Overview

主要用于 measuring the thermal deformation temperature and Vicat softening point temperature of non-metallic materials such as plastics, hard rubbers, nylon, electrical insulating materials, long fiber reinforced composites, and high-strength thermosetting laminates. User-friendly and accurate control, it is an intelligent testing instrument widely used in colleges and universities, scientific research institutions, and product quality supervision and inspection units.

This machine features a Chinese operating interface compatible with Windows 98, Windows 2000, or Windows 7, enabling real-time monitoring of test temperature and plotting curves of temperature and deformation. It can print test reports and save historical data. Clicking on any point on the deformation and temperature curves with the mouse automatically displays the deformation amount and temperature value at that point. It is equipped with an automatic lifting and lowering system for the testing machine and uses a high-precision displacement sensor to measure deformation.

Working Principle

VST Calibration Instrument: Place the sample in a liquid medium or heating chamber and measure the temperature at which a standard pressure needle, exerting a force of (50+1) N, penetrates 1mm into the sample cut from a pipe or fitting under isothermal heating conditions.

Hot Deformation Transformation (HDT) Definition: Standard specimens are subjected to a three-point bending constant load in a flat (preferred) or vertical side position, causing one of the bending stresses specified in the relevant sections of GB/T 1634. The temperature is measured when the standard deflection corresponding to the specified bending strain increment is reached under uniform heating conditions.

Side-standing: Divided into "flat placement" and "side-standing" options, it is explicitly stated that flat placement is the preferred method, with side-standing being an alternative that will be phased out.

Span: The distance between the two contact lines of the bracket and the specimen, changed from one (100mm) to two types: 64mm (flat) and 100mm (side-standing), with tolerance requirements specified, i.e., the span L should be (100+1)mm, and the span L should be (64+1)mm.

Note: Any spacing can be customized to the user's requirement.

Three Methods for Load-Deformation Temperature

Method A: 1.80 MPa bending stress

Method B: 0.45 MPa bending stress

C Method: 8.00 MPa bending stress