Developing HD-BOPE shows working together is a success

A lightbulb moment involving materials and machinery suppliers and a film converter led to the development of a new material that is helping companies improve their sustainability.

The project to create high density-biaxially oriented polyethylene involved three companies coming together to show the value of collaboration in the value chain.

"It's truly a team accomplishment," said Owen Lightbody, who leads the performance films technical service team in Nova Chemicals Corp.'s innovation department. So what is so special about HD-BOPE?

Quite a lot, apparently. As Nova Chemicals describes it, though, it is primarily an important building block to help brand owners reach their packaging sustainability goals.

A lot of application development done at Nova focuses on the development of new packaging solutions, Lightbody said. It is why, several years ago, the company became interested in oriented films and specifically, in BOPE in the first place.

"There is a huge emphasis on recycling, and with BOPE, we saw we could help the industry transition to a circular economy," Lightbody said. First, however, the company had to learn more about the oriented films and the processes used to produce these.

"It began with machine directional orientation and then we started learning about the tenter frame process and biaxial films — how the process dramatically improves the performance of polyethylene. Extremely impressive," he said.

"Then, during one of our first trials, we found that with [linear low density] PE, we could make film the first day. But with HDPE, well, everything was failing, it wasn't running through the machine and that's when the lightbulb went on in our heads: This is what the market needs, this is where innovation needs to happen."

However, it was clear that this was a project requiring more know-how than the company had. It needed to find a partner able to provide the technical expertise that Nova was lacking.

"And when you look at the biax film market, there's really one dominant player, and that's Brückner," Lightbody concluded. Nova reached out to Brückner Group GmbH and explained what it was trying to do. Its contact at Brückner, Senior Sales Manager Sebastian Ruhland, immediately realized the potential for collaboration.

"We also saw HD-BOPE as the key to monomaterial packaging and therefore to recyclable packaging design," he said. The companies have worked closely together ever since.

Using its deep understanding of what was necessary from a resin perspective, Nova went to work on the development of a new HDPE grade specifically for the biaxially oriented film process. The film needed to provide stiffness, heat resistance, low tear and good optics.

Also, for converters processing the film, it needed to be similar to biaxially oriented polypropylene.

"People are always resistant to change," Lightbody said. "LLDPE doesn't have the heat resistance, which gives you usability and a wider process window on packaging lines. And BOPP has great stiffness, which LLDPE can't match, but HDPE can. It's these two aspects of heat resistance and the stiffness that really make HD-BOPE more suitable for packaging, for example for vertical form-fill-seal or long preform-fill-seal, such as stand-up pouches."

Together, Brückner and Nova started learning about the equipment needed to produce HD-BOPE. They found that while it was possible to use an existing tenter frame line, some modifications were needed and the machine was not optimized for PE.

Realizing that another partner was needed — a converter who was open to innovation and new ideas — Brückner introduced Nova Chemicals to one of its customers, Group Polivouga at K 2019, in Düsseldorf, Germany.

"That meeting went very quickly from, 'Are we going to work together?' to 'How are we going to work together?'" Lightbody said. "One of the most important factors in getting an innovation to market successfully is the choice of partners. Collaboration demands openness and transparency, otherwise your project really just gets stuck, you get bogged down and lots of times you don't get anywhere or don't achieve results as quickly as you could."

Polivouga, a Portuguese family-owned business, invested in its first biaxial film lines in 2015 and 2016. The company is very focused, ambitious and serious about new equipment. The company has two lines that run at 3,000-5,000 kilograms per hour.

"Polivouga is innovation-oriented," Production Engineer Diogo Barros said. "Three years ago, we started working with several sustainable projects and one of them was monomaterial packaging."

Polivouga was eager to collaborate, Barros said.

"In addition to being a BOPP producer, we also produce blown and cast film and offer a wide range of solutions in flexible packaging for industrial, food packaging, retail applications and agriculture in a global perimeter. Nova Chemicals has as well a wide resin portfolio for special applications, which can match perfectly in some that we are present," Barros said.

The company was extremely interested bringing a new material to the flexible packaging market, Barros said.

"The first time that we had contact with Nova Chemicals, they presented to us a promising resin for BOPE, with the mechanical properties that we were looking for," he said.

Polivouga also brought a wealth of knowledge about flexible packaging to the partnership. The company understood "what was needed for establishing added value, how you position it and which materials can you replace," explained Lightbody. Brückner's process and stretching equipment expertise and Polivouga's film manufacturing knowledge and capabilities also made it possible to rapidly validate product performance.

"The selection of our partners has really allowed us to enter the market and to move as quickly as we have. There were a great many innovations that needed to happen to bring this onto the market. If it was only resin, if it was only the equipment, it wouldn't be that strong a market adoption, but it's everything together. We now have a total solution," Lightbody said, "and that's why it is really a story about collaboration."

Working together, the three companies were able to quickly develop HD-BOPE film technology and include the initial lessons in improved resins and new line designs.

"Running the film at Polivouga and on Brückner's pilot line allowed us to optimize the resin, the equipment and the resulting film," Lightbody said.

Polivouga can now produce three- to five-layer films.

"We have had the opportunity to test BOPE on our five-layer lines with success. Using the wide range of Nova resins, BOPE has given us more flexibility in film design, which allow us to meet our customer needs," Barros said.

"For us, it wasn't the first BOPE trial, but it was the first time that we tested high density BOPE. We are happy with the mechanical and functional properties results, which can be a very interesting solutions such PET replacement or downgauging in PE structures."

The partnership is currently working on the third generation of film and developing additional grades optimized for a wide range of BOPE applications. The new grades have a broad orientation window and stiffness similar to BOPP. For Brückner, the project has led to a new line design, in which the necessary modifications were implemented.

Launched at K 2019, the new BOPP/BOPE hybrid line is optimized for full output of BOPP as well as BOPE film production. The line had a working width of 6.6 meters and 8.7 meters and generated a huge amount of interest from existing BOPP film producers as well as converting companies.

"And while Brückner continues to make modifications to make BOPE as easy to run as possible, in January, a European company already purchased Brückner's first hybrid line and further investments are expected in the short term," Lightbody said.

The development of the new film is a timely one. At K 2019, global visitors to the Brückner booth were extremely interested in BOPE, due to its potential to provide a recyclable, monomaterial packaging solution.

"It is what the market is asking for. There's been a huge push for monomaterial packaging, or design for recycling, with a number of brand owners who have come out with pledges to have 100 percent recyclable packaging," Lightbody said.

"Everyone wants to implement the circular economy. It's necessary. These are valuable materials, and we want them being reused as we do other materials. We are moving in the right direction."

While this is the main driver, an additional advantage to oriented films is that, due to their properties such as stiffness and toughness, downgauging is real possibility.

"So material reduction is a huge advantage," Lightbody added.

One of the biggest challenges in a collaboration project is the complexity of bringing everyone together, Lightbody said.

"Newness, especially, is the hardest thing to overcome because of the obstacles that arise. But having this group together, our combined expertise meant that we learned together, we were able to solve problems quicker by working together and optimization was more efficient by working together. I truly believe that without that strong collaboration we couldn't have achieved what we did and how quickly we did it," he said.

And the pandemic added to the complexities.

After K, the original idea was to have a number of promotional stand-up pouches ready for the Interpack trade show.

"Right away, that put a milestone down," Lightbody said. "We really got focused, put a schedule in place and we drove towards that target."

With Interpack canceled and travel restricted, however, it has been difficult. Trials have had to be postponed because it was impossible to get all the experts together.

"So right now we're still doing film evaluations, packaging evaluations, sampling, value chain partners, but really from the trial perspective, those are on hold. Hopefully we can resume these soon," Lightbody said.

But the next production run is already scheduled, Ruhland added.

"The target is to provide a stiff HD-BOPE film as printable base layer with good transparency," he said.

Bringing a new material to market means welcoming in a new area of flexible packaging, Lightbody said.

"The BOPE development is a big project with a lot of efforts involved," Ruhland noted. "We will continue this important collaboration for sure over the next years to provide completely new, recyclable BOPE films to the packaging market."

"It is truly a team accomplishment," Lightbody added. "Working with Diogo Barros, at Polivouga, and Sebastian Ruhland, at Brückner, we forged an incredibly strong partnership and everyone's brought their knowledge and expertise to the table to accelerate this development.

"Through this collaboration, we've advanced and developed a new material, and I am pretty sure that when we look back in a few years, we'll think: 'Hey, we were part of the team that brought this new material to market.' To me, that's pretty cool."