## 2 Materials and Methods
### Parameters of Cutting Process  
The cutting of the tested samples was carried out under actual operating conditions at DEMA spol s.r.o (Zvolen, Slovakia), as shown in Figure 1. Thus, a water jet system was from PTV spol. s.r.o. (Prague, Czech Republic) was used, fitted with a high-pressure pump model PTV 37-60 Compact, throughout this study. A cutting table equipped with a WJ 20 30 D -1Z cutting head was supplied by PTV. This system is designed for precision cutting and features advanced technology for managing high-pressure water and abrasive materials, achieving accurate and efficient results in various applications. The high-pressure pump provides consistent water flow and pressure, whilst the cutting head allows precise control of the cutting process, enhancing the overall performance and reliability of the water jet cutting system.  
The cutting process was conducted according to the cutting plan (shown in Figure 2), outlining the optimal method for cutting the samples. This plan included the specification of cutting paths and individual sections to be followed to achieve the desired results. During the cutting of technical beech plywood, we proceeded in a way that took into account the grain orientation in the individual layers of the material. Cuts were performed in the longitudinal direction (so-called longitudinal cut--with the cutting plane parallel to the grain of the outer layer), as well as in the transverse direction (so-called transverse cut--perpendicular to the grain of the outer layer), in order to compare the cut quality,  
Figure 1: Water jet cutting technological equipment used at DEMA spol. s.r.o.  
material behavior during cutting, and the occurrence of potential edge defects. This approach allowed the observation of the influence of grain orientation on the final cut quality, providing valuable insights for optimizing the parameters of plywood cutting using the AWJ method. The input parameters of the experiment were selected based on a theoretical analysis of the issue, as well as practical experience, as follows:  
1. Cutting liquid pressure: 400 MPa;
2. Abrasive: Australian Garnet GMA (grain composition 80 MESH);
3. Abrasive jet diameter: 1 mm;
4. Water jet diameter: 0.013 inches = 0.33 mm;
5. Electric power input: 37 kW;
6. Focusing tube distance above a work piece: 4 mm.  
The traverse speeds and abrasive mass flow were chosen according to the technical capabilities of the equipment and recommendations from professionals, so that any results would be applicable in practice. The selection of experimental parameters was carried out with the aim of obtaining detailed information about the behavior of the cutting process under different levels of abrasive system loading. By including both lower and higher parameter values, it was possible to observe the material's response under deliberately shifted boundary conditions, providing valuable insights for designing cost-effective cuts with reduced abrasive consumption or assessing the maximum performance of the equipment in demanding applications. The parameters were selected to cover the full spectrum of potential operating conditions, thus enabling an evaluation of interactions and establishing a foundation for optimizing efficient and sustainable abrasive water jet cutting. This approach enabled the quantification of the individual variables' effects on AWJ lag. The parameters were also selected with regard to the technical limitations of the machine equipment, which restricted the range of operating conditions that could be realistically set and maintained during the cutting process.  
A suitable combination of traverse speed and abrasive quantity was selected during the testing, with parameters carefully optimized and summarized in Table 1.