High-precision testing and measurement systems

Further highlights are a high-precision, instrumented pendulum impact tester, on which Instron demonstrates Charpy notched bar impact tests, and an electromechanical test machine optimised for low forces, which will be running 3-point bending tests to ISO 178.

The new manual weight selection system available for Instron CEAST Melt Flow Testers is designed for single-weight measurements in accordance with ISO 1133 Methods A and B and ASTM D1238. It bridges the gap between completely manual handling of weights, and the fully automatic weight selection system present on CEAST MMF Multiweight Melt Index Testers, and is suitable for attachment to modular systems equipped with a motorised weight lifting system and encoder. Basic elements are a weight support for a complete set of test weights from 0.325 kg to 21.6 kg and an easy-touse mechanical system for preselecting the required test weight. All weights remain on the machine at all times.

Instron’s CEAST 9050 universal pendulum impact tester is designed for instrumented and non-instrumented impact testing. It consists of a high-stiffness, mono-lithic, cast-iron frame structure, which helps to minimise measuring errors and accommodates all attachments. The impact tester is shown in conjunction with the recently introduced DAS 64K data acquisition system, which provides four measurement channels and a storage capacity of 64.000 data points for high-resolution analysis of transient loading processes.

Three-point bending tests are made possible through the electromechanical tensile tester type Instron 5942. This machine is part of the Series 5940 family of single-column table-top testers which, due to their extremely small footprint require only a minimum of space in the test laboratory. Its stiff mechanical design ensures optimum repeatability of test conditions and reliable test result. With a nominal force capacity of 0.5 kN and 726 mm vertical daylight, the model 5942 is the smallest model in the series. Like the larger models in the series – the 5943 (1 kN, 1123 mm) and the 5944 (2 kN, 1123 mm) – it provides superior measuring accuracy in the lower force range. Consequently, typical applications include testing of biomaterials, textiles, elastomers, small components, plastic fibres and foils. The machine can be equipped with grips type 2810-400 for bend testing up to a maximum test force of 5 kN.

Measuring forces during mould movement
In the same exhibition, Kistler demonstrated a new strain transmitter for measuring forces during mould movement and clamping forces of high-speed injection moulding machines. This transmitter helps protect valuable injection moulds and sensitive automation equipment from damage. Both requirements are easily met by measuring the surface strain, for example on a toggle lever or on the back plate of the clamp unit. Extensions of machine structures are proportional to the applied forces but dependent on the structure’s rigidity, which means that the forces on the toggle are usually greater than those on the back plate.

State-of-the-art injection molding machines are equipped with both clamping force sensors and mould protection functionality. Mould protection during mould movement protects the mould from damage. This function enables machines to react quickly to foreign objects on the mould parting line, e.g. parts that have not been ejected. The clamping force is measured as soon as the two mould halves connect and is used for controlling the locking force. Typically, the forces applied during mould movement are smaller than the locking forces by a factor of between 20 and 40.

The new high-resolution, ultrasensitive, two-channel strain transmitter Type 4350A measures dynamic and static forcesNIKE AIR FORCE