A Feasibility Study of a Robotic Approach for the Gluing Process in the Footwear Industry

Abstract

Manufacturing processes in the shoe industry are still characterized to a large extent by human labour, especially in small and medium craft enterprises. Even when machinery is adopted to support manufacturing operations, in most cases an operator has to supervise or carry out the task. On the other hand, craft footwear industries are called to respond to continuous challenges to face the globalization effects, so that a rapid adaptability to customer needs is required. The industry 4.0 paradigms, which are taking place in the industrial environments, represent an excellent opportunity to improve the efficiency and quality of production, and a way to face international competitors. This paper analyses and proposes a robotic cell to automatize the process of glue deposition on shoe upper, which exploits a new means of depositing the glue compared to State-of-Art applications. While the latter mainly adopt glue gun spraying systems or pneumatic syringes, the proposed robotic cell is based on an extrusion system for the deposition of molten material originally in the form of a filament, similar to all extent to those adopted for Fused Deposition Modeling (FDM). Two cell solutions are designed and tested. In the former the extruder is the robot end effector and the shoe upper is grounded to the cell frame. In the second, being the reciprocal, the shoe last is clamped to the robot wrist and the extruder is fixed to the cell frame. The peculiarities of the two solutions are pointed out and compared in terms of cell layout, hardware, programming software and possibility to develop collaborative applications. A self developed slicing software allows designing the trajectories for glue deposition based on the CAD model of the shoe upper, also allowing driving the inclination of the extruder nozzle with respect to the vectors normal to the upper surface. Both the proposed cell layouts permit to achieve good quality and production times. The solution with the mobile extruder is able to deposit glue at highest end-effector speed (up to 200 mm/s). On the other hand, the solution with the mobile shoe upper and fixed extruder seems to be more appropriate to enhance collaborative applications.

A Lean Robotics Approach to the Scheduling of Robotic Adhesive Dispensing Process

“…In response to the above problems, this study considers the problem of task scheduling in robotized adhesive dispensing. It is worth mentioning that problems of this type have been quite seldom investigated in previous studies [30,31,32] and that the approach employed in this work is an alternative to the methods reported in the literature.…”

Quick Setup of Force-Controlled Industrial Gluing Tasks Using Learning From Demonstration

“…Recently, automated gluing applications have become very popular with the development of new industrial machines and tools, which can be efficiently utilized by collaborative robots. The majority of the work focuses on defining the robot trajectories based on the CAD description of the industrial object (Castelli et al, 2021). Other approaches, utilize simple Cartesian space industrial manipulators coupled with computer vision (Pagano et al, 2020).…”

Development of an Integrated Robotic Workcell for Automated Bonding in Footwear Manufacturing

“…Analyzing the state of the art about the automation of the bonding process in the footwear industry, different research works related to the operation can be found, mainly for gluing application systems, using cartesian robots and a vision system [5], [6], or anthropomorphic robotic arms to spray the outsole [7]. References can also be found about systems for applying adhesive to the shoe upper using adhesive extrusion systems [8], as well as about other systems to deposit glue so as to wet the shoe upper controlling the force between the glue extruder and the surface of the shoe upper during the application [9]. Different approaches can also be identified to automate footwear manufacturing plants from the 3D CAD information of the footwear model [10], but results are not particularly satisfactory or limited to the large-scale manufacturing; however, given the specific characteristics of this sector, where short series of shoe models are usually manufactured and different sizes and feet (right and left) must be considered, fully automating a plant is particularly challenging.…”