The motto of Knoll Maschinenbau GmbH, located in Bad Saulgau, in the centre of Upper Swabia, Germany, is “It works.” Initially established by Walter Knoll as a one-man business in 1970, the company now employs over 1,100 people to produce cutting-edge industrial systems in China, Germany, Poland, and the United States. The Fronius TPS 320i, a dependable welding machine that excels in handling, welding procedures, and functionality, is used for carrying out welding.
In terms of quality, technology, and brand recognition, Knoll holds a leading position. The Swabian family business is economically independent and creates added value for all companies in which metal is machined in the automotive industry, in energy and medical technology, in the building of machinery and plants, and in the aerospace industry.
Elevated Actual Net Output Ratio
The performance of various machine tools is optimised by Bad Saulgau’s cutting-edge technologies. Chip conveyors, pumps, and cooling lubricant cleaning systems with minimal resource consumption are made. Central systems, which are separate pieces of equipment connected to form a single system, are also included in the product line. They are necessary for the completely automated delivery of cooling lubricants and chips to central processing facilities. Automation solutions for assembly lines and intralogistics are another mainstay for Knoll. Examples include assembly conveyor belts, automated guided vehicles or cobot solutions.
Joachim Riebsamen, Shell Construction Production Manager says, “As a solution provider, we offer all the necessary services from a single source: from project planning and manufacturing to service and commissioning. We think that openness and trust are the cornerstones of successful customer interactions. We therefore don’t merely rely on sales presentations, brochures, and websites. We can use actual operations to persuade prospective consumers of the benefits of our products thanks to in-house machining.
Knoll preserves the majority of the added value within its own company as a result of the high real net output ratio. In a sustainable and economical manner, it drastically lowers all related CO2 emissions and the need for logistics.
The Difficulty of Welding Thin Sheets
In Bad Saulgau, not everything is produced in series. Shell building involves a lot of hand welding of components. Throughout this procedure, sheets with varying wall thicknesses up to 25 mm are employed. The professionals at Knoll mostly utilise S355 steel for coolant cleaning and conveying systems. This steel is combined with the wire addition SG3 (G4Si1) and the shielding gas M21 (82% Ar/18% CO2). Parameterization is based on the company’s own welding procedure specification, or WPS for short.
Holger Kleck, the foreman of the welding technology unit, says, “processing thin sheets is one of our biggest welding challenges.” Our components warp really quickly and have a material thickness of 1-6 mm. Thus, low-warpage welding with minimal heat input is required. We frequently produce visible elements that must be flawless not only from a metallurgical standpoint but also must have well-groomed seams. At all costs, we wish to avoid unfeasible reworking in these areas. Therefore, spatter-free welding with little seam build-up is mostly required. We believe that the Fronius TPS 320i welding machine provides the finest answer to all of these needs.
The professionals at Knoll use the pulse welding technology to attach thin sheets. Low spattering and less distortion are characteristics of this. The TPS 320i’s sophisticated MIG/MAG pulse synergistic feature provides Knoll professionals with a controlled material transfer pulsed-arc procedure. The energy input is lowered to the point that the arc barely burns steadily during the base current phase, warming the workpiece’s surface. Targeted droplet detachment is guaranteed during the pulsing current phase by a well regulated current pulse. Over the whole power range, both stages produce precision, low-spatter welding. Unwanted short circuits that coincide with uncontrollably spattering the weld and droplet explosion are virtually nonexistent. splatter-free ignition, or SFI, also aids in preventing needless splatter.
Kleck continues, “The arc stays very stable even at low amperage when pulse welding with the TPS 320i.” “We can use the SynchroPuls function, in which the welding power alternates cyclically between two working locations, if rippling seams are required. Overall, our long-standing cooperation with Fronius has made it possible for us to significantly improve our welding procedures. In the future, we will still rely on the Austrian business. The welding equipment is cutting edge and simple to maintain. We don’t need to wait long for assistance if we need it.
The Welding Machine with Clearly Stated Language, TPS 320i
At Knoll, the sophisticated welding machine is installed in more than 70 manual welding workstations. Its adjustable 7-inch touch screen, penetration and arc length stabilisers, and expandability with task-specific software packages called Welding Packages make it simple to use. LSC (Low Spatter Control), PMC (Pulse Multi Control), and CMT (Cold Metal Transfer) are a few instances of this. Welders can access their individual authorizations and settings by logging in with their own NFC card. There are more than 30 languages accessible for the menu navigation. “Native speaker welding machines” are very useful, since Knoll is employing an increasing number of welders from other nations due to the growing scarcity of competent workers in Germany. The welding machine’s display speaks in multiple languages and is easy to read. For example, welding specialists can follow a step-by-step guidance on resistance alignment with the help of detailed descriptions and graphical animations.
For hand welding jobs, the TPS-320i model with integrated wirefeeder is the best option. Welders will find great convenience in the short wire threading procedure of this instrument, which only requires a few easy steps.
All Parameters at a Glance
The welding machine is operated via a central rotary push-button combined with a touchscreen. The quick-change function allows users to easily switch between properties, processes, and functions. By touching the respective prompt on the status bar of the display, users can immediately access the available parameters. On the central display of the TPS 320i, specialists can see all relevant control variables and adjust them one by one. Innovative animations support welding specialists in entering parameters. For example, a graphical representation shows how a-dimensions change with arc length corrections, whether positive or negative. The “synergic function,” which automatically adjusts related parameters based on the settings and corrections, enables this feature.
Easy Jobs and WeldConnect App
The machine responds perfectly even when operated with welding gloves. Recurring parameter combinations for specific tasks can be saved as personalized “easy jobs” at the touch of a button. For instance, job 1 can be used for welding a 3 mm thick steel plate, and job 2 for a 5 mm thick chrome-nickel plate. If a JobMaster welding torch is used, these jobs are accessible directly on the torch. The Fronius WeldConnect app for Android and iPhone is practical for setting welding specifications. After scanning the base material, filler metal, and shielding gas using a QR code, and entering the weld seam profile, material thickness, welding process, and welding position on the mobile phone, the welding specialist can use NFC (near-field communication) to transfer the calculated values to the TPS 320i or to another employee’s mobile phone, who can then transfer them to their welding machine.
Robot Applications Make Welding Attractive at Knoll
Welding does not necessarily have the best image, often associated with noise, harmful fumes, and monotony. However, the job is quite demanding, especially when robots are involved. Welding technicians who can program robots are in high demand and well compensated. Many companies, including Knoll, create their welding programs offline on a PC or laptop, minimizing downtime and allowing for welding simulation on a digital twin. The software identifies axis limits, calculates starting points, limit positions, and journeys, and sets teaching points independently. Obstacles are visualized, and welding torch positions are corrected before the first weld is made.
Knoll now uses a cobot system, which is user-friendly and does not require traditional programming skills. To create a weld path, the operator moves the welding torch point by point along the joint line, saving each point. The software automatically calculates the weld path and sequence, records them, and makes them available for future jobs. Knoll’s system uses CMT technology, known for its stable arc, reduced heat input, and low spatter. This “cold” MIG/MAG welding process from Fronius is widely used in various industries, including plant, machine, power plant, automotive, aircraft, food, and medical technology, especially for thin sheet welding.
“Operating cobots is intuitive and fun, especially for young welders. They find cobot welding cool, as it is as easy as using a smartphone. Anyone familiar with smartphones can operate a cobot within a few hours. When enclosed and equipped with a fume extractor, welding specialists are protected from unhealthy fumes,” says Kleck, advocating for cobots.
Heart-centered but focused on quality
It is characteristically Swabian that the two managing directors, Matthias and Jürgen Knoll, are deeply committed to precision, especially when welding, in addition to the social development of the town of Bad Saulgau, which they kindly sponsor. This implies that they require experts who maintain the organization’s standards. Knowing this, Knoll feels that the success of the company stems mostly from the collective efforts of numerous talented workers who dedicate themselves to the organisation. Profits are reinvested in the business and used for site improvement. Knoll considers generations ahead of time rather than just quarterly numbers. Both the workers and the area gain from this.
Safety and Health Are Our Main Concerns
Both devoted and healthy personnel are not guaranteed. Knoll employs the best personal protection equipment and ergonomic workstations since they are interdependent. Every welding table has a height adjustment feature, and fresh air supply and automatically darkening welding helmets are standard. The air in the room is also changed four times an hour.
According to Riebsamen, “workplace ergonomics is an important topic.” Not just in terms of well-being but also in terms of financial gain. Short distances between the component and the welding machine, easy, personalised operation—all of these factors inspire motivation, save time, and boost welder productivity.
Of course, other important factors include component quality and safety. For this reason, the professionals at Knoll use a variety of testing techniques, including dye penetration testing (PT), to examine every single part. This is a quick, efficient way to reveal pores and other flaws like surface cracks. It can be applied to workpieces of any size and is appropriate for intricate geometries as well. With PT, even minute mistakes that are invisible to the unaided eye can be found and fixed by the welding expert. The workpiece to be evaluated has a fluorescent dye put to its surface for the dye penetration test. This seeps into existing flaws, holes, and fissures.
After that, a developer spray or a special lamp are used to illuminate it. Because the faults are encircled by the fluorescent dye, the examiners can see them right away. In keeping with its motto, “it works,” Knoll Maschinenbau GmbH provides its clients with dependable, user-friendly individual plants and systems.