Modeling and Analysis of the Effect of Dip-Spin Coating Process Parameters on Coating Thickness Using Factorial Design Method

Statistical modeling of the dip-spin coating process to describe colloidal PTFE dispersion coating on the external surface of a small diameter hollow tube was developed by using 24 factorial design with a center point to predict the coating thickness in a range of 4–10 μm. The coating parameters included viscosity, withdrawal rate, spin speed, and immersion time. The adequacy of the predicted model was verified by coefficients of determination and lack-of-fit test. Model accuracy was verified by comparing predicted values with experimental results. The significant interaction effects on the coating thickness were three-way interaction among withdrawal rate, spin speed, and immersion time and two-way interactions between viscosity and withdrawal rate, viscosity and spin speed, and viscosity and immersion time. Cube plot for coating thickness reveals a trend of increasing coating thickness towards high levels of viscosity, withdrawal rate, and immersion time and lower level of spin speed

Influence of Soda Pulping Variables on Properties of Pineapple ( Ananas comosus

Face-centered composite design (FCC) was used to study the effect of pulping variables: soda concentration (4-5 wt%), temperature (90–130°C), and pulping time (20–60 min) on the properties of pineapple leaf pulp and paper employing soda pulping. Studied pulp responses were screened yield and lignin content (kappa number). Paper properties, which include tensile index, burst index, and tear index, were also investigated. Effects of the pulping variables on the properties were statistically analyzed using Minitab 16. The optimum conditions to obtain the maximum tensile index were soda concentration of 4 wt%, pulping temperature of 105°C, and pulping time of 20 min. The predicted optimum conditions provided tensile index, burst index, tear index, screened yield, and kappa number of 44.13 kN·m/kg, 1.76 kPa·m2, 1.68 N·m2/kg, 21.29 wt%, and 28.12, respectively, and were experimentally confirmed

Energy saving in sintering of porcelain stoneware tile manufacturing by using recycled glass and pottery stone as substitute materials

Commercial porcelain stoneware tiles are vitrified tiles (noted as C) that are composed of clay, feldspar, and quartz. They require high temperature sintering at 1230 °C that result in high energy costs. This study aimed to compare the energy consumption during sintering process of the porcelain stoneware tiles, which recycled glass and pottery stone were used in substitution of clay, feldspar, and quartz (noted as N). The sintering temperatures of the commercial (C) and the substituted (N) tiles were, respectively, at 1230 °C and 1050 °C. The physical, mechanical, and chemical properties of the N tiles were compared with those of the C tiles. As a result, the N tiles showed good properties according to several standards, such as water absorption of less than 0.1% (ISO 10545-3), linear shrinkage of less than 10% (ASTM C326), modulus of rupture of more than 40 N/mm2 (ISO 10545-4), and good resistance of chemicals (ISO 10545-13). The N tiles were in compliance with the ISO 13006:2012 (group BIa) Standard. In the sintering process, the energy consumption and CO2 emission of the N tiles were, respectively, 9191.24 kJ/kgProduct and 0.0782 kg CO2eq/kgProduct, while those of the C tiles were, respectively, 13304.84 kJ/kgProduct and 0.1132 kg CO2eq/kgProduct