VOLUME 58, ISSUE 6/2017

The current occurrence of Industry 4.0 was analysed for four typical sectors of the wood industries: furniture industry, prefabricated house industry, sawmilling industries and secondary lumber manufacturing. In order to achieve this, a model manufacturing system of each of the sectors was designed by applying current machining and IT-systems of the market leaders. The analysis was based on an appropriate scheme of the German VDMA concerning Industry 4.0. The results are shown in spider diagrams which show the occurrence of typical indicators of Industry 4.0 such as integration of sensors, machine to machine communication and IT infrastructure. Based on the results the potentials of the future applications of a smart factory are discussed.

The shrinking and swelling behaviour of wall elements assembled from single members (machined boards for log construction) depends on the properties of the applied basic products (massive timber, glulam or cross-laminated timber). The global material-related differential shrinking and swelling behaviour induced by moisture changes of walls made from machined boards for log construction is strongly determined by the geometry of the board-joints. This must be taken into special consideration when settlement-free log-wall elements are made from orthogonally glued basic structures, e. g. cross-laminated timber elements. In this work, the local deformation effects resulting from the drying process in elements with a standard log board profile are investigated for different structural wall build-ups (machined boards for log construction made of glulam or cross-laminated timber). Based on measurements of the local moisture induced deformations, the opening of the board-joints and the local differential shrinking value are determined.

A flame retardant, which was first presented in 2011 for the deep pene-tration of dried spruce timber, was further developed and investigated with regard to penetration behaviour and flame retardancy in a currently ongoing cooperation project. In the present work, corresponding results from impregnation of eight different dried softwoods and subsequent fire tests are presented. All tested wood types can be adequately impregnated meeting the requirements regarding flame retardancy according to IMO Resolution MSC 307 (88). A versatile use of the flame-retardant in the interior and exterior of buildings is supported due to its non-toxicity.

The second part of this publication describes the application of the laccase mediator system (LMS) as a natural binder for the production of wood fibre insulation boards by hot-air/hot-steam processes. This process operates according to the principle of the controlled flow of hot air and then hot steam through the fibre fleece, enabling curing temperatures of well above 100 °C. In the first part of the publication it was shown that not only the mechanical and physical properties of wood fibre insulation boards bonded with polymeric diphenylmethane diisocyanate (pMDI) are improved by the hot-air/hot-steam process, but also aminoplast resins can be used for the production of insulation boards. When the LMS is applied, the hot-air/hot-steam process is particularly effective, caused by high curing temperatures, which lead to industry-specific strengths and water absorptions of the boards. As a consequence the LMS offers a serious alternative to the pMDI as binder system for the future.

The thermal insulation of buildings does not only saves energy costs, but also helps to reduce CO2 pollution and save resources. This study deals with the production of insulating boards based on biogenic raw materials and the investigation of their material properties. Maize stack and wheat straw as well as miscanthus were used as the raw material for the boards. The binder used was a urea-formaldehyde resin, a sodium water glass and a tannin-hexamine system. The boards were produced by means of a hot pressing process under comparable conditions. In addition to the thermal conductivity of the boards, the particle distribution, the water uptake or release as well as the fire behaviour of the different starting materials as well as of the resulting their panels/plates were examined. The results show that the thermal conductivity of the panels from the raw materials used is in the range of natural insulation materials on the market. The results from the water uptake test show low increase of the miscanthus boards. The influence of the different adhesive systems plays only a subordinate role in the water uptake/absorption. However, differences in adhesives can be determined by the fire behaviour test. Here, the tannin-hexamine binder shows advantages over the two other systems. Through these investigations, the potentials of plant based natural materials as an insulating material and as a binder were raised to provide a basis for further investigations.

Large quantities of bark residues are produced by short-rotation plantations, as a by-product. In this investigation, bark fibers of poplar trees from short rotation plantations were extracted, with thermo-mechanical pulping (TMP). Bark fibers were applied in production of natural fiber-polymer composites (NFCs) as a value-added product. Two polymers were used as matrices: cellulose propionate (CP) and polypropylene (PP). It has been observed that bark fibers can enhance tensile strength and modulus of cellulose propionate. In case of polypropylene matrix, bark fibers slightly reduced the tensile strength where tensile modulus was increased. In comparison to wood, bark fibers had less reinforcing effect in all the evaluated mechanical properties. In addition, the amount of water absorption was lower in samples made with bark fibers in combination with both polymers, comparing with wood polymer composites.

Due to the progressive urbanization, a further shortage of work and living space is to be expected in the future. In addition to the negative effects on the working day (e.g. open-plan offi ces), the lack of space also affects the quality of life in the private sector whereby health and wellness issues are becoming increasingly important. In this context, thin high thermal insulating elements for the realization of an expandable sauna have been developed and evaluated as part of a research project. Although the wall constructions were explicitly designed in a set for a later sauna application, the findings have a general validity for the development of components for delimiting strongly different conditioned areas. The present paper gives an overview of the various questions addressed during the development and evaluation of the novel sauna elements. Aspects concerning the thermal performance and deformation behavior are exemplary selected and discussed in more detail.

The horizontal density distribution is a critical factor for the quality control of wood-based panels. Typically, the density profile is determined offline by radiometric measurement systems in the wood-based panel industry. However, in the range of high density (> 900 kg/m³), these devices have a certain degree of inaccuracy. This is one of the reasons why the measurement of the density profile is hardly used in the quality control of cement-bonded particle boards (1000…1400 kg/m³). The other reason is the lack of knowledge about the influence of the density profile on board properties. The comparison of radiometric and gravimetric density profile measurement shows high accuracy of X-ray measurement for determining the true density profile of cement-bonded particle boards. In future, it will by possible to establish radiometric measuring methods in the quality management of cement-bonded particle board production and to explain the relationships between density profile and board properties.