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US4329387A Expired / Lapsed US ⏱️ 0.0 years remaining

Prepreg material having increased surface tack

Assignee: Hexcel Corp
•
Filing: 1979-09-17
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Granted: 1982-05-11
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Expires: 1999-09-17
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Abstract

Abstract A prepreg having substantially no excess resin while at the same time having an aggressive tack. Small discrete amounts of additional resin are selectively applied to a surface of the prepreg sheets in a regular array. The resin is applied at a sufficient viscosity that it does not sink into the prepreg fabric. The additional resin typically covers less than 25% of the surface and constitutes between 0.1% and 3% of the prepreg weight. The additional resin may be applied by a gravure roller having a surface etched with an appropriate array of indentations. A doctor blade partially defines a reservoir of resin in contact with a portion of the gravure roller and wipes the surface, thereby leaving resin only in the indentations. The doctor blade may be oscillated parallel to the roller axis to prevent accumulations of short fibers from impairing the wiping action.

Inventors

  • 👤 Richard B. Goodrich
  • 👤 Richard J. Moulton

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 13:31
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B29C70/22; B29C70/28; B29C70/54; B29C70/543; C; C08; C08J; C08J5/00; C08J5/24; C08J5/241; C08J5/243; C08J5/244; Y; Y10; Y10S; Y10S428/00; Y10S428/902; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/2481; Y10T428/24942; Y10T428/24992; Y10T428/30

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 175 words
An article of manufacture adapted to be molded into a resin/filament composite product by placing the article in a mold and applying heat and pressure to the article while in the mold, the product being characterized by a desired amount of resin, the article comprising: a fabric defined by a multitude of individual high modulus graphite filaments; an amount of uncured resin impregnating the fabric and being controlled so that it is less than the desired amount of resin in the article, the amount of resin being further such that substantially the entire amount of resin is absorbed into the fabric; and a multiplicity of discrete quantities of uncured resin applied to at least one surface of the fabric and being spaced apart thereon, the quantities of resin having a relatively high viscosity so that they remain on the surface and render such surface relatively tacky, the quantities of resin being selected so that they represent the difference between the desired amount of resin in the article and the amount of resin impregnating the fabric.
Claim 2
Dependent Claim 175 words
An article of manufacture adapted to be molded into a resin/filament composite product by placing the article in a mold and applying heat and pressure to the article while in the mold, the product being characterized by a desired amount of resin, the article comprising: a fabric defined by a multitude of individual high modulus graphite filaments; an amount of uncured resin impregnating the fabric and being controlled so that it is less than the desired amount of resin in the article, the amount of resin being further such that substantially the entire amount of resin is absorbed into the fabric; and a multiplicity of discrete quantities of uncured resin applied to at least one surface of the fabric and being spaced apart thereon, the quantities of resin having a relatively high viscosity so that they remain on the surface and render such surface relatively tacky, the quantities of resin being selected so that they represent the difference between the desired amount of resin in the article and the amount of resin impregnating the fabric.
Claim 3
Dependent Claim 28 words
An article according to claim 1 wherein the quantity of resin applied to the fabric is chemically the same resin as the amount of resin impregnating the fabric.
Claim 4
Dependent Claim 19 words
An article according to claim 1 wherein the quantities of resin are substantially evenly distributed over the entire surface.
Claim 5
Dependent Claim 16 words
An article according to claim 1 wherein the fabric is a fabric defined by woven filaments.
Claim 6
Dependent Claim 18 words
An article according to claim 1 wherein the filaments are arranged in tows of substantially unidirectional, unspun filaments.
Claim 7
Dependent Claim 24 words
An article according to claim 1 wherein the quantity of resin represents between about 0.1% to about 3% of the weight of the article.
Claim 8
Dependent Claim 30 words
An article according to claim 3 wherein the quantities are arranged in parallel strips, at least some of which are spaced apart from each other by at least about 1/4".
Claim 9
Dependent Claim 22 words
An article according to claim 7 wherein some of the parallel strips are spaced apart by a distance substantially less than 1/4".
Claim 10
Dependent Claim 154 words
An article of manufacture adapted to be molded into a resin/filament composite product by placing the article in a mold and applying heat and pressure to the article while in the mold, the product being characterized by a desired amount of resin, the article comprising: a fabric defined by a multitude of individual filaments; an amount of uncured resin impregnating the fabric and being less than the desired amount of resin in the article, the amount of resin being substantially uniformly absorbed into the fabric; and a quantity of uncured resin applied to at least one surface of the fabric, the quantity of resin having a relatively high viscosity and being applied so that it remains on the surface and renders such surface relatively tacky, the quantity of resin being selected so that it represents the difference between the desired amount of resin in the article and the amount of resin impregnating the fabric.
Claim 11
Dependent Claim 154 words
An article of manufacture adapted to be molded into a resin/filament composite product by placing the article in a mold and applying heat and pressure to the article while in the mold, the product being characterized by a desired amount of resin, the article comprising: a fabric defined by a multitude of individual filaments; an amount of uncured resin impregnating the fabric and being less than the desired amount of resin in the article, the amount of resin being substantially uniformly absorbed into the fabric; and a quantity of uncured resin applied to at least one surface of the fabric, the quantity of resin having a relatively high viscosity and being applied so that it remains on the surface and renders such surface relatively tacky, the quantity of resin being selected so that it represents the difference between the desired amount of resin in the article and the amount of resin impregnating the fabric.
Claim 12
Dependent Claim 28 words
An article according to claim 9 wherein the quantity of resin applied to the fabric is chemically the same resin as the amount of resin impregnating the fabric.
Claim 13
Dependent Claim 39 words
An article according to claim 9 wherein the quantity of resin is applied to at least one surface at a multiplicity of areas of that surface, the areas being spaced apart and substantially evenly distributed over the entire surface.
Claim 14
Dependent Claim 16 words
An article according to claim 9 wherein the fabric is a fabric defined by woven filaments.
Claim 15
Dependent Claim 14 words
An article according to claim 12 wherein the filaments comprise high modulus graphite filaments.
Claim 16
Dependent Claim 18 words
An article according to claim 13 wherein the filaments are arranged in tows of substantially unidirectional, unspun filaments.
Claim 17
Dependent Claim 24 words
An article according to claim 9 wherein the quantity of resin represents between about 0.1% to about 3% of the weight of the article.
Claim 18
Dependent Claim 27 words
An article according to claim 11 wherein at least some of the areas are spaced apart from other ones of the areas by at least about 1/4".
Claim 19
Dependent Claim 20 words
An article according to claim 16 wherein some of the areas are spaced apart a distance substantially less than 1/4".
Claim 20
Dependent Claim 50 words
In a net resin prepreg comprising filament fabric and uncured resin, the improvement wherein a major portion of the resin is absorbed substantially uniformly throughout the fabric and the remaining portion of resin resides substantially on at least one surface of the fabric to impart surface tack to the prepreg.
Claim 21
Dependent Claim 50 words
In a net resin prepreg comprising filament fabric and uncured resin, the improvement wherein a major portion of the resin is absorbed substantially uniformly throughout the fabric and the remaining portion of resin resides substantially on at least one surface of the fabric to impart surface tack to the prepreg.
Claim 22
Dependent Claim 23 words
The prepreg of claim 18 wherein the remaining portion of resin represents about 0.1% to about 3% of the weight of the prepreg.
Claim 23
Dependent Claim 18 words
The prepreg of claim 18 wherein the fabric comprises woven tows of substantially untwisted high modulus graphite filaments.
Claim 24
Dependent Claim 78 words
A prepreg comprising: woven graphite fabric representing about 65% of the prepreg weight; and resin representing about 35% of the prepreg weight with a quantity of resin representing about 0.1% to about 3% of the prepreg weight residing on at least one surface of the fabric with the rest of the resin substantially uniformly absorbed in the fabric, the quantity of resin having a higher viscosity when applied than the resin representing about 35% of the prepreg weight.
Claim 25
Dependent Claim 78 words
A prepreg comprising: woven graphite fabric representing about 65% of the prepreg weight; and resin representing about 35% of the prepreg weight with a quantity of resin representing about 0.1% to about 3% of the prepreg weight residing on at least one surface of the fabric with the rest of the resin substantially uniformly absorbed in the fabric, the quantity of resin having a higher viscosity when applied than the resin representing about 35% of the prepreg weight.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-05-10 1985-11-09 1986-05-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-05-10 1989-11-09 1990-05-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-05-10 1993-11-09 1994-05-11 $7700.00 Window Closed / Lapsed

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