The objectives of this research were to create a model for time sereries data prices and yields of natural rubber to be more accurate prediction and to compare the proposed model with the classical time series models such as the Holt-Winters Additive Exponential smoothing model (Holt-Winters ES) and the seasonal autoregressive integrated moving average model (SARIMA). The proposed model was a linear mixed model (LMM) consisting with trend autoregression outliers and sesonal terms. Dummy varialbles and Fourier seasonal effects were studied. Bayesian estimation was used and the estimated prices and yields were used for prediction. The results show that the proposed model with a Fouries seasonal effect is the most appropriated comparing with the dummy seasonal effect the Holt-Winters ES and the SARIMA having the least mean absolute values (MAE) both fiting and validating parts. The proposed model with sesaonal dummy variables should be the first consideration for forecasting spatial time series with a seasonal component.

This research aims to develop the natural rubber and ethylene vinyl acetate (EVA) plastic floor tile with flame resistance property. The 6 ratios of natural-rubber STR 20: zinc oxide: stearic acid: sulfur: mercaptobenzothiazole: diphenyl guanidine: EVA plastic: antimony trioxide were equal to 100: 5: 2: 3: 0.5: 0.2: 20: 0 100: 5: 2: 3: 0.5: 0.2: 20: 20 100: 5: 2: 3: 0.5: 0.2: 20: 40 100: 5: 2: 3: 0.5: 0.2: 20: 60 100: 5: 2: 3: 0.5: 0.2: 20: 80 and 100: 5: 2: 3: 0.5: 0.2: 20: 100 by weight or phr. The samples are ground by two-roll mill and formed by compression molding at 150 degree Celsius with 30x30x0.2 cm of dimension for 4: 29 to 5: 19 minutes. The properties of the natural-rubber floor tiles were tested under ASTM standard. From the results it was found that the natural rubber and ethylene vinyl acetate plastic floor tile with flame resistance property was the suitable ratio for using as the rubber floor tiles in building and extinguished a fire by themselves. The antimony trioxide effected to increase the density hardness and thermal conductivity and decrease the tensile strength tear strength and wear resistance properties of the natural rubber and EVA plastic floor tiles

Molds manufacturing to produce chloroprene rubber product with carbon steel over time the mold surface will wear. From the original. The practice in the industry often uses surface coatings (Hard chrome method) or change materials to create molds. Therefore this research is to study the effect of corrosion or wear. To see the size of surface mold changed in the experiment. Based on a tolerance of 0.1 millimeters at the molding point and after molding in the actual work conditions of a 2-3 weeks sample and mold size measurement. At less than 10 times the permissible coordinate value is 0.01 millimeters. The experiment found that. The wear of carbon steel molds was formed with chloroprene rubber. It has a very small value when referenced to the tolerance coordinates which is not significantly reduced when the rubber specimen size is determined. The allowance range is 10 μm to 100 μm. Therefore the design of chloroprene rubber to make molds with carbon steel. It can help reduce production costs. Without replacing with corrosion-resistant materials or adding coatings.

The objectives of this research are to propose an efficient and proper model that fits the cassava and rubber yields data. A generalized estimating equation (GEE) and a linear mixed model (LMM) with spatial correlation following the conditional autoregressive model (CAR) were adopted. The dependent variables are the cassava and rubber yields collected each month in every province of Thailand. The factors considered are rainfall averaged temperatures and regions. The results from GEE and LMM show that the factors influencing on the cassava and rubber yields are rainfall averaged temperature and region. Both GEE and LMM fit the correlated data. The GEE is used to explain the influence of factors on the yields in all provinces while the LMM is used to explain the influence of factors on the yields in each province.

This continued 2nd year researchaims to study the development of the para rubber press machine with wrought pattern for continued 2nd-year. Used natural para rubber mixed in a Ta-kuong by normally practical para rubber farmer style to evaluate the rubber press machine. A machine consists of the 11 roller sets in vertical pathway with press sticks on top. The components are as follows: a water press roller with a slope surface to reduce the diameter around 1-1.5 mm from a center the 3-pair sets of normal press rollers and the 2 duo sets of wrought pattern rubber press rollers with the induction motor at 1430 rpm. The rotating transmission based on belts and chains with a . The evaluated results produced the dried para rubber sheets thickness at 3.79 mm on average as the 2nd rubber sheet type standardin marketing need. From a top tray a farmer can put a sticky para rubber piece to a roller press machine easier than normal just 5.9 second on average with lower hand power to handler of the rubber pieces. In finally the wrought patternrubber sheets by a worker to carry the ta-kuong to a top tray of a rubber press machine and a rubber press man to put the para rubber pieces to a machine thus the completed 186 wrought rubber sheets per hour on average.