Because of its roots in UPM, Walki is known as a paper converter, which these days also makes products in which there is no paper at all. At the moment, Walki is focusing on producing multilayer materials.
The everyday consumer often unknowingly comes into contact with paper and packaging processed at Walki’s mill in Valkeakoski. They are to be found, for example, around ice cream cones, packs of butter and the lids of yoghurt cartons. House builders come across laminates manufactured in the mill, for example on the surfaces of mineral wool or polyurethane insulation boards. The steel industry protects metal sheets and rolls from scratches and corrosion with Walki’s creped kraft paper.
“In our most simple products, we glue paper and mesh, aluminium or plastic film together. Technically demanding foil laminates for the construction industry consist of lacquered aluminium, paper, adhesive and polyethylene. In a single run, we manufacture 11-layered laminate, which makes our products unique”, says technical customer service officer, product development engineer and laboratory supervisor Saija Kotala from Walki.
The mutual exchange of ideas
Adhesive plays an important role in attaching the different layers of products together. Most of the adhesives come from Kiilto; the company uses Sitol dispersion adhesive and Kiiltomelt hotmelt adhesive. Co-operation in order to find the best possible adhesive solutions began four years ago.
For example, at this very moment an adhesive laminator is testing the suitability of hot-melt adhesive as a coating for building boards that are under development. Sometimes standard adhesive works, but at other times the adhesive is specifically tailored to a product’s requirements.
“We exchange product development ideas. The other day, we co-operated in the development of a fire-retardant adhesive, as fire prevention is important in insulation boards for the construction industry. In another project, we improved the adhesion of hot-melt adhesive to metal rolls. Together, we go through technical properties and product development requirements”, says Kotala.
From the adhesives it uses, Walki demands good adhesion, spreadability and water- and heat resistance.
“Environmental values are also very important to us. You can’t just put anything into the adhesives; they must be safe to handle and it must be possible to dispose ofthe end products appropriately”.
The WALKI mill in Valkeakoski, Finland, can manufacture 11-layer laminate in one production run, which makes the product unique in terms of its manufacture.
- Walki is Europe’s leading producer of technical laminates and protective packaging material. It has a total of about 900 employees in Finland, Germany, the Netherlands, Poland, Russia, the United Kingdom and China.