Thermoplastic compositions, methods, apparatus, and uses
AssigneeDerrick Corporation
InventorsJames R. Colgrove, Keith Wojciechowski
Life of this patent
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Abstract
Thermoplastic polyurethane (TPU) compositions, methods for producing TPU compositions, methods of using TPU compositions, and apparatuses produced therefrom are disclosed. Disclosed TPU compositions include a thermoplastic polyurethane polymer, a heat stabilizer, a flow agent, and a filler material. The filler may be a glass fiber. Disclosed TPU compositions have improved thermal stability and improved flow properties suitable for injection molding of articles of manufacture having a large plurality of fine openings or pores. Articles produced from the composition have superior thermal stability, abrasion resistance, and chemical resistance. Example articles include screening members for vibratory screening machines.
Claims54
A screen apparatus, comprising
- a screening element including a composition that includes a thermoplastic polyurethane configured to melt at a temperature in a range of about 148° C. to about 260° C.;
- wherein the screening element is a single injection molded piece including openings generated during injection molding of the single injection molded piece, the openings have a size that is in a range from approximately 35 μm to approximately 4000 μm, and the screening element has an open screening area of approximately 10% or more of a total screening area.
A screen apparatus, comprising
- a screening element including a composition that includes a thermoplastic polyurethane;
- wherein the screening element is a single injection molded piece including openings generated during micro-molding of the single injection molded piece that melts the composition at a temperature in a range of about 148° C. to about 260° C. and injects the composition into a mold at an injection pressure in a range of about 400 psi to about 900 psi, the openings have a size that is in a range from approximately 35 μm to approximately 4000 μm, and the screening element has an open screening area of approximately 10% or more of a total screening area.
A method of separating materials, comprising:
- placing the materials to be separated on a top surface of a screen positioned between a first wall and a second wall of a vibratory screening apparatus;
- and
- exciting the screen to separate undersized materials of the materials from oversized materials of the materials to a desired level,
- the screen including a single-piece injection molded screening element,
- the screening element including a composition including a thermoplastic polyurethane,
- wherein the screen includes openings having a size that is in a range from approximately 35 μm to approximately 4000 μm, and the screen has an open screening area of approximately 10% or more of a total screening area, and the openings are generated during micro-molding of the single-piece screening element.
Dependencies are inferred from the claim text.