VFI®-4280 75 D Polyurethane Casting Plastic

VFI®-4280 75 D Polyurethane Casting Plastic

VFI-4280 75 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-4280 has a working time of 6-8 minutes.  

VFI-4280 75 D Polyurethane Casting Plastic is a high-impact urethane plastic with high heat deflection and tensile strength.

Features & Benefits

  • Usable in platinum-cured silicone, metal, or prototyping urethane molds
  • High heat deflection temperature (HDT) at 198.86°F (92.7°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

Instructions for Use:  

Mold Preparation  

To extend the life of the mold, VFI recommends using a release agent, and for prototyping urethane molds, it is a requirement. We do not recommend heated molds for this product or any mold over 120°F because it will cause an uneven cure. 

Casting Process  

Premix the B side (Poly) once daily before each use without introducing extra moisture or air into the product. Prepare a container that is an appropriate size for degassing with a recommended headspace of at least 2/3. Pour the measured A side (Iso) into the container and promptly follow by pouring the measured B side into the same container. With a hand or power mixer, mix until the material is uniform. Mixing, vacuum degassing, and pouring must all be completed before the end of the pot life.  

VFI-4280 75 D Polyurethane Casting Plastic cannot be poured less than a quarter inch thick at room temperature. A thicker pour will create the necessary exotherm to fully cure the part. If thinner pours are desired, the mold and molding temperature must be elevated to 115°F. 

After an initial cure of 16 hours at room temperature, full physical properties can be achieved by heat curing at 150°F for 24 hours. Without post-curing in an oven, physical properties will be delayed until after seven days and may not fully develop.  


*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