Slit nozzle application with bitumen onto a carrier material.

State-of-the-art hotmelt coating systems for bitumen processing

Increased efficiency in bitumen application through wide slit nozzle technology

Thermal challenges and an optimal coating application are required not only in hot glue processing. SM Klebetechnik has transferred the benefits of the hotmelt coating to the processing of bitumen compounds. Result: higher product variation and diversity, as well as increased efficiency and cost savings for the customer.

Hotmelt is the general term for thermoplastic and reactive hotmelt products, whose application in the assembly, automotive, packaging or non-woven industries is continuously increasing

Bitumen processing through optimised hotmelt technology

Modern technology enables the use of modular application systems of scalable size and performance, which can also process alternative materials with related process parameters. Nevertheless, individual requirements must be considered when altering production – sometimes a tricky issue that the experts for application and coating systems from SM Klebetechnik are specialised in.

“In our technical centre, we closely examine the rheological requirements of the materials being processed and develop approaches to optimise processing,” explains Rene Schog, Managing Director of SM Klebetechnik. The modern hotmelt machine technology for bitumen processing for the production of welding sheets for roof sealing was scaled and optimised.

Conventional production of welding membrane products for roof sealing

Knife coating systems are generally used to produce bitumen or polymer-bitumen welding sheets, often simply called “roofing felt”. For the bitumen welding tracks, the carrier sheet is coated on both sides with liquefied bitumen mass in one action. The carrier material is embedded in the middle. This leads to undesirable effects such as discrepancies in the layer thickness or edge sharpness and edge inaccuracies. Thermal effects can also influence the viscosity of the bitumen formulation and the desired product properties.

SM Klebetechnik relies on scalable wide slit nozzles instead of knife coating

For a higher efficiency in bitumen processing, SM Klebetechnik has replaced the knife coating technology with in-line coating stands with adjustable wide slit nozzles and volumetric metering gear pumps.
The benefits for bitumen processing companies are clear:

• A stable and even distribution of the application weight across the entire coating width
• A largely viscosity-independent quantity management synchronized with the feed rate
• A high edge accuracy
• An economical, precise adhesive application and optimised energy consumption
• The possibility of integrating variable special edge strips or special sections with other thermoplastics through additional nozzles

In-line coating stand with wide slit nozzle and pumps.

Special case bitumen membrane with self-adhesive surfaces

The complex production of bitumen sheeting with self-adhesive equipment is also made easier and more efficient with the technology from SM Klebetechnik. The self-adhesive areas are applied on the top or bottom side in the lateral edge area of the web. As the material for the self-adhesive strips is significantly more expensive than for the bitumen used for the main surface, economical use is important. This can be reliably achieved with the wide slit nozzle system from SM Klebetechnik. The material of the surface-sticky raw material can be made from 200 L drum ware via drum melter or tank melters of different sizes.

Optimise your systems and conquer new markets with SM Klebetechnik

The example shows how SM Klebetechnik can transfer its know-how and many years of experience from hotmelt technology to other market segments and fields of application. The benefit for our customers: The changes lead to noticeable, cost-reducing improvements that quickly pay for the investment in plant optimisation. Economical use of materials combined with optimised energy consumption also support a sustainable corporate strategy.

GX7 Premium drum melter 200 litre with screw pump.