US4104416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin walled protective coatings by electrostatic powder deposition
Assignee: 555794 ONTARIO Inc
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Filing: 1976-05-06
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Granted: 1978-08-01
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Expires: 1996-05-06
Abstract
Abstract A process for producing thin walled coatings on elongated substrates by the electrostatic application of two superimposed layers of powder material is disclosed. The process comprises the steps of applying electrostatically a first layer of fusible powder material to an elongated substrate, at least partially fusing such first layer of powder material to provide a uniform coating on the elongated substrate, holding the at least partially fused coating at an elevated temperature below the full fusion temperature of the powder material to be applied as the second layer immediately prior to the application of such second layer, applying electrostatically a second layer of fusible powder material to the first layer, and fusing the total applied coating to achieve the desired coating thickness.
Inventors
- 👤 Mellapalayam R. Parthasarathy
- 👤 Douglas C. Nethersole
- 👤 Michael A. Dudley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 02:59
CPC Classifications
B; B05; B05D; B05D1/00; B05D1/02; B05D1/04; B05D1/06; B05D7/00; B05D7/20; B05D7/50; B05D7/52; B05D7/54; B05D7/546; B05D2451/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
173 words
A process for production of thin walled coatings on continuous elongated substrates through an electrostatic cloud application of two superimposed layers of powder material comprising the steps of: (a) applying electrostatically a first layer of fusible powder material to a continuous elongated substrate by passing said substrate through an electrostatic cloud coater; (b) at least partially fusing said first layer of powder material to provide a uniform coating on the elongated substrate; (c) holding the at least partially fused coating at an elevated temperature below the full fusion temperature of the powder material to be applied as the second layer immediately prior to the application of said second layer, said elevated temperature being sufficient to reduce the surface resistivity of the first deposited layer, thereby resulting in a uniform second layer deposition; (d) applying electrostatically a second layer of fusible powder material to the at least partially fused first layer by passing the coated substrate through an electrostatic cloud coater; and (e) fusing the total applied coating to achieve the desired coating thickness.
Claim 2
Dependent Claim
173 words
A process for production of thin walled coatings on continuous elongated substrates through an electrostatic cloud application of two superimposed layers of powder material comprising the steps of: (a) applying electrostatically a first layer of fusible powder material to a continuous elongated substrate by passing said substrate through an electrostatic cloud coater; (b) at least partially fusing said first layer of powder material to provide a uniform coating on the elongated substrate; (c) holding the at least partially fused coating at an elevated temperature below the full fusion temperature of the powder material to be applied as the second layer immediately prior to the application of said second layer, said elevated temperature being sufficient to reduce the surface resistivity of the first deposited layer, thereby resulting in a uniform second layer deposition; (d) applying electrostatically a second layer of fusible powder material to the at least partially fused first layer by passing the coated substrate through an electrostatic cloud coater; and (e) fusing the total applied coating to achieve the desired coating thickness.
Claim 3
Dependent Claim
49 words
A process as defined in claim 1, wherein the elongated substrate is initially preheated to a temperature below the full fusion temperature of the powder material to be applied as the first layer, to increase the rate of reduction of the surface resistivity of the initial deposited powder layer.
Claim 4
Dependent Claim
24 words
A process as defined in claim 1, wherein the first layer of powder material, when full fused, has a minimum thickness of 0.001 in.
Claim 5
Dependent Claim
34 words
A process as defined in claim 3, wherein the first layer of fused powder material represents between about 25 and 80% of the total fused thickness of coating to be applied to the substrate.
Claim 6
Dependent Claim
33 words
A process as defined in claim 4, wherein the first layer of fused powder material represents between 35 and 70% of the total fused thickness of coating to be applied to the substrate.
Claim 7
Dependent Claim
48 words
A process as defined in claim 1, wherein the second layer of powder material when fully fused has a minimum thickness of 0.001 in. and the fully fused second layer represents between about 20 and 75% of the total fused thickness of the coating applied to the substrate.
Claim 8
Dependent Claim
36 words
A process as defined in claim 1, wherein the second layer is deposited using the same powder coating unit as for the first layer and further comprising the step of independently controlling the respective layer thicknesses.
Claim 9
Dependent Claim
28 words
A process as defined in claim 1, wherein the second layer is deposited by a powder coating unit separate from the one used for the first layer deposition.
Claim 10
Dependent Claim
61 words
A process as defined in claim 7, wherein the first layer of powder material is completely fused, lowered in temperature to avoid deleterious deformation on the substrate handling equipment and subsequently reheated to achieve said elevated temperature below the full fusion temperature of the powder material to be applied as the second layer immediately prior to application of said second layer.
Claim 11
Dependent Claim
18 words
A process as defined in claim 1, wherein the two layers of powder material are of similar material.
Claim 12
Dependent Claim
18 words
A process as defined in claim 1, wherein the two layers of powder material are of different material.
Claim 13
Dependent Claim
14 words
A process as defined in claim 1, wherein the elongated substrate is a metal.
Claim 14
Dependent Claim
14 words
A process as defined in claim 1, wherein the elongated substrate is a glass.
Claim 15
Dependent Claim
16 words
A process as defined in claim 1, wherein the two applied layers are powdered resin material.
Claim 16
Dependent Claim
16 words
A process as defined in claim 14, wherein the two layers of resin material are thermoplastic.
Claim 17
Dependent Claim
21 words
A process as defined in claim 14, wherein the first layer of resin material is thermosetting and the second layer thermoplastic.
Claim 18
Dependent Claim
13 words
A process as defined in claim 14, wherein the two layers are thermosetting.
Claim 19
Dependent Claim
31 words
A process as defined in claim 15, wherein the two layer combination are selected from the group of thermoplastics consisting of: ionomer/ionomer, E-TFE/E-TFE, E-CTFE/E-CTFE, urethane/urethane, nylon/nylon, polyester/polyester, and poly (vinyl chloride)/nylon.
Claim 20
Dependent Claim
28 words
A process as defined in claim 16, wherein the two resin layers are the combinations: epoxy/ionomer, thermoset poly (vinyl chloride)/nylon, thermoset urethane/thermoplastic urethane, epoxy/nylon, or thermoset polyester/thermoplastic polyester.
Claim 21
Dependent Claim
26 words
A process as defined in claim 17, wherein the two layers of resin material are the thermoset combinations: urethane/urethane, polyester/polyester, modified polyester/modified polyester, or polyester/modified polyester.
References Cited (Backward Citations)
US3513012A
Cited
US3377183A
Cited
US3814616A
Cited
US3824115A
Cited
US3708321A
Cited
US3937853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-31 | 1982-01-30 | 1982-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-31 | 1986-01-30 | 1986-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-31 | 1990-01-30 | 1990-08-01 | $7700.00 | Window Closed / Lapsed |