What is Uvasys Slow Release?
Uvasys Slow Release is a second stage only (slow release) product which releases a continuous low dose of SO2, suitable for growers pre-gassing their grapes prior to packing. The slow-release stage prevents most dormant spores from germinating under optimal conditions.
How does it work?
- Uvasys Slow consists of laminated plastic membranes, bonded by a wax layer containing precise concentrations, and particle sizes, of Sodium Metabisulfite: Na2S2O5.
- At above 75% relative humidity an autocatalytic reaction is initiated, whereby the sheet starts releasing a time, and concentration-varying stream of SO2.
- Once activated the sheet will emmit a low, continual dose of sulphur dioxide gas, concentrated enough to potentially inhibit most superficial latent or inherent Botrytis cinerea spores from growing, but also low enough to ensure sulfite residues within the table grapes remain safely below the European legal limit of 10 ppm. Infection which occurred at flowering could still develop but will be contained to the affected berry.
- The quantity of SO2 emitted is critical to the efficacy of the product as an excessive release of SO2 can cause bleaching while insufficient release may not prevent the development of Botrytis.
- SO2 not only protects against fungal growths but also acts as antioxidant; helping in maintaining a greener stem colour.
- For more detail on the chemical reactions please visit the Research page.
Use one Uvasys sheet recommended for the corresponding carton size; refer to the below options table.
If needed, line the carton with a perforated (ventilated) liner bag. The optimum ventilation type and size will depend on your unique combination of: Production area; Cooling systems; Post-harvest handling times; Pack type (loose, punnets, carry bag, etc.)
If used, fold open the liner bag once correctly positioned inside the carton. Using a liner bag will also retard moisture loss.
Place grapes inside the liner bag. Punnets (heat sealed or open top), clamshells, Zip-lock bags, polycote bags, carry bags or loose packed grapes may be used.
Place the Uvasys sheet on top of the grapes, with the printed (shiny) side facing away from the grapes. (We recommend not to cut or modify the sheet) Do not reuse the sheet.
Use a MAM on top of the Uvasys sheet if you are expecting excessive condensation.
Fold the plastic liner, back, over the content of the carton, close and cool to storage temperature (-0.5 ℃) as soon as possible.
Please contact us for more detailed instructions and always refer to the package labels on site.
Please click on the download button for a PDF of the Material Safety Data Sheet (MSDS). You will be taken to the Downloads section of the website where a login is required to retrieve the document. A suitable PDF reader will be required. Please use the Contact Us page for specific questions.
|CARTON SIZE(mm)||SHEET SIZE(mm)||PACK SIZE (units)|
|400 x 300||356 x 260||1000|
|500 x 300||460 x 260||500|
|500 x 400||460 x 350||500|
|600 x 400||530 x 350||500|
For frequently asked questions pertaining to this product please click this link where you will be taken through to the FAQ page.
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Disclaimer: This website is for marketing purposes only. All references to values, volumes, timeframes and other variables are guidelines only. If you require precise information please use the contact us page with your query.
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