ilfs uv coating qc seminar

7/28/2019 Ilfs Uv Coating Qc Seminar

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HIGHLY CONFIDENTIAL

UV Coating Quality Control

Seminar


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Overview

60 Gloss Meter Testing of UV Coatings

UV Cure Level Testing

Scratch Resistance Testing (Level of Cure)

Potassium Permanganate Stain Testing for UV Coating

Consistency

UV Coating Adhesion Testing

Press Set Up and QC Procedures for UV Integrated Label

System.


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Testing


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60 Gloss Meter Testing

Ensure that the area to be tested is representative of the total printed

sample or is in accordance with the specifications, and that the print

sample is large enough to cover the gloss meter aperture.

Place the test sample, print side up, on a flat area.

Following manufacturers operating instructions, measure the gloss of

the printed sample in the "machine" direction. Record the values

separately.

Gloss readings above 70 are typically acceptable for direct mail

applications.


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UV Cure Level Testing

Saturate an industrial strength napkin with Methyl Ethyl Ketone (MEK).

With average effort, rub back and forth with the napkin containing

MEK.

Count number of cycle rubs it takes for the coating to begin coming

off.

11-15 cycles back and forth is average. Below this represents a poor

cure situation.


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Scratch Resistance Testing

With a nickel coin, rub back and forth on the surface of the UV coating.

Coating should remain intact for six to eight cycles.


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Stain Testing for UV CoatingConsistency

Prepare a 1% solution of potassium permanganate (KMn04) in de-ionized or distilled water.

Select a portion of the print for testing that is either over white paper orover solid opaque white ink.

Apply a sufficient quantity of the KMn04 solution to both the standardand sample cured film to cover an area approximately 1/4 inch indiameter using a disposable pipette.

Allow the solution to remain in contact with the coating for exactly five(5) minutes using a stopwatch. Blot off solution with a paper towel.

In the area where the solution was in contact with the coating, a brownstain will be apparent. Measure the yellow density of the brown stainimmediately after the potassium permanganate solution is removed.

This is a comparative test.


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UV Coating Adhesion Testing

Place print on flat surface.

Apply a six inch strip of tape smoothly onto the print.

Grasp one end of the tape with thumb and forefinger. Using the other

hand, hold print firmly on the surface.

Pull the tape off print at a 180 angle at a moderate speed.

Examine the print and tape for evidence of ink removal. Ink/overprint

removal of 10% or less are acceptable.


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Press Set Up and Quality

Control Procedures


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Press Set Up and QC Procedures for

ILFS Integrated Label System

(with UV Silicone)

For Flexo Applied Applications

Utilize a photopolymeric plate

Handling and Substrate Requirements:

L9091L UV free radical and PC-605 UV cationic silicone release

coatings are one-component systems that arethixotropic in

rheology, offering excellent hold out characteristics on uncoated

paper stock. These products should be mixed for a few minutes

prior to running. Also, it is best to keep constant agitation on these

products while running.


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Use Nitrile rubber gloves when handling UV during mixing process

Do not leave pails or drums of UV open when not in use due to the

inherent UV light sensitivity of this type of product.

Shelf life for these products is three to six months.

UV Curing Requirements:

200 fpm per 300 watts/inch lamp



(with UV Silicone)


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On Line Quality Control Procedure (before adhesive is applied):

Use a micrometer to ensure that the volume of UV silicone release

coating remains at no less than 0.15 mil.

Check reverse side of web after UV application and make sure no

UV silicone has penetrated. This should be done visually as well as

with a permanent pressure sensitive label (shipping label) by

sticking the label on the reverse side of the web and making sure

fiber tear occurs.

Using your fingernail, scratch the surface of the cured UV to make

sure only an insignificant amount of UV silicone is coming off. This

is a quick test to confirm that cross-linking has taken place.



(with UV Silicone)


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Visually check the curing of the coating. If coating remains in

liquid state after the UV lamps, take the following steps:

Make sure the lamps are operating properly.

Make sure the paper has not been exposed to a high degree of

relative humidity. If high humidity is an issue, increase the UV

application until cross-linking is observed.

Check the effectiveness of the release coating with a permanentpressure sensitive shipping label before hot melt coater is

engaged. If clean release is observed, turn on the hot melt coater.



(with UV Silicone)


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As Final Quality Control Check After Hot Melt Coater is Engaged:

Peel hot melt labels off integrated label piece and make sure no

streaks are observed on the release coating surface.

Directly off line, pinch long way on label; label should almost

fall off.

Make sure dies are not set too deep so as to punch through back

of piece. This will result in fiber tear of the label.



(with UV Silicone)


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Required Equipment for Tests

60 gloss meter is available from UV Process Supply

www.uvprocess.com

Potassium permanganate stain testing kit can be purchased on

www.uvprocess.com but is expensive. Or you can purchase pure

potassium permanganate and dilute down to a 1% solutions (99%water/1% potassium permanganate). This is available from JT Baker at

www.mallbaker.com

Micrometer is available from Mitutoyo (815-444-9538).

Part # 293-761-30. Measurable down to 0.05 mil.

3M 610 Tape is available from ULine (800-958-5463) orwww.uline.com
http://www.uvprocess.com/http://www.uvprocess.com/http://www.mallbaker.com/http://www.uline.com/http://www.uline.com/http://www.mallbaker.com/http://www.uvprocess.com/http://www.uvprocess.com/

ilfs uv coating qc seminar

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