The VinguardTM two stage SO2 gas generating sheet was developed over a period of 7 years at Stellenbosch University. The research was conducted in conjunction with the South African Deciduous Fruit Producers Trust and local table grape farmers. The technology that flowed from this research was both new and innovative, utilising current and up to date knowledge in the fields of polymer science and membrane transfer theory, with a key focus on minimising SO2 residual levels. Thus the VinguardTM two stage SO2 gas generating sheet truly is the most advanced SO2 gas generating sheet on the international market.
VinguardTM consists of three layers: a non SO2 gas permeable polymeric carrier material, a polymer matrix with active SO2 release particles dispersed evenly through the matrix and a gas and moisture permeable non-woven.
High SO2 residue levels on table grapes are unacceptable to both the global table grape consumer and more and more often to governments and regulating bodies around the world. Retailers are striving to supply their customers with healthier and higher quality fruit on an ongoing basis.
The VinguardTM two stage SO2 gas generating sheet has been independently tested by The Volcani Institute in Israel and found to have the lowest SO2 residue level of any SO2 gas generating sheet in use, while still acting as an effective fungicide.
The VinguardTM two stage So2 gas generating sheets’ SO2 residue levels was found to be less than 2 ppm after a ten week period, and this was achieved without decreasing the VinguardTM two stage So2 gas generating sheets efficacy as a fungicide.
Release of SO2 gas takes place through a monolithic release mechanism once the sheet comes into contact with the high levels of moisture present inside the grape packaging. Release of SO2 gas is directed in only one direction by the non SO2 gas permeable polymeric carrier material. The fact that SO2 gas is only allowed to move in one direction combined with the unique gas release properties of the polymer matrix allow VinguardTM to use lower dosages of SO2 to obtain effective Botrytis cinerea control.
The unique construction of the polymer matrix enable the VinguardTM two stage SO2 gas generating sheet to release SO2 gas in a controlled manner in two distinctive phases over an extended period of time. Manipulation of the release rate can be achieved by changing the composition of the polymer matrix.
LTSEM micrograph of the VinguardTM polymer matrix
The VinguardTM SO2 generating sheet comes in three standard sizes.
Sizes and SO2 release profiles can be adjusted to individual customers’ requirements.
* Note: This product has a perforation and can easily be divided into two DR3040-14 sheets by means of tearing.