With the viscosity-independent dispensers from Viscotec, which are all based on the endless piston principle, highly viscous materials can be dosed reliably and precisely. They offer shear-sensitive and high-precision material handling.
The thixotropic 1K silicone "Loctite SI 5970", which hardens at room temperature through contact with moisture, is difficult to process due to its high viscosity. The dosing systems for handling this 1K sealant have proven themselves in extensive dosing tests. In particular the 1K dispenser of the RD series. The curing of this material takes place comparatively quickly: After only approx. 25 minutes at 23 ° C and 50% humidity, the skin forms and the surface is tack-free. Since methanol is split off during hardening, Loctite SI 5970 is one of the neutrally crosslinking silicones.
The properties of the 1K silicone cause z. B. with time-pressure systems great problems in the dosage of a beautiful and uniform caterpillar, since it can come here especially at the beginning of the dosage to a surplus of material and at the end to a strong stringing and dripping. The material is formulated in a thixotropic manner, which in principle reduces the viscosity during shearing and simplifies processing through improved flow behavior. Nevertheless, with low shear, an initial viscosity of about 1,5 million mPas remains - the dosing material therefore still presents challenges, especially in the start-up behavior of the systems. After the application, the silicone relaxes again very quickly and the viscosity increases almost abruptly, which in turn prevents bleeding.
Loctite SI 5970 is primarily used for sealing applications. Viscotec offers the complete dosing system from a single source: Typical systems for this silicone consist of a hobbock removal, a hose line and a 1K dispenser. The 3RD12 or 3RD10 dispensers of the RD series are perfect for this material and its typical applications.