Peel And Stick Roofing Membranes, Cologne Waterproofing Conference W. Comments

Editor's Notes

• #2: Since most of you probably never heard of me or Custom Adhesive Technology, I will briefly describe, what our role in this particular subject is. Why I think that “peel and Stick” is a technology whose time has come for the waterproofing membrane industry, what goes into the development of a peel and stick membrane, and where I see future trends
• #3: We do not sell any “peel and stick” products, but we make them. We do make all the things that you see here You all know the exciting moment, when the salesman comes back from the field …. to the moment, when your controller says that Werner makes too much money and he wants his own plant.
• #4: You are probably wondering, why I am calling it “peel and stick” rather than “Cold Self-adhesion roofing membranes, when I am talking to a well educated audience like you. It is simple, the people who buy the product, ask for something that is easy and familiar. Like “peel and stick”. They know it from other day to day products. That is what the salesman will be asking for when he gets back. But why should we make a “peel and stick” when we have a perfectly good working solution like a good mastic? Well, that’s what the label people thought, way back when, in the 60’s. You remember when you put a label in a typewriter – remember that one? – type on it and then get out the glue brush – or the glue stick if you were really advanced – and then you stick it to the folder. Until somebody - Mr. Avery? came out with a “peel and stick” version, and now the vast majority of labels is “peel and stick”. Or even more recent in the late 80’s or early 90’s, I recall a gentleman from the US printing and engraving office stopping by. They are making the postage stamps. He told me that they are thinking of making a “peel and stick” postage stamp, but only as a gimmick, because “people like licking stamps”. And guess what? As it turns out, people don’t like licking stamps, which is why virtually all stamps in the US are now “peel and stick”.
• #5: But things are surely different in construction, right? HuD made a study among construction people about the use of adhesives. The consensus: Adhesives don’t work. You know why. It’s not the adhesive, it’s the applicator. Because Jose puts down a big blob here, a tiny bit there and a big blob here. On average he has good coverage and it looks all black to him; but adhesion being only as good as the weakest point, you’ll have failure. So, what does work? HUD asked: Tapes do – and what else is a “peel and stick” membrane, but a giant tape.
• #6: So now let’s look into what speaks initially for a glued-on membrane vs. a mechanically adhered one:   But: It needs a lot more labor, is sticky, smelly, and hazardous
• #7: Now, can a peel and stick solution address the problems that come with the “fully adhered” method of mastics?
• #8: And here it is, application of a fully adhered roof, you can do in your Sunday outfit – no mess, no fuss, and five times faster than with the “old” method.
• #9: Clean, ready, no heavy equipment, a happy work crew ready to roof the next building   Sounds too good to be true? Where is the hitch?
• #10: Here it is, the mechanics of adhesion   This is the way it is supposed be: Close contact, excellent wet-out. See these little lightning bolts, they signify the so-called van der Vaal forces, which is the predominant, underlying force of adhesion. But, in order to work, they have to be within 5 Angstrom. For those not in the day to day business of dealing in nanotechnology, 5 Angstrom is about 1/2000th of the thickness of a sheet of paper. So what you see here, is the depiction of a perfectly smooth surface like a polished stainless steel plate, and the adhesive has flown into all the little nooks and crannies for maximum adhesion. Well, that’s the theory, the reality is a little more difficult: The surface of your typical construction material is a little rougher, so you look at a surface like this. It has probably also less surface energy, like a TPO, so you have less magnets. And then there is the problem of flow – water flows nice and you’ll get contact everywhere, but it won’t hold together. So we have to try to find an adhesive that flows, but ultimately has also the cohesive strength to match. It’s like squaring the circle. But nothing that time, money, and putting your mind to it can’t solve.  
• #11: This is where the product design starts. This is what you will ask the salesman: Temperature window: What are the temperatures the adhesive bond will experience: during application during its service life since there are lower limits and upper limits to every adhesive What are the stresses the adhesion bond will undergo in its life cycle? What are the surfaces? Typically steel is easy, TPO and concrete are not. Is water resistance a requirement – very important in a waterproofing membrane What about UV and Ozone resistance? What are the stresses during storage at the lumberyard or on the construction site? Is flame resistance an issue?
• #12: What is the best method to apply the adhesive to the membrane? We have 3 different coating technologies at our disposal, all delivering a nice and even coat of the product, with slight differences in the available adhesive chemistry and differences in the way the adhesive is wetting out. Lets assume we want to use acrylic: It is available in all three technologies, what are the differences ??
• #13: Why did we choose Hotmelt for our TPO roofing membrane?   Environmentally friendly we all know that this is nowadays an important matter, because   Cost – the real overriding issue – it is 100% solid, so we don’t have to flash off solvents or expend lots of energy to evaporate a lot of water. Once you go to 5 mils (125 microns for those still clinging to the metric system) or more, hot melt is really the only economically feasible alternative. And since we are sticking to uneven surfaces, anything less than 5 mils will definitely not work. The adhesive can be shipped safely – no manifest, no fear of freezing during transportation, it is just rubber. E.G. We can use olefin based chemistry under the motto “like likes like”, in this case we came up with a modified butyl rubber system, reinforced with a crosslinkable secondary polymeric system. Most hot melt systems are inherently hydrophobic – we have even PSA’s that stick under water. And- the manufacturing can be placed in any location, which lets you bring your product close to your customers. It is safe, no smell (unless you want to use asphalt), no emissions, nobody will notice it even in an office park.
• #14: After we settled on the adhesive, what else do we have to consider: a. cost effective application to the membrane – i.e. which coating head slot die, reverse gravure, etc. b. What type of release liner PP, Paper, PET – we settled for a PP, since it is cheap, less waste than a paper, stretches and thus conforms to the contours, since we could coat directly onto the substrate. c. what is the most appropriate size of the finished product – determined by industry standards (everything has to be a multiple of squares = 100 sqft), available coating equipment and substrate width, we started with 5’ and later expanded on a new line to 10’ (3m). Weight of the finished roll: small jobs hand carried, large jobs crane availability, etc. d. Logistics, where to produce it, close to the customer base or close to the substrate production e. What type of equipment is best suited for the product, and what is available if it is only short runs, and e.g. black adhesive, slot die is a bad choice due to lengthy clean out time
• #15: How do we handle the lap joints? They are the most critical area for water entry. Adhesive bonded or heat weld? Heat weld is a well proven method of securely bonding thermoplastic substrates and is one of the reasons people choose TPO or PVC over EPDM. However, if you bond the seams with a splicing tape, or similar method, you will have no need for expensive equipment, no open flames, and typically it is faster.
• #16: In our efforts to make it as easy and safe as possible and to leave the choice up to the contractor, we came up with an “adhesive coated landing zone” solution in addition to a “heat-weld solution. Nothing is better than an adhesive to adhesive bond. The extra effort put into this zone coating was also successful in eliminating the “cauliflowering” effect you will get, when having the substrate in a roll thicker on one side than on the other.
• #17: Once the program took off, we transferred all the know how we had assembled in the manufacturing and built for our customer this line, which is dedicated to producing the rolls in the most cost-effective manner.  
• #18: And this is then the finished roof, applied
• #19: Now what are the waterproofing membrane or construction related products that we have so far made in a “peel and stick” version?
• #20: Why do we believe in a future for peel and stick types of Waterproofing membranes? Waterproofing a building – and this is the primary purpose of a building – is to keep the water out - is not any more “just slop the goop on”!   The trade is guided by the maxims of: lighter – less work, easier to install, less transport cost, less weight on the structural part better – use the enhanced properties of new membranes and shift the waterproofing from the “goop” to the membrane. But you will need a high tech adhesive to bond to the concrete or wood or brick. Cheaper – in meaning less expensive – and here the big target is labor cost. Compared to other industries the construction industry is still in the stone ages. More than a quarter of all US manufacturing jobs are in construction! Automate the process as much as possible. And the only way to automate the process of applying an adhesive membrane in place is with “peel and stick”. Greener – when you see more people coming to a “green building” exhibition than to a traditional one, you know how important this factor is. “Peel and stick” fits the bill.
• #21: If you have any questions or think I can be of assistance in any of your projects, this is how you can reach me.