Polymer processing aids

Table 8.47 shows the available options for the analysis of polymer processing aids, namely combustion and instrumental methods. The best method is dependent on PPA type, the level to be measured, and the available equipment (see also Section 8.2.1.2). Fluoropolymer processing aid concentrations can be determined by WDXRF configured to measure either fluorine or a tracer, and by EDXRF to analyse a tracer [29]. Calibration curves are required. At present, EDXRF or benchtop XRF units cannot directly measure fluorine. For resin or masterbatch producers who prefer to make on-line XRF measurements of processing aid concentrations (to letdown levels of 50-100 ppm), processing aids that contain a tracer (usually BaS04) are available. The analysis time is less than two minutes. 

Indirect food additives are adhesives, components of coatings, food-packaging materials, components of paper and paperboard, polymers, processing aids, and sanitizers. 

Hong, Y., Coombs, S. J., Cooper-White, J. J., Mackay, M. E., Hawker, C. J., Malmstrom, E., and Rehnberg, N. 2000. Film blowing of linear low density polyethylene blended with a novel hyperbranched polymer processing aid. Polymer, 41, 7705-7713. 

Use Bonding agents, polymer process aids, catalysts, blowing agent activators, corrosion inhibitors, dispersing agents. 

KYNAR Elex Polymer Processing Aids Arkema Inc. Philadelphia, PA, 2001. 

Bigio D, et al. Sharkskin elimination fluoroelastomer coating evolution as a polymer processing aid. International Polyolefins, conference proceedings. Society of Plastics Engineers 2008. 

SOLEF and TECHNOFLON NM polymer processing aids (PPA), supplier product guide. Solvay Solexis SpA 2007. 

Arkema s Kynar Flex PPA 5300 is another fluorinated polymer processing aid, available in granular form. This product is targeted at linear low-density and high-density polyethylene and metallocene PE grades. It eliminates orange peel surfaces and improves the transparency and mechanical properties of the extruded product. It also increases extrusion speed, eliminating knots and drool in the extrusion dies. 

The latest Viton FreeFlow additives are among those that have a reduced tendency to interact with other constituents of the formulation. Another new non-reactive fluoropolymer additive has been developed by Dyneon in association with 3M Canada to overcome similar problems, and has been found to perform well in LDPE and LLDPE film. The later versions of Dyneon polymer processing aids act as effective process aids in polyamides and PU, without the usual discoloration and processing problems. 

Dyneon acquired Solvay Fluoropolymers in 2001, including a PVDF manufacturing facility. In November 2004 it entered into an agreement with SpecialChem SA to moimt a web-based technical service facility for polymer process aids. The company employs more than 800 people worldwide. 

Several polymer processing aids (PPA) are available to eliminate or reduce melt fracture. An effective method to eliminate melt fracture in high molecular weight polyolefins is to add a small amount of fluoroelastomer [153], about 500 to 1000 ppm (parts per million). When a fluoroelastomer PPA is added to a polyolefin it usually takes a certain amount of time for a critical coating of fluoropolymer to form on the die. This conditioning time can vary from 5 minutes to more than 1 hour [154]. 

Silicon-based polymers such as polydimethyl siloxanene (PDMS) have been used as polymer processing aids for many years. Dow Corning has developed ultra-high molecular weight PDMS additives that work as process aids in polyethylene and polypropylene. Because these materials solidify with the polymer, they reportedly... 

PVC polymer, processing aid, residuai plasticiser, modifier (in suspension), some lubricants... 

Johnson, B., Blong, T., Kunde, J., Duchesne, D. (1988) Factors Affecting the Interaction of Polyolefin Additives with Fluorocarbon Elastomer Polymer Processing Aids. TAPPI1988 PEC Conference. 

Macromolecular Modifiers Used as Polymer Processing Aids... 

Film extruders who routinely process LDPE must often make modifications to equipment, or, at the very least, the temperature profile, to produce films with good physical properties. Melt fracture, or sharkskin, can be a problem at high die shear rates. This can be eliminated by raising extrusion and die temperatures, by increasing the opening of the die to reduce shear, or by using polymer processing aids. The key extrusion parameters that affect final film properties are blow-up ratio (the ratio of the bubble diameter to the die diameter), die gap, output rate and so forth. 

In general, a PVC resin contains aids such as a lubricant and a processing aid, in order to improve its moldability and processability and to enable it to stably pass through various processes. Polymers such as a copolymer mainly composed of methyl methacrylate have been used as such polymer processing aids or lubricants (6,7). 

This class of compounds is also unspecifically addressed as polymer processing aids. 

Certain fluorocarbon processing aids are known to partially alleviate melt defects in extrudable thermoplastic hydrocarbon polymers and allow for faster, more efficient extrusion. Blatz first described the use of fluorocarbon polymer process aids with melt extrudable hydrocarbon polymers wherein the fluorinated polymers are homopolymers and copolymers of fluorinated olefins having an atomic fluorine to carbon ratio of at least 1 2, wherein the fluorocarbon polymers have melt flow characteristics similar to that of the hydrocarbon polymers (4). 

Uses Detergent polymer, processing aid, thickener, and stabilizer for cosmetics, detergents and cleaners, abrasive creams, floor cleaners, rinse aids, dishwash liqs., alkaline toilet cleaners, water treatment, min. processing, other industrial markets foam stabilizer food-contact paper/paperboard Features Very thixotropic Regulatory FDA 21CFR 176.170,176.180... 

Uses Detergent polymer, processing aid, thickener for detergents and cleaners Properties M.w. 2,000,000 pH 3 18% solids Acusol 860N [Rohm Haas]... 

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