemicals must be disposed of as hazardous waste.

PPE to avoid all unnecessary exposure:

  • Eye protection – wear approved safety glasses and any additional eye protection as necessary
  • Hand protection – wear chemically resistant protective gloves (nitrile, butyl, or neoprene)
  • Skin and body protection – wear suitable protective clothing
  • Respiratory protection – in case of insufficient ventilation, wear suitable respiratory equipment. Respirator selection must be based on known or anticipated exposure levels, the hazards of the product, and the safe working limits of the selected respirator

Product Limitations

This product contains isocyanate, which may irritate the skin and is toxic if inhaled.

  • Incompatible materials – A side: amines, strong bases, water, alcohols, and heavy metals. B side: oxidizers
  • Conditions to avoid – A side: contamination with water; keep away from heat, ignition sources, and incompatible materials. B side: heat and incompatible materials
  • Chemical stability – stable under normal storage conditions
  • Reactivity & hazardous reactions – no dangerous reaction known under normal use
  • Hazardous decomposition products – may include, but are not limited to, oxides of carbon. Also, oxides of nitrogen and isocyanates for the A side

Potential Health Hazards

  • May cause respiratory irritation. A side material may also cause allergy and asthma symptoms or breathing difficulties.
  • May cause stomach distress, nausea, or vomiting if swallowed.
  • May cause skin irritation and sensitization: redness, edema, drying, defatting, and cracking.
  • May cause eye irritation: discomfort, pain, excess blinking and tear production, marked redness, and swelling of the conjunctiva.

*If you are experiencing any of these symptoms, seek medical advice or attention. Call a poison control center or doctor if swallowed.  

Application Methods:

  • Pour Pour

Available Packaging:

  • Drum
  • 5 Gallon