PrimeService for Modern Tissue Machines: Extending Life Cycle Key to Lower Costs

MARK RUSHTON

Andritz AG, Graz, Austria, is strengthening its service activities for tissue machines and has a series of new tools designed to make life a lot less complicated for mill managers and production personnel. Tissue 360o magazine recently met with two key Andritz service people, Johannes Kraxner and Erwin Walcher, to discuss new ideas for an ever-challenging service environment. The essence of this discussion is summarized in the following Q&A below.

Tissue360o: Can you tell us what you are noticing about the service market in the pulp and paper sector?

Andritz: The tissue industry is characterized by severe competition and cost pressure. This is why service is gaining more and more importance, with customers recognizing the benefits of improving the performance of their equipment, adapting and extending the overall lifetimes. In addition, in the tissue sector, service activities are often requested to solve runnability, quality, or energy issues. Customers are also recognizing how professional services such as consultancy, training, and measurements can help improve their business performance.

In what areas are you noticing growth—rebuilds? conversions? overhauls?

In all three areas. When talking about rebuilds, yankee hood rebuilds seem to become more and more important. The prevention of sheet breaks and fires in the drying section and especially in the area of the yankee is one of the key challenges in tissue production. Drying hoods on a yankee dryer need to have a balanced air system; however, due to the suction slot ahead of the ingoing nozzle box, there is typically an infiltration of dirt into the system. This leads to a plugging of the first nozzle and the immediate area surrounding it. Sheet breaks and sometimes even fires might be the consequence. Andritz offers a rebuild with a specially designed air nozzle. The existing part is removed by cutting off the suction slot and the new AirKnife is added. The rebuild ensures that the dirt is no longer drawn into the slot, but is blown away by pressurized air.

When talking about overhauls, headbox overhauls come foremost to mind—they are a real speciality of our service teams. Headboxes work in very demanding environments: heat, moisture, and vibration. Over time, their performance will degrade as the forces of corrosion, damage to the lips, the wear of adjustable components, and defects in the heating channels take their toll. When this happens, sheet quality and operational safety can be impacted. The decision then becomes “replace” or “recondition?”

Andritz offers an annual service to inspect, recondition, and, when necessary, rebuild headboxes from any OEM to restore the performance—while extending the life of the customer’s initial capital investment. The headbox overhaul service includes a lot of specific actions, including lip repairs. Since any damage to the top or bottom lip—even the smallest scratches—will have a negative impact on CD sheet profiles, we offer lip repair service as an alternative to costly replacements. Our specialists will perform all of the operations—levelling, planing, grinding, shaping, and deburring—to bring the lips back to specifications. These operations can be directly done on-site in the mill or in our workshops in Austria (Graz).

Is Andritz offering anything new in terms of service to mills?

A real highlight of the Andritz tissue services is the yankee lifecycle management. It includes customized solutions for new yankees and rebuilds and escorts the customer through the complete yankee life cycle. No matter if cast or steel, no matter what brand and what end product (tissue, paper, board, MG paper, tobacco). The services include solutions and support for upgrades and replacements, safety, production, and analysis (e.g. on the run measurements). A real highlight is the Andritz coating and grinding with mobile units directly at the customer’s site—this is worldwide unique. Grinding up to 6,800 mm yankee shell length is possible, and coating is done with three spray guns at the same time.

Can you talk more in depth about what ANDRITZ is offering mills to save on maintenance costs?

Andritz has spent a lot of effort in developing service solutions to improve production efficiency and quality at the same time as reducing maintenance costs. One innovative result is, for example, the Andritz wire and felt guide unit that enables reliable wire tracking. Conventional mechanical tracking systems comprise many parts, which require a lot of maintenance and perform a machine directional movement that is failure-prone. A reliable, well functioning wire tracking system is crucial for ensuring trouble-free operation.

The wire and felt guide unit enables precise control due to pneumatic design. It features a pivoting saddle to which the bearing housing of the wire tracking roll is bolted. The saddle is pivoted by two reciprocal air bellows (one constant pressure, the other variable), resulting in a skewed position of the guide roll. The guide centers the wire by a finely proportioned air flow into the controlling air bellow.

Is the use of digitization, Big Data, and aspects of Industry 4.0 coming into the service division of Andritz? And what are the challenges a modern mill faces?

Andritz is already preparing the basic data and tools for future implementation in new service products, and we are already gaining experience from the first automation installations of tissue machines. Our focus is to approach Industry 4.0 from a technology-enabling and lifetime-prolonging standpoint. Digitalization is the vehicle, smart applications are the driver, customer need is our focus. This is quite to the contrary of available solutions, which are promoting digitalization as the primary focus. Customer need is profitable production, with quality, productivity, and sustainability constraints. Our products in this segment already deployed at pulp and paper mills provide information to mill staff where it is needed, and are able to steer processes well ahead of substantial hiccups due to prediction capabilities derived out of data analytics.

The customer’s challenge is to find a service partner who understands the customer’s equipment, processes, and procedures and knows the complete production process and the factors of influence. There are many “maintenance” companies; unfortunately, many of these companies do not understand the unique processes, equipment demands, and safety requirements of a paper mill. Based on its long-term experience and tradition as a paper machine supplier, Andritz helps—from replacement parts to comprehensive service programs –protect and extend the life of equipment and lower life cycle costs. 

Mark Rushton is Tissue360o magazine senior editor, Asia & Europe. His email address is [email protected]

A part of yankee hood rebuilds, Andritz offers steel yankees for new machines and rebuilds.

“The right service helps to improve the efficiency of your tissue machine and keep maintenance costs to a minimum” —Johannes Kraxner, Andritz service specialist

“Yankee service starts by being near the customer, ready to act. We accompany the customer through the complete yankee life cycle” —Erwin Walcher, Andritz service specialist

Example of installation: wire and felt guide unit installed in a 1,800 m/min. tissue machine at Corelex Shin-Ei Paper, Japan.

 

 

 

 

 

 

 

 

 

Andritz automation installed at Sun Paper Yanzhou (two 2,000 m/min. tissue machines).

The wire and felt guide unit for steady guidance of the wire and low maintenance costs—no unplanned shutdowns, highest reliability due to uniform and rapid response, lowest maintenance costs.

A perfectly maintained tissue machines leads to cost optimized production at highest quality.

 

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