The Slip melting point (SMP) or "slip point" is one conventional definition of the
melting point
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends ...
of a
waxy
solid
Solid is one of the four fundamental states of matter (the others being liquid, gas, and plasma). The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structura ...
. It is determined by casting a 10 mm column of the solid in a glass tube with an internal diameter of about 1 mm and a length of about 80 mm, 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
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the p ...
, and because the outside surface of the solid is molten.
This is a popular method for fats and waxes, because they tend to be mixtures of compounds with a range of
molecular mass
The molecular mass (''m'') is the mass of a given molecule: it is measured in daltons (Da or u). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The related quant ...
es, without well-defined melting points.
America Palm Oil Council glossary
/ref>
References
Phase transitions
Threshold temperatures
{{statisticalmechanics-stub