Quality Improvement of NLFM Manufacturing Process: Estimating Optimal Combination of Influencing Factor Levels

Part 1: Knowledge-Based Performance ImprovementInternational audienceNatural latex foam mattresses (NLFMs) are manufactured using the latex extracted in its purest form of milky white liquid, which is tapped from the trunks of mature rubber trees. The natural latex foam mattress manufacturing (NLFMM) process undergoes several processing stages before the natural latex is converted into an ultra cushioning material with a wide range of firmness and comfort. Among the other processing steps, the gelling process has been found to play a significant role in controlling the quality of the final product, provided that quality raw materials have been supplied to the manufacturing plant. This manuscript suggests a methodology for estimating optimal levels of parameters that affect the gelling process, focusing on minimizing the influence on mattresses’ surface quality deterioration. A case study has been performed in collaboration with one of the natural latex foam manufacturing plants to recognize main quality deterioration mechanisms and corresponding process parameters using the engineering robust design approach to establish the optimal combination of influencing factor levels

Effect of the Phenological Stage in the Natural Rubber Latex Properties

Natural Rubber Latex (NRL) from Hevea brasiliensis is a material studied because of their industrial applications. For its natural origin, it is possible to find rubber particles, proteins, phospholipids and ashes. These non-rubber content are responsible for the latex colloidal stability. H. brasiliensis tree goes through four stages during the year, changing its nutritional requirements and as a result the rubber yield and stability. Most studies have correlated latex characteristics and yield with tree age and clonal origin but none of them with phenological stages. The impact of the phenological stage on the material properties has not been completely identified yet. In this work, the influence of the clonal origin and the phenological stage with the material properties is studied. Thermal behavior, microstructural analysis, morphological study, colloidal stability and rheology are analyzed for FX3864, IAN710 and AIN873 clones during 1 year. NRL is an amorphous material but during the high-yield period, a melting point is observed. Flowering is the stage when phospholipids, protein and isoelectric point are higher. Phenological stages do not affect the rubber, but the main changes are in the non-rubber content. © 2018, Springer Science+Business Media, LLC, part of Springer Nature