PET Film Puncture Resistance Technical Data

The Test Question This Record Is Designed to Answer

This record covers uncoated PET/BOPET, surface-treated film, hard-coated PET, adhesive-coated protective film, and selected laminates under localized probe or impact loading. It supports grade comparison and investigation of perforation, whitening, cracking, or layer separation.

It excludes product ranges, roll formats, and guaranteed minimums. Slow-rate penetration, dart impact, tensile, tear, scratch, and peel tests are not interchangeable; compare results only under matched methods, specimens, equipment, and acceptance criteria.

A Specimen Map Before Any Number Is Reported

A usable report begins with the tested construction. Record PET grade, base-film and total thickness, adhesive, primer or hard coat, liner, relevant optical condition, MD/TD orientation, and the probe-facing side. Check these details against the available PET and PE film materials before specimens are cut.

Assess the effect of film thickness within the same grade and method. Added adhesive or coating gauge does not imply proportional toughness, and opposite test faces may produce different failure patterns.

Main Technical Data Sheet

Item	Typical Value / Reference Range	Test Method or Condition	Notes
Film construction	Actual tested PET/BOPET structure	Material and layer identification	State single-layer, coated, adhesive-backed, or laminated construction.
Base-film thickness	Project-confirmed measured value	Calibrated film-thickness gauge	Measure the PET base film separately from adhesive, primer, or hard coat.
Total thickness	Project-confirmed measured value	Calibrated thickness gauge	Report the complete tested construction and thickness tolerance.
Probe-facing side	PET face, coated face, or adhesive face	Specimen-side identification before testing	The entry face may change crack initiation, whitening, or delamination.
Specimen conditioning	Recorded project condition	Agreed temperature, humidity, and conditioning period	Condition and test specimens from the same lot under matched conditions.
Peak puncture force	Project-confirmed value, N	Controlled slow-rate or agreed penetration test	Do not compare with falling-dart mass or an unmatched probe setup.
Probe penetration to failure	Project-confirmed value, mm	Displacement recorded in the same puncture test	Shows how far the specimen deforms before perforation.
Puncture energy	Project-confirmed value, mJ or J	Area under the force-displacement response	Compare only when method, units, speed, and specimen geometry match.
Tensile strength and elongation	Based on tested grade	ASTM D882 or equivalent	Supporting properties; they are not substitutes for local penetration data.
Haze and light transmittance	Project-confirmed when optical appearance matters	ASTM D1003 or equivalent	Useful when stress whitening, microcracking, or clarity change is unacceptable.
Peel adhesion	Project-confirmed on the actual substrate	ASTM D3330, FINAT FTM 1, or agreed internal method	State substrate, dwell time, peel angle, speed, and tested side.
Failure mode	Observed on the tested specimen	Visual and photographic inspection	Record clean perforation, radial cracking, brittle split, whitening, or layer separation.
Storage history	Actual lot and packaging record	Recorded before conditioning and testing	Include sunlight, humidity, storage time, transport pressure, and package damage.

Deciding Between Slow Penetration and Impact

Select the method from the loading event. Slow-rate penetration suits gradual probe or edge contact; instrumented impact suits rapid strikes. Falling-dart mass is useful only when specified and is not equivalent to puncture force or energy.

Test Methods and Conditions

Test Item	What It Checks	Suggested Method or Reference	Why It Matters	When To Request It
Slow-rate puncture	Gradual probe penetration, force, displacement, energy, and failure pattern	ASTM F1306 or an agreed equivalent setup	Provides a controlled comparison of flexible PET and laminated specimens.	Grade, thickness, coating, or laminate comparison; sharp-edge screening.
Instrumented impact puncture	Load and deformation during rapid penetration	ASTM D7192 or ISO 7765-2 when applicable	PET may respond differently when loading rate increases.	Drop, rapid tooling contact, handling impact, or equipment strike risk.
Falling-dart impact	Impact failure mass under the specified dart condition	ASTM D1709 when explicitly required	The output is not a slow puncture force value.	Existing packaging or internal specifications written around falling-dart data.
Tensile behavior	Uniaxial tensile strength, elongation, and directionality	ASTM D882 or equivalent	Helps interpret stiffness and orientation but does not predict local penetration alone.	New PET grade, heat-treatment, or MD/TD comparison.
Peel and dwell behavior	Time-dependent adhesion, lifting, removal-force change, and surface interaction	ASTM D3330, FINAT FTM 1, plus controlled dwell checks	A puncture-resistant base film can still fail through unsuitable adhesion or surface interaction.	Each new adhesive construction, surface, coating condition, or dwell period.
Optical change	Haze, transmission, whitening, or visible surface disturbance	ASTM D1003 plus controlled visual inspection	Mechanical damage may be unacceptable before complete perforation occurs.	Display, decorative, high-gloss, and optically clear surfaces.
Failure documentation	Crack path, delamination, adhesive exposure, clamp slip, and entry-side effects	Photographic record and agreed internal inspection method	The same peak value can represent different damage mechanisms.	Failure investigation, lot comparison, or project qualification.

Read the Curve Before the Peak Value

Peak force is the highest load, penetration is movement before failure, and puncture energy is the work recorded through that movement. A high peak with an abrupt drop may indicate brittle failure, while a lower peak with greater displacement may indicate more deformation before perforation.

Review the PET film force-displacement curve with the specimen image and failure record. For a hard-coated PET film, the tested side is especially important because the hard coat may initiate whitening, radial cracking, or coating separation before the PET base film fully penetrates.

The First Layer to Fail Changes the Meaning

The first failure may occur in the hard coat, primer, adhesive interface, or laminate before the PET base film perforates. Record crack direction and stress whitening; reject results affected by clamp slip, edge tearing, or probe misalignment.

Surface-Coupled Validation

Actual support changes local stress. Glass and polished metal provide relatively uniform backing; painted or coated surfaces add cure and removal concerns; rough surfaces reduce adhesive contact; low-energy plastics may promote edge lifting. Precision converting should compare puncture findings with electronics PET film structures.

For stamped edges, burrs, concentrated loads, cargo shape, or transport movement, follow laboratory results with trials using the intended metal surface protective film. A rounded probe may not reproduce a sharp burr, long transport, or repeated vibration.

The 24 h – 72 h – 7 Days Evidence Trail

Apply a representative sample to the cleaned target surface using the intended equipment, pressure, and operator method. Reproduce the relevant substrate, coating, environment, load geometry, and removal conditions.

At 24 h, inspect wet-out, bubbles, early edge lifting, and distortion. At 72 h, record adhesive trace, shadow, gloss change, coating interaction, crack growth, and peel-force shift. At 7 days, check longer-dwell residue, film tearing, separation, and delayed changes.

Report observations only for the tested sample. Final acceptance should follow the actual substrate, dwell period, storage history, and observed result.

Common Data Mismatch and Failure Risk

Data Point	If Too Low	If Too High	Risk in Application	Check Before Full Use
Base-film thickness	Early penetration or limited section at a local pressure point	Reduced conformability around details	Tear-through, bridging, processing difficulty, or edge lifting	Confirm measured base-film and total thickness, including tolerance.
Peak puncture force	Early local failure under the matched test	May reflect stiffness followed by abrupt splitting	Unexpected perforation or misleading grade comparison	Review the full curve, displacement, and failure image.
Penetration at failure	Brittle crack with little deformation	Excessive stretching before rupture	Sudden splitting, sagging, contact with the protected part, or whitening	Reproduce actual clearance, support, and edge geometry.
Puncture energy	Limited ability to absorb work before failure	May be irrelevant if produced by another method or unit	Invalid ranking between grades, laboratories, or loading rates	Match method, probe, speed, clamp, specimen size, and unit.
Peel adhesion	Edge lifting, movement, or incomplete contact	Difficult removal, film tearing, or coating interaction	Loss of coverage, adhesive trace, surface shadow, or gloss change	Complete 24 h, 72 h, and 7 days checks on the actual substrate.
Surface treatment or adhesive anchorage	Coating or adhesive may detach from the PET	A stiff treated face may crack before the base film	Delamination, whitening, adhesive exposure, or residue observation	Test the intended face and inspect each layer after failure.
Probe geometry and test speed	Sharper contact or slower loading may change crack initiation	Broader contact or faster loading may shift deformation behavior	Results may not represent the actual burr, tool, or impact event	Record probe radius, shape, loading rate, entry side, and equipment setting.
Storage condition	Material may be tested before adequate conditioning	Long heat, humidity, sunlight, or roll pressure exposure can alter the sample	Changed flatness, stiffness, adhesion, optical appearance, or removal behavior	Record storage time, transport distance, package condition, and lot history.

Storage History Belongs in the Test Result

Keep rolls in intact original packaging indoors, away from sunlight, heat, humidity, dust, and solvent vapor. Avoid crushed cores, unsupported stacking, concentrated pressure, and damaged wrapping. Record transport and packaging condition because they can affect flatness, stiffness, adhesion, liner release, and appearance.

Condition stored material and retain lot identity. Specimen cutting, side identification, precision slitting, and traceability should follow documented film converting and quality-control capabilities. Treat results with unknown storage history as incomplete.

FAQ

How should PET film puncture resistance values be compared?

Match method, probe, loading rate, clamp, specimen geometry, thickness, conditioning, tested side, and unit. Compare the curve and failure pattern, not only the peak.

What is the difference between a typical value and a guaranteed value?

A typical value represents tested material under stated conditions. A guaranteed limit requires an agreed method, sampling plan, tolerance, and acceptance criterion.

Can tensile strength or elongation replace a puncture test?

No. Tensile properties measure uniaxial loading; puncture creates concentrated, often biaxial deformation. Tensile data support interpretation but cannot replace penetration testing.

Why are 24 h, 72 h, and 7 days peel checks needed?

These checks reveal time-dependent wet-out, edge lifting, peel-force changes, adhesive trace, shadow, gloss change, and coating interaction. An immediate peel cannot show longer-dwell effects.

Can storage conditions change the reported result?

Yes. Heat, humidity, sunlight, roll pressure, transport, and package damage can change flatness, stiffness, adhesion, or appearance. Record the storage history before comparison.