Masterbatches, use

Figure 431 Schematic representation of the production of a masterbatch using the premix process...

NYsynblak . [Copolymer Rubber] Acrylonitrile-butadiene copolymer blade masterbatch used to extruded and molded goods. 

The masterbatches used for HIPS are of the universal or, of styrene-based types a typical concentration is 1%, i.e. 25 grams (0.88 ozs), per 25 kilo (55. libs) bag of polymer. Higher concentrations may be necessary depending upon the denseness of the color required in the finished product. Color matching can be carried out using solid masterbatches. 

The color concentrates (masterbatches) used for ABS are of the universal or of the ABS-based types. A typical let down ratio (concentration) for the universal type is 1 to 2% whereas a ratio of between 3 to 7% is used for the ABS based master-batch. Before using a universal masterbatch it is important to ascertain it s compatibility with ABS. Pastel shades can now be readily achieved due to the availability of polymers with a lighter (i.e. whiter) base color. Back pressure is often used with masterbatches so as to assist in the dispersion of the pigment within the polymer melt. 

Cabot claims that the most important criteria for producers of masterbatches used to make black plastics film are opacity, weatherability, film smoothness and ease of dispersion. Customers do not always rate these qualities in the same order. Photographic and surface protection film needs first smoothness and ease of dispersion, whereas agricultural film needs good weathering. 

The attainment of these characteristics and the properties resulting therefrom is shown in Table II, which describes 70/30 and 50/50 HDPE/clay composites prepared from 30/70 PE/clay masterbatches using 15 and 22 MI HDPE as coating PE and 0.7 MI HDPE as matrix PE . The properties of unfilled blends of the high and low melt index HDPE in the proportions used in the composites are shown for comparison. 

Typically, injection molding grades are used for masterbatches. One of the main masterbatches used in the polyolefins industry is LDPE-based silica masterbatches, since Si02 is used in film applications as an antiblocking additive. 

Red Phosphorus. This aHotropic form of phosphoms is relatively nontoxic and, unlike white phosphoms, is not spontaneously flammable. Red phosphoms is, however, easily ignited. It is a polymeric form of phosphoms having thermal stabiUty up to ca 450°C. In finely divided form it has been found to be a powerful flame-retardant additive (26,45—47). In Europe, it has found commercial use ia molded nylon electrical parts ia a coated and stabilized form. Handling hazards and color have deterred broad usage. The development of a series of masterbatches by Albright Wilson should facihtate further use. 

In order to test this concept a series of compounds was prepared in a 5 L Shaw Intermix (rubber internal mixer, Mark IV, Kl) with EPDM (Keltan 720 ex-DSM elastomers an amorphous EPDM containing 4.5 wt% of dicyclopentadiene and having a Mooney viscosity ML(1 +4) 125°C of 64 MU 100 phr), N550 carbon black (50 phr), diisododecyl phthalate (10 phr), stearic acid (2 phr), and l,3-bis(tert-butylperoxy-isopropyl)benzene (Perkadox 14/40 MB ex Akzo Nobel 40% active material 6 or 10 phr). A polar co-agent (15 phr) was admixed to the masterbatch on an open mill and compounds were cured for 20 min at 180°C in a rheometer (MDR2000, Alpha Technologies). The maximum torque difference obtained in the rheometer experiments was used as a measure of... 

To facilitate in-plant compounding, most suppliers have developed systems which efficiently and repro-ducibly deliver a controlled additive package to a compound, using either a specialised concentrate or a masterbatch formulation. Some of the polymer manufacturers have also made available advanced additive delivery systems, which they have often developed originally for their own use (e.g. Eastman, Montell). 

Workplace safety has been taken care of by the reworking of some classes of additives into more environmentally acceptable forms. Some trends are the increased use of additive concentrates or masterbatches and the replacement of powder versions by uniform pellets or pastilles which release less dust and flow more easily. Moreover, the current move to multicomponent formulations of stabilisers and processing aids in a low- or nondusting product also takes away the risk of operator error, aids quality control, ISO protocols and good housekeeping. An additional benefit is more homogeneous incorporation of the additives in the polymeric matrix. 

Fig. 1.9 (A) Exfoliation of clay platelets (white Cloisite25A and Cloisite30B after (B) two and a arrows) in a commercial polylactide matrix using half months hydrolysis and (C) after five and a a masterbatch process. (B, C) Visual aspect half months hydrolysis. (A) adapted from [144] of unfilled PLA, microcomposite based on reproduced by permission ofWiley-VCH, and CloisiteNa+, and nanocomposites based on (B, C) from [147] with permission from Elsevier.

Pigments are classified by an internationally recognised convention, published in the International Colour Index by the Society of Dyers and Colourists in Bradford, in association with the American Association of Textile Chemists and Colorists. The Index issues a generic name to chemically identical products (e.g., titanium dioxide is classified as C.I. Pigment White 6). Where structures are known, pigments are also given a constitution number (e.g., titanium dioxide has the constitution number Cl 77891).This number is reserved for the essential colorant, other ingredients, such as the carriers used in a masterbatch, do not affect this classification. 

A mix consisting of elastomer and generally only one other ingredient, the proportion of which is much higher than will be present in the final production mix. Masterbatches are used for cleanliness, convenience, accuracy of weighing small quantities of accelerators, etc. Although it... 

Processing aid-80, a masterbatch in the form of pressed crumb consisting of an 80 20 blend of crosslinked to ordinary natural rubber. The correct proportions of vulcanised latex and field latex are blended, coagulated and the resulting crumb pressed into 100 lb bales. The use of PA 80 confers Superior Processing properties on any natural or styrene-butadiene rubber with which it may be mixed. See Superior Processing Rubber. 

An imprecise term used sometimes in the sense of masterbatch, sometimes with the meaning of a blend of compounding ingredients for subsequent addition to the elastomer on a mill or in an internal mixer. Premix moulding is the same as dough moulding. 

Zinc peroxide is used as the curative for carboxylated acrylonitrile-butadiene rubber (XNBR) compounds. It confers better scorch safety than does zinc oxide. It is usually added in a masterbatch form. 

Master-alloy production, 23 318-319 Masterbatching, 11 307-308 Master contracts, 24 373-374 Master curves, 21 746-747 uses for, 21 747 Master flowmeters, 11 653 Master Oscillator Power Amplifier (MOPA) configuration, 14 697 Masticatory substance, 12 32 Mastic, for protecting art, 11 410, 411 MAT a cells, 26 453 Matched die molding, 20 117 Material balance problems, 10 748 Material balances, in minerals processing, 16 606... 

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