A TDI casting machine is a special equipment for producing polyurethane elastomer products. It is widely used in the manufacture of polyurethane wheels, roller, sieve, seal and industrial parts. Its main function is to accurately mix toluene diisocyanate with polyether polyols and chain extenders in a certain proportion, and then obtain high-performance polyurethane products by casting.
1.Raw Material Preheating and storage
All raw materials need to be maintained in a suitable temperature range to ensure stable reactivity and fluidity before production begins.
Key raw materials include:
TDI (toluene diisocyanate)
Polyether polyols
MOCA or other chain extenders
Color pastes and functional additives
Proper preheating can improve mixing uniformity and reduce the formation of bubbles and defects.
2.Precise Metering and Delivery
The TDI casting machine is equipped with a high-precision metering system that delivers each component to the mixing head at a a preset ratio through a a metering pump.
This process needs to ensure that:
Accurate proportioning
Steady flow
Uniform pressure
Any deviation in the ratio will affect the hardness, elasticity and mechanical properties of the product.
3.High-Efficiency Mixing Reaction
Add the ingredients to the mixing head and mix quickly and evenly under high-speed shearing.
At this time, a polyurethane chemical reaction occur:
Isocyanate reacts with polyols
Forming polyurethane molecular chains
Initiation the cross-linking and curing process
The quality of the final product is directly affected by the mixing effect.
4.Casting
The mixed liquid polyurethane is injected into a pre-prepared mold.
Common products include:
Polyurethane wheels
Industrial rollers
Screen
Sealing rings
Buffer pads
The casting process requires continuous and uniform flow to avoid voids or size deviations.
5. Curing and dismantling
After casting is formed, the mold enters the curing stage.
At the appropriate temperature:
The polyurethane continues to react
Molecular structure gradually stabilizes
Product strength is increasing;
After the specified curing time has been reached, the molding can be carried out.
6.Post-Curing Treatment
Many polyurethane products require post-removal post-curing treatment.
Its objectives include:
Improving mechanical strength
Increased abrasion resistance
Enhanced dimensional stability
Improved physical properties
Post-curing is a key step in ensuring high-quality polyurethane products.
Conclusion:
TDI casting machines converts liquid raw materials into high-performance polyurethane products by preheating raw materials, precise metering, efficient mixing, casting, curing, dismantling and reprocessing. TDI casting machines, with its precise proportioning, high automation and stable product quality, has become an indispensable equipment in polyurethane elastomers, widely used in mining, machinery, logistics, automotive, industrial manufacturing and other industries.