Patent ID: 6273347
Filing Date: 2001-08-14
Classification: C08J,C08L,Y10S

Abstract:
A flow-restricting device, which is used for a releasing part at preparing expanded particles by dispersing thermoplastic resin particles into an aqueous dispersion medium in a pressure vessel, impregnating a blowing agent and releasing the mixture into a lower atmosphere;said flow restricting device is equipped with at least one opening satisfying either of the following two conditions,(1) L/Hf.gtoreq.1.5 mm, Hn=1 to 4 mm, d=0 to 5 mm(2) L/Hf<1.5 mm, S=0.5 to 10 mm.sup.2, d=0 to 5 mmwherein a front width or a long diameter of the opening attached to the flow-restricting device is L, a height or a short diameter is Hf, a height or a short diameter at the narrowest part in the opening is Hn, an area at the narrowest part in the opening is S, and a depth (land length) is d.