Modelling of polymer seal strength: response surface methodology

Van Jaarsveld, Ivan (2018-03)

Thesis (MEng)--Stellenbosch University, 2018.

Thesis

ENGLISH ABSTRACT: The response surface methodology (RSM) approach was followed to construct a predictive model concerning the seal strength between film to gland fitments. The proposed method provides a replacement for the current trial and error approach followed by the industry partner. With the new approach, the manufacturer can tailor specific solutions to comply with changing requirements, allowing them to adapt in limited time to manufacture gland seals that comply with specific requirements. The final constructed model was able to account for 90% of the total observed variance of the training set, 3:6% of the 10% unaccounted variance was due to lack of fit, and 6:4% was due to the variability between replicates. Independent validation tests were conducted to verify the use of the model. The predicted optimum corresponded to a seal strength of 21:9MPa, and process variables of temperature = 320 °C, pressure = 4:4 bar and dwell time = 5:5 sec. The results obtained were within the constructed 95% confidence interval, and the mean approximated the true response. As a result, the model accounted for 89% of the observed variance of the validation set.

AFRIKAANSE OPSOMMING: Die reaksievlakmetodologie (RVM) benadering is gevolg om statistiese modelle te genereer met betrekking tot die seëlsterkte tussen film en plastiese klierpassings. Die prosedures gevolg in hierdie projek word voorgestel aan die bedryfs vennoot om hul huidige benadering te vervang. Met die nuwe benadering kan die vervaardiger spesifieke oplossings vind wat voldoen aan vereistes wat moontlik kan verander. Dit sal hul toelaat om in ’n beperkte tydperk te reageer en voldoende seëls te vervaardig. Die finale model kon 90% van die totale variasie verklaar; 3:6% van die ongedefinieerde 10% was die gevolg van modelpassing en 6:4% was as gevolg van die geraas tussen opeenvolgende toetse. Die model het voorgestel dat die proses optimum ’n seëlsterkte van 21; 9MPa sal hê vir die vervaardigingsveranderlikes van temperatuur = 320 °C, druk =4:4 bar en verwerkingstyd = 5:5 sek. Onafhanklike validiteitstoetse is uitgevoer om die gebruik van die model te verifieer. Die resultate was binne die 95% sekerheidsinterval, en die gemiddelde hiervan het die ware reaksie weerspieël. Die model het dus 89% van die totale variasie van die onafhanklike validiteitstoetse verklaar.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/103796
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