Engineering problems during pulling-down of hop strings and their attachments
2011
Hermanek, P., Czech Univ. of Life Sciences, Prague (Czech Republic) | Rybka, A., Czech Univ. of Life Sciences, Prague (Czech Republic) | Honzik, I., Czech Univ. of Life Sciences, Prague (Czech Republic) | Masek, J., Czech Univ. of Life Sciences, Prague (Czech Republic) | Vent, L., Czech Univ. of Life Sciences, Prague (Czech Republic)
The current way of hop strings attachment (being mostly wires of different diameter) to a supporting structure by means of polypropylene twines bears the risk of hop product contamination by these attachment residues. Hop-string attachments must enable the pulling machinery an easy and fluent hopvine pull-down, and the hop-string attachment residues on the supporting structure must not make the hanging in the following years impossible. The present conception does not present an ideal strength proportions between hop strings and their attachments. When the hopvines are being pulled down (during the harvest), the hop strings are mostly broken and the attachments, possibly together with some parts of wires, are left on the hop-field trellis. In the following years these attachments get loose of themselves and are one of the causes for penetration of impurities into another stage of technological process where they are separated only with difficulty. The paper presents a comparison of wire and twine strength measurements before and after the harvest. Furthermore, it mentions also a theoretical analysis of tensile strength calculation and measurement methodology.
اظهر المزيد [+] اقل [-]