Patent US5165985A successfully refreshed from Google Patents.
US5165985A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a flexible, transparent film for electrostatic shielding
Assignee: 3M Co
•
Filing: 1991-06-28
•
Granted: 1992-11-24
•
Expires: 2011-06-28
Abstract
Abstract A method of making a flexible, transparent film providing electrostatic shielding by applying a plurality of thin, conductive slivers to a sheet having a dimensionally stable layer and a thermoplastic layer, the slivers being applied to the thermoplastic layer, and then laminating a cover sheet over the thermoplastic layer, the cover sheet being formed of the same material as the thermoplastic layer. The thermoplastic layer is heated to its melting pint, and the cover sheet is extruded and laminated in a molten state whereby the cover sheet blends with the thermoplastic layer to form a single, homogenous layer. The slivers form an essentially two-dimensional, conductive network which is suspended in the homogenous layer.
Inventors
- 👤 Orville M. Wiste
- 👤 Santosh Collison
- 👤 Vijay A. Kumar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:36
CPC Classifications
B; B32; B32B; B32B3/00; B32B3/10; B32B3/18; B32B27/00; B32B27/06; B32B27/08; B32B27/30; B32B27/306; B32B27/308; B32B27/32; B32B27/34; B32B27/36; B32B37/00; B32B37/14; B32B37/15; B32B7/00; B32B7/02; B32B7/027; H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0079; B32B2307/00; B32B2307/20; B32B2307/21; B32B2307/40; B32B2307/412; B32B2367/00; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10S428/922; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
175 words
A method of making a film which provides static shielding, the method comprising the steps of: obtaining a first sheet having first and second layers, said first layer formed of a carrier material which is electrically insulative, flexible and transparent, and said second layer formed of a polymeric material which is electrically insulative, flexible, transparent, and thermoplastic, the melting temperature of said polymeric material being lower than that of said carrier material; applying a plurality of conductive slivers to said second layer of said first sheet, forming an essentially two-dimensional, conductive network on said second layer, said slivers having a melting temperature above said melting temperature of said polymeric material; and laminating a second sheet to said second layer of said first sheet, said second sheet being in a molten state and formed of a material which is miscible with said polymeric material whereby, as said second sheet is laminated to said second layer, said second sheet and said second layer become a homogenous, single layer, said conductive network being suspended in said homogenous layer.
Claim 2
Independent Claim
175 words
A method of making a film which provides static shielding, the method comprising the steps of: obtaining a first sheet having first and second layers, said first layer formed of a carrier material which is electrically insulative, flexible and transparent, and said second layer formed of a polymeric material which is electrically insulative, flexible, transparent, and thermoplastic, the melting temperature of said polymeric material being lower than that of said carrier material; applying a plurality of conductive slivers to said second layer of said first sheet, forming an essentially two-dimensional, conductive network on said second layer, said slivers having a melting temperature above said melting temperature of said polymeric material; and laminating a second sheet to said second layer of said first sheet, said second sheet being in a molten state and formed of a material which is miscible with said polymeric material whereby, as said second sheet is laminated to said second layer, said second sheet and said second layer become a homogenous, single layer, said conductive network being suspended in said homogenous layer.
Claim 3
Dependent Claim
61 words
The method of claim 1 wherein said slivers are constructed of a magnetic or paramagnetic material, and said applying step comprises the steps of: providing means for electromagnetically attracting said slivers; feeding said first sheet over said attracting means, with said second layer of said first sheet facing upwards; and laying said slivers onto said second layer proximate said attracting means.
Claim 4
Dependent Claim
98 words
The method of claim 1 wherein said applying step comprises the steps of: drawing said first sheet over a cylinder with said first layer of said first sheet contacting said cylinder, said cylinder being sufficiently hot to melt said second layer of said first sheet; feeding a tow of sliver material through first and second pairs of counterrotating rolls, said second pair of rolls rotating faster than said first pair of rolls, whereby said slivers are pulled away from said tow at said second roll; and blowing said slivers onto said melted second layer of said first sheet.
Claim 5
Dependent Claim
54 words
The method of claim 1 wherein said applying step comprises the steps of: providing mechanical means for deflecting said slivers toward said first sheet; feeding said first sheet over said deflecting means, with said second layer of said first sheet facing upwards; and laying said slivers onto said second layer proximate said deflecting means.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein said second layer of first sheet is also in a molten state during said laminating step.
Claim 7
Dependent Claim
28 words
The method of claim 1 wherein said slivers are applied to said second layer of said first sheet in an amount not exceeding about 15 g/m 2 .
Claim 8
Dependent Claim
28 words
The method of claim 1 wherein said slivers are applied to said second layer of said first sheet in an amount not exceeding about 2 g/m 2 .
Claim 9
Dependent Claim
30 words
The method of claim 1 wherein said carrier material is polymeric and is stretched prior to forming said first sheet whereby said carrier material is biaxially oriented and dimensionally stable.
Claim 10
Dependent Claim
31 words
The method of claim 1 further comprising the step of mixing an antistatic agent with either said carrier material in said first sheet or said polymeric material in said second sheet.
Claim 11
Dependent Claim
27 words
The method of claim 1 further comprising the step of coating either said first layer of said first sheet or said homogenous layer with an antistatic agent.
Claim 12
Dependent Claim
52 words
The method of claim 1 further comprising the step of forming said film into a package by: folding said film to define a folded edge; heat sealing said film along two lines which are generally perpendicular to said folded edge, forming two heat-sealed edges; and cutting said film at said heat-sealed edges.
Claim 13
Dependent Claim
17 words
A film made in accordance with claim 1, said film passing at least 70% of visible light.
Claim 14
Independent Claim
241 words
A method of making a film which provides static shielding, the method comprising the steps of: obtaining a first sheet having first and second layers, said first layer formed of a first polymeric material which is electrically insulative, flexible, transparent and dimensionally stable, and said second layer formed of a second polymeric material which is electrically insulative, flexible, transparent, and thermoplastic, the melting temperature of said second polymeric material being lower than that of said first polymeric material; drawing said first sheet over a first cylinder with said first layer of said first sheet contacting said first cylinder, said first cylinder being sufficiently hot to melt said second layer of said first sheet; feeding a tow of sliver material through a pair of feed rolls and a pair of accelerator rolls, said pair of accelerator rolls rotating faster than said pair of feed rolls; blowing said slivers onto said meted second layer of said first sheet, forming an essentially two-dimensional, conductive network on said second layer, said slivers having a melting temperature above said melting temperature of said second polymeric material; and laminating a second sheet to said second layer of said first sheet, said second sheet being in a molten state and formed of said second polymeric material whereby, as said second sheet is laminated to said second layer, said second sheet and said second layer become a homogenous, single layer, said conductive network being suspended in said homogenous layer.
Claim 15
Independent Claim
241 words
A method of making a film which provides static shielding, the method comprising the steps of: obtaining a first sheet having first and second layers, said first layer formed of a first polymeric material which is electrically insulative, flexible, transparent and dimensionally stable, and said second layer formed of a second polymeric material which is electrically insulative, flexible, transparent, and thermoplastic, the melting temperature of said second polymeric material being lower than that of said first polymeric material; drawing said first sheet over a first cylinder with said first layer of said first sheet contacting said first cylinder, said first cylinder being sufficiently hot to melt said second layer of said first sheet; feeding a tow of sliver material through a pair of feed rolls and a pair of accelerator rolls, said pair of accelerator rolls rotating faster than said pair of feed rolls; blowing said slivers onto said meted second layer of said first sheet, forming an essentially two-dimensional, conductive network on said second layer, said slivers having a melting temperature above said melting temperature of said second polymeric material; and laminating a second sheet to said second layer of said first sheet, said second sheet being in a molten state and formed of said second polymeric material whereby, as said second sheet is laminated to said second layer, said second sheet and said second layer become a homogenous, single layer, said conductive network being suspended in said homogenous layer.
Claim 16
Dependent Claim
27 words
The method of claim 13 further comprising the step of magnetizing said first cylinder whereby said slivers are attracted to said second layer of said first sheet.
Claim 17
Dependent Claim
24 words
The method of claim 13 further comprising the step of rolling said laminated first and second sheets through chilled cylinders to stabilize the film.
Claim 18
Dependent Claim
52 words
The method of claim 13 further comprising the step of either (i) mixing an antistatic agent with either said first polymeric material in said first sheet or said material in said second sheet, or (ii) coating either said first layer of said first sheet or said homogenous layer with an antistatic agent.
Claim 19
Dependent Claim
28 words
The method of claim 13 wherein said slivers are applied to said second layer of said first sheet in an amount not exceeding about 2 g/m 2 .
Claim 20
Dependent Claim
29 words
The method of claim 13 wherein said blowing step is performed using a venturi-type blower which creates laminar air flow towards said melted second layer of said first sheet.
Claim 21
Dependent Claim
17 words
A film made in accordance with claim 13, said film passing at least 70% of visible light.
Claim 22
Independent Claim
260 words
A method of making an antistatic, static-shielding, flexible and transparent film, comprising the steps of: obtaining a first sheet having first and second layers, said first layer formed of biaxially oriented, dimensionally stable polymer selected from the group consisting of polyethylene terephthalate, polypropylene or nylon, and said second layer formed of a thermoplastic polymer selected from the group consisting of low-density polyethylene, linear low-density polyethylene, high density polyethylene, ethylene methyl acrylate, ethylene vinyl acetate, or ethylene ethylacrylate, said first sheet having a thickness no greater than about 80 μm; drawing said first sheet over a first cylinder with said first layer of said first sheet contacting said first cylinder, said first cylinder being sufficiently hot to melt said second layer of said first sheet, and further being magnetized; feeding a tow of stainless steel slivers through a pair of feed rolls and a pair of accelerator rolls, said pair of accelerator rolls rotating faster than said pair of feed rolls; blowing said slivers onto said melted second layer of said first sheet, forming an essentially two-dimensional, conductive network on said second layer, said network having a density not exceeding 2 g/m 2 ; and extruding a second sheet onto said second layer of said first sheet, said second sheet having a thickness no greater than about 80 μm, being in a molten state, and formed of said thermoplastic polymer whereby, as said second sheet is extruded onto said second layer, said second sheet and said second layer become homogenous, single layer, said conductive network being suspended in said homogenous layer.
Claim 23
Independent Claim
260 words
A method of making an antistatic, static-shielding, flexible and transparent film, comprising the steps of: obtaining a first sheet having first and second layers, said first layer formed of biaxially oriented, dimensionally stable polymer selected from the group consisting of polyethylene terephthalate, polypropylene or nylon, and said second layer formed of a thermoplastic polymer selected from the group consisting of low-density polyethylene, linear low-density polyethylene, high density polyethylene, ethylene methyl acrylate, ethylene vinyl acetate, or ethylene ethylacrylate, said first sheet having a thickness no greater than about 80 μm; drawing said first sheet over a first cylinder with said first layer of said first sheet contacting said first cylinder, said first cylinder being sufficiently hot to melt said second layer of said first sheet, and further being magnetized; feeding a tow of stainless steel slivers through a pair of feed rolls and a pair of accelerator rolls, said pair of accelerator rolls rotating faster than said pair of feed rolls; blowing said slivers onto said melted second layer of said first sheet, forming an essentially two-dimensional, conductive network on said second layer, said network having a density not exceeding 2 g/m 2 ; and extruding a second sheet onto said second layer of said first sheet, said second sheet having a thickness no greater than about 80 μm, being in a molten state, and formed of said thermoplastic polymer whereby, as said second sheet is extruded onto said second layer, said second sheet and said second layer become homogenous, single layer, said conductive network being suspended in said homogenous layer.
References Cited (Backward Citations)
US3572499A
Cited
US3888711A
Cited
US3801418A
Cited
US4154344A
Cited
US4156751A
Cited
US4208696A
Cited
US4326003A
Cited
US4528222A
Cited
US4407872A
Cited
US4471872A
Cited
JPS59190829A
Cited
JPS6034099A
Cited
JPS6081900A
Cited
JPS60143699A
Cited
US4645566A
Cited
US4623594A
Cited
JPS60210667A
Cited
JPS60257234A
Cited
US4875581A
Cited
JPS6247200A
Cited
US4756414A
Cited
US4906494A
Cited
US4756414B1
Cited
US4658958A
Cited
JPS62122300A
Cited
US4992329A
Cited
JPS62275727A
Cited
US4899521A
Cited
US4983452A
Cited
US4939027A
Cited
US4957943A
Cited
US5028490A
Cited
JPH02276297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-24 | 1996-05-25 | 1996-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-24 | 2000-05-25 | 2000-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-24 | 2004-05-25 | 2004-11-24 | $7700.00 | Window Closed / Lapsed |