What differentiates J&H Screens from almost all the other screen manufacturers is our ability to easily optimize the amplitude of vibration on the wire cloth. Fabricated wire cloth is not perfect, often having slight variations in width. Wire cloth that does not have uniform tension will have variable vibration amplitude, creating vibration nodes and dead zones. Even worse, without an optimizer system, it is easy to apply non-uniform tension that can pull the wire cloth off center or inadvertently stretch parts of the cloth while leaving other parts loose . Once this happens, you cannot un-stretch the wire cloth. Correcting the tension after the fact only leaves a saggy part of the cloth for blinding and collecting product. Wire cloth that is not tensioned will rapidly deteriorate due to fatigue failure from the high frequency vibrations.
When a wire cloth is installed into a J&H Screen machine, a set of five rubber tensioning buffers on each side of the screen load the tension onto the wire cloth. These act like springs, but the rubber will not corrode and unlike metal, its spring constant is not temperature dependent, rapidly loosing strength as temperature increases. The rubber formulated for our buffers is impervious to heat up to 300°F.
The most innovative feature of the rubber spring buffer is the ability to directly measure the amount of tension being applied to the wire cloth. At left you can see an example of J&H’s unique tensioning gauge (Metallic gray U-shaped tool). As shown, a specific value of tension can be determined using this gauge. Used properly, this allows the tension on the wire cloth to be evenly and uniformly optimized for all ten buffers around the wire cloth panel. When all ten buffers are at the same gauge value, the laws of physics and the conservation of energy dictate that the tension in the wire cloth must also be at the same value everywhere, regardless of the small imperfections originally in the wire cloth, or when changing from an old wire cloth to a new one.
Wire cloth panels of different mesh size, wire diameter, or wire material can be given individual tensioning values to ensure that not only an individual wire cloth panel is properly tensioned, but that different screen types on the same machine (like the upper and lower deck of a double deck screen) are vibrating together as one. When the tension on the wire cloth is optimized, your screen machine will hum like a well tuned sports car, the efficiency of the screen process goes way up, energy use for the vibrating motors goes down, and the life of the wire cloth and the entire machine is extended.
Optimizer kits can be purchased from J&H to upgrade your screen machine with new hardware, wire cloth level gauge, and the optimizer tensioning gauge. See your J&H Representative.