Acid Free U.V. Resistant Acrylic ATG Transfer Tape.
Suitable for craft projects and photo mounting.
Needs to be used within the 3M ATG 700 gun
Please Note: - Water Extractable Impurities
An occasionally asked question is whether certain products are "acid free". The usual test to measure this is the water extract test in ISO EN 60454 (formerly BS3924) and the relevant DEF STANS. The primary object of this test is for electrical tapes, where the presence of ionic impuristies, and in particular acidic species, would be likely to cause corrosion of the conductor wires the tape is protecting. For double sided tapes the question is usually associated with very long term freedom from staining of delicate acid sensitive materials.
In this test a known weight of product is immersed in deionised water, and then boiled for a given time. After allowing to cool, the PH and electrical conductivity of the water is measured. Any ionic impurities in the adhesive will cause a measurable electrical conductivity. For those not familiar with the PH scale, it runs from 0 to 14. PH7.0 is neutral, below 7.0 is acidic, increasing so as the PH value goes down. Anything over 7.0 is alkaline, again becoming increasingly alkaline as the PH value goes further from 7.0. The other important point is that the scale is not linear, but logrithmic. It should be pointed out that extremely small amounts of either acid or alkali will cause the PH value to deviate from neutrality.
Several different products were tested according to the above test method, representative of the main group of products, IE: hotmalt, emulsion Acrylic and solution (solvent) Acrylic adhesives. It was found that in all cases the PH of the water extract was between 7.0 and 9.0. This would indicate that the water extractable compounds from the products are very slightly alkaline, and therefore can be described as "acid free". The conductivity values of the water extracts were all less than 3.5 mS/m. This would indicate a very low water extractable ionic compound content.
Dispite the results, it is essential that products are properly tested for any particular sensitive application.
For full specifications for 3M pdf datasheet
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