(1) The main feed channel that runs from the outer face of an injection mold to the gate in a single-cavity mold or to the runners of a multiple-cavity mold. The liquid polymer is forced through this orifice from a nozzle till the mold is filled to capacity. Some polymer remains in the sprue after the mold is closed, leaving a projecting piece that must be removed after the product is ejected. The viscosity of the polymer must be low enough to permit it to pass through the sprue readily.(2) A disease attacking the digestive organs as a result of inadequate nutrition, especially in tropical areas.