Internally lubricated acetal aids green fingers

A LNP Engineering Plastics Europe product story

Edited by the Engineeringtalk editorial team Apr 29, 2003

Toro turned to LNP Engineering Plastics when developing materials for its new EZ Adjust sprinkler.

When Toro sets out to design new sprinklers, its goal is to create best-in-class products that "one up" the competition in terms of features, performance and durability for the category.

In fact, its corporate tagline is "count on it".

That's why Toro turned to LNP Engineering Plastics when developing materials for its new EZ Adjust sprinkler.

An internally lubricated Lubricomp acetal from LNP is used in the transmission cluster gears and bearings, providing exceptional abrasive wear resistance and durability.

The sprinkler also uses internally lubricated Lubricomp polyurethane in seals and gaskets in the cap that houses the riser, promoting smooth, nonsticking operation.

The Toro EZ Adjust sprinkler offers exceptional versatility and range for a light industrial commercial sprinkler.

Its state-of-the-art features include visual arc adjustment with automatic full-circle/part-circle conversion, trajectory adjustment, radius adjustment, eight interchangeable nozzles, reversible check valve, and a flow shut-off mechanism for dry nozzle changes, among many others.

It also features two internally lubricated Lubricomp compounds from LNP that help the EZ Adjust sprinkler perform optimally season after season.

According to Jeff McKenzie, Senior Principal Designer at Toro, the sprinkler's cluster gear and turbine shaft bearings must show minimal abrasive wear when run 28 out of every 30min at maximum pressure for 1.kh.

This is essential because excessive wear leads to backlash in the gear train, reducing its efficiency and ultimately leading to failure.

Unfilled acetal was evaluated initially in the bearings, with poor results.

"They simply wore out before they met Toro's standards.

We looked at the abrasive wear of many plastics and metals running on the stainless-steel shafts, including graphite-filled and silicone-filled acetal", said McKenzie.

"The LNP material, a PTFE and aramid filled Lubricomp acetal, gave us more than five times better resistance to abrasive wear than unfilled acetal, and also outperformed the other plastics we tested".

Next, Toro focused on the seal and wiper gasket in the cap housing the riser.

"When the sprinkler is activated, the riser pops up from the housing, and retracts again when the sprinkler is shut off.

We needed a low-wear and low-friction material that would not stick when extending or retracting, and one that would prevent leakage when the riser extends".

In the past, Toro had used Hytrel and polypropylene for the seals, but has been moving toward polyurethane because it is more resistant to grit in the recycled sprinkler water.

A Lubricomp polyurethane containing a proprietary filler provided the needed lubricity, a tight seal and exceptional durability.

Lubricomp internally lubricated compounds from LNP offer inherent lubrication through the addition of PTFE, silicone, aramid fiber and other materials to a wide range of engineering thermoplastics.

The industry's first internally lubricated compounds were introduced by LNP in 1965 and find use in demanding wear applications across a variety of applications in the industrial, automotive, medical and business machine markets.