Izod Impact Tester for Plastics

What is the Izod Impact Tester for Plastics?

An Izod impact tester breaks a notched specimen held as a vertical cantilever and reports the energy absorbed per unit of width. It is the impact method most often quoted in thermoplastic resin and moulding material specifications.

Overview

The specimen is clamped upright in a vice, notched on the side facing the hammer, and struck by a pendulum released from a defined height. Energy absorbed is derived from the difference between the release angle and the maximum follow-through angle, or measured directly with an angular encoder, and is divided by the specimen thickness to give impact strength. Standard specimen dimensions are 63.5 × 12.7 mm with a thickness of 3.2 mm for the common ASTM geometry, with metric equivalents in ISO 180, and several hammers of different energy are available so that the reading stays in the sensitive part of the scale. Accessories include a motorised notch cutter, a notch depth gauge, and a low-temperature conditioning bath for brittleness testing, together with a specimen alignment jig for repeatable clamping.

How does it work?

Impact tests apply a defined energy in a very short time, so the material responds in a brittle or semi-brittle manner that differs from slow tensile behaviour. Pendulum instruments release a weighted hammer from a fixed angle; the hammer strikes a supported or cantilevered specimen and the energy absorbed is calculated from the difference between release and follow-through angles, or measured directly by an encoder. Instrumented hammers add a strain-gauge striker that records force against time, so crack initiation and propagation energies can be separated. Drop weight and dart methods use a falling mass: a dart striking a clamped film gives the energy for 50% failure, while a tup striking a pipe section assesses resistance to external damage. Specimen geometry, notch radius, support span and conditioning temperature all control the result.

What are the key features?

• Interchangeable hammers from 1 J to 22 J
• Angular encoder for direct energy reading
• Pneumatic or manual specimen clamping
• Motorised notch cutter and depth gauge
• Low-temperature conditioning bath option
• Automatic result calculation per unit width

What are the technical specifications?

A typical izod impact tester for plastics configuration offers hammer energies of 1 / 2.75 / 5.5 / 11 / 22 J, impact velocity of 3.5 m/s (ASTM D256), energy resolution of 0.01 J, release angle of About 150°, specimen size of 63.5 × 12.7 × 3.2 mm typical and notch types of Type A 0.25 mm radius, others per ISO 180. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Izod Impact Tester for Plastics is used in resin specification testing for rigid moulding grades, impact quality control of polyamide and polycarbonate, low-temperature brittleness assessment and comparison of impact-modified formulations. Across the wider Impact Analysis class, laboratories also deploy it for impact strength qualification of moulding grades, notch sensitivity comparison between formulations and low-temperature toughness testing.

Which standards and certifications apply?

Relevant standards and methods include ISO 179-1, ISO 180, ISO 6603-2, ISO 8256, ASTM D256, ASTM D6110, ASTM D1709, ASTM D2444 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Cut specimens with the notch in the specified orientation, because anisotropy from moulding flow changes the result substantially; use a motorised notch cutter and verify the notch radius with a profile gauge. Condition specimens at 23 °C and 50% relative humidity, or in a bath at the test temperature when low-temperature toughness is measured, and transfer them to the machine quickly. Verify the pendulum by releasing it without a specimen, confirm that friction losses stay within the standard limit, and check the blade and supports for wear or damage. Report the specimen type, notch geometry, hammer energy and observed failure mode together with the numerical result.

How do I select the right Izod Impact Tester for Plastics?

Select an Izod tester when your material specification cites Izod impact strength, which is usual for North American resin data sheets. Confirm the hammer set covers the energy range of your materials, and order the notch cutter and a low-temperature bath if brittle-failure performance matters. Ask for the friction-loss verification procedure and the alignment jig, because clamping position strongly affects results.

How does it compare with other Impact Analysis variants?

Select the method named in your material or product specification, because results are not interchangeable between geometries. Izod suits rigid moulding materials and is common in resin specifications, while Charpy is preferred for plate, sheet and weld evaluation and is more widely used in Europe. Instrumented hammers are chosen when the failure mode itself must be studied rather than only the absorbed energy. Falling dart testing applies to films and thin sheets where a pendulum cannot hold the specimen, and falling weight testing applies to pipes, fittings and thick sections. For any of these, specify the energy range, specimen conditioning options, notch-cutting equipment and whether low-temperature conditioning is required.