Christian Fürll

Fibre boards and composites from wet preserved hemp

It is absolutely necessary to reduce plant investments and processing costs in order to make natural fibres more attractive for farmers and industry. Conventional hemp fibre production is based on field drying and straw retting – connected with a high weather risk. Therefore, a novel weather-independent technique has been developed. Hemp is harvested by means of a chopper followed by anaerobic storage. A pilot plant with a processing capacity of 300 kg h −1 (dm) fibre material has been built up and tested. The whole plant material can be processed to products like insulation materials, fibre boards or granulate for injection moulding.

Wet Processing of Hemp: An Overview

Normally, the production of fibers from agricultural fiber crops is based on field drying and retting of plant straw. As weather conditions at the usual harvest time are often problematical for harvesting and retting, the development of weather-independent supply chain technologies is very important. The weather risk can be avoided, if, e.g., hemp after being harvested with a conventional forage harvester is directly processed to final products, or stored by wet preservation. Furthermore advantageous is that the whole plant material without any loss is processed to final products like fiber boards, insulation materials, or fibrous materials for natural fiber reinforced composites. Especially for this purpose a pilot plant has been built up and is tested till present. The investigations have shown that conventional technologies of ensiling are capable for the preservation of hemp for more than one year.

Untersuchungen zum Einfluss des Pressdrucks und der Vibration auf die Verdichtung von Anwelksiliergut

Wilted grass has to be compressed during the ensiling in bunker silos. An increasing number of farmers are using compactors with vibrating roller drums to achieve a higher compression effect. On the basis of a servo-hydraulic material testing system quasi static and vibrating compression cycles were carried out and compared with each other. The oscillating movement of the roller drums cannot result in a higher compression performance which is observed in praxis. The observed increased compression performance is a result of the centrifugal force of the vibrating roller drums which can be several times higher than the weight of the vehicle.

Energiesparendes Zerkleinern von erntefeuchtem Getreide mit einem Keilscheibenzerkleinerer

A grinding machine with wedge-shaped discs was developed for grinding of wheat, barley, rye and maize with a moisture content up to 25 %. The grinding machine realised a mass fl ow > 40t/(h • m) with a energy consumption of < 3 kWh/t and with less than 1 % whole grains after crushing. The low specifi c energy consumption supplies an important contribution for energy conservation.

Eine neue Methode zur belastungsarmen Ernte von Kartoffeln

To reduce mechanical stress on potatoes from harvest to storage and to attain improved potato quality in long-time storage, a new method for box filling on the harvester was developed. By using selected criteria, this new method, which is called direct box

Mechanisches Schälen von Kartoffeln ohne Wasserzusatz

Most potatoes are peeled before consumption or before processing, whereby increasingly mechanical processes are coming into use. Depending on the tubers’ peeling suitability, peeling results in considerable mass losses. Using water for peeling results in additional costs for its purchase and purification. The goal of the project is to design a simple mechanical peeler which works without water and with little peeling waste.