Balancing Low Density with Superior Appearance in Sealing Materials w/ Yuya Sakamoto

[Audio transcription via]

Callum Gibson:

Hello and welcome to the latest Lunch & Learn in the series from Foam Expo North America and Adhesives & Bonding Expo. It’s great to see that well over 200 of you have registered to attend today’s event. My name is Callum, and I’m the conference producer for both shows. We would like to say a special thank you to Sekisui Specialty Chemicals for sponsoring the session.

Today’s session is entitled Balancing Low Density with Superior Appearance in Sealing Materials. There will be a brief presentation followed by Q&A with the audience, so please don’t forget to enter your questions, which will be asked directly to our speaker via the Q&A widget at the bottom of your screen. I’ll now hand over to Yuya.

Yuya Sakamoto:

Thank you so much, Callum. And hello. Good morning. Good afternoon. I’m Yuyu Sakamoto from Sekisui Specialty Chemicals America. And first of all, I’d like thank all of you for those joining this session, and your interest in this session. And also special thanks to Foam Expo for facilitating this very exciting opportunity.

Now in this session, we’ll be going through the advantages of Sekisui’s expandable microspheres material, Advancell, by an actual case study which presented many challenges, and how we were able to overcome these challenges. This will be followed by a brief introduction to the Sekisui Chemical Group to hopefully convey who we are in our global presence to help customers worldwide, not only for this material but for a variety of segments as well.

Now we’ll jump into the actual presentation. For those of you who are not familiar with expandable microspheres, our material is based on acrylonitrile copolymer, which basically comes in powder form. As you can see from these images, when the heat is applied to the material, it expands up like the balloon, up to four times in diameter, and 80 times in volume. We do have a line of multiple grades, depending on the diameter and temperature, when the expansion initiates from the material to be used in a variety of size requirements and processing conditions.

As for the basic nature of this material, material will start expanding at a certain temperature, which we call the T-start. Oh, I’m sorry. Oh, I’m sorry about that. Oh, I’m sorry. I’m sorry. The animation is not coming in correctly, but just to kind of explain verbally. So for the material itself, the expansion starts at a certain temperature called a T-max, where the core structure which is made by the hydrocarbon evaporates, and when it reaches a certain temperature, which we call the T-max, the shrinkage starts. And due to this, most of our users tend to keep the processing temperature below the T-max temperature to avoid the shrinkage. And during the processing stage, I would like to know that even if the temperature drops after expansion, the sphere will not shrink. It will keep the expanded state.

Now we’ll dive into the actual case study regarding this project. And in this case study, the customer that we are working with will be a major manufacturer of automotive ceiling material, who supplies to multiple lineups, to most of the OEMs and automotive. The application for this case will be ceiling material, which is categorized as either weather strips, when it’s applied to the trunk, or glass-run channels, when applied to the either door or the window of the automotive. This material can be seen in any car, and please keep in mind that this is exposed to the human eye, and one of the most important criterias for the material will be the appearance of the material, which requires smoothness and also the uniformity of the appearance as well.

The mission that we need to accomplish with the customer was to achieve a much lighter weight level, compliant to the growing demand for electric vehicles, which makes it imperative to reduce the weight of the car gram by gram. For this to happen, to target the customer set was lower the density up to 40%, which is basically twice as much as our current formulation. And at the same time, it was also very crucial to maintain the current appearance of the material, in terms of smoothness and uniformity, even after expansion can be done, to achieve the high hurdle of the lower density.

And the major challenge that we faced to conscious to accomplish these two aspect was the trade-off of higher expansion and also rough surface as well. So we have seen from our past evaluations and work with the customers that to achieve a certain expansion level, we will need to anticipate a rougher surface due to the nature of this material.

And how and why this occurs will be in order to achieve higher expansion, to show the material needs to be enhanced to endure the target expansion level, and delay the shrink as much as possible. If you are to focus on the higher expansion, there will be a stage where the agglomeration and the contraction that shows happen simultaneously, causing the service to be uneven and rough. And by taking these two aspects into consideration and also doing multiple evaluations, we were able to come up with the material that we called high durability grades, which we categorize as this in terms of enduring high expansion, and also prevent agglomeration at the same time.

So during this high durability grades, the focus was to enhance the shell’s spheres, and also by doing that, preventing and also delaying the agglomeration and the contraction of material, which will be the basic nature of this material.

Oh, I’m sorry. And I apologize, since the animation is not going correctly, but just to kind of go through this verbally, as for the main advantage of this material, as you may have seen in the previous slides, there is expansion curve, where the expansion happens at a certain temperature, called T-start and the T-max, and also reaches a temperature called the T-max, and the contraction starts from there. So if possible, if it’s possible to be seen, here will be much better. But the takeaway for this slide will be that in order for the higher durabilities to really kick in, in terms of higher expandability and durability, the curve itself is much higher compared to the standard grades. And due to that aspect, the contraction, the shrinkage will happen at a much lower stage, which will maintain the expansion level, which is kept at a high level compared to our standard grades.

So when we compare the density of our EMT grades, compared to two of our standard grades, we were able to see that while our two standard grades achieved a 25% decrease in density, our new EMT grades were able to achieve a 47% drop. And as you may recall, the customer’s mission was to achieve at least a 40% decrease in the density. So from these valuations, we were able to suffice that target with change as well.

And this is the density drop. The significant density drop was something that we were able to anticipate. Now comes the hard part, when it comes to the appearance. So when it comes to the appearance, in terms of our evaluations, so to measure how rough the surface is, we use the method, in measuring the roughness, SA of the surface, by the density of the material.

And the takeaway that you can see from the graph on the left side here will be that the lower the roughest SA, the smoother the surface. So as you can see in the graph here, we were able to see the same level of smoothness with our standard grades, even at the lowest density level, when it comes to when the material tends to be at its roughest. So as you can see from these visualized images here, though I admit that it’s kind of difficult to see, we will also visual be able to confirm visually the appearance of material, that it is smoother, and at least if not better, pretty much at the same level as the standard grades as well. So in terms of the [inaudible 00:09:12], which comes to the appearance, we were able to suffice our customers needs in terms of also both expansion and also appearance as well.

And another advantage of this material that I believe is worth mentioning is the superior pressure resilience that our customer is able to confirm compared to our standard grades. In our internal evaluations to determine the resilience of the material, we also saw much better recovery rates compared to our standard grades and particles, when it’s exposed to the external pressure. So due to this aspect, I believe that not only for automotives, but also for applications which require obviously high recovery rate to external pressure, such as flooring and other infrastructure materials, I believe this also has a very good potential in covering those aspects.

So by the extensive evaluation, based on the new EMT grades, we were able to overcome the challenges to achieve higher expansion, in securing the smoothest surface, and also, which also suffice aggressive customers’ needs. I would also like to mention that this was made possible due to our technical support, and our team worked to provide, I would say, insight, and also resources, in terms to optimize the formulation. And one thing that I would also like to emphasize as well is that we do pride ourselves of having the resources and experience to develop material which will suffice the challenging needs the customer may have. As a result, we were able to agree with the customer, to move forward with this customer based on the proposal of our new DLL EMT grades.

So just going over the summary of this case study, our new DLL EMT grades will provide higher expansion and lower density, which we believe can contribute to lower usage of the base material. That can also lead to the basic cost reduction of the entire formulation. This material can also secure the appearance of the material, regardless of the high expansion rate, and also add advantages and the pressure resilience, which we hope will open doors to applications which we have not anticipated before. I would also like to add that as Sekisui, we do have the resources to back up customers and follow through to achieve challenging targets with our technical capabilities, and fulfill those goals that needs to be cleared.

This will wrap up the expandable microsphere part of the presentation, and I’d like to breeze through our company overview. The Sekisui Chemical Group is a Japanese-based chemical manufacturer with approximately $1 billion US dollars in net sales, and over 26,000 employees worldwide. So we do have two head offices, one in Osaka, Japan, also one in Tokyo, Japan as well.

And as one of the highlights that I would like to emphasize as well as, in terms of the Sekisui Chemical Group, is that we have been chosen as one of the Global 100 companies for five consecutive years, as one of the most sustainable corporations in the world. And that we take great pride in being chosen due to our endless effort to provide material and solutions that are environmental friendly, and contribute to sustainability to society.

And one of the aspects that makes Sekisui Chemical unique is that we are made of three divisional companies: The housing company, the urban infrastructure and environmental company, and the high performance plastic company. Our range of products and solutions cover a vast range of segments with society, and will have the capability of providing the answer to these segments worldwide. And as for our presence in North America, we do have more than several companies that cover not only chemicals, but material for infrastructure, and also medical as well. This will go through the same with Europe, as we strive to expand our presence worldwide.

And this will conclude the presentation from my side. I apologize for the technical issues that I had with the animations, and if any of the contents were not clear due to that. But in any case, last but not least, I would like to thank all of you for your time, and I was hoping I was able to convey the advantages, and further, I would say, encourage your interest. And for more information, just feel free, as Callum mentioned, to reach out to me, to our organization. And another thing is that I would highly encourage for you to visit our newly developed website,, which is very straightforward, for further information. And there will also be a contact form if you’re interested in any materials, any questions that you might have regarding this material. And this will conclude my presentation, and thank you again for your time.

Callum Gibson:

I’d like to remind everyone to please enter their questions via the Q&A widget at the bottom of their screen. Yuya’s colleague, Tomohiro, will now be turning on his microphone, and he will be asking the questions to his colleague, Yuya. Thank you very much.

Yuya Sakamoto:

Oh, thank you. So yes. Again, thank you for listening. And so if I may, I would like to go through a few questions that have been addressed. And first of all, I received a question regarding the further explanation of agglomeration process. So though it may be a little bit unclear when it’s explained verbally, so when it comes to agglomeration itself, the shell, when you look into the shell, when it expands, so when it reaches a certain stage in expansion, the durability of the shell itself will weaken up, as it expands more and more, and has become thinner and thinner. And when it reaches a certain point, so the shell that’s weakened in terms of durability and thickness, it collides together, and that’s how the agglomeration happens.

So for instance, even if you want a smooth surface within the expansion, due to agglomeration, you may see uneven surfaces, which is one of the most, I would say, challenges when the agglomeration happens. So in any case, there are further reference in our website as well, and for that, please prefer to reach out to us for, I would say, more details on the question. And I hope I was able to provide insight on that question.

And so as for another question that I just had will be, is the expandable sphere suitable to be used in different polymers? The answer to that will be yes. So in any case, though, when it comes to our past experience with the customers, basically all kind of plastic polymers can be compatible with this material, such as PVC, PP, all kinds of [inaudible 00:16:45] material, TPV, TPU, and those are, I would say, all kinds of material that we have experience in, and also can provide insight in terms of compatibility.

So in any case, if you are curious in terms of what kind of actual polymers can be used, so this is something that we’ll highly encourage to actually try. And we are very open to sending out samples for your initial evaluations. So in any case, please free to reach out for that as well.

Yes. Okay. Oh, and for another question, in terms of, so the question will be the shipping classification of raw material, and can it be shipped by air? The answer to that will be yes. So there will be no issue in terms of logistics by air or by ocean, so in that case, there will be no problem in the distribution. And for those in the audience that perhaps is located in the US, and also Europe as well, we do have warehouses located in the US and also Europe as well. So depending on the project and also requirements, we do have the capability of distributing this within that domestic range.

Yes. And another question is, what will be the color of the expandable spheres? Basically the powder itself will come in a white form. So the powder itself is white. And so just to let you know, just to be clear, so when the actual expansion happens, due to the raw material, including this material, depending also on the temperature, there is a tendency … Not a tendency. I’m sorry. There are cases where the material become a little bit yellowish. But so in any case, there will need to be some kind of maneuver, depending on the application and also temperature, to keep it white as much as possible. But in any case, answering that question, the basic color will be white. But also another thing that I would to add is that something that we at Sekisui have been working on, if there is a certain color that, for instance, that you may be interested for the material to be in, that is something that we can discuss as we’re working on that aspect as well.

And another question would be, that I’d like to address would be, can the microspheres be filled with any gas? So I apologize if I’m not understanding this question correctly, but the basic structure of this material, so the shell will be based on acrylonitrile copolymer, and the core will be based on hydrocarbon. So this will be the basic, I would say, structure of the material. If the question is based on whether it can be filled with any kind of other gas, that is something, I’m sorry to say, that would most possibly be difficult to do. But in any case, please feel free to address if I’m not either answering a question, or if it was based on different aspects.

Okay. Oh, yes. This is a very good question. So other examples of applications for this material. Anything that has to do with lightening up the weight and lowering the density, this can be applied, and has been applied, from our past experience. So not only for this automotive application, such as shoe soles, and such as flooring material, and for instance, we do have multiple applications in terms of adhesives, coatings, and in terms of, for instance, lowering up the density. And also when it comes to adhesives, by the expansion that happens within that formulation. There is a very good advantage where when it reaches a certain heat temperature, by putting in adhesives, it’ll be easier to peel.

And another interesting, I would say, application that [inaudible 00:20:59] mentioned will be, I would say, for instance, wallpaper, and also for the internal material in the automotives. And this will be to achieve, I would say, a luxurious look, and also due to the uniformity and the smooth surface that this material provides when expanded. So those are just a few of the examples for the applications of this material.

And, oh yes, another question will be, expansion take place and the injection process, the answer to that will be yes. So this material can be used in more than several processing conditions, extrusion, that goes for sure, injection, and also calendar, and also coating as well. And also just note injection is something that is very highly used, a highly used injection process for our material.

And another question I would address is, have the spheres flame-resistant properties? That is something that I believe will need to be looked into. And since the material is based on acrylonitrile copolymer, and since as I’ve mentioned, the core material itself will be hydrocarbon, which is in a way flammable. So in any case, if you’re asking whether this has flame resistance, or improves the flame resistance of the material by adding this material, this is something that would be difficult to do. But in any case, this all depends on the actual application and how it’s used, the formulation. So in any case, this is something that I would highly recommend actually trying out for your further interest.

And as for, yes, what is the maximum use temperature? So when it comes to the temperature maximum, the material, the grade lineup that we have will go up to just below 300 degrees Celsius. So the highest grades that we have in terms of the T-max will be around that area. So just a quick note is that compared to our, let’s say, competitors, we have received feedback that our material does have more stability in terms of high temperatures. So this is an area that we are, I believe, we are good at. So in any case, there will be a good … We have laid out a very good, I would say, overview of our material in our website. So I would highly encourage if you could visit our website for that, for further insight on that.

And another question is, does it have to be compounded with base plastic, or it can be tried blended? So this can go both ways. So one of the, I believe, experience that we had, is that when it comes to … So basically for the application that I mentioned earlier, in terms of the ceiling material, this will be basically compound. And that the compounded itself will be extruded, which makes the ceiling material. So that is something that is very common usage, and when it comes to blend as well, I believe that one of the blends will be based on, for instance, the coating applications. So in that case, the answer to that is, from our experience, we believe that it can be used for both cases as well.

And another question I’d like to address is, do we have the percentage increase or decrease in cost compared to the original material used? That is a very good and tough question to address at this time. But in any case, though, I do not have the liberty of being giving out the actual numbers. But as you well know, when it comes to materials such as TPV, elastin material, the base material itself is a very, I would say, high. And due to the fluctuation volatility of the market as well, it is a very good trend to reduce the base material use as much as possible.

And as I mentioned during the presentation, one thing that I can mention is that for instance, when we come to the current EMT, new grades with high durability, the density that we were able to achieve was more than 40%. So just going straight forward, that 40% means that less usage of that base material. And I hope that kind of conveys how much cost reduction that might achieve due to that.

Oh, okay. Oh, I’m sorry. I think I believe I missed a question. So a question that I’m sorry I missed is that, so does this help with the FR grade of the materials? I’m sorry to say, forgive my ignorance, but if you could chat in, what do you mean by the FR grade? That’ll be great.

Okay. So another question is, for injection application with hot runner, this tool or tip needs to be modified with mixing the sphere? Oh, so that is something that is a very good question. I do not have a straight answer for that, but the one thing that I can say is that whether this material can be used properly in that process, is it all comes down to, I would say, the temperature, of how much temperature is exposed within that condition. So in any case, and also when it comes to not only the temperature but also the time of how much that temperature exposed with the hot runner. So in any case, and also I’m not sure whether the size of the tip of the tool for the hot runner, but as I mentioned, the diameter size will come, and within, I would say, the initial diameter size will be around up to 40 microns, 50 microns before the expansion state. So if it can, I would say, squeeze through that, I believe that is something that can be considered. Yes.

And, yes. Another question I’d like to address is that, any solubility data on the microspheres. So yes, this is something that can be, I would say, referred to, that we can provide, I would say, through our contact form. So this is something that our technical team can look into. For instance, if you could provide any, I would say, solubility formulations, or the actual substance that you’re interested in, that is something that we are more than interested, that we are more than capable, I would say. Measuring and see how that behaves within our material.

Okay. So another question is that, so 170C your highest temperature star-T grade. Do you have material with a T-star with 200s, what was it, below 200C? Oh, I’m sorry. Oh, above 200C. I’m sorry. Yes. So I believe that one of the grades that we have is close to that. Let me address that to my colleague here.

[foreign language 00:28:35]

Tomohiro Horinouchi:

[foreign language 00:28:45]

Yuya Sakamoto:

[foreign language 00:28:48]

So, yes, addressing that question, we do have a grade called EM505. This will be one of our highest T-star grades. It will start around just around 200C. And again, I believe the time is coming up, so in any case, thank you so much for your time, and feel free to reach out to us through our website, or directly if you have any questions. So again, thank you so much for your time, and hope you have a great rest of the day. Thank you so much.

Callum Gibson:

I’d like to say a massive thank you to Yuya for his presentation, and you, the audience, for all of your great questions. It was fantastic to see so many of you here with us today. I would like to thank Sekisui Specialty Chemicals for sponsoring the session once again. If you did want to watch the presentation on demand, or you have a colleague that wasn’t able to attend today but would like to do so, the conference proceedings be available via our website, and you can watch the presentation on demand. Don’t forget the registration for Foam Expo Europe and Adhesives & Bonding Expo Europe will be taking place via our website. That is the eighth to the tenth of November in Stuttgart, Germany, for any of our international audience. Thank you so much for attending today, and we look forward to seeing you all there.