Universal lead screw nut with flange from igus allows for a quick 1:1 conversion without design adjustments

Design engineers who want to replace the lead screw nuts of lead screw drives with PFAS-tested alternatives often face a dilemma: there are hardly any versions that are free of the controversial chemical, meaning that expensive adaptations would be necessary. igus is changing this with a new PTFE-free and PFAS-tested universal flange lead screw nut made of iglidur high-performance plastic. It allows a quick 1:1 conversion and promises an above-average service life thanks to a special thread geometry.

A design engineer of a packaging machine has been assigned a new task: replacing all plastic components with versions that do not use the chemical group PFAS. They might be more strictly regulated in future as they represent a potential burden for people and nature. The conversion is intended to ensure future legal certainty. But the devil is in the details. The design engineer cannot find an alternative for the small plastic nuts of a lead screw drive. There are hardly any PFAS-tested lead screw drives on the market. And the few that are available have a flange with different connection dimensions for the nut mount. “To solve this dilemma, we have developed a universal lead screw nut with flange that is PTFE-free and has been tested for the 96 most critical PFAS compounds,” says Thorben Hendricks, Head of dryspin® Lead Screw Technology at igus. “The injection-moulded component has a flexible hole pattern with closed and open holes, which allows for quick 1:1 replacement without requiring design adjustments.” The universal lead screw nut with flange from the dryspin series is now available with thread diameters of 6.35mm, 8mm and 10 mm.

Longer service life thanks to special thread geometry

Another special feature is the threads’ flexibility: igus initially manufactures blanks for the universal lead screw nuts with flange in an injection-moulding process from a material called iglidur JPF. Different thread types can be
inserted into these blanks according to customer requirements. “Our patented dryspin thread is becoming increasingly popular in the industry,” explains Hendricks. The reason: in contrast to classic sliding threads, where the lead screw and nut have symmetrical profiles, the dryspin nut’s thread teeth are enlarged by a factor of up to 1.3. “Thanks to the asymmetry, we were able to increase the service life by around 30% compared to conventional trapezoidal threads, as tests in our in-house laboratory have shown,” emphasises Hendricks.

PTFE coating of the lead screw no longer required

The new universal lead screw nuts with flange also allow for dry operation. Microscopic solid lubricants are integrated into the iglidur JPF material, which permit the material to slide. The advantage: external lubrication is no longer required. This reduces the system’s maintenance requirements and susceptibility to dirt. “Another benefit of low-friction dry operation is that the lead screws no longer require PTFE sliding layers. This provides our customers with complete system solutions that are PTFE-free and PFAS-tested,” says Hendricks.

You can find more information about the new lead screw nuts in the igus web shop: Lead screw nut | Lead screw nut from dryspin