The results indicated that commonly used foam plastic roof msula tions will be damaged if exposed to foot traffic, and that their protection with fi brous overlay boards as recommended by roofing ...contractor associations 1,2 con tinues to be good roofing practice. The results also indicated that finished roof surfaces will be damaged if exposed to frequent roof traffic and that surface protec tion of the membrane is good roofing practice.
The paper deals with determination and classification of the mechanical parameters of cement fibre boards (CFB) with cellulose and PVA reinforcing fibres. The cement fibre material with reinforcing ...fibres is produced using the Hatschek process, where the fibres are arranged in the production direction and the curing is subsequently verified. Test experimental samples, specimens are created from the same production batch, and are produced orienting all of them in the production direction to determine the characteristic for an orthotropic material. The fracture mechanical parameters such as fracture energy and work of fracture were then determined and verified as well. Records will be made for the determined crack mouth opening displacement (CMOD) and displacement (d) of test specimens. The loading directions are given to cover the determination of the mechanical parameters of the material. These measurements are intended to complement the mathematical model that uses FEA modelling for subsequent implementation of the material into civil engineering structures or details.
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•Determination of fracture properties of CFB with cellulose and PVA fibre.•A new CMOD measurement method was developed for smaller test specimens.•The obtained fracture energy values were implemented in the FE Analysis.•Validation of the numerical model with fracture parameters via experimental tests.
This paper presents the details of three fire tests conducted on light-steel-framed (LSF), load-bearing wall systems, which consist of polyurethane insulation injected into the cavities of the steel ...frame between two or three layers of gypsum fibreboard. To investigate the thermal and structural performance limits under standard fire conditions, observations were made during the tests, and temperatures and vertical displacements were recorded. Although combustible insulation was used, the results obtained are promising for the application of studied LSF wall systems in buildings, where fire resistance of more than 60 min is required.
The incubation of wood fibres with a phenoloxidase (laccase) results in the oxidation of the lignin crust on the fibre surface which finally is released from the fibre surface into the incubation ...medium. During this reaction, the lignin is highly oxidized, as can be seen from its high
carboxyl content. When fibres treated with the enzyme are pressed together under conditions usually employed during the process of making fibre boards, boards are obtained which meet the required standards for German medium density fibre board (MDF). The enzymatically activated fibres in the
wood composites made by this process are bound together in a way which is closer to the situation in the naturally grown wood than any other process used today in the present production of wood composites.
Abstraet-When commercially produced wood fibres were treated with the enzyme peroxidase and H
2
O
2
for a certain time and then pressed together under conditions usually employed during the process ...of making fibre boards, boards were obtained which came close to the
required standards for German medium density fibre (MDF) boards. Thus, surprisingly, peroxidase in this system gives the same results as laccase, for which this reaction has been described previously. Successful implementation of this process will yield wood composites which can be produced
without any addition of resins, solely from naturally grown products.
The Institute of Hygiene was requested to determine causes and scope of health complaints made by the employees of Haldensleben district administration after sound absorbing mineral fibre boards had ...been installed as suspended ceilings. The boards were coated with a lean water-carried paint; however, the edges, which were partially frayed, were not coated. The air inside the rooms was measured on all four storeys of the building, followed by scanning electron microscopy in compliance with VDI Code 3492. In addition, measurements showed fibres with diameters of > 3
μm which are not subject to the regulations for carcinogenic substances, but, in contrast to the thinner fibres, they may cause irritations of skin and mucosa. The employees were questioned about their health problems. At the beginning of 1994, a total of 79 of the 133 employees complained about itching, reddening and burning of their eyes as well as irritations of the upper respiratory tract. More than 50% had consulted a doctor. Late in 1994, another questionnaire survey was completed. The fibre content of the office air was determined to vary from 1000 to 3500 fibres/m
3 and, in addition, 100–200 fibres with diameters of > 3
μm. Our investigations showed that there is an interrelationship between the degree of dust accumulation in the offices and health complaints. Independently of the current discussion of the cancer causing potential of thin man-made mineral fibres, the very long and thick mineral fibres (> 3
μm in diameter) are of topical importance to health.
Ultra violet curing bio-fibre composites P. Kosheela Devi; R. N. Kumar; Rozman Hj. Din ...
Proceedings of Oleo & Specialty Chemicals Conference: PIPOC 2007: International Palm Oil Congress: Palm Oil: Empowering Change,
2007
Conference Proceeding
Research was carried out to study the physical and mechanical properties of value added bio-fibre composites made by employing environmentally benevolent ultra violet (UV) curing technique. Standard ...mercury UV lamp was used for the investigation. Unsaturated polyester resin along with bisacylphosphine oxide was usedas polymer matrix. Rubberwood fibre (TMP fibres) residues, a waste and unutilized fibre from one of the medium density fibre board (MDF) plants, were used as the reinforcement fibres. Un-delignified TMP fibre mats could not be impregnated due to its high bulk factor. Improper cure of the composites was also expected due to the presences of lignin in the fibres. To overcome this problem and to enhance the interfacial adhesion between the matrix and fibre, anthraquinone-kraft (AQ-kraft) pulping known for its efficiency in the removal of lignin and for producing high strength fibre was adopted. Since the operating variables of pulping process control the ultimate strength of the fibre reinforcement, Response Surface Methodology (RSM) was employed to investigate the effect of the following pulping parameters (i) active alkali (ii) sulfidity (iii) temperature and (iv) time of cooking on the responses such as mechanical properties of composites, degree of cure and water absorption. The optimum conditions for AQ-kraft pulping are 17.0 % active alkali, 27.0 % sulfidity, 162°C pulping temperature and 95 minutes of pulping time. The mechanical properties of AQ-kraft pulped fibre composites showed properties superior to TMP fibre composites. This was due to better mechanical interlocking between the fibres and the grafted unsaturated polyester in AQ-kraft pulped fibre composites. Besides that, the gel content and resistance towards water were also better in AQ-kraft pulped fibre composites. Scanning electron microscopy (SEM) studies were carried out on both the type of fibre composites to confirm above findings. In references to the above studies similar type of research can be carried out on palm oil empty fruit bunches (EFB), which are available abundantly and unutilized.
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