ISO 6603-2 Instrumented Puncture Impact Testing of Rigid Plastics

What the test does

A striker is driven through a flat plastic plate while force and deflection are recorded throughout the event. The plate is clamped or supported around its edge, the striker hits the centre, and what comes back is not a single number but a curve — force against deflection, or force against time, captured at nominal constant striker velocity.

That instrumentation is the whole difference between the two parts. Part 1 answers whether the plate survived; Part 2 records what happened on the way, which is what separates a brittle failure from a ductile one at the same total energy.

The impact is normally delivered from a 1 metre drop height, corresponding to a striker velocity of 4.43 m/s. Specimens are flat and between 1 mm and 4 mm thick.

Scope is broad: rigid thermoplastic moulding and extrusion materials, filled, unfilled and reinforced compounds and sheets; rigid thermosetting compounds, sheets and laminates; and fibre-reinforced composites.

What it measures, and why it matters

Puncture is multiaxial. A tensile bar loads one axis and a notched bar concentrates everything at the notch; a plate struck centrally is stretched in every in-plane direction at once — much closer to something hitting a housing, a trim panel or a pipe wall.

The force-deflection curve is where the value is. Peak force tells you how much load the plate took. The area under the curve is the energy it absorbed. The shape between them tells you how it failed: a curve that rises and drops sharply is a brittle plate that shattered; one that rises, plateaus and tails off is a ductile plate that stretched and tore. Two materials can absorb identical total energy and behave completely differently in service, and only the curve separates them.

This matters most where a material has been modified. Impact modifiers, filler loading and glass content all shift the balance between peak force and ductility, and a single energy figure hides the trade. So does temperature: a plate ductile at 23 °C can be brittle at −30 °C.

For a design engineer it gives strength, ductility, toughness and energy absorption in one measurement, on a geometry resembling a real part rather than a coupon.

Specimen

Flat plates, and the thickness limits are a real constraint rather than a convention.

Thickness

1 mm to 4 mmBelow 1 mm the plate behaves as a membrane; above 4 mm the striker geometry stops being appropriate.

Form

Flat plates, moulded or cut from sheetClamped or supported around the edge, struck centrally.

Materials

Rigid thermoplastics, rigid thermosets, fibre-reinforced compositesFilled, unfilled and reinforced compounds and sheets; thermoset laminates; various reinforcement types.

Measure the thickness

On the specimen, not from the toolDakPuncture results scale strongly with thickness, so a nominal 3 mm plate that moulded at 2.7 mm reads low for a reason nothing on the curve reveals.

Test speed

The striker velocity is nominally constant through the event, which is the assumption the force-deflection curve rests on.

Impact velocity

4.43 m/sFrom a 1 m drop height in the usual falling-weight arrangement.

Drop height

1 mHeight and mass together have to deliver the velocity and enough energy that the striker is not appreciably slowed by the specimen.

Velocity constancy

Nominally constant through the eventIf the specimen slows the striker materially, the constant-velocity assumption behind the curve stops holding and the curve stops meaning what it appears to.

Sampling

Fast enough to resolve a few millisecondsDakThe whole failure is over in milliseconds. A system that reports only total energy is a Part 1 instrument.

What the machine must be capable of

An instrumented falling-weight or servo-hydraulic impact system with force measured at the striker and deflection recorded through the event, at a sampling rate fast enough to resolve a failure that is over in a few milliseconds. A system that reports only total energy is a Part 1 instrument.

Drop height and mass have to give the specified velocity — 1 m and 4.43 m/s in the usual arrangement — and the striker must retain enough energy through the event that it is not slowed appreciably by the specimen, or the constant-velocity assumption behind the curve stops holding.

Low-temperature work needs a conditioning chamber and the discipline to test quickly after removal. A plate warms fast, and a specimen tested a minute late is not at the temperature on the report.

How the test runs

1. 01Measure the actual plate thickness.
2. 02Condition to the test temperature; for low-temperature work, test promptly after removal.
3. 03Clamp or support the plate around its edge.
4. 04Release the striker to give a nominally constant 4.43 m/s at contact.
5. 05Record force and deflection through the event at a sampling rate that resolves milliseconds.
6. 06Read peak force, the energy as area under the curve, and the shape between them.

What travels with an ISO 6603-2 result

The curve is the result. An energy figure alone throws away what the instrumentation was for.

• The force-deflection or force-time curve, not only the total energy.
• Measured plate thickness.
• Test temperature, and how long after conditioning the plate was struck.
• Striker velocity and drop height.
• Whether failure was brittle or ductile — the shape of the curve, stated.

What goes wrong in practice

Quoting energy without the curve is the commonest, and it is the one thing the instrumented method exists to prevent.

Assuming nominal thickness is the second, and it biases every result on the batch.

Testing too slowly after conditioning is the third, and it moves ductile-brittle results in the direction that flatters the material.

Finally, comparing a Part 2 result with a Part 1 one. They are different tests answering different questions, and only one of them produces a curve.

Related and equivalent standards

ISO 6603-1 is the non-instrumented companion. ISO 7765-2 is the equivalent instrumented method for films and sheeting rather than rigid plates, and ASTM D3763 is the ASTM counterpart, run at the same 4.43 m/s from a 1 m drop. ASTM D7136 uses a drop-weight impact for a different purpose again — to create controlled damage in a composite before a residual-strength test.