The Valmet Advantage™ Yankee drying solutions are proven for all tissue making technologies. The key to success is the combination of experience, craftsmanship, modern technology and well-controlled processes. Our experience is your advantage.
Steel or cast iron
Proven solutions for all processes
High quality material and workmanship
Rigid quality control
Optimized for high and uniform drying by minimizing variations
Proven, well-working internal equipment
Market leading thermal coatings
More than a century after it was invented, the Yankee is still the heart of the tissue machine. Nothing has surpassed it. Of course, technical development has been extensive. Modern Yankee cylinders are safe and reliable and offer great performance along with energy efficiency. Customer needs have evolved too, and not all tissue-making is the same.
We believe in providing the ability to choose, and therefore we offer both steel and cast-iron Yankee cylinders. And we are the only manufacturer that can do so. We also offer the most complete range of machines and solutions for tissue, paper and board manufacturing.
The most important benefits of Valmet Advantage Yankee dryers come down to two words: proven and choice. Matched exactly to your needs, rest assured you have top safety, availability, long service life and excellent performance along with simple design, quality materials and high-precision machining and welding.
Among our installed machines and Yankee cylinders are found the world’s absolute fastest, most energy efficient and most productive. You can also count on unbeatable process knowledge and support with a worldwide service network.
In addition to principal requirements from the Yankee, such as safety and drying performance, there are also specific needs for different paper making processes. Conventional processes typically mean wide operating ranges and high pressing loads in combination with demands for uniformity and low vibration levels. Emerging hybrid processes, like the Advantage NTT technology for manufacturing textured tissue, as well as the Advantage ThruAir or TAD process for structured tissue, require the Yankee dryer to function at varying condensing rates, withstand high doctor loads and have a surface susceptible to specialized process chemicals.
Drying capacity, energy savings and safety are, of course, important in Yankee selection. Yet there are other critical characteristics to consider when choosing a Yankee dryer for the paper machine and process. This comparison chart provides a quick overview to help you get started with defining your needs.
|Drying capacity (theoretical)||+++||++||Stronger steel allows for thinner shell but can be compensated by deeper grooves for cast. Practical, process dependent drying limitations.|
|Energy efficiency (theoretical||+++||++||Relates to drying capacity. Drying more with Yankee reduce losses in AirCap. Yankee itself does not use less energy.|
|Safety||+++||++||Steel is generally a better material for pressure vessels. But design and quality are equal important. Valmet has excellent safety record.|
|Surface properties (metalized)||+++||+++||Both cast and steel shells are metallized with the same type of thermal coatings.|
|Surface properties w/o coating||N/A||+++||Cast iron provides a good papermaking surface as is. A steel shell is too soft and must be metallized for papermaking.|
|Long time reliability and durability||++?||+++||Cast iron has been used and proven for over 150 years. Ribbed steel dryers have been in operation for much shorter time.|
|Surface temperature uniformity||++||+++||High quality cast iron is uniform with even properties. A welded shell has small variation between weld and plates. Thinner shells more sensitive.|
|Vibration damping properties||+||+++||Grey cast iron has excellent vibration damping properties, 10-20 times that of steel.|
|Corrosion and erosion resistance||+||+++||The free graphite of cast iron forms a barrier to corrosion. Steel has no free graphite and is more exposed to fatigue and erosion.|
|Maintenance and inspections||++?||++||Well established recommendations and methods for cast Yankee. Knowhow for steel Yankee under development.|
|Process compability (TAD, hybrid)||++?||+++||TAD and hybrid processes utilize higher doctor loads known to quickly deteriorate metallized shells. Steel largely unproven.|
|High press load capability||++?||+++||Limited experience in the industry with steel YD and high press loads. Steel is stronger but cast iron has good fatigue resistance.|
|Others (top speed, stability)||++?||+++||Limited experience in the industry with steel Yankees in top speed tissue machines.|