Expanded styrene-polymers and polyolefin micro-bits and their preparation
US4207378A · kind A · utility
Inventor
Key dates
| Filing date | Sep 15, 1977 |
| Grant date | Jun 10, 1980 |
| Priority date | — |
| Expiry date | Sep 15, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2998
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Involved are (I) expanded, thermoplastic, non-brittle as expanded polymers selected from a styrene-polymer and a polyolefin from polyethylene to poly-methylpentene, said expanded polymer being in form of micro-bits which (a) are from about 40 to about 325 microns long and from about 20 to about 325 microns wide, (b) are substantially completely to entirely completely free (i) of intact cells of expanded polymer bit-pieces from which they were produced and of (ii) any uniformity in outline of individual micro-bit particles, and (c) in density are from about 85 percent of, to about substantially the same as, the specific unexpanded polymer from which there was provided the aforesaid expanded polymer, and (II) a method of preparing these micro-bits by impelling a mixture of them in water in a confined comminuting zone through a circular path by repeated impact by a plurality of impact surfaces spaced axially and radially at apart from one another and rotated about the circular path's axis from about 4700 to about 8000 r.p.m. thereby driving the bit-pieces against cornered edges of a plurality of from circular to substantially rectangular orifices arranged in screening array in an arcu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.