Testing standard
Standard Test Method for Slow Rate Penetration Resistance of Flexible Barrier Films and Laminates
Written and technically reviewed by Dak System Inc. engineeringLast reviewed
ASTM F1306 measures slow-rate penetration resistance of flexible barrier films. A 3.2 mm hemispherical probe is driven at 25 mm/min through a 35 mm circle of clamped film until it perforates, and the whole force–travel curve is captured. The film draws down around the probe before it gives way, and reproducing that drawing behaviour is the point of the method.
A sheet of flexible film or laminate is clamped between two rings so that a circular area 35 mm across is left unsupported. A hemispherical probe, 3.2 mm in diameter as standard, is driven through the centre of that circle at 25 mm/min, normal to the film, until the film perforates. Force and probe travel are recorded from first contact to rupture, so the whole slow-push curve is captured rather than a single breaking figure. The film draws down around the probe before it gives way, and that drawing behaviour is what the method sets out to reproduce.
Three quantities come out of the curve: maximum force, probe travel to that point, and the energy absorbed, found by integrating force over penetration. Peak force alone ranks films badly. A stiff, highly oriented laminate can carry a high load and then fail almost without warning, while a softer structure carries less but draws further and absorbs far more energy before it opens — and in a filled pack it is usually energy that separates a structure surviving a bone or a sharp product corner from one that does not. Because the probe advances slowly, the figures describe a deliberate push and must not be read across to impact.
F = peak force at perforation, in newtons
d = probe travel from first contact to perforation, mm
How far the film drew down before giving way — the ductility half of the answer, and often the more discriminating of the two.
W = area under the force–travel curve
The quantity that separates a film which resists strongly then splits from one which yields early and keeps stretching. Two films can share a peak force and differ substantially here.
The nearest fixture family we list: a probe attachment advanced into a clamped specimen with force recorded. The probe form differs between methods, so the tooling is made to the geometry the method specifies.
SpecificationsNo force capacity is prescribed. The governing requirement is that puncture occurs between 20 % and 80 % of the load range in use, which for thin barrier films normally means a compression load cell reading in the tens to low hundreds of newtons. The frame rating is rarely the limit; the load cell is, and choosing it is the most consequential decision here.
Crosshead speed is fixed at 25 mm/min. Polymer films are strongly rate-sensitive, and the method deals with that by removing the variable rather than exploring it, so a test at another speed yields numbers nobody can compare with. Acquisition must give at least one point per 0.1 mm of penetration; anything coarser rounds off the peak and corrupts the energy integral. No extensometer is involved — penetration comes from crosshead travel, which is acceptable because the forces are low and load-train deflection with them, though a compliant adaptor still shows up as extra apparent travel.
The fixture is a ring clamp, pneumatic or mechanical, presenting the 35 mm test diameter with the probe driven through its centre. Other probe diameters are allowed provided the ratio of clamped diameter to probe diameter stays at least 10:1. That ratio keeps the deformation a membrane-stretching problem across the whole disc; drop below it and the probe shears the film locally instead — a different failure and a different number. Testing is in the conditioning atmosphere, not merely at room ambient.
Slip at the clamp is the commonest fault and the hardest to see. Film drawn in from outside the ring adds travel that never came from the test area, inflating penetration and energy while leaving a curve that looks plausible. Polished clamp faces, or clamp pressure set for a thicker structure, are the usual causes.
A probe that is not centred loads one side of the membrane first and punctures early; once alignment has drifted, the error is systematic rather than random. Probe wear is the same fault in slow motion — a hemisphere that has scratched or flattened stops stretching the film and starts cutting it, so results drift downwards over months without any single test looking wrong.
Load-range mismatch is endemic in shared laboratories: a cell sized for tensile work on the same frame puts a small puncture event down in its own noise and returns energy values that are largely integration error.
| ASTM F1306 slow | Impact puncture | ASTM D882 tensile | |
|---|---|---|---|
| Rate | 25 mm/min | Impact | 12.5 to 500 mm/min |
| Loading | A blunt probe, biaxial draw | A projectile | Uniaxial strip |
| Reports | Force, distance and energy | Energy | Strength, elongation, modulus |
| Represents | A blunt object pressed steadily | A dropped or thrown impact | Web tension |
Rate changes the answer, so a slow penetration figure and an impact puncture figure describe different hazards. A film that resists a slow probe well can still fail an impact test, and the packaging question decides which is relevant.
It is the ASTM test for slow-rate penetration resistance of flexible barrier films and laminates. A 3.2 mm hemispherical probe is driven at 25 mm/min through a 35 mm clamped circle of film until it perforates, and force and travel are recorded throughout so the whole curve is captured.
Because it reproduces a specific hazard: a blunt object pressed steadily against a package — a corner in transit, a component inside the pack, a stacked load. That is a different failure mechanism from an impact puncture, and film that resists one well can fail the other. Rate is not a convenience here, it is the definition.
Because two films can share a peak force and behave quite differently. One may resist strongly and then split abruptly; another may yield earlier and go on stretching for many more millimetres. The area under the curve captures that difference, and for packaging it is often the more meaningful figure.
So it stretches the film rather than cutting it. A sharp probe would measure the film's resistance to being cut, which is a different property with different governing factors. The blunt hemisphere forces the film to draw down around it, which is what a real blunt object does to a package.
Not in the way a tensile test is. The probe draws the film in every in-plane direction at once, so an oriented film's machine and transverse behaviour are combined into one result — much as in a burst test. That makes it a good whole-film measure and a poor substitute for a directional tensile test.
Because a package that has been punctured has failed completely, regardless of how strong its seals are. Medical device trays, pouches and IV bags meet sharp corners, connectors and the contents themselves during handling and shipping, and a slow steady push is a better model of that than an impact. For a sterile barrier, penetration resistance is a safety property rather than a quality one.
In rate, and therefore in what it exercises. F1306 pushes a blunt probe through the film at 25 mm/min, so the polymer has time to draw and orient, and the result reflects its ability to deform under a sustained load. A dart drop applies the load in milliseconds, where toughness is governed by different behaviour entirely. A film can perform well in one and poorly in the other.
Dak verifies against whichever standard the method names, and where a class applies our frames sit a class tighter than it asks.
| The method asks for | Dak supplies | |
|---|---|---|
| Capacity | No force capacity is prescribed. The method asks only that puncture occur between 20 % and 80 % of the load range in use, which for thin barrier films and laminates normally means a compression load cell in the tens to low hundreds of newtons rather than a large frame; the frame rating is almost never the limit, the load cell is. | Load cells from 1 kg to 60 ton on the Series 7200, and 0.5 to 100 kN on the Series 9000 |
| Gripping | Pneumatic or mechanical ring clamp with a driven hemispherical penetration probe | Our compression anvils, built to the specimen |
| Environment | 23 ± 2 °C and 50 ± 5 % RH; condition at least 40 h to Practice D618 Procedure A and test in the same atmosphere | 3009 series chambers, −150 °C to +400 °C — temperature only |
This page describes the method as practised. The governing text is the current edition from the issuing body. Tell us what you are testing and we will answer with the machine, the fixture and a quotation.
