The Evolution of Custom-Made High-Pressure Mixing Heads for the Most Demanding Polyurethane Manufacturing Applications

摘要

Polyurethane dosing equipment manufacturers face more and more stringent requirements in the contemporary marketplace, due to the fast progress on the chemistry side and increasingly sophisticated requisites by manufacturers and their suppliers. High flexibility in industrial production is pushing the technology of mixing and dosing towards levels of technical excellence never reached before. The purpose of this paper is to share with the industrial technical community the latest achievements in high-pressure polyurethane mixing from the Cannon Group's point of view. From automotive applications, where flexible foams require mixes composed of multiple streams, the building and furniture industries, to growing segments such as elastomers for shoe soles applications, the well-established FPL mixhead scries is still widely used, with the possibility to have the third color stream along with polyol and isocyanate in the mix. We will proceed presenting the maturation of the Quick Color Change (QCC) technology, combined to the legacy of the L-shaped mixheads. A brand new range of groundbreaking heads has been refined, defining new opportunities for the quick change of a third component, color or any other additive, directly in the mixing head and recycling through a dedicated nozzle. With the 2QCC variation, today it is easy to foresee the quick change of a third and a fourth component, without wasting a single shot for flushing the mixing chamber. Different sizes and models are now readily available for QCC and 2QCC blocks, including 8, 10 and 12 mm mixheads. With the FP2L mixheads we can offer another fascinating alternative to the use of multiple colors with complex but effective mixheads provided with 2 different mixing chambers where up to 4 different streams can get together (polyol, iso and 2 colors possibly). Moreover, the development of a 4QCC quick change of up to 4 different colors/additives is underway for such mixheads. Finally, we are going to present the multi-awarded AX's most impressive features, making this mixhead a versatile invention for TIER ls flexible foam fabrication. Today this mixhead is capable of dispensing up to 7 different components, according to a free selection of 1 axial and 6 radial streams, characterized by low weight and a compact design, modular injection and variable adjustment of total output. A multi-position stroke adjuster helps to achieve a more consistent laminar flow, while the self-cleaning piston is now able to open in less than 0.4 seconds for an overall cycle time shorter than a second.