Some Ingenious Techniques for Imaging Multiphase Processes of Micro Plastic Resin Particles under Abrupt Heating

Abstract

In order to observe and elucidate multiphase process of micro plastic resin particles under abrupt heating, some ingenious techniques are devised and introduced in this investigation; two devises for optical imaging and four devises for abrupt heating and extinguishment. One of the two optical devises is a mini optical composite which enables simultaneous photographing of direct silhouetted image and schlieren image, and another is a magnifying particle tracking system which realizes a wide and straight tracking range up to about 50 mm. In the latter four devises, on the other hand, reforming of a ragged resin particle into a spherical one around a fine tungsten wire of 5 μm diameter, a vertical type cylindrical mini burner for abrupt heating, a mini-puff generator for abrupt extinguishment of all flames around a PET particle at an arbitrary assigned time after the abrupt heating, and a slot burner having extremely fine two-dimensionality are introduced. According to various optical observations using these devised techniques, many characteristic behaviors, such as occurrence of internal multiple micro bubbling, micro explosions and jets, and transformation of a slender wake flame into a long and thin cluster consisting of multiple micro brilliant spots within a short passage about a few millimeters, are clarified with respect to multiphase process of plastic resin particles under abrupt heating.