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English Views: 0 Author: Site Editor Publish Time: 2026-10-10 Origin: Site
A PET synthetic paper sample can produce sharp graphics and still fail during cutting, rubbing or customer use. For commercial printers, converters and distributors, appearance alone is not enough to approve a material for bulk purchasing.
The practical question is whether the selected PET grade works consistently with your UV ink, printer settings and finishing process.
This guide explains how to prepare a useful UV ink adhesion test on PET synthetic paper, interpret failures and turn sample results into a clear purchasing specification.
UV curing and adhesion are related, but they describe different aspects of print performance. Curing forms the ink film; adhesion describes how well that film remains attached to the printable surface.
A surface that feels dry should not be treated as proof of reliable adhesion. Mimaki notes that cured UV ink may not adhere to every surface and that surface type and pretreatment affect the result.MIMAKI
When qualifying PET synthetic paper for UV inkjet printing, evaluate the exact combination of:
Material grade and printable surface.
UV ink series, including white ink or varnish where used.
Printer model and production mode.
Curing conditions.
Finishing process and service environment.
A successful result on one PET grade or print mode does not automatically qualify another.
Before testing UV inkjet printable PET sheets or rolls, ask the supplier to identify the sample clearly.
Confirm the grade, thickness, surface finish, printable side and intended printing process. If both sides will be printed, evaluate both surfaces separately.
The sample should represent the construction proposed for the bulk order. Ask whether the sample and production material will use the same surface treatment or coating specification.
For roll-fed production, small sheets are useful for an initial print assessment, but they cannot establish web handling performance. A representative trial roll may also be needed to assess tracking, tension, winding and output consistency.
For sheet-fed or flatbed work, test the intended sheet dimensions and holding arrangement before production approval.
A useful adhesion test must be repeatable. Before printing, record the material, printer settings and assessment conditions so different samples can be compared fairly.
Record temperature and relative humidity during conditioning, printing and testing. Follow the relevant suppliers’ environmental guidance rather than assuming one universal temperature or humidity range applies to every PET coating and UV ink system.
Use the following trial record:
Record item | Information to capture |
|---|---|
Material identification | Grade, batch, thickness, surface finish and printable side |
Printer and ink | Printer model, UV ink series, white ink and varnish |
Production settings | Print mode, pass count, speed, ink limits and available UV settings |
Sample preparation | Conditioning period and any approved cleaning or pretreatment |
Environment | Temperature and relative humidity during printing and testing |
Assessment timing | Elapsed time between printing and each test |
Adhesion test | Selected method, cutter specification and sample support |
Test tape | Manufacturer, full product name, model, width and lot where available |
Acceptance criteria | Agreed rating or permitted loss, photographs and approval decision |
Do not change tape products between comparisons without documenting the change. If a buyer specifies Scotch 610, Scotch 810 or another tape, confirm its suitability for the agreed procedure before testing.
Keep the actual printed samples alongside the trial record.
A small logo or lightly printed image may miss problems that appear in demanding production work.
Use a test layout containing:
Solid colours and the job’s highest planned ink coverage.
Fine lines, small text and gradients.
Actual barcodes, where relevant.
White underlayers and varnish, if included in production.
Printed areas that will later be cut, bent or folded.
Start with the supplier-recommended operating conditions and test the intended production mode. If settings need adjustment, change one variable at a time and retain each sample.
Mimaki’s troubleshooting guidance identifies UV irradiation, print mode and surface treatment as factors to review when adhesion is unsatisfactory. Apply such adjustments only within the guidance for your particular equipment and ink system.MIMAKI
The aim is to find a usable production window, including the speed and artwork coverage your business actually needs.
A cross-cut adhesion test can help compare how a printed ink system resists separation from its substrate. It adds a defined cut pattern to the assessment, rather than relying only on a tape pull over an uncut print.
A cross-cut tester uses a suitable cutting tool to create intersecting cuts through the coating to the substrate. Tool selection and the subsequent assessment procedure must follow the chosen method.byk-instruments.com
Before testing, agree on:
The applicable method and its suitability for the material.
Sample conditioning and assessment timing.
Cutter spacing, cut pattern and tool condition.
The supporting surface for flexible sheets.
Tape specification and removal procedure, where required.
The rating system and acceptance threshold.
On thin PET synthetic paper, inspect whether the cutting operation has damaged the substrate. Tearing or distortion caused by the tool can make the result difficult to interpret.
Do not select cutter spacing from the PET sheet thickness alone. Follow the method’s requirements for the coating system and substrate.
After completing the agreed procedure, photograph the test area and inspect any removed material.
Distinguish between:
Ink separating from an otherwise intact printable surface.
A printable coating lifting together with the ink.
Separation between printed layers.
Damage caused by cutting or handling.
These observations help the supplier and printer identify the next investigation step. They do not, by themselves, establish a single cause.
For an internal tape comparison, keep the tape, application, dwell time, removal method and assessment timing consistent.
If a customer requires a formal rating, follow the complete selected procedure. ASTM D3359 identifies limitations for non-metallic substrates, including plastics, and calls for agreement on the method used. An improvised grid or tape pull should not be described as ASTM-compliant.store.astm.org
Adhesion screening should be followed by tests that reflect the finished product. A flat sample may perform differently after cutting, bending, wiping or repeated handling.
Use a defined contact material, load and number of rubbing cycles. Record whether the test is dry or wet.
Inspect for colour transfer, scratching and loss of fine detail. If barcodes are part of the product, verify readability after the relevant handling test.
A quick hand rub can reveal obvious weaknesses, but it should not replace a repeatable purchasing acceptance procedure.
For flexible tags, menus and instructions, use the intended bend or fold geometry.
Inspect the printed area before and after flexing. Record the direction, radius or crease construction, and number of cycles where relevant. Look for cracking, flaking and changes in appearance.
Passing a cross-cut or tape assessment does not establish resistance to repeated bending.
Test the actual liquid or cleaning product expected in service. Define contact time, wiping method and assessment conditions.
Evaluate the complete printed construction. Water resistance of the PET substrate does not automatically establish resistance of the ink, coating or primer to cleaning.
Use observed failure patterns to guide further checks.
Observed result | What to investigate |
|---|---|
Ink lifts from an apparently intact surface | Surface compatibility, preparation and ink selection |
Print remains tacky or smears | Cure assessment, ink loading and equipment condition |
Flat print passes but cracks when folded | Ink flexibility, film build and fold geometry |
Failure appears only in heavy coverage areas | Layer construction and curing at the intended coverage |
Coating lifts together with the ink | Coating integrity and the suitability of the test procedure |
Results vary across samples | Handling, sample identity and material or process variation |
These observations are diagnostic starting points, not proof of a single cause. Review results with the material supplier and printer or ink support team before changing the purchasing specification.
Avoid approving a material simply because it “looks good.” Define what acceptable performance means for your job.
The buyer and supplier should agree on:
Exact material grade, thickness and printable surface.
Test equipment, ink system and production mode.
Assessment timing and test procedures.
Required adhesion rating or permitted loss under the agreed method.
Rub, fold and exposure requirements relevant to the application.
Sampling arrangements and handling of nonconforming results.
Retain an approved sample and its trial record. Include the agreed material specification in the purchase order so the bulk supply can be checked against the same reference.
For ongoing purchasing, establish when requalification is needed—for example, after changes to the material construction, ink system or production conditions.
No. Select a grade intended for the process and evaluate it with your actual printer and UV ink. PET composition alone does not establish print compatibility.
Use the timing specified by the relevant suppliers and customer requirements. Where delayed changes matter, agree on an additional assessment interval and record it consistently.
No. Adhesion screening does not establish resistance to weathering, sunlight, chemicals or repeated handling. Outdoor applications require separate, relevant evaluation.
That depends on the material surface, ink system and application. Confirm requirements with the suppliers and evaluate the complete process, including any primer application.
Sheet samples can help screen print compatibility. For roll-fed production, also assess a representative roll under the intended web handling and printing conditions.
LZ New Material offers PET synthetic paper options for UV inkjet printing. Before selecting a grade, share your printing and converting requirements so the proposed material can be evaluated for your application.Flexible UV Inkjet Printable Substrate
For a sample or quotation enquiry, provide:
Printer model and UV ink series.
Required thickness and surface finish.
Roll width and length, or sheet dimensions.
Single-sided or double-sided printing needs.
Finished application and adhesion requirements.
Estimated trial quantity and bulk purchasing volume.
