Factors Affecting Thickness of Prosthetic Socket in Thermoforming Fabrication

Abstract

Nowadays, there are two socket fabrication methods in Thailand, which are resin casting and thermal vacuum method. The thermal vacuum forming method has more advantages than the resin casting method that ruins technicians' health from the volatile matter. Nevertheless, the thermal vacuum forming method can fabricate the socket with poor wall thickness distribution. The purpose of this paper is to study the effects of the feed rate of stump mould and the temperature distribution of the plastic sheet on the prosthetic socket wall thickness during the thermal vacuum forming process. The feed rates of stump mould were varied by using an industrial robot. The temperature distribution of the plastic sheet was controlled by circular and annular fiberglass insulators placed in its center. The results showed that the prosthetic socket wall thickness increases around the central area of the socket with a decreased feed rate of stump mould. The annular insulator increases the wall thickness slightly, while the circular insulator increases the thickness significantly. The wall thickness at the thinnest location increased from 1.6 mm up to 2.8 mm. In addition, wall thicknesses of areas beneath the circular insulator increased significantly between the marked positions-25 through +25.

The use of utility function for optimization of thermoforming

“…Although this process is similar to other polymer processing me thods [17][18][19], it requires separate studies due to its specificity. Despite the fact that the origins of thermoforming go back to the 1870s and its practical aspects have been thoroughly examined, the process is still the subject of numerous research studies [20][21][22][23][24][25][26][27][28][29][30][31][32] and publications for manufacturers [33][34][35]. In this paper, a thermoforming process for producing polystyrene sheet by vacuum forming and vacuum assisted drape forming with and without pre-blow is investigated.…”

The Design of Total Knee Replacement Prosthesis Suitable for Anteroposterior Movement for Thai Female

“…Knee can be divided into two types of fixed bearing moveable particular stretch and bend with the wear of the polyethylene mobile bearing, but more stable than the mobile bearing a mobile extension-flexion and rotation around the vertical axis. There is less than the fixed bearing wear but may have problems with stability below knee [7].…”

The Effect of Process Parameters on Thickness Distribution in Thermoforming

“…In order to balance the wall thickness distribution in the bottom and sidewalls of the ther-moformed part, plug assist thermoforming may be a quick solution. Parameters such as plug geometry, plug temperature and plug material are very critical during the forming by changing wall thickness and friction between the sheet and mold [1,9]. During the forming process, firstly the plug touches the heated sheet surface.…”