VFI®-4242 78 D Polyurethane Casting Plastic

Features & Benefits

• High heat deflection temperature (HDT) at 206.96°F (97.2°C)
• Convenient 1A:1B mix ratio by weight for quick and easy application
• Neutral, off-white color that can be easily primed and top-coated
• Excellent processing and demold times between 5-6 hours
• Non-mercury based, TDI-free, MOCA-free, odorless polymer

Instructions for Use:  

Mold Preparation  

All surfaces should be clean, dry, and free of dirt, dust, and debris. Release agents are recommended for any molding application to extend the life of the mold, and for prototyping urethane molds, it is a requirement. Heated molds are not recommended for this product or any mold over 120°F because it will cause an uneven cure. These materials are compatible with prepared platinum-cured silicone, metal, and prototyping urethane molds.

Casting Process  

The material should be at least 65°F before use for proper mixing and application. The B side (Poly) must be premixed once daily before each use, being careful not to introduce extra moisture or air. The A side (Iso) does not need to be premixed.

Prepare a container that is an appropriate size for vacuum degassing. It is recommended to use one with at least 2/3 of head space. Pour 1 part of the A component into 1 part of the B component by weight, 89.5 parts A component to 100 parts B component by volume. Mix until uniform by hand with a gallon paint stick or power mixing equipment. Transfer to a new, clean container and mix again before use. Be sure to scrape the sides and bottom of the container for uniformity.

To create the necessary exotherm to fully cure the part, it cannot be poured less than 1/4 inch thick at room temperature. For thinner pours, you must elevate the mold and molding temperature to 115°F.

After an initial cure of 5-6 hours at room temperature (77°F), you may post-cure in an oven at 180°F for 16 hours to achieve full physical properties faster. Physical properties at room temperature will be delayed for 5-7 days and may not fully develop without post-curing.

Safety  

*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: water, alcohols, amines, bases, and acids. B side: oxidizers  
• Conditions to avoid – heat and incompatible materials
• Chemical stability – stable under normal storage conditions 
• Reactivity & hazardous reactions – no dangerous reaction known under normal use
• Hazardous decomposition products – A side: carbon monoxide, carbon dioxide, nitrogen oxides, hydrocarbons, and HCN. B side may include, but are not limited to, oxides of carbon

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.   

Click here for more information on the full technical data sheet.