Market Focus: Lawn and garden

If you haven't already, please add the following buzz phrase to your molding lexicon: soft touch. Although the term is not new, it's quickly taking on new meaning for the molding industry. During the last few months, several material suppliers have announced the availability of ABS-, polycarbonate-, and nylon-bondable thermoplastic elastomers (TPE) and thermoplastic vulcanates (TPV). This is the first of a few trends working their way through the lawn and garden market.

Soft Touch
Previously TPEs and TPVs were overmolded on products and parts molded from polypropylene; the only way to bond nylon with a TPV was by mechanical interlocking, not always a feasible option. No grade existed that allowed the TPEs and TPVs to naturally bond with nylon, ABS, or polycarbonate. Now, Advanced Elastomer Systems (AES), Shell, and other material producers are making elastomers that bond to one or all three of these materials. This will allow elastomers to boldly go where they've not been before. Initial applications include housings and handles for lawn and garden tools, sporting goods grips and handles, appliance knobs, furniture grips, electrical switches, and connectors. Handle grip applications, in particular, should give users better control and help minimize vibration on power tools.

While several markets can take advantage of this development, the lawn and garden market is positioned especially well to feel the good vibrations. This is because of a joint marketing alliance formed between nylon specialist AlliedSignal Plastics (Morristown, NJ) and AES (Akron, OH) to develop soft-touch applications, many for lawn and garden use. AlliedSignal will focus on its Capron and Nypel nylons.

The nylon-bondable elastomer from AES is colorable, exhibits good heat aging, resists oil, and can also bond with polypropylene. It's available in three durometers of 55, 70, and 85 Shore A hardness. AES recommends two-shot molding for best results. It's also insert-moldable. Shell has two new grades of its Kraton G compound. Grade G7675, with a 45 Shore A hardness, bonds with polycarbonate and ABS. Grade G7685, with a 50 Shore A hardness, bonds with nylon.

Air Cooled vs. Liquid Cooled
John Caamano, an account manager at Ticona (formerly Hoechst Technical Polymers), lists the rising popularity of liquid-cooled lawn and garden engines as one trend worth watching. Liquid-cooled engines are smaller than air-cooled versions, last longer, and most importantly, generate less heat. Noting that air-cooled engines typically run at 300F to 400F (higher than auto engines), he says this may be an opportunity for molders to do some part conversions, putting plastic in an engine where high temperatures kept it out before. "If you're going to a liquid-cooled design," Caamano says, "you might be able to convert more metal to plastic." If you do, you'll have to watch your chemical resistance to common engine coolants.

Also of corrosion consideration, says Caamano, is the rising popularity and required use of alternative fuels in lawn and garden machinery. To reduce and control emissions, oxygenated, alcohol-based additives are becoming the government-mandated norm in states such as California. Molders should check the resistance properties of their materials to verify that they will still withstand alternative fuels.

Caamano has also noticed an increasing demand in the market for larger, industrial-sized equipment, such as lawn mowers, blowers, and trimmers, away from residential-sized equipment. He attributes this to the fact that more homeowners are opting for professional landscape and lawn services to maintain their yards, shrubs, and trees. This consolidation may mean a reduction in molding opportunities. "From what I can see," says Caamano, "there may be a little bit of cannibalization as larger engines take over some of the smaller ones."

Gas Assist
Chuck Hoar, a business development manager at AlliedSignal, is especially excited by the potential gas-assist molding brings to the market. He says AlliedSignal has enjoyed particular success gas-assist molding its Capron nylon into handles on lawn and garden equipment.

Tests at AlliedSignal have shown part mass reductions of 30 to 40 percent, greater than 70 percent retention of flexural strength, more than 80 percent retention of cantilever bending strength, about 75 percent retention of Gardener drop-weight impact strength for reinforced grades, and significant reduction in sink marks. Not measured, but surely reduced, was part cost, a driver that should help other parts move to gas assist.