For the past 125 years, Hirtler Seifen GmbH has been manufacturing soap products. As one of the largest manufacturers of fine soaps and cleansing products in Europe, delivering to customers around the world, the Heitersheim, Germany -based company needed to ensure that its production processes were as efficient and productive as possible. Automation solution providers Mattke AG from nearby Freiburg used Parker Hannifin’s LBB080 toothed belt linear actuators, SMH-Series low-inertia brushless servo motors and COMPAX3S single-axis servo drives in its total upgrade of Hirtler’s existing two-decade old plant to bring the production line completely up-to-date with the latest precision movement technology – all with the end goal of stepping up its production levels.
Parker supported Mattke through a very tight overhaul period of just four weeks – and by the third week, the mechanical axles were ready to be installed in the new production line.
The soap-making process
Since the ancient Babylonians first documented the production of soap over 5,000 years ago, the manufacturing processes behind soap making have changed considerably, particularly since the advent of factory automation.
To make classic solid soap, the recipe has not changed much for centuries: coconut oil, pure vegetable oils or beef tallow is heated, to which is added a chemical base, usually of sodium hydroxide or potassium hydroxide mixed in an aqueous solution. The resultant soapy mass is dried in a spray drying process, after which further ingredients such as essential oils, perfumes or skin-nourishing substances are added. The soap mass will be extruded into long strands which are then cut, shaped and stamped at various stages in the automated production line.
In addition to traditional soap bars, Hirtler also makes soap-free cleansing bars, which contain other non-soapy surfactants bound in a waxy matrix. While the manufacturing process is underway, the mixture tends to heat up and go greasy due to its composition, so after extrusion the soaps need to be cooled to room temperature before continuing on the rest of the production. A pick-and-place mechanism sets the soaps on cooling plates, which are carried continuously through a purpose-built refrigerator. After about 45 minutes, the cooled soap pieces exit the other end of the refrigerator and are taken by conveyor belt to a handling portal where final packaging takes place.
Increasing production demands
The Hirtler plant runs 24 hours a day, seven days a week, and the end goal of the automation system overhaul was to bring the current production rate from 5,000-6,000 pieces of soap per eight-hour shift up to 15,000 pieces.
Reliability and minimizing downtime became of paramount importance to the soap manufacturer due to the age of its current system. 20-year-old digital servo controllers had reached the end of their useful lifespan, and the system behind it could not be upgraded without an entire system overhaul. Mattke was called in to design an automated system that would meet the factory’s increasing production requirements.
“In the connection between the servo controllers and the motors, positions were lost again and again. That is why the handling portal has not been driven as it should,” said Simon Hübner, Technical Director, Mattke AG. He recounted how the error logs could not accurately determine the source of the positioning errors, which brought even the hand-held controller unit under suspicion as well.
“That is why, together with Hirtler, we decided to completely replace the mechanics and the electrics. So the linear axles, engines and the servo controllers – everything was replaced,” he said. “In short, the two handling portals before and after the cooling system had to be completely renewed.”
A fast turn-around
Mattke had to solve the problem as quickly as possible to minimise production downtime. “The time pressure was enormous, because we had only four weeks. Within this time, we had to plan, build the system up and make it work.”
CAD drawings were prepared and the engineering requirements were worked out, and then the individual products such as the linear actuators, motors, servo controllers and the control system had to be put in place.
“Our partner, Parker, who manufactured the mechanical axles, put in a great deal of effort and provided a high degree of technical expertise,” said Hübner. “Under normal conditions, the construction of the axles would have taken six weeks, but they completed the axles for the handling portals in just three.”
While Parker was putting together the electric thrust cylinder, linear actuators, servo motors and drives, Mattke engineers worked at structuring the software, and in the week after the mechanical equipment arrived at the plant, the entire system was installed and set up, ready for production to start up again.
According to Mattke’s application engineer Carl Jachulke, the deadline would not have been workable if not for the extraordinary support given by Parker in the manufacturing of the mechanical components.
“Within a week during commissioning at the customer’s premises, we made everything workable, tested and adapted according to the customer’s requirements. We achieved the complete delivery of the project after just three weeks,” Jachulke said.
In addition, and underlining the flexibility of the new system, Hirtler can now add new products to the production line with relative ease, providing something extra on top of the significant increase in production volumes achieved by the refit.
Image caption: Simon Hübner, Technical Director at Mattke AG, says Parker’s fast production of the mechanical components according to the customer’s specifications helped them deliver the new automation line in record time.