Clara and the Perfect Ribbon

BOSTIK B2B VOLUMETRIC TECHNOLOGY FOR 1K CYANOACRYLATES DISPENSING 2026, v0 Carles Oriol, Patxi Garra, Eva Pérez, Quentin Hacquart 1 1K PRODUCTS DISPENSING The challenge of cyanoacrylate (from now on “CA”) dispensing has long been a complex issue within the industry, including the application of single-component adhesives (“1K”) as well as dual-component adhesives (“2K”). In the context of 1K CA adhesives, there is a wide range of available dispensing technologies and choosing one or another will be crucial for success in each case study. Several systems have been proved useful and robust for regular industrial use: peristaltic pumps, time-pressure (pneumatic, diaphragm), etc. However, in the most demanding applications – those requiring extreme precision and repeatability – the preferred option is to rely on volumetric systems such as progressive cavity pumps. While other technologies have shown only moderate precision in these cases, volumetric technology provides excellent accuracy control and consistency. At Bostik, our extensive research has led us to certify the Viscotec Preflow system as the premier choice to attain the finest precision. The initial key to this breakthrough has been the use of a stator part coated with FFKM elastomer, which ensures smooth operation of the system without clogging. Besides, the pump technology is not the only factor to keep in mind. The robots, the tips, the packaging of adhesives, the maintenance routines, the understanding of the limitations and of course the best adhesives developed and validated for industrial dispensing will allow our customers to easily success and create great and amazing products. Generic overview of key ways to dispense Cyanoacrylates in the industry (*Bostik has some ongoing developments to make this happen) 2 VOLUMETRIC SYSTEMS Why What’s volumetric Advantages/disadvantages Viscotec volumetric technology is based on a displacement system (endless piston screw) which consists of a rotor and stator. The controlled rotating motion of the rotor causes the product to be displaced in the stator and generates a uniform, free of pulsation, conveying movement of the product. This means the volume of adhesive product being dosed remains constant, leading to an improved accuracy inconsistency control. This makes the difference in comparison to classic time-pressure devices, where volume dispensed can vary from cartridge to cartridge or even during the beginning and the end of the same cartridge (same product dispensed). 1K CA adhesives are known for being able to cure quickly in small gaps. One would think it cannot be different in volumetric pumps, where rotor and stator create only a narrow space for product to move, thus clogging the system. However, the use of a stator part coated with FFKM elastomer – as such provided by Viscotec – helps prevent this fast polymerization and ensures a smooth operation. Rotor and stator in volumetric systems. Differences of elastomers between FKM (some compatibility with cyanoacrylates) and FFKM (very inert to cyanoacrylates cure) It is possible to reverse the conveying movement by changing the direction of rotation. This adjustable “suck-back” action allows to break the product thread just after dispensing, giving improved dripping control and no accumulation of product at the beginning of the dispensing. Again this is a significant difference with time-pressure systems (only one-way circulation of fluids). This all is translated into better dosing precision, with lines of consistent and uniform width. Moreover, dynamic flow control is possible by tuning the voltage input of the pump, which leads the conveying motion. The flow of product being dosed can be modified independently to the rest of the configuration, so that the robot speed movement does not necessarily have to be modified to adjust the product flow. The 1K volumetric system is useful for a wide range of product viscosities: from low viscosity to gel. As intuition may tell us, it is possible to reach the narrower bead size with the higher viscosity adhesives (up to 0,3-0,4 mm for gels). One of the most important drawbacks of the volumetric dispensers is their relatively high cost in comparison to other common – but not as accurate – technologies. It is worth noting that the cost could be admissible in cases that require automatization, justified by the need of a huge volume of product, a fast application and/or extreme dosing precision for high end application (medical, electronics, luxury, automotive, …). An example of external evaluation of the dispensing stability is available in Annex 8.3. Another consideration is the inherent complexity of the technology. Whereas other systems are easier to operate and maintain, volumetric dispensers usually require more advanced knowledge. For optimum performance it is advisable to operate relying on a technical trouble-shooting guide, which includes maintenance advices as well.