Classification of wood surface texture based on Gauss-MRF Model

The basal theory of Gauss-MRF is expounded and 2-5 order Gauss MRF models are established. Parameters of the 2-5 order Gauss-MRF models for 300 wood samples＇ surface texture are also estimated by using LMS. The data analysis shows that： 1） different rexture parameters have a clear scattered distribution, 2） the main direction of texture is the direction represented by the maximum parameter of Gauss-MRF parameters, and 3） for those samples having the same main direction, the finer the texture is, the greater the corresponding parameter is, and the smaller the other parameters are; and the higher the order of Gauss-MRF is, the more clearly the texture is described. On the condition of the second order Gauss MRF model, parameter B1, B2 of tangential texture are smaller than that of radial texture, while B3 and B4 of tangential texture are greater than that of radial texture. According to the value of separated criterion, the parameter of the fifth order Gauss-MRF is used as feature vector for Hamming neural network classification. As a result, the ratio of correctness reaches 88%.

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.

A Melamine–Dialdehyde Starch Wood Particleboard Surface Finish without Formaldehyde

Melamine-dialdehyde starch resins used for wood surface finishes have been developed.The reaction of melamine with dialdehyde starch has been shown to occur by FTIR and MALDI ToF spectrometry,with several oligomer species due to the reaction of the two materials being identified,and the resin thermal stability was studied by thermogravimetric analysis.The resins were prepared by two different procedures when it was realized that dialdehyde starch is sensitive to too high a temperature for prolonged times.The melamine-dialdehyde starch resins were applied on particleboard supports as a direct liquid surface finish and a resin-impregnated paper.The surface finishes were tested for adhesion by the cross-cut test,their initial sessile drop contact angle,and the contact angle evolution as a function of time.The best results were obtained by the resins catalyzed by 2% ammonium sulfate and applied to the support surface as a resin-impregnated paper hot pressed for 3 min at 200℃,although the results at 180℃ also looked promising.

Optimization of CNC cutting parameters using design of experiment(DOE) and desirability function

In this study,2~5 （five factors at two-level factorial design） design of experiment was applied to investigate a set of optimal machining parameters to achieve a minimum surface roughness value for Abies nordmanniana.Wood specimens were prepared using different values of spindle speed,feed rate,depth of cut,tool radius,and cutting directions.Average surface roughness （R_z） values were applied using a stylus.The objectives were to：（1）obtain the effective variables of wood surface roughness;（2） analyze which of these factors had an impact on variability in the CNC machining process;（3） evaluate the optimal cutting values within the range of different cutting levels of machining parameters.The results indicate that the design of experiment（DOE） based on the desirability function approach determined the optimal machining parameters successfully,leading to minimum R_a compared to the observed value.Minimum surface roughness values of tangential and radial cutting directions were 3.58 and 3.21 μm,respectively.