Vinyl Microbeads are developed for automotive market.

Press Release Summary:




As alternative to powder blends and plastisols, Tek-Spheres(TM) provide automotive instrument panel, airbag cover, and interior trim manufacturers with molded-in color and tactile properties. Vinyl, 0.004 in. dia microbeads, produced in Shore A durometers from 55-90, flow freely over inside of hollow molds in processes such as slush molding and rotomolding. Completely homogeneous material melts rapidly in contact with heated mold, resulting in uniform dispersion of color and additives.



Original Press Release:



Automotive Manufacturers Have New Source of Vinyl 'Microbeads' for Improving Thin-Skin Interior Components



Tek-Spheres(TM) from Teknor Apex Offer Processing and Performance Advantages over Conventional Vinyls Used on Instrument Panels, Headrests, Trim Parts

PAWTUCKET, RI, U.S.A.: Vinyl "microbeads" now available from Teknor Apex Company provide manufacturers of automotive instrument panels, airbag covers, and interior trim with brilliant molded-in color and appealing tactile properties while being simpler to process and less energy-intensive than powder blends and plastisols, according to Teknor Apex.

Only 0.004 in. (0.1 mm) in diameter, microbeads flow freely over the inside of hollow molds in processes like slush molding and rotomolding. After years of producing beads with this micro particle-size distribution for non-automotive markets, Teknor Apex has acquired the rights to market the beads internationally to the automotive industry through an agreement with Bayer MaterialScience AG. Teknor Apex will supply the microbeads under the trade name Tek-Spheres(TM) and can produce them in Shore A durometers from 55 to 90.

Teknor Apex manufactures microbeads by melt compounding PVC resin with color, plasticizer, and other additives, producing a completely homogeneous material that melts rapidly in contact with a heated mold.

"Molding with Tek-Spheres microbeads is less time-consuming and energy-intensive than with plastisols or powder blends, both of which must be fused in the mold to be converted into fully integral solid parts," said Steve McCormack, manager of Teknor Apex's Automotive Group. "The melt compounding process for microbeads also ensures a more uniform dispersion of color and additives, makes possible a broader range of durometers, and provides greater scope for incorporating new ingredients, including solid plasticizers."

Tek-Spheres(TM) Provide Advantages in Molding and End Use

Of the various hollow-mold processes available for thin-skin applications on automotive components such as instrument panels and headrests, one of the most commonly used is slush molding, in which a partially open mold rotates on a single axis. Another method, rotational molding, uses a closed mold in a two-axis system. To meet the requirements of these processes, Teknor Apex supplies Tek-Spheres products at different size levels.

The direct product of the melt compounding method used for making Tek-Spheres is actually minibeads, with diameters in the 0.020 to 0.060 in. (0.5 to 1.5 mm) range. This is already considerably smaller than the standard 0.125-in. (3.2 mm) pellet compound used in injection molding and extrusion, and it is suitable for various open-mold processes, including slush molding. In a subsequent step, Teknor Apex produces microbeads with a particle size of 0.004 in. This smaller particle-size distribution is more suitable for rotomolding and for slush molding applications involving deep draw areas, severe undercuts, or fine detailing.

In contrast to these solid materials, plastisols are liquid formulations of PVC resin in a carrier consisting primarily of plasticizer. "Microbeads avoid a range of problems posed by plastisols," said McCormack. "Plastisols vary in viscosity in accordance with ambient temperature and other mixing conditions, may contain entrapped air that causes pinholes or voids in finished products, may undergo separation of components during storage, can require up to three times longer for color changeovers, and entail use of volatile organic solvents for cleanup after spills."

Another type of conventional vinyl material used in slush molding is that of powder blends, highly plasticized mixtures of PVC and other additives. "The high plasticizer content of powder blends places a limit on low-durometer formulation, since this would require adding even more plasticizer, preventing the material from acting as a free-flowing powder," McCormack said. "By comparison, achieving Shore A durometers as low as 55 is no problem in Tek-Spheres manufacture, and our melt compounding process leaves the door open to using alternative ingredients, such as high molecular weight plasticizers to reduce windshield fogging."

The VINYL DIVISION of Teknor Apex Company is a leading manufacturer of compounds based on PVC, including Apex flexible vinyl, Flexalloy vinyl elastomers, and Fireguard low-flame, low-smoke compounds for wire and cable. Headquartered in Pawtucket, Rhode Island, U.S.A., the Division is an international supplier to the appliance, automotive, construction, medical device, wire and cable, and other industries. Parent company Teknor Apex operates manufacturing facilities around the world and sells in 90 countries. Six of the eight Teknor Apex business units focus on plastics compounding, including bioplastics; color concentrates; nylon, PET, and other engineering thermoplastics; thermoplastic elastomers; toll and specialty compounds; and vinyl. Visit www.teknorapex.com.

READER INQUIRY INFORMATION: Address all mail inquiries to Teknor Apex, 505 Central Avenue, Pawtucket, RI 02861 U.S.A. Tel: 1-401-725-8000. Tel. from U.S. only: 1-800-554-9892. Fax: 1-401-729-0166. E-mail: vinyl@teknorapex.com.

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