Process variable

About: Process variable is a research topic. Over the lifetime, 3983 publications have been published within this topic receiving 43130 citations. The topic is also known as: process parameter.

An experimental investigation of the surface roughness of parts produced by LOM process

Abstract: Purpose – To investigate the influence of different process parameters of the laminated object manufacturing (LOM) process on the roughness of vertical surfaces along Z‐axis on ZX‐plane of parts produced by LOM.Design/methodology/approach – The process parameters tested were layer thickness, heater temperature, platform retract, heater speed, laser speed, feeder speed and platform speed. A typical test part has been used, and matrix experiments were carried out based on Taguchi design. Optimal process parameter values were identified and finally, a regression model was applied onto the experimental results, and compared with bibliography models, using arbitrary experiments.Findings – The statistical analysis of the experimental results showed that the surface roughness depends mainly on the heater temperature, layer thickness, and laser speed. Moreover, the regression model gave good predictions when heater temperature values were within the initial experimental area and inaccurate predictions when heater...

A study on extruded filament bonding in fused filament fabrication

Abstract: The performance of parts produced by fused filament fabrication is directly related to the printing conditions and to the rheological phenomena inherent to the process, specifically the bonding between adjacent extruded paths/raster. This paper aims to study the influence of a set of printing conditions and parameters, namely, envelope temperature, extrusion temperature, forced cooling and extrusion rate, on the parts performance.,The influence of these parameters is evaluated by printing a set of test specimens that are morphologically characterized and mechanically tested. At the morphological level, the external dimensions and the voids content of the printed specimens are evaluated. The bonding quality between adjacent extruded paths is assessed through the mechanical performance of test specimens, subjected to tensile loads. These specimens are printed with all raster oriented at 90o relative to the tensile axis.,The best performance, resulting from a compromise between surface quality, dimensional accuracy and mechanical performance, is achieved with a heated printing environment and with no use of forced cooling. In addition, for all the conditions tested, the highest dimensional accuracy is achieved in dimensions defined in the printing plane.,This work provides a relevant result as the majority of the current printers comes without enclosure or misses the heating and envelope temperature control systems, which proved to be one of the most influential process parameter.

Univariate method for monitoring and analysis of multivariate data

Abstract: A method and system of monitoring multivariate process data in a process plant, where the multivariate process data comprises a plurality of process variables each having a plurality of observations, includes defining each process variable as a process variable vector comprising a set of observation components, where the set of observation components comprises time dependent process data corresponding to the observations of the process variable, calculating a multivariable transformation as a function of a plurality of process variable vector transformations each corresponding to one of the process variables, where each process variable vector transformation is a function of a univariate variable unifying the process variables, and representing the operation of the process based on the multivariable transformation, where the representation of the operation of the process designates a multivariate projection of the process data by the univariate variable for each of the process variables.