Study of the Viability of laser welding processing of polymers using welding by transmission

• Grant number: 20/00596-4
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE
• Start date: July 01, 2021
• End date: March 31, 2022
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Renato Boschilia Junior
• Grantee: Renato Boschilia Junior
• Company: Procoding Tecnologia para Rastreabilidade Industrial Ltda
• CNAE: Comércio atacadista de máquinas e equipamentos para uso comercial; partes e peças
• City: São José dos Campos
• Associated researchers: Eduardo Antonelli ; Fabio Roberto Passador ; Milton Sergio Fernandes de Lima
• Associated scholarship(s): 21/06697-0 - Study of the viability of laser welding processing of polymers using welding by transmission, BP.PIPE; 21/06700-0 - Study of viability of laser welding processing of polymers using welding by transmission, BP.TT

Abstract

The first demonstration of welding in thermoplastic laser polymers emerged in the decade of 70 occurring from the years 90 a massive use in the mass production industry. This technology has provided application in several branches of the industry, being the main industries of electronic components, fabrics, biomedical devices, windows, food packaging and hospital materials, display displays and components Automotive. The technique is used to add two parts of polymeric materials, which may be in the form of films, molded thermoplastic plates and even tissues in which using a laser beam in the contact region, the softening of the material occurs and the Union of Both parties. In order to obtain a good laser welding parameters such as the power used on the application site, beam size, type of beam mover and the clamping system with pressure in the region to be welded must be controlled. The polymer weld usually is of two forms in the industry, in direct form (top to top) and indirect (welding by transmission), known as Laser transmission welding (LTW) by industry. The types of lasers most used for such application are those of diode, 780-980nm, and fiber, 1000-2100nm, the diode being the most used due to its cost and efficiency in the weld. The most widely used form by the industry is the indirect LTW, being already applied in countries such as Germany, USA and China. The technique occurs through the transmission of the beam in a transparent or transluded medium, superior material, up to the point of welding the absorbable layer, inferior material. Normally additives such as black smoke are used to increase the energy absorption of radiation in the contact region. In order to perform the weld, a pressure fixation system is required at the point of application of the laser so that the weld occurs more effectively. To enable the technique, two types of thermoplastic polymeric materials, polycarbonate (CP) and polymethylmethacrylate (PMMA) are used, in natural conditions and dosed with smoke black, crystal and fume respectively, being welded only to Materials of the same class (PCcrystal + PCsmoked and PMMAcrystal + PMMAsmoked). Control parameters such as power, and pressure will be used to obtain the best soldering conditions. Will be used three types of lasers, continuous fiber 500W (1036nm), in Senai/SC, Joinville, fibre-Yb pulsed 30W (1064nm), Promarking and 200W diode (980nm), in Germany represented in Brazil by the company ReB Laser (Coherent-Rufin) to test the feasibility of technology. Subsequently, these welded samples will be characterized and analyzed together with the Federal University of São Paulo (UNIFESP). Structural characterizations such as optical microscopy and scanning electron microscopy (SEM) will be performed to observe the weld morphology and mechanical characterizations, such as hardness and tensile strength, to validate the weld resistance, seeking the best parameters for a sturdy weld with considerable visual quality. Procoding will, in contrast, develop a pressure fixation system to weld the samples. In addition to the technical feasibility, the commercial viability of the project will also be developed through the use of the technical, economic, commercial, environmental and social impact study tool, called EVTECIAS. For the success of the project of study of the feasibility of the weld, will have participation of a scholar, associate professors, technicians in conjunction with the company Procoding in the development and innovation of research and technology. (AU)