Acid Free U.V. Resistant Acrylic ATG Transfer Tape.
Suitable for craft projects and photo mounting.
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
(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 fiound
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
Dispite the results, it is essential that products are properly tested for any particular sensitive application.
MOQ: 12 Rolls
For full specifications click here for 3M pdf datasheet
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