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TECHNICAL INSTRUCTION ON HOW TO USE SURFACE TENSION / WET ABILITY TESTER
OBJECTIVE OF Dyne Pen TEST
Wetting test as measured by this test show treatment level achieved by the surface of plastic film or substrate, which has been treated electrically or other means [or wet ability of non treated surface] to get satisfactory print or coating adhesion or anchoring
This quality control test, is highly recommended for printing Coating and plastic blow molding industries
Each test fluid of onur Dyne Pen gives an accurate means of surface tension level in terms of dynes/cms when applied to the surface to be tested
Test procedure of Dyne Pen
Lay the specimen to be tested on a clean flat surface with treated side on the top transparent films should be kept on the top of white paper for better visibility of marking spread the test fluid or ink from the felt tip of test pen lightly over an area of 7 cms² of the test specimen (i.e. strip of 7 cams x 1cms). Note time taken for continuous film on ink to break into droplets. And not peripheral shrinkage. (border shrinkage ).
Wetting is satisfactory or adequate ,when a continuous film of test fluid remains intact 3 seconds or more on the substrate to be tested .breaking of the ink film into droplets, in less than 3 seconds indicate a lack of wetting and a lower numbered test fluid to be tried. if the ink film remains intact for more than 3 seconds . The surface tension of this ink in dynes/cm “wetting tension” and these values are already marked on each of these pens/bottles.
Please note that observations of the liquid film behavior should be made in the center of the liquid film. Shrinkage of the liquid film on the edges of the applied ink does not necessarily indicate a lack of wetting. Breaking of liquid film into droplets within 2 seconds, indicate lack of wetting this is especially true for substrate having treatment level above - 40 dynes cams ²
Some experience with this will give excellent insight, to enable an accurate reading to be made. Extreme care must be ensure the film or substrate is not touched or contaminated in the area of lest.
It is recommended that when testing is done during the production, the test fluid or ink to be applied across the full web width. |
QUALITATIVE RATINGS OF TREATMENT LEVEL OR WETTABILITY
Sr. No. |
Treatment level
in Dynes/cm |
Expected quality rating in terms of print or coating Adhesion / anchorine |
1 |
Below 32 |
Very poor printing or coating adhesion. |
2 |
34 |
Poor printing or coating adhesion. |
3 |
36 |
Fairly good printing or coating adhesion. |
4 |
38 |
Good printing or coating adhesion. |
5 |
40 |
Very good printing or coating adhesion. |
6 |
> 40 |
Excellent printing or coating adhesion. |
Special instructions to avoid erroneous readings :
This is a delicate test, users should observe following instructions carefully otherwise the test result will be erratic/inconclusive or users may conclude that the TESTER is faulty.
Erratic of inconclusive readings are observed under following testing conditions :
Inconsistent (corona) treatment on the substrate, may result in erratic readings.
Loss of treatment or surface wetting tension due to repeated winding/unwinding of the material or due to friction on the machine may give erratic readings.
Contamination due to dust or frequent handling of the treated material may also give erratic or inconclusive results. Therefore it is advisable to perform test on fresh (untouched) samples.
Insufficient fluid (test ink) in the working pens, insufficient fluid at the tips of the pens. Resulting in error. Therefore if testing is done after a long gap, please hold the test pens upside down for few seconds so that fluid flows down to the tips of the pen. As the fluid at the tip is exposed to atmosphere there is possibility of erroneous reading, therefore please dispense this exposed fluid by marking a few lines on white paper. This is only if pens are used after long storage (more then one month)
If treatment level of material is 40 dynes/cm or more, all the pen stains from 32 dynes/ cm to 40 dynes/cm will look alike i.e. All the stains will appear uniform and unbroken, and the user may conclude that the tester is faulty. Please read point no. 3 of test procedure once again, i.e. do not count peripheral shrinkage as lack of wetting.
Quality Warranty
Quality rating and other recommendations concerning properties and applications are based on tests carried out and experience of the manufacturer in this field. The purpose is to provide general description of our product and to give basic outline and guidance to the users. Therefore buyer must satisfy himself about suitability of such goods for specific purpose, before putting them to use and seller shall under no circumstances will be responsible for any direct or indirect loss to the buyer for using goods delivered. |
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