Additives for Polymers July 1994

and can be used with any colour. Contact: Wilson Color SA, 2 rue Melville Wilson, B-5330 Assesse, Belgium. Tel: +32- 83-660251. Fax: +32-83-660363.

Glass reinforcements range from Owens-Corning

Owens-Corning produces glass reinforcements in a variety of different types and packages. Continuous rovings are bundled, twine-like strands supplied as cylindrical packages. No cores are used to reduce waste and provide smooth transfer of roving for continuous processing. For some moulding processes, the rovings are chopped to specified lengths and combined with resin to provide isotropic strength properties within the finished part. For other processes, the roving is used continuously within the resin for exceptional strength in the fibre’s longitudinal direction.

Reinforcing fibres are also supplied as roll goods engineered for specific process and end-product needs. Roll goods are supplied in various densities, or weights per square unit. Rolls of mat are made with randomly- dispersed chopped fibres or continuous fibre strands that are laid down in a swirl patter. In either case, fibres are held together with a resin-compatible binder. Woven roving is a heavy, drapable roll good that it woven from continuous rovings.

Owens-Corning also makes Bi-Ply combination product that offers woven roving and chopped strand mat as a single, time- and resin-saving roll good.

The company makes chopped strands and milled fibres that are combined with resins, fillers and additives to produce moulding compounds. “Long fiber ” compounds are made by impregnating continuous fibres with resin and chopping the resulting product to lengths greater than one inch, or 25 millimeters. Fiberglas reinforcements are also used to make intermediate forms, such as

“preforms” of fibres held together with a binder and “prepregs” or resin-impregnated fibre. These preliminary forms facilitate the moulding process and/or improve the end- product. Contact; Owens-Corning, Fiberglas Tower, Toledo, OH 43459, USA. Tel: +1-419-248- 8ooO.

Revert6 fillers to be marketed in the UK

Microfine Minerals Ltd, the UK manufacturer of high performance functional fillers, has concluded an agreement with SA Revert6 of Spain to supply its products to the UK and Irish markets.

The Revert6 range of high-brightness, ultratine natural calcium carbonates is produced in the Tarragona region of Spain. Manufactured from some of the world’s whitest calcite and marble deposits, Revert6 products are said to be highly effective in formulations across a wide spectrum of industries. Revert6 products include Microcarb 95T, specially developed for PVC window profile. This product, and the larger mean particle size Microcarb 60T, is said to offer an excellent combination of processability, colour and final product performance, all at a competitive price. Contact: Microfine Minerals Ltd, Raynesway, Derby, DE21 7BE, UK. Tel: 673131. Fax: +44-332-677590.

+ 44-332-

Micra1 alumina trihydrate in PVC

Solem Division/JM Huber Corp has recently completed evaluation of its two new grades of Micra1 alumina trihydrate in PVC applications. These products - Micral 1000 and Micra1 1500 - are said to impart excellent physical properties, improved processability and excellent extrusion rates as well as providing flame retardance and smoke suppression.

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July 1994 Additives for Polymers

In a typical semi-rigid PVC wire and cable formulation, extruder throughput was 40% higher with Micra1 1500 than with ultrafine alumina trihydrate grades traditionally used in this application, says the company. Extrusions were performed at temperatures of up to 200°C without any thermal degradation. The unique particle size distributions of these new grades provide low shear rates, resulting in lower compound viscosities and improved flow characteristics.

Solem Division/JM Huber Cot-p is a leading supplier of alumina trihydrate flame retardants, and is one of the largest producers of calcium carbonate, carbon black, kaolin clay and synthetic silicas. Contact: Jh4 Huber Corp. Solem Division, 4940 Peachtree Industrial Boulevard, Suite 340, Norcross, GA 30071, USA. Tel: +I- 404-441 -I 301. Fax: + l-404-368-9908.

ICI licenses thermoplastic composite prepregs

ICI UK, is now licensing Mitsui Toatsu, Tokyo, for the production of thermoplastic composite prepregs. Initially, the continuous fibre-reinforced material will be available in polypropylene/glass, but other combinations are possible. ICI originally developed the material under the tradename Plytron. Mitsui Toatsu’s license is exclusive to Southeast Asia, and non-exclusive in China and North America. In Europe, ICI licensed the technology to Statoil in 1992, which has rights to the Plytron name. Contact: ICI Technical Plastics Ltd. Hopehill Road, Glasgow, G20 7NF, UK. Tel: +44-41- 332-l 331. Fax; + 44-41-332-3129.

Alumina trihydrate

Recent advances in flame retardant legislation and code development, advances in flame retardant technology and advances in the understanding of overall fire hazard, all make alumina trihydrate (ATH) a product to be considered when flame retardance and low

O1994 Elsevier Science Ltd

smoke materials are required. When evaluating the overall fire hazard of burning plastics, points to be considered include its ignition time, rate of heat release, heat of combustion, smoke and toxicity. Because of ATH’s endothermic decomposition and low smoke evolution properties, it is a product that justifies consideration by the plastics compounder when trying to lower the overall fire hazard of plastics.

ATH manufacturers have developed material less than one micrometer in diameter. Whiter and higher purity grades have been developed for better appearance and better electrical properties. Improved plastics processing techniques and the advances in the use of coupling agents have helped in the dispersion of ATH in plastics products and enhancement of end-use physical properties. Recent technical reports demonstrate that ATH can be used with other flame retardant products, for example, zinc borate and magnesium hydroxide, for enhancement of flame retardance and for reducing smoke emissions. ATH has been used successfully for over 30 years. The recent advances in ATH and the techniques on how to use it should ensure an even greater role for ATH in the future. Contact: Solem Division, JM Huber Corp, 4940 Peachtree Industrial Boulevard, Norcross, GA 30071, USA. Tel: + I-404-441 - 1301. Fax: + I-404-368-9!W8.

Highly concentrated pigments with strong colours

A new process for developing ready-to- compound, concentrated pigments is being introduced by Ultra Tight Pigment in the USA. The technology yields a full line of predispersed colours, including white, with wax carriers. The company says the proprietary system enhances the tinting strength of commercial pigments through a process that reduces them to their elemental particle size - less than one micron average - without grinding or heat history, which typically diminishes colour sheen. While premium priced, the new colorants are said to

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