Sullivan Palatek, one of North America’s premier manufacturers of air compressors, has taken delivery of a new, ultra-precise TG350E CNC helical rotor grinding machine from UK-based rotor milling and grinding machine tool manufacturer, PTG Holroyd.

Helping double Sullivan Palatek’s rotary screw compressor manufacturing capability, the TG350E joins a previous-generation PTG Holroyd TG350 rotor grinder and a PTG Holroyd 3EX-R rotor milling machine – both of which have been in reliable daily operation at the air compressor manufacturer’s production facility in Michigan City, Indiana, since 2009.

Together, the three PTG Holroyd machines will be used to manufacture helical rotors in a range of diameters from both dura-bar and cold rolled steel. They will also help confirm Sullivan Palatek’s status as a leading provider of rugged, dependable and highly efficient air compressors, ready for when the new minimum efficiency standards for air compressors come into force in the United States next year.

With plans to increase the size of its Michigan City manufacturing facility by 50%, and an order book that has almost doubled in size since 2023, Sullivan Palatek will be making full use of its new TG350E rotor grinding machine as well as its older PTG Holroyd TG350 and 3EX-R models. “As finish grinding each compressor rotor typically takes twice as long as the milling process, having two rotor grinders in operation will increase our productivity considerably,” says Sullivan Palatek’s Director of Plant Operations, Scott Newcomb.

“With the two PTG Holroyd rotor grinding machines, we will also be able to manufacture both male and female rotors simultaneously, something that will further boost our efficiency. While to further streamline our rotor manufacturing processes, PTG Holroyd will also be upgrading the CNC on our older TG350 rotor grinder to the latest standards. We have a great relationship with PTG Holroyd. They provide the highest levels of service and support and will always do whatever it takes to get the job done.”

Installed during the fall of 2023, Sullivan Palatek’s new TG350E is actually its sixth PTG Holroyd machine. The air compression machinery manufacturer’s relationship with PTG Holroyd goes back to the 1960s, when the business invested in two Holroyd rotor milling machines and a cutter sharpening machine at its original rotor manufacturing facility in Claremont, New Hampshire.

“We moved from Claremont to Michigan City in the US mid-West during 2009 to consolidate our operations and maximise the performance of the new rotor milling and rotor grinding machines we would need at the new combined facility,” adds Scott Newcomb. “More than satisfied with the reliability of the old 1960’s Holroyd machines we’d used in Claremont, we quite naturally turned to PTG Holroyd for the 3EX-R rotor miller and our first TG350 rotor grinder. Fourteen years later, in 2023, and still impressed by the performance, accuracy and reliability of those machines, we reached out to PTG Holroyd again for our new TG350E helical rotor grinding machine.”

“It has been an absolute pleasure to provide Sullivan Palatek with our rotor milling and rotor grinding technologies over the years,” adds PTG Holroyd Sales Director, Mark Curran. “As there can be no better testimony to the quality of a company’s products than repeat orders, I am delighted to say that on each occasion Sullivan Palatek has chosen to invest in a new PTG Holroyd machine, that decision has been based on our deep understanding of their manufacturing requirements, the reliability of our machines and the support we provide. Sullivan Palatek is a fantastic business to work with and I meet with Scott and his team on a regular basis.”

High speed and high accuracy

PTG Holroyd’s TG Series machines, such as those used by Sullivan Palatek, are widely recognised as providing the industry benchmark for high speed, high accuracy, efficient stock removal. Advanced automation means reduced setup time, while a significant amount of production time can be saved due to the fact that each machine’s diamond dressing disks are continuously dressed during the semi-finish grinding cycles. The TG range starts with the TG50E, a machine designed to precision grind components of up to 50 mm in diameter and 610 mm in length, with models offering stepped increases in capability up to the production of helical components measuring  520 mm in diameter and 2750 mm in length.

Equally suited to prototyping, batch and volume production, TG Series machines are designed primarily for the finish grinding of helical screw components such as worm screws and rotors after they have been milled to a rough or semi-finished state. TG models offer production rates and accuracies to suit precise manufacturing strategies. Fully automated on-machine probing provides closed loop feedback of corrections to the dresser wheel and does not require a high level of operator skill.

PTG Holroyd TG Series rotor grinding machines, at-a-glance:

• High levels of accuracy and efficient stock removal
• Developed for prototyping, batch and volume production
• Accelerated and simplified setup
• Fully automated grinding wheel balancing system
• Powerful, intuitive touch screen programming
• Unique on-board Holroyd 3D CMM component scanning probe with fully automatic compensation feedback
• High-power, high-speed grinding spindles
• Optional hollow spindle for longer components
• Advanced, in-process wheel dressing system
• Large diameter grinding wheels for maximum wheel life
• Optional Holroyd Profile Management System (HPMS)
• Component diameters from 0 mm to 520 mm depending on component and profile
•  Maximum component weight: 1500 kg