Drying color

Thermoplastics. The highest consumption of color concentrates is in thermoplastic resins, such as low and high density polyethylene, polypropylene, PVC, and polystyrene. Processing techniques for thermoplastics are usually based on dry color dispersion in a compatible resin (36). 

Colors and Pigments Dry colors and dyestuffs generally are pulverized in hammer mihs (see Table 20-21 or 20-23). Tne jar mill or... 

Trocken-element, n. dry cell, -entgasung, /. dry distillation, -extrakt, m. dry extract, -farbe,/. dry color, pigment pastel color. 

Production of the color involves centrifugal separation of the biomass, cell breakage, and extraction. Use of a salt solution rather than water as an extraction medium increases stability of the color during extraction. Methods for partial exclusion of the polysaccharide from the color extract in order to enhance resolubilization of the dried color were developed. These processes include either microfiltration or co-precipitation of the polysaccharide with an added positively charged polysaccha-... 

KOH plants, environmental awareness in, 20 634. See also Potassium hydroxide KOH solution, 12 215 meta-Koksowy coal grade (Poland), 6 713t Kolbe-Schmidt reaction, 2 208 of salicylic acid synthesis, 22 7-8 Kolmogoroff microscale, 16 697 Konica Dry Color System, 19 348 Konjac glucomannan, 4 7241... 

Dry Color Manufacturers Association, now CPMA (Color Pigments Manufacturers Association, USA). 

DCMA. 1989. Comments (May 12) to Edward J Skowrowski, ATSDR, on ATSDR draft toxieologieal profile for 3,3,-dichlorobenzidine. Dry Color Manufacturers Association. Alexandria, Virginia. 

Equitable Environmental Health, Inc An Epidemiologic Study of Workers in Lead Chromate Plants. Final report submitted to Dry Color Manufacturers Assoc, June 25, 1976... 

The term mixed metal oxide pigment denotes a pigment that crystallizes in a stable oxide lattice, and in which the color is due to the incorporation of colored cations in this lattice. Such compounds are regarded as solid solutions. The American Dry Color Manufacturers Association has abandoned the term mixed metal oxide inorganic colored pigments , it denotes these colorants as complex inorganic color pigments [3.73],... 

Dry Color A high-intensity blend of pigments and/or dyes with additives provided to the user in the form of dry, free-flowing powders. 

DRY COLOR COMPOUND LIQUID CONCENTRATE RESIN SUPPL1 ED YES / NO ... 

Blend the formulated colorants with the appropriate additives to produce a dry color. 

Dry Color. Raw pigments or additives are mixed with a lubricant in a high-intensity mixer without melting. 

Wax concentrates may be in the form of prills, bars, flakes, or granules. Prills are very small spherical pellets, usually made from a pigment blend and wax. They may be blended, like dry colors, or dispensed by a metering device at the throat of the extruder. If they are blended, it is best to use a powder resin, such as polyvinyl chloride (PVC), so they do not sift to the bottom of the container. The other physical forms are applied in different ways some are designed to be metered in at the hopper, the rest to be blended in before reaching the hopper. The carrier may lubricate, so letdown ratios are limited. 

Figure 20.4. Common methods of coloring plastics (a) 100 pellets of natural regin (b) liquid color on pellets (c) 4% pellet concentrate (d) excess of dry color.

Companies will custom formulate colorant and additive products designed to be used by plastic molders, who will, in turn, produce the final consumer products. The raw materials for colorant and additive products may be in powder, liquid, or solid form. The products formulated from them may also be in powder, liquid, or solid form. Dry color formulations (powder form) currently comprise less than 5% of the total colorant and additive products being produced today. Liquid formulations account for another 5% however, this form of product is increasing in popularity and is expected to capture a larger share of the colorant and additives market in the near future. The solid form, known as concentrates or masterbatch products, are concentrated ingredients encapsulated in a carrier resin that is usually in pellet form. This type of product comprises the overwhelming majority of the formulated products used by molders and compounders today. A discussion of the basic production processes associated with the production of the various colorant and additive product types is presented below. 

Unlike dry color or additive formulations that require the use of powdered raw materials, formulation of pelletized color and additive concentrate products may... 

The mixing process for concentrate pellet product production via Leistritz-type extrusion equipment is essentially identical to that of dry color product mixing. Once weigh-out has been completed, the formula is usually transported to a mixer where the ingredients must be mixed to uniformity. The ingredients are usually manually dumped into the mixer, after which the lid is sealed and the mixer is operated until the formula reaches the desired uniformity. After mixing, the formula is manually removed from the mixer and placed into a hopper or container with a controlled outlet and is ready for the next operation. 

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