regarding which discusses details the very important issue of wafer baking plates or books (some manufacturers like to refer to the plates as tongues) can be manufactured on an oven within th module set by the respective manufacturers with 60, 45 and 30 being m common on older installations although these days in modern plants several older units of which there 96 being the average) running length ways are still a few around the world have the plates (longitudinally) through the oven whilst more modern or recent designs have the plates mounted in thetransverse direction. This helps reduce the oven length when large numbers of plates are involved. The usual plate size is 290 mm x 470 mm although mid-sizes of 370 mm x 240 mm and 350 mm x 470 are in use. "Jumbo" plates of 700 mm x 350 mm are not uncommon. Plates can be mounted in strong robust carriers or be self-supporting, either way, travel through the oven is achieved via a chain linked conveyor and heavy duty flanged ball bearing wheels (4 to each plate) running in guide ils. Each baking plate should ideally be consecutively numbered in a place posed to the operator for quick and easy reference. The most common design takes the form of "V" grooves or reeding positioned at 5 or 10 grooves per 25 mm (1.0 inch) across the plate. Apart from the numbering previously mentioned on the exterior, it is also common to engrave the plate number on the baking surface, so that the sheets can be identified with their respective plates post bake. The number is engraved discreetly in what is usually the off cut or trimming area of the sheet. For added wafer strength the grooves or reeding are engraved on the bottom plate at right angles (90%) and on the top plate diagonally (45°). The depth of reeding can range from 0.3 0.8 mm with 0.5 0.8 mm being the most common at an angle of 60-900. The manufacturer can guarantee a variation of less than 0.002 mm in the depth of engraving to provide uniformity Two alternative plate finishes are usually available with the objective of good release to the baked wafer sheet. These would be a micro machined finish and alternatively a chrome plated finish. The latter is more expensive, but is preferred as it helps prevent sticking more than the micro machined finish. Some manufacturers believe that a chrome finished plate produces a harder wafer, a it is said to require more heat; this is proba debatable Careful consideration should be given to the pitch and size of the engraving based on the anticipated end use of the wafer sheet. Too shallow or fine an engraving may highlight wide color variation caused by the difference in a of deposit compared to the rest of the sheet. This could be a problem for plain filled (naked) wafers, but acceptable for coated wafers. With coated wafers a shallow engraving is preferred, as a deep engraving could retain more chocolate on enrobing, increasing costs. Where the wafer(s) are required for a multiplicity of end uses, it is possible to have bottom and top plates engraved with fine and deep engravings respectively. Prior to creaming, the wafer which is to make up the top sheet of the creamed book, can be programmed to be turned over automatically as required. This presents a fine or deep engraving for coating or direct wrapping as needed. The plates have venting strips along the edges. Front and back of the top plate and both sides of the bottom plate. The venting strips have animportant dual purpose often not appreciated or perhaps overlooked. To retain the batter in the closed book whilst it travels through the oven and more importantly to allow the escape of steam through notches accurately machined along their length. These "V" or "U" shaped notches (depending on the manufacturer), whilst allowing steam to escape, also allow excess batter to come from the plate in the form of bubbles. The oven manufacturer has worked out the position and depth of these vents notches. Nevertheless, once in situ using the available batter, adjustments may be necessary to lift or lower these strips tobetter control the venting and