## 1 Introduction  
One of the technologies for processing plastics is the 3D printing technology namely fused filament fabrication (FFF). In technical practice, it is a widely used technique due to its ease of use, low cost of input material, and minimal waste generated by the process. The FFF technique can reduce production costs of a product while maintaining high reliability of plastic parts [1, 2]. In the field of 3D printing, a number of research activities have been carried out in order to examine the mechanical properties of components which have been produced using new technological processes. Strength, stiffness, weight, and other properties of components made by 3D printing depend on various conditions such as layer thickness and height, shell thickness, and fill density. The most common materials used in 3D printing are acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). Many studies have addressed the mechanical properties of 3D-printed parts; a study by [PERSON] et al. [3] was among the most notable studies, which investigated the tribology of 3D-printed parts and mainly focused on the mechanical properties of polymeric materials, in particular, PLA material [4, 5, 6, 7]. However, research on the ULTEM 9085 material is lacking. Research by [PERSON] et al. aimed to measure the mechanical wear of 3D-printed parts made of PLA [8]. Mechanical properties of colored PLA types were described by [PERSON] et al. [9]. Research by [PERSON] et al. addressed ABS plastic parts, the influence of orientation of the individual printed layers, and their mechanical properties, such as tensile strength and impact resistance [10]. Suitable orientation of a part in 3D printing can affect the structure of its surface (roughness), which affects the tribological properties of components manufactured in such a way [11]. Lack of information about the tribological properties of components produced by 3D printing can in practice lead to their excessive wear and subsequent failure of function. [PERSON] et al. investigated tribological properties such as the coefficient of friction and wear behavior in samples produced by 3D printing from ABS material [12]. [PERSON] et al. described the tribological behavior of ABS composites with added alumina [13]. [PERSON] and [PERSON] et al. reported that tribological properties of 3D-printed polymer components could generally be improved by appropriate settings of the printing parameters [14; 15]. These studies were followed by [PERSON] et al., who took temperature and the color of the fiber into consideration [16]. [PERSON] and [PERSON] conducted research on the friction and wear of ABS polymer produced using the FFF technique. They took note of three parameters: (1) load, (2) speed, and (3) face-centered central composite design (FCCCD) orientation and their influences on the coefficient of friction as well as abrasive wear. It was shown that yield speed was affected by the friction of a firmer load [14; 17]. Parts manufactured using the FFF technique show unevenness, but as the surface smoothens over time, the coefficient of friction decreases and becomes stable. Damage to contact surfaces is usually caused by wear and tear such as abrasion, fatigue, and surface undulation, or erosion and cavitation. Abrasive wear often leads to irreversible changes to the surface of a part which leads to a change between the bonds of the material particles. The friction coefficient usually rises sharply from low values to a peak value and stabilizes at slightly lower value following nearly linear curve [18]. Optimization of parameters from the point of view of tribology was addressed by [PERSON] et al., who analyzed the coefficient of friction and wear rate of components made of ABS using the (Box-Behnken Design) methodology [18; 19; 20].