Filtration and Separation - Bonding for filter life

F+S: What does Jowat have to offer to the filtration industry? And what exactly does Jowat do?

IH: Adhesive technology is of central importance to the filtration industry and high-performance adhesives play a key role in facilitating efficient and reliable filters. Jowat SE, headquartered in Detmold, Germany, is one of the world’s leading suppliers of industrial adhesives. The company was founded in 1919 and has manufacturing sites in Germany as well as four other producing subsidiaries: Jowat Corporation in the USA, Jowat Swiss AG, Jowat Manufacturing in Malaysia, and Jowat China Adhesives Co Ltd in Dushan, China. As a supplier of all adhesive groups, Jowat manufactures 100,000 tonnes of adhesives per year, with 1,300 employees. The group’s portfolio for the filter sector covers products for bonding air filters and media, filter pleating and frame bonding applications as well as for the lamination of activated carbon filter media.

F+S: There are many manufacturers selling adhesives for the filtration industry. What sets Jowat apart?

IH: Our work is based on both expertise and a deep understanding of our customers, their processes and their products. We supply not only adhesives but tailor-made solutions which suit our customers’ needs precisely. Our customers can rely on support for all bonding-relating questions beyond the actual application of the adhesive.

MD: Quality assurance is also integral to our service. We analyze processes and applications and offer support in addressing any potential issues. At our location in Detmold, for example, we have a wide array of machines and equipment for that purpose. Our customers are the most important factor in our day-to-day work. Their wishes and requirements are a paramount priority for us. Our experts develop tailor-made solutions for every challenge. Throughout the process, we provide a comprehensive advisory service and assistance as a matter of course. We want to ensure that every last member of our team can offer the very best expertise to our customers. The tradition and experience from over 100 years of corporate development enable us to be an active technology leader. Our role as a leader in innovation is facilitated by committed and competent employees who are adhesives experts and are always finding the best solutions for our customers.

F+S: How has the filter market changed over recent years?

MD: We all live on the same planet and share its resources. In this environment, clean vehicles, air and water are a common good. Air and water filtration have become an integral part of our daily lives, protecting our health and quality of life – at home as well as at work. Demand for air filters has been growing in recent years, especially since the Covid-19 pandemic. We have no doubt that filtration improves our lives. That’s the reason why this industry is a growth market and crucial for Jowat.

F+S: How does Jowat support filter pleating and frame bonding?

MD: Pleated filter media consist of different materials, for example paper of various nonwoven fabrics. Thermoplastic adhesives from Jowat for pleating and bonding the frames of filter media are characterized by a wide range of adhesion and ensure bonding applications with sealing and forming properties with the highest possible process reliability. The special characteristics of these adhesives maintain the shape of the finished filters throughout their lifespan, even when the compound is exposed to mechanical stress, eg during installation, or to high temperatures. Special polyolefin hot melts can be used for pleating as well as for filter frame bonding and meet all necessary requirements. Increasingly compact engine designs mean that filters often have to be warped and twisted when being replaced, which represents a high mechanical stress for the bonded frame and requires high bonding strengths. The adhesive – or the bondline, to be more specific – must not break and the filter pocket must remain tight. In addition, the adhesives are not allowed to have any detrimental effect on the filtering performance.

IH: Jowatherm and Jowatherm-Toptherm adhesives for pleating, laminating and frame bonding are flexible and reliable in processing, facilitating a long service life and superior quality of the filter elements.

The use of hot melt adhesives in the pleating process significantly increases the filter's filtration surface

F+S: And what about activated carbon filters?

MD: Laminating activated carbon filter media presents a unique challenge. Jowat’s thermoplastic PO and reactive PUR hot melt adhesives excel in this application, facilitating a full-surface bonding without sacrificing permeability. The lamination process does not affect the absorption capacity and air permeability of the filter media. Only a minimal adhesive amount is needed to achieve high filter medium strength, preserving the maximum surface area for filtration and air purification.

F+S: What distinguishes Jowat’s adhesives for filter manufacturing?

IH: Our adhesives developed for activated carbon binding are odorless and have very low fogging and emission values – crucial for their use in vehicle interiors. PUR hot melt adhesives meet the heat resistance levels required by automotive manufacturers and facilitate the production of passenger compartment filters in OEM quality. Thermoplastic Jowat adhesives for the pleating and frame assembly of particle filters are characterized by a wide range of adhesion and ensure bonding applications with sealing and forming properties with the highest possible process reliability. They facilitate high bond strengths with low application amounts as well as a long service life and superior quality of the filter elements. PO as well as PUR hot melt adhesives from Jowat facilitate a fast processing of the filter media and therefore efficient manufacturing due to optimum spraying performance and high green strength, and support all downline processing steps. Both adhesive systems are characterized by low fogging and emissions, and are odorless. Jowat filter adhesives meet the heat resistance levels required by automotive manufacturers and facilitate the production of cabin filters in OEM quality.

F+S: What are your best-selling products for the filter industry?

MD: Jowatherm 262.25 is a tried-and-trusted “all-rounder” for the manufacture of HEPA and ULPA filters. Its short open time, high initial strength and quick downline processing supports high production speeds, even at processing temperatures as low as 125°C. The technical characteristics of Jowat-Toptherm 263.25 are adapted to the production speeds of filter frame bonding procedures and the adhesive is used in both manual and automated processes. The monomer-reduced PUR hot melt adhesives of the Jowatherm-Reaktant MR product range have a low content of diisocyanate monomers of less than 0.1% and are therefore free of hazard labeling requirements. They facilitate processes free of pollutants in many production fields. This protects processors and allows adhesive applications without additional training of employees. Jowatherm-Reaktant MR 614.50 is an adhesive that can be used for the lamination of activated carbon filters and multi-layer filter elements. It provides very good bonding results with small application amounts. Compared with established products, the adhesive can be processed at low temperatures between 100–120°C ensuring highly resource-friendly and optimized bonding processes. Apart from the health-related aspects and the extra safety, the sustainable use of this adhesive therefore also provides economic benefits.

F+S: Could you share an insight into ongoing research endeavors?

IH: For filter frame bonding, we have developed Jowat-Toptherm 263.25, a new, nonblocking PO hot melt adhesive which is ideal for automatic feed systems. It is flexible, allowing for filter frame to be deformed without damage. There is also growing demand for label-free PUR adhesives. We have ongoing development projects for media lamination and activated carbon binding which show excellent results in all tests, binding significantly more activated carbon without increasing the adhesive application amount compared with conventional PUR.