Innovative coating needs clean webs – KELVA at Lenzing Plastics 

Lenzing Plastics is the world’s leading manufacturer of products and functional laminates made of engineering plastics, polyolefins, fluoropolymers and biomaterials. Whether roofing membranes, vapour barriers, MDO films, fabric applications or a wide variety of PTFE products – the company is a competent partner to many industries in plastics processing and the development of special solutions for the highest quality roll materials in numerous markets worldwide. Web cleaning solutions from KELVA play an important role in the coating of nonwovens and glass fiber fabrics.

Customer-oriented innovations: Continuous development at Lenzing Plastics

Web cleaning is a process that involves removing contaminants or unwanted substances from a continuous web of material as it moves through various industrial processes. The process is common in industrial applications such as printing, coating, laminating, or converting where a continuous roll or web of material undergoes multiple treatments. Examples of materials used in these industries are packaging, paper-, solid board and corrugated production, medical. 

The internal research and development department is busy day after day to optimally implement customer-specific product requirements and to constantly expand the product portfolio. Over 1500 new products are developed for partners every year.
In addition to innovative functional laminates for the construction industry in the form of tailor-made, modern, energy-efficient vapour barriers and vapour barriers, Lenzing Plastics also produces end products for the medical sector. The special feature of all these products from Lenzing Plastics is the protective plastic layer. Depending on the area of application, various innovative plastics, aluminum, metallized foils or monolithic or microporous membranes developed by Lenzing Plastics are used for lamination. Efficiency and effectiveness, but also environmental protection and sustainability play an important role

Creativity and process engineering know-how as the key to innovative end products

The hub for complex production with coating and packaging is the new Plant 4, where the Technical Center, an innovation and competence center for plastics with test laboratories, is also located. In the other production halls, everything that is delivered as roll goods is coated and assembled on compact or impressively large, fully automatic systems.

One of the responsible plastics experts at Lenzing Plastics in Seewalchen is Dipl. Ing. Hubert Grieshofer, Head of Production Thermoplast. He and his team create the process engineering prerequisites for the implementation and successful manufacture of many forward-looking products. We asked him about his experiences with coating nonwoven and glass fiber materials, how the machinery on site is successively geared to high-quality production and what the reasons are for equipping all coating systems with web cleaning technology.

How to achieve top quality in plastic coating – Innovative ways to improve quality

It started back in 2019 with a project where tests showed that threads, lint and cut particles were still visible in the coated fabric. This was not acceptable given the given quality requirements and the question arose as to how to remove the dirt and thus ensure the quality of the end product.

Various web cleaner systems were then tested. Due to KELVA’s CLEANFLOW® principle, which uses vibration in the web cleaning head to remove and suck off the smallest dirt particles from the material surface, the decision was made in favour of the KELVA HS 85 non-contact web cleaning head with a profile width of 2400 mm, with which the coating system already existing at the time was upgraded and the material roll width of 1.5 m relevant for the project could be successfully cleaned. The contamination particles were captured and collected in the AFF-K42 filter/fan unit.

After the positive experience and the clear increase in quality, another KELVA HS85 web cleaning system with a profile width of 3,400 mm was installed in a newly designed coating system in November 2021. The fact that the dedusting system was taken into account in the new machine configuration from the outset made it possible to lay certain piping in the underbody to save space.

Since then, this dedusting system has also efficiently and reliably cleaned all disturbing particles from the most diverse material web surfaces that are coated in the more than 3m wide system, ensuring that the bond adhesion is optimal and that no imperfections remain on the surface of the end product.

What experiences, benefits and added value result from web cleaning?

For Hubert Grieshofer, the question of the ROI of KELVA web cleaning systems is a “philosophical” one. For the handling of the complex projects with flawless coating quality at Lenzing Plastics, the use of dedusting systems is essential for quality assurance reasons:

“If the quality requirements require such a technology to be installed, then the ROI of the investment is directly linked to the success of the product or to the customer’s requirements.”

However, the efficiency of web cleaning is not only noticeable visually on the surface of the material. The dirt particles trapped in the web cleaning heads are blown into the large filter units and trapped in the filter plates. Due to the automatic cleaning of these filter plates, the dust falls down into the respective collection containers and is emptied from there 1x a month.

In other industrial applications, such as printing, the use of web cleaning systems leads to significantly fewer and shorter cleaning cycles as well as less wear and tear on machine parts. This is not relevant for Lenzing Plastics, as there is no contamination of rollers or the application system during the coating process.

Web cleaning also increases employee satisfaction

In the meantime, Lenzing Plastics is increasingly coating and processing complex glass fiber fabrics, in which the finest glass fiber parts and splinters can not only contaminate the material surface if they remain but can also affect other products in the environment. Possible skin irritations caused by glass fibers are also to be minimized by suction. Lenzing Plastics attaches great importance to the fact that the workplace and environment for the employees is designed to be as pleasant as possible. In addition to the quality of the end product, employee satisfaction is also an argument for the consistent use of web cleaning.