PET Film Density kg/m3 Technical Data Sheet

What the 1390 kg/m3 Reference Represents

A typical density of 1.39 g/cm3 equals 1390 kg/m3 for common clear, uncoated BOPET base film. The reference range of approximately 1380-1400 kg/m3 applies only when grade and test condition are known. Modified or multilayer films require confirmed data.

Match the density value to the material condition.

Use this reference for common industrial BOPET base-film grades; confirm modified structures separately.

State whether the calculation covers PET film only or the complete construction.

Layer-by-Layer Mass Contribution in Protective Film

A protective film may include a PET carrier, pressure-sensitive adhesive, functional coating, and release liner. The density reference applies only to the carrier. Add adhesive, coating, liner, core, and packaging according to the agreed calculation boundary.

Finished construction GSM = PET base-film GSM + adhesive coat weight + other layers + liner GSM

Separate the layers before calculating finished-roll weight.

A practical PET adhesive film structure shows why carrier density, coat weight, and liner mass require separate review.

Check the completed structure by measured thickness, actual GSM, and net roll weight.

Density and Construction Data Matrix

Item	Typical Value / Reference Range	Test Method or Condition	Notes
PET base-film density	Approx. 1390 kg/m3; reference 1380-1400 kg/m3	ASTM D1505, ISO 1183-2, or agreed equivalent	Confirm modified grades.
Film thickness	Nominal and measured project value	ISO 4593 or calibrated thickness method	Record average thickness and profile.
Theoretical PET GSM	Density in g/cm3 x thickness in um	Calculation using confirmed inputs	Excludes adhesive, coating, liner, core, and packaging.
Actual GSM	Measured result	Known-area sample and precision weighing	Checks the calculation.
Adhesive coat weight	Project-confirmed g/m2	Coating-line or gravimetric check	Add to carrier GSM.
Total thickness	Project-confirmed	Calibrated total-thickness measurement	Use the defined layers only.
Peel adhesion	Project-confirmed value	Actual substrate, stated speed, angle, pressure, and dwell	Surface- and condition-dependent.
Tensile strength / elongation	MD / TD data from tested grade	ASTM D882 or agreed equivalent	Supports handling and removal.
Haze / light transmittance	Project-confirmed for clear grades	ASTM D1003 or agreed equivalent	Measure the finished construction.
Net roll weight	Calculated reference plus actual weighing	Gross weight less agreed core and packaging tare	Follow the agreed scope.

Verification Plan: From Density to Finished-Roll Check

Test Item	What It Checks	Suggested Method or Reference	Why It Matters	When To Request It
Density	PET carrier mass per volume	ASTM D1505 or ISO 1183-2	Sets the weight input.	New grade or weight change
Thickness	Average and cross-web profile	ISO 4593 or calibrated method	Explains GSM and weight variation.	New roll or process route
Actual GSM / yield	Mass per unit area	ASTM D4321 or known-area weighing	Checks supplied material.	Approval or discrepancy
Peel adhesion	Adhesive force under stated test	ASTM D3330 or actual-substrate method	Density cannot predict adhesion or removal.	New surface or dwell
Tensile / elongation	MD / TD strength and stretch	ASTM D882 or agreed equivalent	Supports handling and peel.	Thin film or complex shape
Haze / transmittance	Finished-film optical appearance	ASTM D1003 or agreed equivalent	Checks visibility and haze.	Clear or polished surface

Record grade, batch, sample position, conditioning, instrument status, substrate, dwell, and calculation scope. Compare reports only when test conditions align. For multi-laboratory projects, align sample preparation, instrument settings, and reporting units before comparison.

Turning Density Data into Usable Decisions

Density and measured thickness determine theoretical PET GSM; width, length, and GSM support base-film roll weight. They do not predict peel adhesion, coating interaction, haze, edge lifting, or removal. Tensile strength and elongation indicate stretching and tearing, while total thickness and coat weight describe the finished construction.

Mechanical and optical properties remain separate.

Review PET film mechanical and optical data for MD / TD, optical, surface, and processing properties.

Use confirmed inputs for coated, pigmented, filled, or modified grades.

Where Density Stops Predicting Performance

On glass, coated metal, painted panels, and plastic, density supports mass calculations but cannot confirm peel force, haze, shadow, gloss change, or coating interaction. Rough or low-energy surfaces may increase edge lifting. Cargo shape, load, transport, sunlight, climate, equipment, and operator method can change performance without changing PET density.

Separate application risks from weight calculations.

For substrate, dwell, and removal review, use the surface and dwell-time compatibility guidance with these technical values.

Repeat sample testing when surface, coating, process, storage, or transport changes.

Four-Stage Sample Approval Protocol

Initial: inspect wet-out, bubbles, wrinkles, edges, and surface change.
24h: record peel, edge lifting, adhesive trace, shadow, and gloss.
72h: review adhesion build, bubbles, coating interaction, deformation, and residue.
7 days or planned dwell: inspect tearing, transfer, ghost marking, color, gloss, and clarity.

Use the actual surface, cleaning, pressure, climate, equipment, and operator method. Retain the approved sample and record.

Mismatch Diagnostics: Calculation vs Actual Use

Data Point	If Too Low	If Too High	Risk in Application	Check Before Full Use
Density input	GSM and mass understated	Demand overstated	Incorrect yield decision	Confirm grade and scope
Measured thickness	Lower stiffness or tear margin	Less conformability; larger roll	Wrinkles or handling risk	Measure thickness profile
Adhesive coat weight	Weak contact or edge lift	High adhesion or trace	Movement or removal risk	Check coat weight and timed peel
Peel adhesion	Lifting or bubbles	High removal force	Tearing or coating interaction	Test timed dwell
Elongation	Splitting at geometry	Removal stretch	Incomplete removal	Run peel simulation
Actual roll weight	Short length or missing mass	Extra mass or tare error	Material discrepancy	Check GSM, length, tare, coating

Roll Condition, Storage and Data Retention

Keep rolls in original packaging in a dry indoor area away from sunlight, heat, condensation, dust, and pressure. Support cores and prevent crushed edges, telescoping, and unsupported stacking. Storage time, climate, vibration, transport, damage, and compression may affect unwind, adhesion, flatness, and removal. Retest unusually exposed material.

Technical Cluster Connections

Connect calculations to finished-roll verification.

Use coating, slitting, and roll-weight control to verify thickness, coat weight, winding, and repeat-roll consistency.

Records support, but do not replace, grade specifications and sample results.

FAQ

What is the density of PET film in kg/m3?

Approximately 1390 kg/m3, or 1.39 g/cm3, is a common clear-BOPET reference. Confirm modified, filled, coated, or multilayer grades.

How is PET film GSM calculated from thickness?

Multiply density in g/cm3 by thickness in um. A 50 um carrier at 1.39 g/cm3 gives 69.5 g/m2 before other layers or tare.

Why can actual roll weight differ from the calculation?

Differences may come from thickness, length, coating, liner, tare, winding, moisture, or weighing. Check known-area GSM and calculation scope.

Why is sample testing still required?

Density supports weight calculations, not compatibility or removal. Test the actual substrate at 24h, 72h, and planned dwell under representative conditions.