Injection molded screening apparatuses and methods

Patent metadata

Field	Value
Publication number	US-10835926-B2
Application number	US-201916269646-A
Country	US
Kind code	B2
Filing date	Feb 7, 2019
Priority date	May 25, 2012
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

Screening members, screening assemblies, methods for fabricating screening members and assemblies and methods for screening materials are provided for vibratory screening machines that incorporate the use of injection molded materials. Use of injection molded screen elements provide, inter alia, for: varying screening surface configurations; fast and relatively simple screen assembly fabrication; and a combination of outstanding screen assembly mechanical and electrical properties, including toughness, wear and chemical resistance. Embodiments of the present invention use a thermoplastic injection molded material.

First claim

What is claimed is:

1. A screen assembly, comprising:
a plurality of independently formed thermoplastic screen elements forming a screening surface, the screen elements having:
screening openings that are elongated slots having substantially uniform width W and substantially uniform length L; and
surface elements separating the screening openings, the surface elements having a thickness T that is approximately 70 μm≤T≤400 μm.

2. The screen assembly of claim 1 , wherein each screen element is a single thermoplastic injection molded piece.

3. The screen assembly of claim 1 , wherein the screen assembly has an open screening area of approximately 5% to approximately 35% of a total area of the screening surface.

4. The screen assembly of claim 1 , wherein the length L of the screening openings is approximately 0.7 mm≤L≤2 mm.

5. The screen assembly of claim 1 , wherein the width W of the screening openings is approximately 40 μm≤W≤200 μm.

6. The screen assembly of claim 5 , wherein:
the surface element thickness is T≈356 μm;
the length of the screening openings is L≈1.9 mm; and
the open screening area varies from approximately 6% to approximately 24% as the width W of the screening openings varies from approximately 45 μm to approximately 180 μm.

7. The screen assembly of claim 5 , wherein:
the surface element thickness is T≈178 μm;
the length of the screening openings is L≈1.2 mm; and
the open screening area varies from approximately 10% to approximately 28% as the width W of the screening openings varies from approximately 45 μm to approximately 180 μm.

8. The screen assembly of claim 5 , wherein:
the surface element thickness is T≈127 μm;
the length of the screening openings is L≈0.8 mm; and
the open screening area varies from approximately 12% to approximately 32% as the width W of the screening openings varies from approximately 45 μm to approximately 180 μm.

9. The screen assembly of claim 5 , wherein:
the surface element thickness is T≈76 μm;
the length of the screening openings is L≈0.7 mm; and
the open screening area varies from approximately 13% to approximately 33% as the width W of the screening openings varies from approximately 45 μm to approximately 180 μm.

10. The screen assembly of claim 1 , further comprising:
a support structure having support structure openings,
wherein at least one of the screen elements is secured to the support structure over support structure openings.

11. The screen assembly of claim 10 , wherein multiple screen elements are secured to the support structure over the support structure openings such that the screening surface is a continuous screening surface.

12. The screen assembly of claim 10 , wherein:
the support structure is a subgrid, and
one or more screen elements are secured to the subgrid by laser welding.

13. The screen assembly of claim 12 , wherein:
the subgrid includes multiple elongated subgrid structural members forming a grid framework having grid openings; and
screen elements each include a plurality of screen element support members,
wherein subgrid structural members are aligned with respective screen element support members so that the subgrid structural members provide mechanical support to the screen element support members.

14. The screen assembly of claim 13 , wherein:
a spacing of subgrid structural members is configured to correspond to a spacing of screen element support members, and
the spacing of subgrid structural members and the spacing of screen element support members is a decreasing function of surface element thickness T.

15. The screen assembly of claim 14 , wherein:
the screen assembly has an open screening area of approximately 5% to approximately 35% of a total area of the screening surface, and
the spacing of subgrid structural members and the spacing of screen element support members varies from a first value corresponding to open screening area of approximately 5%, to a second value corresponding to open screening area of approximately 35%, wherein the first value is larger than the second value.

16. The screen assembly of claim 12 , wherein:
multiple independent subgrids are permanently secured to each other to form the screen assembly,
the screen assembly is an independent structure configured to be removably secured to a vibratory screening machine, and
the screen assembly has a continuous screen assembly screening surface having multiple screen element screening surfaces.

17. The screen assembly of claim 10 , wherein the screen assembly is configured to withstand accelerations in a range from approximately 3G to approximately 9G, and to withstand compressive loading forces in a range from approximately 2,000 lb to approximately 3,000 lb.

18. A screen assembly, comprising:
a plurality of independently formed thermoplastic screen elements forming a screening surface, the screen elements having screening openings that are elongated slots having a substantially uniform width W that is approximately 40 μm≤W≤200 μm, and a substantially uniform length L that is approximately 0.7 mm≤L≤2 mm,
wherein the screen assembly has an open screening area of approximately 5% to approximately 35% of a total area of the screening surface.

19. The screen assembly of claim 18 , further comprising:
surface elements separating the screening openings, the surface elements having a thickness T that is approximately 70 μm≤T≤400 μm.

20. The screen assembly of claim 18 , further comprising:
a support structure having support structure openings,
wherein at least one of the screen elements is secured to the support structure over support structure openings.

21. The screen assembly of claim 20 , wherein the screen assembly has a total screening area in a range of approximately 0.4 m 2 to 6.0 m 2 .

22. The screen assembly of claim 20 , wherein the screen assembly is configured to withstand accelerations in a range from approximately 3G to approximately 9G, and to withstand compressive loading forces in a range from approximately 2,000 lb to approximately 3,000 lb.

23. A method of fabricating a screen assembly, comprising:
injection molding a plurality of thermoplastic screen elements, the screen elements having:
screening openings that are elongated slots having substantially uniform width W and substantially uniform length L; and
surface elements separating the screening openings, the surface elements having a thickness T that is approximately 70 μm≤T≤400 μm; and

forming a screening surface that includes the plurality of screen elements.

24. The method of claim 23 , further comprising:
injection molding each screen element to be a single thermoplastic injection molded piece.

25. The method of claim 23 , further comprising:
injection molding the screen elements to have screening openings that have a length L that is approximately 0.7 mm≤L≤2 mm.

26. The method of claim 23 , further comprising:
injection molding the screen elements to have screening openings that have a width W that is approximately 40 μm≤W≤200 μm.

27. The method of claim 23 , further comprising:
securing at least one of the screen elements to a support structure, having support structure openings, to generate a screen assembly having a screening surface having an open screening area of approximately 5% to approximately 35% of a total area of the screening surface.

Assignees

• Derrick Corp

Inventors

• Wojciechowski Keith

Classifications

• B07B1/469

  Perforated sheet-like material · CPC title

• B29D28/00

  Producing nets or the like, {e.g. meshes, lattices}(by knotting D04G) · CPC title

• B07B1/4609

  constructional details of screening surfaces or meshes · CPC title

• B07B1/4654

  Corrugated Screening surfaces · CPC title

• B01D29/012

  Making filtering elements (making bag, cage, hose, tube, sleeve or like filtering elements B01D29/111) · CPC title