3D printing technology plays a key role in the design of prototypes and final parts. The ability to quickly and easily produce almost any shape using the Fused Filament Fabrication (FFF) method is used in almost every industrial sector, science and research. Materials for the FFF method can be divided into two groups, namely rigid and flexible. Flexible materials, in combination with pneumatics or hydraulics, offer a wide range of applications. However, in the FFF method, where individual fibers are stacked on each other and side by side, the question arises of whether the fibers will bond sufficiently to prevent water or air from passing through. This paper aims to design a methodology for the printing parameters of an FFF printer when printing from flexible materials to ensure that the filaments bond sufficiently for the printed part's water and air tightness. The proposed methodology is verified on printed samples by two tests, namely waterproof and airtightness tests. Two of the most commonly used highly flexible materials, namely TPU 30D and TPE 88, were selected for testing. The results of the work are intended to help the designers and technologists to calibrate the printing parameters for the printing of flexible materials for use in pneumatics or hydraulics.

3D printing technology plays a key role in the production of prototypes and final functional parts. The ability to produce almost any shape using this technology in combination with lightweight materials is often used to minimise the weight of the designed components. However, for some applications, such as robot gripper jaws, conventional most commonly used materials, such as PLA, may be unsuitable due to their low coefficient of friction on the material of the manipulated object, which in some cases may cause the object to slip in the robot jaws. This article describes a technical problem from practice, where a manipulated object made of steel material slipped in the printed PLA jaws of the robot during its working cycle. This work is devoted to increasing the friction force of the robot jaws by adding 3D printed soft inserts. Two insert surface shapes made of two flexible materials TPU 30D and TPE 88 are tested. The increase in friction force is measured on a measuring device with an industrial robot and a force measuring sensor. The most suitable type of inserts and material is then tested on a collaborative robot at its required working cycle. The results of this experiment are intended to help designers as a source of information or inspiration in designing similar applications.