Melt Shear History and Contaminant Catalyzed Scission in Post Consumer Polyolefin Silo Blends
Deactivate metal catalysts and neutralize acid traces with targeted additives to stabilize viscosity drift and optimize landed cost per good recycled part.
Synthetic Hydrotalcite
Meaning
Manufactured layered double hydroxide minerals act as acid scavengers and stabilizers in polymer resins. By adding synthetic hydrotalcite to a polymer formulation, compounders neutralize acidic residues left by catalysts during polymerization. This addition prevents the resin from degrading during high-temperature melt processing.
It ensures that the plastic retains its color and mechanical strength.
Acid Neutralization
The crystal structure of the mineral consists of charged layers that trap acid anions. When synthetic hydrotalcite is distributed throughout the polymer melt, it immobilizes harmful chloride ions.
Corrosion Prevention
Acidic residues from catalysts can attack the steel surfaces of extruders and injection moulding machines. When synthetic hydrotalcite is used, it prevents the formation of hydrochloric acid which would otherwise etch the metal surfaces of the tooling. This protection reduces the frequency of mould maintenance and extends the lifespan of the expensive machinery.
It ensures that the moulded parts have a consistent surface finish and are free from rust-induced cosmetic defects.
Compounding Benefits
This additive must be chosen based on its thermal stability and compatibility with other polymer ingredients. In polymer formulations, synthetic hydrotalcite provides high thermal stability, allowing it to be used in high-temperature extrusion without releasing water. This prevents the formation of steam bubbles and voids in the extruded films or sheets.
It is an effective alternative to traditional lead or calcium-based stabilizers. The use of this additive allows for the production of environmentally safe food packaging materials.