are not all adhesive tapes similar or the same? where's the difference? they look
different they have different colors yellow red blue white whatever they have
use paper as a carrier material PE foil or spunbund but I can tell you
there is quite an interesting difference and the difference is found in the
glue which is used I think that 95% of the tapes available in the market are
produced out of so-called acrylic dispersion glue. acrylic dispersion glue is
produced this way. that you bring on the carrier material a liquid which is white
as you see it here on those pictures and this white liquid you see here is a
dispersion which which has the following ingredient acrylics which are
these red circles which are solved into water water is the blue parts and
normally not in all but but I guess in most of the acrylic tapes they put a lot
of resins in resins are this yellow part here and resins and as you know when
you cut into wood and the wood is producing the resins it's a very sticky
material so they put it inside to make those tapes sticky edges or some sticking
better to surfaces and to avoid that the acrylics swimming above are up in
the in in the water and the resins are down with water we have to bring
emulsifiers in so when the emulsifiers are responsible that you have a constant
make sure a constant dispersion and what happens now during the production so you
bring it on the carrier material and they define thickness and then you bring
heat to the liquid and then the water is evaporating away and during the drying
process dispersion is turning from white into crystal clear and here you see that
it's drying and when all the water is out of the dispersion it's crystal clear
as long as you have some water content in its it's white and after the whole
humidity is gone it looks like the glue all of you most of you know from this
acrylic dispersion tapes available on the market what happens when there
collects get in contact they are creating long molecular chains then
you have besides acrylics you have this resins in and resins I made the
picture before it's something you know from what when you cut into wood resins
are coming out and then they are extremely sticky but what happens if you
wait a couple of months or a couple of years what happens with it with the
resins then they get brittle and there are some resins used in these acrylic
tapes which are in doubt to be long-time age resistant so maybe some of you
knows these hooks you can stick in your bathrooms to the tiles to put your towel
on or whatever and these glues are sticking normally very aggressive so
when you put it to the tile you cannot remove it but what happened after five
six seven or ten years sometimes they are falling off and when you take a look
at the backside of the glue the glue has turned to yellow and this can be
the reason maybe or can be the reason when they use resins which are not age
resistant and for us it was clear we do not want to work with the glue
technology which are using a lot of resins which are in doubt if they are
age resistant or not and some producer says we have acrylic-free
acrylic dispersion tape or they say our resins are age resistant it might be
but for us of course we like things that we can control and so resins was not the
first option for us the second problem we have is we still
have the emulsifiers in and emulsifiers had only the reason to create a stable
mixtures so the only purpose for them is to put moisture around them and if any
acrylic dispersion tapes are getting in contact with moisture again the
emulsifiers do what they have to do they and react with water so when they get in
contact with water they are putting water around them and do we have
humidity on the building site? yes. we have and of course is moisture is not
good for the connection and so we said we want to have something different we
do not want to have a resins in which are not age resistant
enough is we like them to have and we do not want emulsifieds inside which
are reacting with water because we want something
absolutely different and so we found the Pro Clima solid acrylic technology so it's
the same it's acrylic tape but it's a solid acrylic and the production is
quite similar we have this jumbo roll of carrier material in this case you see
on this image this Tescon Vana where there are a couple of thousand running meters on
it and then we coat the Vana with pure acrylic we bring the acrylics to
the carrier material and the acrylics are more or less like a very liquid
honey not very strong like honey it looks on the tape like this small
acrylic chains which are not bounded with each other so with the special mixture
a special chemical process to produce it but this is what we do we
just bring in pure acrylic to the material then we are creating by
bringing energy special energy to the tapes which is blue and the acrylics are
connecting with each other and depending if we bring a lot of energy a low energy
to the to the glue to the acrylic to the solid acrylic we have a softer or harder
to so we have a good influence which glue do we want to produce good so you
see it we bring energy on it and then we creating the bonding and this is how we
are dealing with with the glue and the good thing is that due to the fact that
acrylic they cannot be solved into water without emulsifiers and we get an
absolutely water-resistant glue the question is and now okay how does a tape
stick when we want to get a connection between a surface that glue
itself must stick to the surface so this is called adhesion so we need we need a
good connection to the surface and then the force must be transported through
the glue itself so the glue must offer a certain strength itself and this is
called cohesion what is adhesion? adhesion is very simple and if we bring
two surfaces very close close to each other surfaces because of the different
electronic molecules found on the surface of it it can create a connection
with each other which is called adhesion besides adhesion we achieve connection
to the surface by the flowing of glue in the
membrane structure so when we take a closer look to the membrane the
microscope 300 times and last you can see this is a PE foil yeah it's
not it's not you see it's a structured surface or when you take a look next
slide the Solitex you see the small nice fibers out which
spunbund is produced or you have a picture of the Intello so it has a
alleys and valleys and hills so it's not structured and if the glue
follows the structures and it's floating all around it and if we want to remove
it the glue has to float out of the structure and by this we achieve besides
adhesion a mechanical connection to the surface this is why it's important
and the glues independent if they are acrylic dispersion or solid acrylic they
are so-called PSA glues so pressure-sensitive adhesive so we have
to press them into the surface because we want to bring them closer
together to have adhesion and we want to press them into the structure to have the
micro-molecular connection between the surface if we work with a piece of tape
give some time to glue the glue needs time to permeate into the surface to
create a good bonding so here you see one our Tescon Vana once
adhered which is quite good but you see a clear difference between the
advance adherence and if you wait six hours contact time then the bonding is
getting stronger and stronger over time so the test
some people do just stick it to the surface and try immediately to remove it
it does not respect how a glue is really working second point is cohesion we are
working with yeah very big thicknesses of glue so we're working with 200
grams per square meter which is nearly half a pound per 10 square feet when I
calculate it very fast to US measurement and this is quite high and so we need a
certain stability of the glue that the force can be transported through the
glues from one part of the connection to the other cohesion is the definition is
the molecular force between particles within the body of substrates that acts
to unite them to make it easier to understand we have to jump to the next
slide you and take on the one hand a very liquid
honey everybody knows it when you go with the spoon into the honey and you
turn the spoon around what happens the honey is dripping down and only a very
thin layer of honey remains on the spoon so this is a material that is very sticky so
has a good adhesion but in low cohesion because the honey itself has no inner strength
the other extreme is hard concrete that of course it's sticking to
no surface but you can see has a very strong cohesion so the question
is the perfect air tightness tape or glue which force must the tape resist
should it stick to the finger this is a test everybody is doing everybody
normally one takes the tape and removes the transfer liner puts it on something and
then you think it's sticky or not sticky then must it resist short and long
strong and short tear forces so then other times people stick it on a surface
and then they pull very strong on it and then they see is sticking good or not or
must tape resists small but long lasting forces yeah for the building
site it's clear the answer this is what we found on the building site so we have
the membrane field and the insulation is pressing through the connection on the
next image you get better you have the battens to support the insulation is
pressing with very low force but for a long time to the connection this is the
tape which is extremely sticky so when you make a test and somebody gives me
ends I test it you would say well the best tape I've ever tested and the
reason why the finger tack is for some tapes better than then with others if
you can achieve better finger tack when you make the glue softer more into
the direction of honey then the glue penetrates very easily in the structure
of your fingers and if you try to remove it it gives you the impression it's a
good glue but you see what happens here on site they've used these tapes and they
wanted to press the insulation material a little bit into place and they
had tension so a tention on the connection and you see that's a glue
because it's a soft started to swim and yeah it will collapse
after time so the glue is so soft then you see it even on the membrane here and
on the timber of the roof so it's a very soft glue not really good for airtightness
what you can do everybody every one of you is to make this very
simple test you just take a PE sheet one inch height two inch wide just cut it out
of woood 1/2 pound 250 grams so half a pound staple it to the timber make the
connection make your little mark with a marker and hang so this is it done in my
in my office this is Vana and some other airtightness tapes and you can see what
happens after 24 hours you see the first of the tape started to move after
48 hours yeah one connection is ready to collapse
good and of course why have I chosen these 4 tapes because I know good and bad
tapes why do I know them because we made one long term test in our lab or in the
basement you can see it on the next slide so we bought all available tapes
or not all available but a lot of these tapes available in Germany and
then we put this weight on it and we want to see okay how long do they last
if they have and the permanent stress by this 250 grams and this picture I made
three days later so you see the three tapes which already collapsed even after
three days but we let it hang for a long time so after three years only five
tapes from 56 are still resisting the force and all three Pro Clima tapes are
still hanging why is it because we optimized our glue to
cohesion and not to the finger tack to convince people to a fast buy
by so we said okay for us and important that we produced tapes which are
resisting the forces we found really in the life time of the building it
seems just normally they have a low cohesion good glues come by initial tack
with a good cohesion so this is what you always keep in mind think on the honey
the next time you you check adhesive tapes and think about the tests
I've shown you