# Effect of Feed Rate on the Force and Energy in the Cutting Process Using Planar Technical Blades
## 2 Materials and Methods
### Experiment Methodology  
The measurement involved a series of preparatory steps, such as placing the specimen in the jaws, attaching the blade to the strain gauge bridge, and defining the feed rate for the test. As the cutting process was performed, the strain gauge bridge measured the cutting force \(F\) at an interval of 3-4 ms. The collected data was stored in the device's memory. In order to maintain the best possible repeatability of the measurements, a clamping method was provided that allows the specimen to be preloaded with a force of 28 N (which results in a 10 mm elongation of the specimen). Figure 5 shows the sample mounted in the jaws before cutting occurs.  
In previous studies [9], the authors considered a cutting speed of \(v_{f}\) = 214 mm/s. Such a value was previously adopted, due to the fact that it is close to the process feed rate  
Figure 5: Sample mounted in jaws and supporting bracket during cutting test.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Tensile strength DIN 53504 & 45–50 MPa \\ Elongation at break DIN 53504 & 450–680\% \\ Abrasion DIN 53516 & 25–50 mm\({}^{3}\) \\ Elastomer density & 1.25–1.30 g/cm\({}^{3}\) \\ Shore hardness DIN 53505 & 55–95\({}^{\circ}\) ShA \\ Maximum temperature resistance & 80 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table}
Table 3: Properties of the material (polyurethane) used as specimens in the study.  
used in an industrial plant processing flat fish (the cutting speed was adopted on the basis of data from fish processing plant Espersen Koszalin Sp. z o.o., Koszalin, Poland). Here, the authors decided to test a wider range of cutting speeds, from \(v_{f}=70\) mm/s up to \(v_{f}=400\) mm/s, which is the maximum cutting speed achievable on the used test bench.  
The methodology for measuring the cutting force \(F\) is described in the following steps:  
* Fixing blade in the blade retaining body;
* Fixing the test sample using supporting bracket in jaws;
* Closing the main door;
* Enabling the main servomotor;
* Zeroing of the Z-axis;
* Entering the feed rate value \(v_{f}\) according to experiment plan;
* Disengagement of the main safety switch;
* Tare of the force \(F\) sensor reading;
* Starting of the measuring procedure;
* Engaging the main safety switch;
* Opening main door and unclamping the cut sample.  
After all the repetitions, all the measurement data files were transferred to a PC using a portable flash drive. The data files were saved in the system manufacturer's proprietary format for the sensor. It was necessary to convert these files using UniStream Data Converters Suite 1.0.17 software (Unitronics, Airport City, Israel). The converted files were further processed and analyzed using Microsoft Excel spreadsheet version 2211 compilation 15831.20190 (Microsoft, Redmond, WA, USA).  
For this study, a total of 60 tests were conducted. The range of \(v_{f}\)velocities (70-400 mm/s) was adjusted in 30 mm/s increments. This led to 12 measurement points, for which 5 repetitions were performed. The collected data were pre-prepared for analysis in Excel software. The results of the data processing were force diagrams in individual charts, plotting fields under the average cutting force diagrams for given feed rates. Work \(W\) and power \(P\) calculations were also made for the averaged forces for each cutting speed \(v_{f}\). Based on all the collected data, the unit energy intensity index [26] of the cutting process was calculated for each cutting speed tested. The unit energy intensity \(e_{j}\) of the cutting process was defined as the work \(W\) required to cut a unit area \(A\) of the material (Figure 4).