Process for manufacturing plastic microspheres
US5525274A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1994 |
| Grant date | Jun 11, 1996 |
| Priority date | — |
| Expiry date | Jun 29, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Spherical particles having a diameter between 0.007" and 0.040" are formed from melt extruded thermoplastic material suitable for casting on a heated mold surface and melting thereon to form a thin layer of material having a nominal thickness of 0.040" that is cooled and removed from the mold surface as a part having a porosity less than a visually observable threshold. The process includes the steps of providing microspheres formed of blended and melt extruded thermoplastic, plasticizers (if necessary) and pigment additives that constitute less than 5% by weight of the blend and shaped as a smooth round spherical particle. The microspheres may then be distributed as predetermined charge of such microspheres against the heated casting surface to melt the microspheres as a layer of thermoplastic material having a porosity less than 0.003 inches and thereafter cooling and removing the non-porous layer from the casting surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.