Published on : Thursday, May 10, 2018
Siempelkamp, the German machine manufacturer, unveils its technological innovations for the production of MDF and particleboards made of rice straw and other annual plants at Xylexpo 2018 in Milan. Annual plants are growing in importance in view of the worldwide shortage of wood. Climate-neutral boards with a positive CO2 balance can be produced using rice straw, a waste product from the rice harvest. As a result, Siempelkamp is positioning itself globally as a technological driver in the use of annual plants for the production of MDF and particleboards. The Siempelkamp Group is at the same time sending a clear signal in favor of green business and efficient management of resources.
Although rice straw is produced in significant quantities all around the world, it is rarely processed industrially. In addition, wood has been exploited to a growing degree for some years now to generate heat and power, leading to a scarcity of timber and a rise in the prices demanded for wood as a raw material on the world market.
MDF, OSB and particleboards made from annual plants consist of 100% annually renewable resources which, as they are a natural waste product, do not compete with food production. They are recyclable and merely require an environmentally friendly binder during production such as PMDI in the case of rice straw. In addition, it is possible to produce MDF and parti-cleboards made of rice straw that equal the general material properties of wood-based panels and offer a chance to occupying product niches where special characteristics are in demand. “Rice straw barely accounts for three percent of the raw materials used in industry. We believe that this share will increase significantly in coming years, and this is evident in the intensive discussions we’ve been having with our customers,” explains Dr. Hans Fechner, Managing Director of the Siempelkamp Group. Siempelkamp will have constructed all the plant needed for a factory producing 200,000 square meters of MDF per annum made of rice straw by the end of 2018 in the USA. The volume of orders relating to this amounts to 75 million euros.
Around 5.1 billion metric tons of rice straw are produced worldwide each year as a low-cost agricultural waste product. The majority of this rice straw is produced in China (approx. 1,500 million metric tons), India (approx. 1,110 million metric tons), Indonesia (approx. 541 million metric tons) and Bangladesh (approx. 368 million metric tons). Europe is also responsible for producing around 12 million metric tons of rice straw every year. The largest cultivation areas in Europe are in Italy. However, a large percentage of these sizable volumes of rice straw remains unused, being burnt directly on arable land or left to rot in the fields.
Rice straw boards require two-stage sifting
The development of suitable production facilities posed a particular challenge to Siem-pelkamp. Processing of rice straw to produce an MDF or particleboard is much more com-plex than wood. This is due to the high proportion of inorganic constituents in rice straw, es-pecially silicates, and impurities such as sand and loam from the straw harvest. Up to 20% of the dry fiber weight was determined to consist of natural inorganic constituents free of foreign substances. The raw material needs to be cleaned, as downstream plant components will otherwise suffer wear too quickly in the further production process and sufficient workability of the boards cannot be ensured.
Separation of inorganic constituents and impurities is realized in a new two-stage process developed by Siempelkamp. The first step involves the separation of impurities and coarse constituents such as entrained sand and silicate dust released during processing of the rice straw and their elimination through an airflow process. The cleaned rice straw is then processed in the refiner using mechanical and thermal pressure to create high quality fibers and then further purified in a second step.
NEO Blender: Wear-resistant and maintenance-friendly resin blender for rice straw and annual plants
In contrast to normal MDF production, resinating of rice straw fibers only occurs after the dryer. Siempelkamp employs a process for the dry application of resin here using a newly developed continuous blending system. This blending system enables optimum adaptation of the glue system to production conditions. Glue consumption is lower than in the conventional gluing process as losses due to pre-curing are avoided.
The newly developed NEO Blender ensures uniform, continuous gluing of fibers, is extremely resistant to wear and, thanks to a screw-on mixing chamber cover, is easy to maintain. The material properties of rice straw in production were consciously taken into consideration during the process.
The main features of the new NEO Blender are:
• A high peripheral speed up to 100 m/s for optimum wetting and thorough blending
• Optimized, wear-resistant mixing and transport tools
• An innovative housing design with doubled-walled cylinder jacket and wear-resistant inner cylinder jacket
• A maintenance-friendly overall concept
• Integrated system monitoring through vibration measurement
Proven quality and precision: The ContiRoll 9
• A core element of wood-based panel plants is the ContiRoll continuous press which has been in successful use around the world for many decades in the production of MDF, OSB and particleboards. The ninth generation of the press has been included in the Siempelkamp product portfolio since last year. The ContiRoll reaches a speed of 2500 mm/sec, enabling the achievement of high capacities during the production of thin MDF boards.
• In order to be able to exploit the production speeds of ContiRoll without any loss during final production, Siempelkamp will be presenting its new 6-fold saw at Xylexpo. By using six saws, lab cuts can be executed precisely and without loss of speed. “Even with high-speed production, the new Siempelkamp saw makes it easy to change individual saw blades during operation,” explains Dr. Fechner.
Further highlights at Xylexpo 2018
In addition to the latest innovations employed in the production of MDF and particleboards made of rice straw, Siempelkamp will be presenting further technical innovations at Xylexpo 2018. These include the EcoFormer from CMC TEXPAN, Siempelkamp’s Italian subsidiary, and the Ecopulser for contactless comminution of wood chips and particles. The KT400 and KT700 short-cycle presses come with reliable Siempelkamp technology for coating MDF and particleboards.
Tags: annual plants, Climate-neutral boards, ContiRoll, Dr. Hans Fechner, German machine manufacturer, Managing Director, MDF, Milan, NEO Blender, paticleboards, production, rice straw, Siempelkamp, technological innovations, unveil, Xylexpo 2018