Transformation algorithms for image preparation in spiral growth manufacturing (SGM)

摘要

Purpose - The purpose of this paper is to report on software development in which mathematical algorithms apply geometric transformations to digitised images in preparation for layer manufacturing by printing a binder onto a rotating powder substrate. Design/methodology/approach - Spiral growth manufacturing (SGM) is a high-speed rapid manufacturing technique in which objects are built up, layer by layer, by simultaneously depositing, levelling and selectively consolidating thin powder layers onto a rotating build platform. Consolidation occurs by infiltrating the powder layer with a binding agent deposited in droplet form using inkjet technology. During each rotation, the build platform falls away from a stationary doctor blade and print head assembly. This gives a continuous spiraled layer of powder with a constant layer pitch. To faithfully print digitised images onto a rotating substrate, polar and linear transformations have to be applied. Findings - In support of this work, dimensional accuracy measurements of transformed printed images are reported and the measured results were found to be within ±0.2 mm of their predicted size. The experimental work is briefly extended to the printing of transformed images, using an aqueous binder, onto plaster powder to demonstrate the build speed capabilities of SGM. Primitive multiple layer parts built at speeds of 10 layers/min are reported. Practical implications - From a practical standpoint, SGM has the potential to increase build speed by an order of magnitude over existing commercial rapid prototyping/manufacturing systems. Originality/value - There is no commercial system available that allows high-speed simultaneous deposition and processing of powder material and so this method could have implications in large batch manufacture.