Projeto e protótipo de um dispositivo mecânico para realizar o corte da pestana em pão francês

Abstract

Bread is one of the oldest foods consumed by humanity and has maintained its popularity over the centuries. However, its production processes and methods have been continuously updated to meet contemporary demands. In Brazil, the most popular type of bread is pão francês (French bread), whose recipe and manufacturing process are relatively simple, contributing to its widespread acceptance across the country. A distinctive feature of pão francês is the pestana, a longitudinal cut made on the surface of the raw dough. This cut, which must not be too deep or cause shear, is essential for allowing gas exchange and proper dough expansion during baking. In bakeries, this process is performed manually by bakers, making it not only labor-intensive but also prone to imprecision and inconsistencies in quality control. Poor execution of the pestana can significantly affect the appearance and quality of the bread, leading to nonconformities in external characteristics. Another important aspect related to the pestana is its ergonomic impact on bakers. The repetitive motion required to make the cut can cause work-related musculoskeletal disorders (WMSDs), leading to health issues for professionals. This study aims to develop a mechanical device to standardize the pestana cutting process in pão francês, ensuring greater uniformity in production and eliminating the risk of WMSDs for bakers. To structure the collected data and guide the prototype development, the methodology proposed by Pahl et al. (2005) was adopted, offering a systematic model for product and technical solution development. A survey of customer needs was conducted, along with field research to verify the cutting parameters influencing the pestana, and benchmarking of existing solutions. Based on this, ten unique design concepts were developed using a morphological matrix, and the most promising solution was selected. A preliminary design was then created, including the definition, detailing, and selection of components and materials. To validate the project’s objective—the pestana cutting process—a proof-of-concept prototype was built. The results demonstrated the device’s effectiveness in producing pão francês with pestana that met predefined standards.