Detectable plaster is basically standard plaster with a concentration of very fine iron-oxide powder added to it. It has the same favourable qualities as standard white plaster, so it can be produced quickly and economically, but one important quality is added: detectability.
The added iron-oxide powder in its purest form is also known as E172 and can be used as a colouring agent in your product. This addition leaves all the usual qualities of standard plaster intact, so it has the same printing quality as standard plaster, but it adds detectability.
The tests with detectable plaster have shown that with a metal detector small pieces of detectable plaster can be detected ranging from as small as 0.1 grammes*. Our research shows that application of the iron-oxide addition in combination with the use of standard metal detectors significantly reduces the risk that particles of plaster end up in the final product. Deltavorm recommends the application of highly effective magnetic filters that will filter out even the smallest parts of detectable plaster.
* For the tests, a metal detector was used that is widely used in the confectionary industry. It was operated with regular settings. The smallest detected parts correspond with a 1,0 mm iron ball (REF No F495), phase 3 degrees, sensitivity 95%, work frequency 300kHz (medium) and the used transit size was 350 x 150 (painted detector head). The tests were assessed in close collaboration with Safeline, part of Mettler-Toledo.