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Quasi static mechanical tests

Owner: Xiaojie Zhou

Principle:

The test specimen is extended along its major longitudinal axis at a constant speed until the specimen fractures or until the stress (load) or the strain (elongation) reaches some predetermined value. During this procedure, the load sustained by the specimen and the elongation are measured.

Capabilities:

Tensile tests (ISO 527 and ASTM D-638)

Flexural tests(ISO 178 and ASTM D790)

Asset:

Instron 5567

30 kN testing machine.

Environmental chamber could be applied for high-low temperature (-70-350°C) tensile (not available for flexural) tests.



Instron AT3

30kN Load Cell

 

Variable Pressure Hydraulic Control Unit

 

Axial Extensometer

 

Equipped with automation system(80 bars)

Impact tests

Owner: Xiaojie Zhou

Principle:

The pendulum is raised to a measured point, and it is then released. The weighted end of the pendulum gains speed as it swings toward a mounted molded bar of the test plastic. It strikes the bar, breaks it, and the pendulum loses energy while breaking the plastic bar. Therefore it does not swing as high. The energy lost by the pendulum is equated with the energy absorbed by the test specimen during the breaking process.

Capabilities:

Charpy, Unnotched and notched specimens. ISO 179

Izod, Unnotched and notched specimens. ISO 180

Asset:

Ceast resil impactor

Pendulum impact tests.

It is equipped with ISO hammers Charpy 4J and Izod 1J, 2.75J, 11J and 44J.


Tinius Olsen 899


Remaining Width (mm)

ISO：8.0±0.2

ASTM：10.16±0.05

Environmental Stress Cracking resistance

Owner: Tingting Zhang

Principle:

Immersion of test specimens in fluids under controlled stress or strain.

The simultaneous action of the chemical and of the stress on the specimen can lead to stress cracking phenomena, hardly predictable by the simple immersion without stress.

Capabilities:

Test at constant tensile load according to ISO 22088-2

Bent strip method according to ISO 22088-3

U-bending method based on ASTM D1693

Asset:

ESCR

Bending bars with different curvature radii

Test at constant strain, even at high temperature


Memmert HCP 50

Humidity Control: 20 – 95 % rh

temperature range: +18 to +90 °C


Accelerated weathering tester

QUV/SE

Simulate outdoor accelerated aging conditions of materials, including UV radiation intensity, temperature and humidity effects, etc.

Heat Deflection Temperature（HDT） tests

Owner: Xiaojie Zhou

Principle:

The tests most commonly used by the plastics industry to measure short-term thermal capability are ASTM D648, Standard Test Method for Deflection Temperature of Plastics Under Flexural Load and ISO 75, Plastics –Determination of Temperature of Deflection Under Load. These tests are commonly referred to as Heat Distortion Temperature (HDT) or Deflection Temperature under Load (DTUL).

Both tests are similar in that the test specimen is supported at two points while a load is applied to the center. The temperature is increased at a constant rate until the specimen deflects a specified amount as indicated by a dial micrometer.

HDT can only be used as a general indicator of short-term thermal capability. It is useful for comparing similar materials but can be misleading if, for example, an amorphous material is compared to a semi-crystalline material. It doesn’t provide any information about long term thermal stability.

The actual loads and performance requirements will dictate the suitability of the material. Many semi-crystalline resins can be used in applications that experience temperatures higher than their deflection temperature value.

Capabilities:

HDT

VICAT

Asset:

Instron HV6M HDT VICAT Testers

ASTM D648/ ISO 75-2

 

The most common and critical error is to compare the results from testing performed at 1.8 Mpa (264 psi) with results obtained from testing at 0.45 Mpa (66 psi).

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