Compounding options

The market for small-batch and specialty custom-compounded materials is growing, and the buyers are both large and small processors alike. Shorter product life cycles and the quest for market differentiation is driving this growth.

“We’re living in an era where everything is customized,” says Les Goff, general manager, GE Plastics Specialty Products & Services. “Everyone wants to be an individual.”

He says the trend that started with the colored housings for i-Mac computers has caught on with other products in personal care lines, recreation, electronics and other markets. This in turn is giving compounders more opportunities to develop color and appearance products to meet these special needs.

The business of GE’s Specialty Products & Services division is comprised of three entities. These are custom engineered products, a color management program called Color Xpress and small lot custom color service for customers requiring color compounds in quantities under 5,000 lb.

Goff says GE Plastics is able to leverage its entire portfolio of engineering resins into the custom engineered product line using filler technology to fill small lot orders. Typically these compounded grades have one or more enhanced performance characteristics, such as improved wear resistance, high modulus, or electrostatic discharge properties.

Both Color Xpress and small lot color service are intended to be service strategies for customers. GE has over 30,000 color combinations plus special effects which can be viewed and accessed on-line (gecolorxpress.com) by customers. Small lot color service is aimed at processors that don’t want to keep an inventory of a specialty resin and wish to have delivery on demand. Canadian customers are serviced by GE’s Cobourg, Ont. compounding facility, which was recently expanded. Fourteen-day delivery on an order is standard but the company will guarantee a shipment in as little as four days.

Nanocomposite technology on hold?

Aclo Compounders Inc. (Cambridge, Ont.) has experimented with nanocomposite technology, which involves using tiny clay particles in a base resin to enhance structural properties of the material. At this stage of development, according to sales manager Dan Dorscht, nanocomposites appear to be more compatible with nylon than with polypropylene.

“The problem with using nanocomposites in a base of polypropylene is that it is extremely difficult to wet-out the resin,” says Borscht. “It is easier to mix oil and water.”

When and how nanocomposite technology will see its first large-scale commercial use in plastics is uncertain. One study conducted by Bins & Associates (see Canadian Plastics, Oct. 2000) predicts the first application of nanocomposite materials will reach the automotive market this year. Details about the base resin or the type of application were not released to the press. Several nanocomposite research and development projects in the automotive sector are on-going and involve both OEMs and suppliers.

In a more traditional vien, Aclo is supplying Mitsubishi with high-flow, high flexural modulus TPO which is used to produce injection-molded fascias. The property-profile of the TPO compounds, which are produced using Idemitsu technology, is designed to allow Mitsubishi to achieve injection rates required for thin-wall molding, says Dorscht.

Aclo is completing a warehouse expansion and has added three new compounding lines over the past few years, as well as new materials handling equipment. Its core business is custom compounded polypropylene, which it produces in a variety of grades, including glass-fibre reinforced, colored and many other blends. The company also supplies compounded ABS and PC. One growing business, says Dorscht, is for reinforced and/or colored polyacetal used for gears and high-temperature applications.

Albis Canada, with a compounding plant in Pickering, Ont., has seen sales growth for glass-filled nylon grades used in office furniture and other applications, says sales manager Michel Vinette. It is also producing more colored polycarbonate, which is increasingly being used to personalize or brand electronic devices such as hand-held computers. Albis has seven twin-screw extruders at its Pickering plant and an additional eight lines at its facility in Texas.

New player in B.C.

Germany-based Constab has opened a 22,000 sq. ft. compounding plant in Langley, B.C. The plant, the company’s first in North America, will produce silane cross-linked HDPE, as well as additive masterbatches for polyolefins, excluding colored materials.

Silane cross-linking is one of three possible routes for cross-linking polyethylene; the other two being peroxide cross-linking and irradiation cross-linking. Silane cross-linking is characterized by the formation of bonds of co-polymerized or grafted silane sidechains.

According to vice-president Rolf Sabo, one of the advantages of silane technology in comparison to other cross-linking methods is that it is uses more cost-effective technology that does require a high capital investment. The material is also easy to adapt to standard pipe extrusion equipment, requiring only a few adjustments to the screw and die, says Rolf.

Piping made from silane-based PEX is used for domestic hot and cold water, air conditioning systems, under-floor heating, transport of gases and chemicals and others. It also increasingly used to make shrinkable tubing used to protect electrical connections in electronic and automotive applications.

Market grows for electrical and thermally conductive polymers

RTP Company has developed inherently conductive polymer (ICP) compounds for applications requiring electrostatic discharge (ESD) properties. The compounds are used to provide a protective environment for electronic devices such as chip trays, telephone components and medical devices; as well as provide shielding from electromagnetic and radio interference, says Larry Rupprecht, manager of conductive materials development.

The compounds maintain the physical properties of the host polymer and can be mixed with a “tunable” surface resistivity of 105 to 1010 ohms/sq. in. ICP compounds are colorable in approximately six standard colors. Polyolefin-based compounds are available for injection molding, extrusion and blow molding.

“Our technology is the technology of mixing,” says Rupprecht. “If a customer needs EMI shielding we’ll look at the additive method that will give a thermoplastic those properties.”

Rupprecht says ICPs are not suitable for some applications, for example EMI shielding in extremely thin wall cell phones. Additives in the compounds make the viscosity of the melt too high, impeding flow in thinwall sections during molding.

Rupprecht believes shorter life cycles required by manufacturers of products in today’s markets have contributed to the growth of small lot custom compounding. The view is seconded by GE’s Goff.

“We’ve seen lot size go down a little but people ordering more frequently,” he says.

By all indications, small lot and specialty compounds will be an increasingly important part of the processor’s tool kit.