Wood Surface Roughness Research Articles

Experimental Study of Optical Scattering and Fiber Orientation Determination of Softwood and Hardwood with Different Surface Finishes

Optical scattering from wood of different surface finishes has been experimentally investigated. It has been found that for planed-Hemlock samples the scattering intensity distribution in the direction across the wood fibers is very close to perfect diffuse reflection, while that in the direction along the fibers appears as the combination of diffuse and specular reflection. The increase of wood surface roughness reduces the difference between these two scattering intensity distributions. The difference provides the basis for determining wood fiber orientation by measuring the scattering intensity variation with fiber orientation. When the sample surface becomes very rough, such as a rough sawn or porous hardwood sample, the scattering from the uneven surface overwhelms the difference and creates a difficulty in fiber orientation measurement. To solve the problem, we have been employed optical polarization detection in the investigation. With this detection method, for the samples used in this work, the intensity variation of the scattering vs. fiber orientation appears periodic despite the different surface finishes. With the help of Fourier analysis, fiber orientations of the rough sawn softwood and porous hardwood samples under investigation can be precisely measured.

Durability of Portland Cement Concrete Surfaces Using Wood and Steel Forms for Casting

Forms made of wood and steel in its different types are considered one of the widely used techniques in construction of Portland Cement Concrete structures. The effect of such forms on the physical and chemical properties of hardened Portland Cement Concrete (PCC) are under consideration relative to the durability of the exposed outer surfaces. This can be of great importance in structures exposed to weathering caused by either water-exposed structures or sever weathering of natural temperature cycles. In such structures, protective measures are used to insulate the hardened concrete against weathering. Such techniques are of no benefit if the chemical reaction between wood form and fresh concrete is already taking place. In other instances, high quality non-reactive ingredients are used to improve durability of Portland Cement Concrete. This is expected to deter deterioration of hardened cement surfaces, but casting is of concern in this case as well as the need for such measure. The type of interaction between wood forms and fresh concrete is a chemical reaction between acids which exists in the different types of wood and the ingredients of Portland Cement Concrete as well as a physical one in terms of the size of surface area exposed caused by the wood surface roughness.

Nondestructive Measurement of the Subsurface Structure of Biological Material Having Cellular Structure by Using Near-Infrared Spectroscopy

Biological materials–wood is a typical example–are widely used in a state where not only the cellular structure but also its bulky shape is retained. NIRS (near-infrared spectroscopy) may be called for as a promising technique to analyze the physical state of such materials as well as the chemical composition. In this report, the effects of physical conditions found in wood on the absorption of NIR radiation are examined. In the experiments, conifers (Sitka spruce) that had various degrees of surface roughness and different orientations of fibers to the direction of incident light were used. Results of these measurements showed that the orientation of fibers and the surface roughness of wood were directly related to the absorbance. In addition, it became clear that the behavior of diffusely reflected light in wood could be expressed by Kubelka–Munk theory and fell into three categories according to the characteristic of the absorption and scattering coefficient. On the basis of these results, a new concept for the behavior of NIR light passing through material made of hollow fibers has been proposed.

Using Haralick method to measure wood surface roughness

Wood surface roughness is one of the important indexes of manufactured wood products. This paper presents an attempt to use Haralick method to evaluate manufactured wood surface roughness through the utilization of imaging processing and pattern recognition techniques. Through the use of the methodology presented in this paper, We can give features of wood surface by spatial dependence matrices. The preliminary results indicated that the method has the advantages of non-contact, three-dimensional, high-speed. This method can be used in classification and in-time measurement of manufactured wood products.

The effect of wood surface roughness of different species of trees on wood color in working operation

The multinomial wood surface roughness parameters and wood color parameters of 5 kinds of species of trees were measured in working operation by the stylus surface roughness meter and colorimeter, and the measurement results were compared. The results indicated: The variations of wood surface roughness had the effect on the wood color of some kinds of species of trees on working operation, with the surface roughness decreasing, the brightness and luminance exponent increased, the hue angle increased lightly, but the variation of color saturation was different to the different wood color hue of species of trees.

Einfluß der Partikelgröße und der Konzentration bei der IR-Spektroskopie von Holz in Transmission und diffuser Reflektion

FTIR spectra of the tropical hardwood Guibourtia sp. (Caesalpinia-ceae) have been recorded using the KBr pellet technique and diffuse reflection (DRIFT) in KBr powder. It was demonstrated by variation of the wood concentration in KBr and the particle size of the milled wood that the spectroscopic data of wood- mainly those of the intense carbohydrate band around 1100 cm−1—are strongly influenced by these parameters. The KBr pellet technique gives reproducible results for concentrations between 0.1 and 0.5% with a particle size below 25 μm. The. DRIFT spectra of wood powders in KBr are very much influenced both by particle size and concentration. Wood spectra are also presented which were obtained by transmission spectroscopy and FTIR microscopy of 25 μm microtome cuts and by reflectance on solid wood surfaces. The influence of heterogeneous dispersion of wood in KBr and the roughness of wood surfaces on reflectance spectroscopy is discussed. A simple baseline correction is recommended to increase interlaboratory comparability of wood spectra.

Study on measurement of wood surface roughness by computer vision

The working processes, machining devices and tools, cutting amount, consumption of materials, productivity and quality of products are directly affected by wood surface roughness. This paper gives an extensive review of methods used previously to measure wood surface roughness, and concludes that computer vision is the most suitable technique. The preliminary study shows that computer vision method has the advantages of a noncontact, three-dimensional measurement, high speed and well correlates with stylus tracing method. This method can be used in classification and in-time measurement of wood surface roughness after being improved.