Pigments pellet production

Thermotropic LCPs in the form of engineering resins are sold for molding into parts, such as interconnect devices. This requires high flow into the mold and high thermal stability to withstand post molding processes and end uses at elevated temperatures. The resins are sold as composites in extruded pellet form, compounded with fillers, such as glass fibers, carbon fibers, minerals and pigments. The product literature contains exten-... 

Based on results from a field demonstration to enhance titanium dioxide recovery in the production of high-grade titanium dioxide pigment, treatment costs (including electrical power, aluminum pellets, and labor) to achieve an 85 to 90% recovery of titanium dioxide from an infiuent stream of 1100 mg/liter of titanium dioxide was estimated to be 0.10 to 0.15 per 1000 liter of overflow (D121573, p. 788). 

As formed, carbon black is a fluffy powder possessing low density. The densification process involves the removal of occluded air by agitation and followed by dry or wet process pelletization. In both the dry and wet pelletization process, nearly spherical pellets or beads will form that are typically composed of >99% carbon black and trace impurities such as sulfur. Thus, carbon black is sold as a low density powder or as a pelleted form in pigmenting and other end uses. The choice of a fluffy or pelleted carbon black for dispersion in a given system depends upon the dispersion and handling equipment and end use. For example, pelleted carbon blacks are used most frequently in production of black masterbatch carbon black powders are typically used to tint chromatic compounds. 

Pelleting machines Animal feeds, rubber raw materials, catalysts, lubricants, stabilizers, pigments, polymers, clay, chemicals, pharmaceutical products, insecticides, herbicides, fungicides, etc. 

Any additive is a potential source of change to the overall processability from pellet feed to melt rheology. The not uncommon operator comment that one particular color always runs well and another always causes problems is more likely to be fact than superstition. Many products are colored by using masterbatches. whilst extruded products may contain antiblock and slip additives. Injection moldings may contain lubricants to aid mold release or provide product lubrication, e,g., bottle caps. In many cases such nias-terbatches contain low-viscosity polymer waxes to promote additive dispersion (particularly pigments) and masterbatch distribution throughout the natural polymer. There are in fact many additives, including fillers, flame retardants, and antioxidants, that can influence processability. 

A representative selection of commercial color concentrates (Colortech Inc, Brampton, ON) were used for this study. Each pelletized sample consisted of a blend of organic and inorganic pigments dispersed in Linear Low Density Polyethylene (LLDPE) carrier resin. Pigment loading varied between 3,6 and 50.0 wt,% and some formulations contained up to 33.1 wt.% calcium carbonate filler. All were prepared on a production-scale 40 Liter Gelimat-style... 

Pelletization pe-b-to- za-shon (1942) n. Processing of pigments or other chemical products into very small, free-flowing beads, which eliminates the dust nuisance. 

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