Test ink according to DIN ISO 8296:2008-03 for determining the wetting tension of plastics – film and sheeting
The standard DIN ISO 8296:2008-03 (draft DIN 53364) defines a simple method using test inks to determine the surface energy for plastic materials, films, composite materials and other surfaces.
Before polymers or metals can be coated or laminated, treated, finished, bound, printed or painted with a medium, precise information about the surface energy is often indispensable.
With our test ink, production processes can be designed more efficiently, and the reject rate can be reduced.
In ongoing production processes in particular, quick testing of the surface tension of materials or surfaces is often advantageous. It enables optimisation measures to be taken during the coating or treatment in the course of the ongoing process. After the production process, defective parts or entire batches can be identified by means of quality tests with test inks according to DIN ISO 8296:2008-03 (draft DIN 53364).
We have developed a series of environmentally compatible test inks using a mixture of water and ethanol. The entire product range comprises 22 test inks with various surface tensions. The surface tensions range from 30 to 72 mN/m, progressing in steps of two (i.e. 30, 32, 34, …, 68, 70, 72), with a tolerance of +/-0.6 mN/m. All the test inks are delivered in brown 30 ml glass dropper bottles with brush caps.
The test procedure according to DIN ISO 8296:2008-03 (draft DIN 53364)
The surface has to be smooth and/or horizontal and level. In order to determine the surface energy, a number of our test inks with gradually increasing surface tension is painted onto the surface. For this purpose, an area of approx. 6 cm² is quickly painted with the brush. This process is repeated until a test ink is found that wets the surface only just for 2 seconds. The applied ink has to remain on the surface as a liquid film for at least two seconds without shrinking back into drops. If the test ink remains extended for more than two seconds, the test has to be repeated with a test ink with a higher surface tension. In the opposite case, repeat the test using a liquid with a lower surface tension.
DIN ISO 8296:2008-03 Plastics – Films and sheeting – Determination of wetting tension is available here: http://www.beuth.de/de/norm/din-iso-8296/106380041
In case of questions, please do not hesitate to call us, or send us your request by e-mail.