Monday, November 16, 2009


Hello again, this is Rhyce from Dymco Shanghai. In a chilly winter day with driving rain, US President Obama flied to Shanghai at the midnight of yesterday. Uh, I will keep my fingers crossed for the President a better weather during his first China visiting. This week let’s talk about pumice, Hess Pumice, which also comes from the US.

Pumice is composed of highly micro-vesicular glass pyroclastic with very thin, translucent bubble walls of extrusive igneous rock. Pumice is commonly pale in color. Pumice is a common product of explosive eruptions and commonly forms zones in upper parts of silicic lavas. Pumice has an average porosity of 90%, and initially floats on water.

Pumice is widely used to make lightweight concrete or insulative low-density breeze blocks. When used as an additive for cement, a fine-grained version of pumice called pozzolan is mixed with lime to form a light-weight, smooth, plaster-like concrete. This form of concrete was used as far back as Roman times.

In China, pumice is widely used in industry, such as eye glasses grinding and polishing, circuit board prep and polishing. Dymco Shanghai is the sole agency selling Hess Pumice in China. Almost all the PCB manufacturers in southern and eastern China use Hess Pumice in their production lines. Dymco Shanghai is thriving to explore and expand more industrial uses of pumice.