The BMSTU has solved a task of developing an original processing method to join cylindrical adhesive joints, which allows joining quality improvement. A key point of the method is that joining is vertically arranged and a forced air supply with a given amount of the airflow pressure and temperature is directed from the bottom end towards upper one. This method allows locking the adhesive composition in the gap and arrangement of conditions for curing an adhesive composition without its outflow. In this case it is possible to adjust mutual bracing of joining pieces to reach a specified joining accuracy till the cure of adhesive composition.
To study a new method of joining, the BMSTU has built an experimental unit and carried out a set of experiments with an anaerobic adhesive composition Loctite 638 with varying the gap in the join within the range from 0.1 to 0.7 mm. In the course of experiments an empirical dependence of the critical shearing force on the gap value in the join has been derived, as well as the recommended conditions for air quality to hold the adhesive compositions depending on viscosity has been revealed. As a result of experimental research, it is found that for adhesive composition of low-viscosity from 20 to 1000 cSt, a range of air quality for holding the adhesive composition in the assembly gap is from 9.8 to 196 Pa; for adhesive composition of middle-viscosity from 1000 to 2000 cSt, the recommended conditions lie in the range from 197 to 735.5 Pa; for adhesive composition of high-viscosity from 2000 to 5000 cSt, the recommended assembly conditions are from 736 to 1471 Pa. The realized studies have shown that using a new joining method, the amount of used adhesive composition is by about 25% less, the labor hours of the joining process are two times decreased, and the joining strength obtained is increased on average by 10-15% as compared to the traditional assembly methods of the adhesive cylindrical joint. This method allows assembling the joints in the increased gaps, excluding the of adhesive composition outflow from the gap and the use of additional components.