Technologie und Verfahrenstechnik zementgebundener Spanplatten

Pampel, Hans-Peter; Schwarz, H. G.

doi:10.1007/bf02626536

Cited by 7 publications

(3 citation statements)

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“…Many cement boards have been used as building partitions for over one century [1,2]. However, the specific gravity of cement boards is still high, more than 2000 kg/m 3 .…”

Section: Introductionmentioning

confidence: 99%

“…In the recent years, by increasing the variety and numbers of the building materials many significant efforts have been done on implementation of different types of fibers particularly in concrete and cement panels. Many cement boards have been used as building partitions for over one century [1,2]. However, the specific gravity of cement boards is still high, more than 2000 kg/m 3 .…”

Section: Introductionmentioning

confidence: 99%

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Using equal cross-section theory to investigate bending properties of cellulosic fiber reinforced cement panels

Ghasaei¹,

Masumi

Hejazi

et al. 2014

Journal of Industrial Textiles

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Cellulosic fibers, which are widely available in Iran, can be used as convenient materials for cement panel matrix reinforcing with respect to adequate mix design. This paper at the first stage presents a simple model for predicting the fiber reinforced cement panel behavior during flexural loads by implementing ''Equal Cross-section Theory''. At the second stage, experimental study was carried out to validate the proposed theory. In order to do the experiment, different types of cellulosic fibers were used as cement replacement of 1% by weight. In addition, to solve the problem of swelling of cellulosic fibers within cement matrixes, fibers were treated by UV/ozone and coated with sodium silicate. Compressive strength, flexural strength and density of cement composite samples were investigated in terms of different cellulosic fiber types including viscose, Leafiran, milkweed and hemp and the sodium silicate consumption amount. The results revealed that the use of cellulosic fibers diminished the density and compressive strength of the cement panel specimens. Improvement of flexural strength was only achieved by adding the hemp fibers into the cement panels which showed a good agreement with ''Equal Cross-section Theory'' outputs. Moreover, the reductions in the compressive and flexural strength of cement panels contained sodium silicate were much smaller than the cement panels with uncoated fibers.

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“…Many cement boards have been used as building partitions for over one century [1,2]. However, the specific gravity of cement boards is still high, more than 2000 kg/m 3 .…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Using equal cross-section theory to investigate bending properties of cellulosic fiber reinforced cement panels

Ghasaei¹,

Masumi

Hejazi

et al. 2014

Journal of Industrial Textiles

View full text Add to dashboard Cite

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“…Usually, the cement content is higher in the surface layers than in the core layer. Furthermore, and comparable to adhesively bonded PB, the wood particles in the surface layers are much smaller and have a higher moisture content than those in the core layer (Pampel and Schwarz 1979;Fan et al 2006;van Elten 2006;Saunders and Davidson 2014).…”

Section: Introductionmentioning

confidence: 99%

Factors influencing the mat forming process via aerodynamic spreading in cement-bonded particleboard production

2020

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The production of three-layered cement-bonded particleboards (CBPB) differs in most cases from that of adhesively bonded particleboards. However, one production step is quite similar: mat forming. A homogeneous mat is formed by aerodynamic or by mechanical spreading or by a combination of both methods. The distribution of the particles is influenced by their separation and flight characteristics. Those characteristics are in turn influenced by particle size and the combination of the particle’s surface area and weight. Because density of cement is higher than that of wood, the cement/wood (c/w) ratio will influence the particles’ separation and flight characteristics significantly. In the current study, laboratory-made particles of different sizes were mixed with different amounts of cement. An aerodynamic former was then used to help determine the influence of the different particle types and the c/w ratio of the mix on mat forming. The strewn particles were analysed for their distribution of mass, size and cement content as a function of spreading distance. The particle size decreased with increasing spreading distance. In addition, the cement content and spreading distance were positively correlated. For a c/w ratio of 1.9, increasing cement content correlated with increasing distance. This means, large particles and less cement tended to fall earlier than smaller ones and more cement. This corresponds to the observation that the specific surface area of the particles increases with increasing spreading distance. Vice versa, the density of the particles decreases with increasing spreading distance. The effect is more apparent when the particle mixture is heterogeneous in size at constant process parameters (e.g., air velocity). Looking at the density profile of a CBPB board, the surface layers consist of small particles with a higher cement fraction, and the core layer consists of large particles with smaller cement fraction. Thus, the production of CBPB requires two aerodynamic formers working in opposite directions. With the results of this study, it is possible to optimise production parameters, such as the speed of the transport caul and the air velocity with regard to the infeed raw material parameters in order to create a symmetrical particle distribution from top to bottom of the mat, resulting in an optimized and application-oriented density profile.

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