The Joensuu Plywood Mill in Finland celebrates its 100th year this summer. While the applications of the products have changed over the course of a hundred years, the high-quality and durable Finnish birch plywood is still in worldwide demand. Global megatrends – such as urbanization, digitalization, increased stream of goods, energy requirements and environmental awareness – ensure the prosperity of birch plywood, manufactured from renewable raw material, far into the future.
The manufacture of birch plywood started at the Joensuu Plywood Mill a hundred years ago, when a factory designed for manufacturing bobbins was sold to Backman & Co in 1916. The company named its factory Itä-Suomen Faneeritehdas Oy a year later.
After the change of ownership, the factory was quickly modified to suit plywood manufacturing; however, the eruption of the Finnish Civil War in January 1918 delayed the start of manufacture, which only got under way after the war ended in May 1918.
According to Kimmo Wilska, Mill Director of the Joensuu Plywood Mill, the plywood manufactured in the early days of the mill was mainly used for tea chests and, to a lesser extent, for furniture and products used in building and construction.
The production processes and applications have changed in the hundred years since, and at present, the UPM-owned mill manufactures WISA Plywood mainly for two end-use applications: truck and trailer floors, and insulation components of tankers used in the transportation of liquefied natural gas (LNG).
Manufacturing at the mill is divided almost in half between these two applications, and the production capacity of the mill is 55,000 cubic metres per year: enough plywood for approximately 10 LNG carriers and 15,000 to 20,000 trailers.
Wilska explains that the plywood for both applications is manufactured using birch logs from the surrounding area, which are shipped to the mill from within a 150-kilometre radius. Birch is an almost unique material, not to mention one that grows continuously in our forests.
Strictly certified LNG plywood
The manufacture of LNG plywood is strictly certified and the best raw material is required. The fact there are only a handful of manufacturers in the world is an indication of the strict quality certification, and out of the 500 tankers sailing through international waters, over 300 have insulation components manufactured by UPM. “The quality standards for the material are so high that only a few others can reach them besides UPM,” states UPM Plywood’s Area Sales Director Mikko Iso-Kuusela.
According to Iso-Kuusela, aside from the high-quality material, UPM’s overwhelming market share in the LNG plywood market is based on two cornerstones: trust and long-standing collaboration with clients dating back to the late 1960s. “We have always been able to respond to the needs of our customers, and they trust us,” explains Iso-Kuusela.
Wilska tells that the Joensuu Plywood Mill has manufactured LNG plywood since the early ’90s. The Joensuu Mill manufactures enough LNG plywood for approximately 10 carriers every year. Manufacturing the plywood material for one carrier takes roughly one month. “One ship requires 2,500 cubic metres of LNG plywood on average. That is a huge amount, best demonstrated by the fact that 84 sea containers are needed to transport them to the client,” says Wilska. In addition to Joensuu, LNG plywood is manufactured at the mills of Otepää in Estonia and Chudovo in Russia.
The important role of LNG plywood
LNG plywood plays an important role in the trunks of tankers. In order to transport natural gas with the LNG carriers, the natural gas is liquefied by cooling it to minus 163 Celsius, which condenses it 600 times.
Iso-Kuusela states that in the circumstances in which liquefied natural gas is transported in carriers, the temperature of the sea water varies greatly. An additional challenge to the changes in temperature is the natural gas that is cooled to minus 163 Celsius. “In order to keep the sides of the ship from freezing during the sea voyage, its trunk has to be well insulated, and Finnish plywood has an important role in this.”
The use of plywood as insulation material for the carriers is based on the high strength of birch wood and its dimensional stability during drastic temperature changes. The weight of the material in comparison with metal is also a significant advantage.
An indicator of the material’s durability is that although LNG plywood cannot be called eternal, it is very long-lasting. “Last winter, I heard that the first carrier to which UPM shipped LNG insulation at the turn of the ’70s is still in use,” states Wilska.
According to large fuel suppliers, global energy consumption is expected to rise in the next decades by 30%, and natural gas is estimated to cover a significant part of this growth. Therefore, we can assume that there will be demand for LNG plywood in the future.
An ecological product for the transportation industry
The second of the two main product groups of the Joensuu Plywood Mill is the WISA plywood used for floors and walls of lorries and trailers. According to Wilska, specially coated WISA plywood has been manufactured in Joensuu for over forty years, responding to the needs of transportation industry. In addition to Joensuu, plywood for trailer floors is also manufactured at Savonlinna and Jyväskylä mills in Finland, and at Otepää in Estonia, and Chudovo in Russia.
UPM Plywood End-Use Manager Juha Patovirta states that 90% of all the plywood for vehicle floors manufactured by UPM is exported to Europe.
UPM’s market share in the manufacture of trucks and trailers in Europe is around 40%, and on an annual level, UPM supplies the plywood for the floors of 40,000 to 50,000 trailers. About one cubic metre of plywood is used for the floor structure of one trailer, while the construction of the floors of refrigerated vehicles requires slightly more.
Patovirta states that plywood is a strong and durable material that lasts as a floor material throughout the entire lifespan of a trailer, almost without exception. “The average lifespan of a trailer is eight to ten years, and one trailer travels 100,000 to 120,000 kilometres a year,” Patovirta elaborates.
Ecology and urbanization underlying the modern product
The use of plywood in floor construction is based on its excellent strength-to-weight ratio. The material is durable, but it is also ecological in a number of ways. “The ecological nature is apparent not only in the use of renewable material but also, for example, in fuel consumption, which is affected by the lightness of plywood compared to other materials,” explains Patovirta.
Although plywood has been used in the floors of trailers for decades already, it can also be called a product of the future. “Our vision of a bright future is helped by a constant increase in the volume of transportation, due to urbanization and a rise in living standards, as well as ever-more-pronounced green values. In the long run, we are dealing with an unquestionable growth industry,” states Patovirta.