The effect of heat and compression on the behavior of flask press springs.

In a previous study a method for calibrating the loud deli­ vered by flask /tress springs was described. This method did not allow for changes in the mechanical properties of the springs when exposed to boiling water and spring compres­ sion. The effect of 20-25 cycles o f heal exposure and spring compression associated with flask press usage for the curing of denture base resin on the mechanical characteristics of flask press springs was determined in 5 flask presses. The results indicate a mean increase of 7.35 per cent in the •loud delivered bv the flask presses. These findings suggest that strain age hardening o f the springs occurred. This factor needs to be considered in controlled studies on the awing of denture base resins. OPSOMMING ’n Vorige ondersoek het geliandel oor 'n metode waardenr die lading wat op ‘n drukflesveer uitgeoefen word gekalibreer kon word. Hierdie metode her egter nie voorsiening genuiak vir die moontlikheid dal blootstelling nan kookwater en samedrukking veranderings in die meganiese eienskappe van die vere kon veroorsaak nie. Vvfdrukflesse is gebruik out die uitwerking van ontbloling aan bine en veresamepersing op die meganiese eienskappe van die drukflesvere vas te stel. Hetrokke drukflesse is elkeen onderwerp aan 20-25 kunrsiklitsse. Die resullate toon it geiniddehle toename van 7.55 persent in die lading w ar dear die drukflesse gelewer word. Hierdie bevindings dot op verouderingsverharding wat as gevolg van vervorming van die vere plaasgevind liel. Hierdie fltklor belioort in aanmerking geneein te word by gekontrolleertle studies met betrekking tot die knur van kunsgebitharse.