WINETECH Technical Yearbook 2021

BRINGING IT HOME This research proved that grapevine cuttings can contribute to making the manufacturing of particle board more sustainable, while improving the final product. At the same time, greenhouse gas emissions from burning of crop waste is reduced and the forests get a bit of a breather. South Africa is the seventh largest wine- producing country in the world. Add the table and raisin grape industries, then you have a substantial amount of vineyards producing vine cuttings. While some producers keep their vine cuttings for mulch, others remove it from the vineyards to decrease the risk of grapevine trunk disease spread. Does everyone have a purpose for these cuttings?

in varying ratios for the core layer and concluded that 10% vine cuttings to 90% pine was the magic number to produce particle board that met all the required industry standards. Adding up to 25% vine cuttings worked, but to make up for the reduced strength, bigger grapevine particles needed to be used. Even though most standards were met with the larger percentage of grapevine cuttings, it didn’t tick all the boxes. WHAT MAKES VINE CUTTINGS THE IDEAL ADDITIVE? A high lignin percentage and satisfactory pH and grit values of grapevine particles contribute to delivering a product with desirable qualities. In particle board manufacturing, the pH has to be within

specific limits to ensure that the chemical- bonding processes can be adequately completed. If a crop with a high grit value is used, there is more wear and tear on the tools used during fabrication. Grapevine cuttings have a lower grit value than other crop alternatives. There was no significant difference in the lignin content of vine cuttings versus pine. Furthermore, by adding a small fraction of finer grapevine particles, improved hot pressing is achieved in these hybrid boards. This means that its surface density and steeper vertical density is improved, compared to a 100% pine core board. Grapevine particles fill the gaps between the pine particles and hence improve the mechanical properties of hybrid boards.

In a country where more affordable housing and construction solutions will surely benefit the growing population, could there be a partnership between construction and agricultural industries to introduce more innovative, affordable and sustainable alternatives? As they say, one man’s trash is another man’s treasure. REFERENCE Wong, Marcus C., Hendrikse, Simone I.S., Sherrell, Peter C. & Ellis, Amanda V., 2020. Grapevine waste in sustainable hybrid particleboard production. Waste Management 118: 501-509.

For more information,contact Lucinda Heyns at lucinda@winetech.co.za.

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