Casting PU Elastomer Production and Application

   

Production Method of Casting PU Elastomer

   
CPU elastomer is generally produced using thermosetting PU casting resin. Common CPU elastomer products include PU rods, PU sheets, PU rollers, PU wheels and customized items. Due to its excellent shock absorption and elasticity, CPU elastomer is also suitable for springs, shock-absorbing pads, and strips in stamping equipment, as well as for manufacturing large PU elastomeric products. The molding process for PU elastomer is as follows:

1. Vacuum to degas the liquid CPU resin.
2. Mix and stir the CPU resin with hardener.
3. Pour the mixture into prepared molds.
4. Heat up the molds to cure the mixture and form PU elastomer.

The equipment and materials required for manual CPU resin casting include:

• Industrial oven
• Vacuum degassing chamber and motor
• Resin mixer
• CPU casting resin and hardener
• Mold release agent

Important Considerations for Manual CPU Resin Casting:

• Proper vacuum chamber sealing: Ensure the vacuum chamber is well-sealed to prevent gas infiltration or external air entry. Regularly check and replace seals to maintain sealing effectiveness.
• Mold preparation: Before casting, apply mold release agent to the molds and preheat them to avoid significant temperature differences between the molds and the resin.
• PU resin temperature: Slight heating can increase PU resin fluidity, but it will also shorten the workable time after mixing. Excessive temperature can negatively impact PU resin quality. Ensure the operating temperature does not adversely affect the PU resin or subsequent casting operations.
• Choice of resin container: When degassing PU resin, the gas causes the resin level to rise. Use a taller container to prevent resin overflow.
• Pressure control: Carefully control the vacuum motor to avoid excessive degassing, which can cause resin overflow. When the resin level approaches the top of the container, turn off the vacuum motor and wait for the level to drop before resuming operation. Repeat until there are no significant rises and no bubbles.
• Vacuuming before stirring: Vacuuming before stirring allows the PU resin to fully degas.
• Stirring: During mixing, avoid air incorporation. Pay special attention to the pouring time to prevent the resin from curing in the mixing container.
• Vacuuming after stirring: Only recommended if there is sufficient workable time for pouring after stirring.
• Reducing curing time: Increasing the oven temperature can shorten the curing time of CPU casting resin. When the CPU prepolymer resin reacts with amine hardeners (such as MOCA), higher temperatures help speed up the formation of PU elastomer. To ensure product quality, control the oven temperature below 120℃, typically around 100℃.

 
Learn more about: PU Casting Resin    
 

Applications and Characteristics of PU Rods

   
PU rods, also known as PU bars, polyurethane rods, polyurethane bars, PU strips, PU solid rods, polyurethane round bars, and PU spring rods, come in solid and hollow forms. They are widely used in engineering parts such as stamping molds, fixtures, shock-absorbing tools, mechanical rubber linings, sleeves, buffers, and protective materials. PU rods offer a longer lifespan and wider hardness range than traditional plastics. Moreover, PU rods can be easily processed into various mechanical rollers, gear seals, and die cushions for punch presses, as well as spring strips for bending forming.
 
Characteristics of PU Rods:

• High abrasion resistance
• High elasticity
• High load-bearing capacity
• High shock absorption and impact resistance
• High tensile strength
• Low compression set
• High tear resistance
• Wide selection range of size and hardness

 
Learn more about: PU Rods
 

Applications and Characteristics of PU Sheets

   
PU sheets, also known as PU plates, cow tendon sheets, PU gaskets, PU pads, PU mats, PU boards, polyurethane sheets, polyurethane plates, polyurethane boards, polyurethane soft pads, and polyurethane mats, are used in industrial parts and leather processing cutting boards with wide selection range of size and hardness. Cutting boards protect cutting edges during leather cutting and punching. Many uses black rubber sheets, but they are harder, making prongs prone to breakage or misalignment. Selecting the right cutting board is crucial since some prongs are expensive and difficult to repair. Compared to black rubber sheets, PU sheets are softer with lower compression set, better flexibility, high abrasion resistance, oil resistance, sound and shock absorption. They effectively prevent cutting edge dulling or prong breakage and misalignment. When punching holes with PU sheets as the cutting board, the cutting tip easily penetrates but doesn't punch through, protecting the blade and making the punching process easier.
 
Learn more about: PU Sheets
 
TPUCO Product Links
PU Casting Resin
https://www.taiwanpu.com/en/product/Casting-CPU
PU Sheet
https://www.taiwanpu.com/en/product/PU-Moulded-Products/PU-Sheet
PU Rod
https://www.taiwanpu.com/en/product/PU-Moulded-Products/PU-Rod