Melting Point

The temperature at which a product changes phase from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point. Unlike the boiling point, the melting point is relatively insensitive to pressure because the solid/liquid transition represents only a small change in volume. Melting points are often used to characterize organic and inorganic compounds and to ascertain their purity. The melting point of a pure substance is always higher and has a smaller range than the melting point of an impure substance. The more impurity is present, the lower the melting point and the broader the range.

For fats and waxes consisting of compound mixtures the Slip melting point is used to determine the transition temperature from solid to liquid. It is determined by casting a column of the solid fat or wax in a glass tube, and then immersing it in a temperature-controlled water bath. The slip point is the temperature at which the column of the solid begins to rise in the tube due to buoyancy, and because the outside surface of the solid is molten.

• Washing at 15-20 º C above the MP

• No cold adjacent cargoes, no ballast

• Watch freezing in cold pipeline systems

• If high MP wash a.s.a.p.

• Watch IBC chapter 17 column o (specific and operational requirements) for 16.2.9