Attempts to save on butyl extruder led to the emergence of various substityutov: butyl cord sticky tape or aluminum range with a pre-deposited layer of butyl. All these methods have limited use for several reasons: * Low productivity * Increased cost of components (butyl cord distance with a pre-deposited layer of butyl); * poor quality of the finished glass (tape). The main function of the second layer of containment – the tradition of double-glazed windows of the strength properties. It should be remember that windows during the operation are subject to wind, thermal, vibration, and so forth influences. Secondary circuit, along with durability and elasticity should have to compensate for the higher these effects. Currently, the following types of secondary sealants: * hotmelty * Polyurethane * polysulfides (Thiokol) * silicones.
Hotmeltami sealing technologies were widely circulated in Europe in the 70 early 80-ies. Made on the basis hotmelty is a single component thermosetting compositions are reversibly softens under heat and solidifying in the cold), for example, behaves construction bitumen. Hotmelta obvious advantages – cheap, simple, machine design process, the possibility of re-use in the production process waste materials, a short time curing sealant application (measured in minutes). For application hotmeltov used hotmelt extruder representing heated to 170-190 'with heated tank, from which the pipeline is fed by termoizoliruemomu melt hotmelta (5000-15000 euros). Hotmelty packages are available from 1,5 to 50 kilograms, intended for different machines. Main packing a 6-pound block of x x. However, thermosetting properties hotmelta lead to the following consequences: when heated in the sun softening the sealant layer leads to a deterioration of mechanical properties of glass.