Thermoforming shrinkage prediction

Authors
Citation
Hh. Xu et Do. Kazmer, Thermoforming shrinkage prediction, POLYM ENG S, 41(9), 2001, pp. 1553-1563
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
POLYMER ENGINEERING AND SCIENCE
ISSN journal
0032-3888 → ACNP
Volume
41
Issue
9
Year of publication
2001
Pages
1553 - 1563
Database
ISI
SICI code
0032-3888(200109)41:9<1553:TSP>2.0.ZU;2-R
Abstract
Most thermoforming product development processes rely on costly and time-co nsuming forming trials to determine the adequacy of the mold and process. I n this paper, an analytical method is developed for shrinkage predictions o n the basis of a visco-elastic constitutive material model with initial con ditions from a commercial thermoforming simulation. The theoretical analysi s has been developed to accommodate different sets of materials, process co nditions, and mold geometry. The shrinkage model consists of a transient th ermal analysis for temperature solution; a stretching phase analysis for in flation-induced stress estimation; a post-contact analysis for thermal stre ss and relaxation; and a post-molding strain analysis based on stress solut ion. The shrinkage prediction analysis has been developed and validated wit h a complex geometry thermoforming application. The results indicate that t he shrinkage estimates provided by the analysis were within the objective t olerances of 0.1%, as measured in terms of absolute prediction error of par t dimensions.