# Composites Containing Felt Wastes from the Automotive Industry
## 2 Research Results and Analysis
Successively for the F0.1 composite, the value was 44.77% (23.62 Mpa) lower. For the F1.6 composite, the value was 52.30% lower (20.4 Mpa). For the F0.3 composite, it was 53.55% lower (19.86 Mpa). Relating the present results to those presented in the literature, some inconsistency was noted. In the literature, for example, [PERSON] et al. [80], using a nylon fibre addition of 1 to 2%, obtained an increase in compressive strength from 40.7 to 61.8 Mpa. Similarly, [PERSON] [83, 86] found 25.5 to 34.1 MPa with 0.5-1.5% carpet waste. Similar trends with marked increases of up to 20% in strength parameters have been observed in other works [78, 79, 80, 81]. Relating test results with felt to those presented in similar works, it was found that composites with recyclates behaved differently from others with textile waste. The reason for this was probably the use of very fine fibres. Carpet waste fibres, for example, can be up to 5 mm in diameter, whereas the individual felt fibres used here were between 0.08 and 0.3 mm in diameter. Although they may have been made of the same material in terms of transferring local loads in the composite samples, they performed quite differently. It is known that the failure pattern of a dozen or so individual yarn fibres is different from the failure of the same number of fibres connected in a veave. Fibes in veaves working together can carry greater loads. However, a fact that coincides with observations reported in the literature of the failure course of the tested composite samples containing recyclates is worth noting. In their case, in contrast to the typical brittle fracture, the composite, especially with a 3% fibre content, showed some plasticity during failure. Despite the pronounced fracture and failure of the specimens, the damaged fragments of the specimens did not detach, as is the case with conventional concretes. Figure 6 shows the results of the composite tensile strength by bending in a three-point scheme. The results of the bending strength test are presented in Figure 6. The composite without the addition of the CONTR recyclate had the highest recorded value of 7.22 MPa. The other composites had a lower strength the higher the recyclate addition. Successively for the F1.0 recyclate, the value was 21.54% lower (5.94 MPa); for the F1.6 composite, it was 45.84% lower (3.91 MPa); and for the F0.3 composite, it was 49.58% lower (3.64 MPa). Some inconsistency was also noted by relating the present test results to those presented above. [PERSON] et al. [80] used 1 to 2% nylon fibre to increase tensile strength from 4.2 to 4.35 MPa. Similarly, [PERSON] [83, 86], with 0.5-1.5% carpet waste, proved an improvement in this parameter and changes of 3.0-3.5 MPa. Therefore, this study concluded that carpet fibres have a higher tensile strength than cement stone, so their addition could be considered a microreinforcement of the composite. The results of the own tests only confirmed the hypotheses raised in the paragraph on felt waste. Individual thin felt fibres uniformly distributed in the cement matrix broke during stretching, and their tensile strength appeared lower than that of the cement stone alone. This was the reason for the strength decreases observed in the subsequent test series. Figure 6: Results of tests on the tensile strength of composites by bending in a three-point scheme. The data obtained when the hot air flow was applied to the composite insulation panels are presented in Figure 7.  
As is not difficult to see, despite the relatively short exposure, the temperature increases in all cases were relatively uniform, with successive temperature increases over time being smaller the higher the recyclate content of the composite. In the study, as would be expected, the sample with a felt content of 3% showed the highest insulating properties. As mentioned in the literature section, this was related to the insulating properties of the recylcate fibres and was evidence of the transfer of technical properties from the recylcate to the composite.