Largest soil plant in Portugal has been relying on Lehmann-UMT bioextruders for over 10 years
LEHMANN—UMT GmbH, a medium—sized family business, manufactures bioextruders in-house and supplies innovative, complete environmental technology systems from the Saxon Vogtland region all over the world. The patented bioextrusion process is based on the hydrothermal digestion of organic biomass. With the help of two counter-rotating screws, which are specially adapted to the materials used and the processes, biological source materials are defibered and partially broken down into the cell structure. The extruder therefore not only offers advantages in substrate processing for biogas plants, but has also proven its worth in the production of (wood) fibers in particular. It makes it possible to defiber the raw materials, resulting in a greatly increased surface area, while at the same time ensuring constant output rates and consistently high quality.
The LEHMANN—UMT extruder enables the use of renewable raw materials in soil production. The bioextruder can be used, for example, to produce peat substitutes in the form of fibrous materials from various types of wood, coconut, straw and many other materials. As a result, the environmental impact is reduced as peat extraction for potting soil is no longer necessary.
A project for more sustainability
In cooperation with its Portuguese partner Leal & Soares S.A., LEHMANN-UMT implemented a complex project with the aim of expanding production capacities and optimizing existing processes. Leal & Soares S.A. was founded in 1995 and it is the largest soil plant in Portugal, which also has its own sawmill and compost plant. The company mainly produces peat—free and peat—reduced soils for professional and amateur landscape gardening. «We have been using peat substitutes right from the start. Well over 50°â of our range of soils has been peat-free for more than 10 years», — explains Mr. Nestler, head of the research and development department at Leal & Soers S.A.
Sustainable alternatives are more important than ever in order to quickly reduce peat extraction, which is harmful to the climate and the environment.
Mr. Nestler continues: «After testing various systems for the production of fibres, we opted for LEHMANN-UMT’s extruder technology, as the resulting wood fibres from this process appealed to us the most». This is because fibrous materials from the extruder already have many of the properties required for earth production.
No compromises with fibers from the extruder
Mr. Nestler emphasizes: «For us as a potting soil supplier, the consistent and high quality of the wood fibres is particularly important in order to meet the high demands of our customers». The fibers from the extruder ensure that the end products do not shrink. The extrusion process also enables the individual addition and incorporation of additives. The extruder is also suitable for processing different materials and guarantees the user a high degree of flexibility. The process also ensures the creation of a homogeneous end product, which makes it particularly suitable for soil production.
Expansion of production capacity by more than 150
The a potting soil supplier invested in a 90 kW extruder from LEHMANN-UMT back in 2014. This processes 1.2 m3 of woodchippings into 3 m3 of wood fiber per hour. «The 90 kW extruder also ran 24 hours a day for weeks without any problems», says Mr. Nestler. The system is extremely durable, resilient and has been working reliably for years.
In order to meet the growing demand, the a potting soil supplier decided to expand its plant concept with the new 180 kW extruder. The new plant was put into operation in March 2024. It processes 2.2 m3 of fresh wood chips into 4.6 m3 of wood fiber per hour. «Our production times range from at least 8 to 16 hours a day», explains Mr. Nestler. Both extruders can run in parallel or independently of each other. The systems impress with their long service life, low wear and uncomplicated maintenance. With this investment, Leal & Soares S.A. (SIRO) has more than doubled its production capacity.
Efficient processes precisely coordinated
In the process of wood fiber production by extrusion, Leal & Soares S.A. uses fresh pine wood chips from regional logging, which originate from the company’s own sawmill. Fresh wood chips (a few hours old) with a high cell sap content guarantee low-friction production, in which the cell sap serves as a natural lubricant for the screws of the extruder and consequently extends their service life.
An ingenious self-regulating feed system from a large feed bunker and several intermediate bunkers, which are connected via screw conveyors, ensures a homogeneous material flow into the two extruders. A drainage system is installed under the extruders so that the condensation water from the extrusion process can run off directly and be reused in the composting plant.
Both extruders can be fed in parallel or independently. Any necessary water is added by means of self—regulating and temperature-controlled sensors in order to achieve optimum defibration results. Furthermore, additives (other materials) can be fed flexibly from the outfeed belt and added to the process as required. The extruders command the entire upstream technology as required with the help of various sensors and thus create optimum conditions for themselves.
Resource and climate protection
The electricity requirements of the extruder at the a potting soil supplier are partly covered by the company s own solar system, which is installed on the roofs. This increases the sustainability of the entire production process and contributes to environmental protection. The long service life of the system also protects limited resources and the low level of wear ensures that the system requires fewer spare parts. Furthermore, the wearing parts have a modular design so that only the worn parts need to be replaced, which greatly reduces costs.
Partnership and service for over 10 years
Leal & Soares S.A. recognized the need for peat substitutes early on and thus became aware of LEHMANN-UMT’s extruder technology. Over the years, SIRO has continued to optimize its processes so that the extruder can work at optimum performance on a permanent basis and thus achieve maximum output rates.
LEHMANN—UMT is always on hand to advise the earthworks, supply wear and spare parts and provide support with training and maintenance work at the beginning. All LEHMANN-UMT systems are designed to be extremely easy to maintain. Mr. Nestler confirms: «We maintain our extruders ourselves and are therefore very independent and flexible. It’s all pretty straightforward, you don’t need a crane and you can replace the modular wear parts quickly and easily».
«The machine doesn’t cause any problems. If the process is right, then the extruder works perfectly» ends Mr. Nestler.
