Feature Article Figure 7. Process diagram for coil-roller distance of 35 mm. of the process diagram. These critical temperatures are defined for Polyamide 66 in following discussion. Before reaching the roller, the joining area has to be heated above the melting temperature of 260°C. Thereby, the polymer chains have enough thermal energy to move freely. After melting and before reaching the contact area of the roller the temperature in the joining area has still to be above the crystallization temperature of 225°C. When the temperature falls below crystallization temperature the bonding between the polymer chains are too strong to allow them to diffuse across the bonding line. This temperature limit is called ´joining area consolidated´. After consolidation under the roller, the temperature in the joining area must remain below the crystallization temperature to avoid deconsolidation. If the temperature rises above crystallization temperature, voids will occur and the joining or the adherends partly delaminates. This temperature limit is called ´joining area voids´. In addition the maximum process temperature has to be always below the degradation temperature of 320°C. To ensure a constant joining quality, the power input from the generator has to be controlled by a control signal. Because the temperature in the joining area is measurable from the outside, the temperature of the laminate surface is used as control Figure 8. Overview of user-interface for end-user. 46 SAMPE Journal, Volume 53, No. 1, January/February 2017