Semi-Metallized PET Film Selection Guide

Semi-metallized PET is purchased for a controlled visual effect, not simply for “silver color.” Buyers must define how much light should pass, how uniform the appearance must be, what artwork or substrate sits behind the film, and whether the web will be printed, laminated, formed, or exposed to heat. A semi-metallized PET film selection guide therefore starts with optical targets and ends with a full-width converting trial.

Choose Light Transmission by End Use

The published product range includes DZ-15, DZ-16, DZ-18, and DZ-22. Listed light-transmission ranges are 35-40%, 40-45%, 45-50%, and 65-70% respectively. All are identified as 12 micrometer PET grades. These are typical grade references; confirm the current specification and measurement method before ordering.

Lower transmission creates a stronger metallic or privacy effect, while higher transmission reveals more of the substrate or product behind the film. The perceived result also depends on lighting, viewing angle, print, adhesive, backing color, and air gaps. Approve the film in the real construction.

Check Haze, Uniformity, and Adhesion

The published table lists haze of no more than 3.0% under ASTM D1003, aluminum uniformity of 5%, and aluminum adhesion of 2.5 N/15 mm under the stated method for the listed grades. Buyers should clarify the acceptance limit, sampling location, and whether visual bands, scratches, or transition marks are controlled separately.

Aluminum adhesion does not guarantee final laminate bond. Ink anchorage, adhesive wetting, coat weight, drying, cure, and surface cleanliness still determine the converted result.

Match the Film to Printing and Lamination

Print colors can shift over a translucent metallic background. White ink, opacity, and trapping should be tested using final artwork. Confirm whether printing occurs on the metallized or non-metallized side and record roll orientation.

For lamination, use the actual adhesive and backing material. Check appearance immediately and after cure, because adhesive refractive index and trapped air can change brightness or transparency. Aging under heat and humidity may reveal bond or optical changes not visible at startup.

Procurement Checklist

• Specify grade or target light-transmission range and the measurement method.
• Define allowable haze, color, brightness, bands, scratches, and roll-to-roll variation.
• Confirm thickness, width, roll length, core, winding direction, splices, and packaging.
• Provide the final substrate, ink, adhesive, artwork, and viewing conditions for approval.
• Run a production-width trial and inspect across the web and through the roll.
• Agree on retained samples, certificates, complaint handling, and change notification.

Mechanical and Thermal Considerations

The published data lists tensile strength of at least 170 MPa in both directions and heat shrinkage no more than 3.0% under the stated 150 degree C, 30 minute condition. These values support screening, but the actual converting process may create different stress.

Check tension, registration, curl, winding, and dimensional change at the real line temperature. Decorative laminates, labels, and electronic applications can impose very different forming and thermal requirements.

Barrier Expectations

A translucent metal layer can contribute light and gas barrier, but buyers should not infer the barrier of an opaque high-OD VMPET. If oxygen or moisture protection is critical, request grade-specific OTR and WVTR under stated conditions and test the final laminate. Optical transmission alone is not a barrier specification.

FAQ

Can two grades with similar transmission look different?

Yes. Haze, metal uniformity, backing color, adhesive, lighting, and viewing angle can change perception.

Can light transmission be approved from a small swatch?

A swatch supports screening, but full-width roll uniformity, winding, printing, and lamination require a representative trial.

Is semi-metallized PET a transparent high-barrier film?

Not automatically. Obtain specific OTR and WVTR data if barrier is a purchasing requirement.

Conclusion

Control Optical Approval Conditions

Visual approval should use defined lighting, background, viewing distance, and sample orientation. A film viewed against white paper can look very different over a dark printed layer or transparent adhesive. Photographing samples is useful for records, but camera exposure and screen settings should not replace physical master samples.

For decorative or privacy applications, inspect both transmitted and reflected light. Agree whether the critical result is measured transmission, visual metallic intensity, color neutrality, or concealment. When more than one criterion matters, include all of them in the specification and supplier sample approval.

Sampling should cover the roll width and several positions through the roll. Record transmission and appearance by lane so gradual coating drift or edge variation is visible. For repeat orders, compare the same locations with the approved master and retained data. This is more reliable than judging one hand sample from the roll center or relying only on an average measurement.

When the film is used outdoors, near heat, or behind glass, ask whether UV exposure, temperature cycling, or adhesive yellowing could change the appearance. Do not assume a decorative sample approved indoors will remain unchanged in service. Build aging conditions around the real application and compare aged samples with the original master before commercial release.

Semi-metallized PET film selection should convert a visual concept into measurable light transmission, haze, uniformity, adhesion, roll, and converting requirements. Review the verified Vacuum Semi-Metallized PET Film page, choose a candidate DZ grade, and approve it in the final printed or laminated construction.