US3376810A - Duplicating stencils - Google Patents

Duplicating stencils Download PDF

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Publication number
US3376810A
US3376810A US588426A US58842666A US3376810A US 3376810 A US3376810 A US 3376810A US 588426 A US588426 A US 588426A US 58842666 A US58842666 A US 58842666A US 3376810 A US3376810 A US 3376810A
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United States
Prior art keywords
stencil
tissue
sheet
carbon
ink
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US588426A
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English (en)
Inventor
Blake Alan Francis
Green Cyril
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NRG Manufacturing Ltd
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NRG Manufacturing Ltd
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Publication of US3376810A publication Critical patent/US3376810A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
    • B41N1/00—Printing plates or foils; Materials therefor
    • B41N1/24—Stencils; Stencil materials; Carriers therefor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon

Definitions

  • the invention provides a duplicating stencil, designed to be cut electrically, made of a sheet of thin light stencil tissue strengthened with a modified polyamide resin and impregnated with ink-impervious material containing electrically conductive particles, the said sheet being attached to a backing sheet having a relatively highly electrically conductive layer coated thereon.
  • This invention relates to duplicating stencils which can be out both mechanically (as with a typewriter) and electronically.
  • the conventional duplicating stencil used in enormous numbers all over the world consists of a thin sheet of highly porous tissue impregnated with an ink-impervious material.
  • the impregnated sheet of tissue is called the stencil sheet
  • the stencil sheet When the stencil is cut, the ink-impervious material is displaced, e.g., by the impact of a typewriter key, the fibres of the porous tissue are exposed, and, since the tissue itself offers little or no resistance to the passage of ink, the stencil will then pass ink in the cut areas.
  • the highly porous tissue in this type of duplicating stencil is known in the art as stencil tissue.
  • impervious thin papers It is quite different from ordinary impervious thin papers since it is made from relatively long fibres, generally unbeaten abaca fibres in Europe and the United States and kozo (also called yoshino) fibres in Japan, and contains at least about of void-area, whereas impervious thin papers are made from short fibres (e.g., fairly well beaten, flax fibre) and contain very low void-areas.
  • the thin paper used in the duplicating stencil described in Patent No. 3,151,548, of common assignee with the present application has a porosity corresponding to less than 0.01% of void-area.
  • Such impervious paper however thin, cannot pass ink until it has actually been perforated, e.g., with a spark or mechanically with a sharp instrument such as a wheel pen.
  • a known stencil of this kind comprises a stencil sheet of stencil tissue impregnated with an ink-impervious material rendered conductive by inclusion of carbon or other conductive particles, the stencil sheet being capable of being cut me- Patented Apr. 9, 1968 chanically, as with a typewriter, a backing sheet attached to the stencil sheet along one edge, and a layer of relatively high electrical conductivity located between the stencil sheet and the backing sheet.
  • This relatively highly conductive layer is generally coated on the backing sheet but it can also be carried on a separate sheet between the two.
  • the present invention provides an improved form of stencil of this general kind in which a novel kind of stencil sheet is used.
  • the stencil of this invention is less likely to give rise to set-off during duplicating because of employment of a stencil tissue lighter in weight, more porous and thinner than that generally used in the manufacture of pressure-sensitive stencils, including that used in the French patent quoted above. It can also be more sharply cut electrically (so as to give clearer duplicated copies).
  • the stencil of the invention can be made so that the void-area produced by the application of a given voltage is linearly related to that voltage within wide limits, so that it is possible to use the new stencils to obtain truer results in the facsimile reproduction of continuous tone originals.
  • the duplicating stencils of this invention comprise a stencil sheet made of stencil tissue weighing less than 8 grams per square metre and less than 0.0015 inch thick, i.e. thus lighter and thinner (and also more porous) than conventional stencil tissue, strengthened with a modified polyamide resin (as hereinafter defined) and optionally incorporating a highly conductive carbon, the said tissue being impregnated with an ink-impervious material, including electrically conductive particles, e.g., of carbon black, but of relatively low electrical conductivity, the said stencil sheet being capable of being cut mechanically, a backing sheet attached to the stencil sheet along one edge and a relatively highly electrically conductive layer coated on the backing sheet and located between the stencil sheet and the backing sheet.
  • a modified polyamide resin as hereinafter defined
  • the modified polyamide resin used for strengthening the tissue is a product formed by condensing a polyamide with an epihalohydrin, e.g., epichlorohydrin, so that the secondary amido groups react with formation of an azidine ring (see US. Patent No. 2,926,154).
  • a preferred such modified polyamide is that sold under the trade name Kymene 557 by the Hercules Powder Company.
  • Kymene 557 by the Hercules Powder Company.
  • Conventional stencil tissue is of the order of 9-13 grams per square metre and 00018-00025 inch thick. As already stated, it has a void-area of at least about 20%. Attempts to make thinner paper by calendering have led to a loss of porosity with consequent loss of sensitivity of the coated stencil and introduction of the disadvantage of cut-out. If, on the other hand, the weight of the paper is reduced to 6-7 grams per square metre, the paper becomes too weak and tearing of the stencil in use could occur.
  • modified polyamides increase the strength of the tissue both in the dry and wet state with a minimum of interference with both the electric cutting properties of the paper and its cut-out resistance when typed on in the traditional manner.
  • the stencil tissue used in this invention weighs preferably 6-7 grams per square metre, is preferably 0.0013-0.0014 inch thick and is strengthened by impregnation with a modified polyamide resin, e.g., that sold as Kymene 557 by the Hercules Powder Company. Its porosity is greater than that of conventional stencil tissue and corresponds to a void-area of at least about 30%.
  • the stencil tissue may also incorporate a conductive carbon.
  • the electrical resistance of the stencil tissue may be reduced to the same order as that of the ink-impervious material with which the said tissue is impregnated and in consequence a sharper final duplicated copy is obtained because of the elimination of interference by the non-conductive cellulose fibres.
  • the conductive carbon e.g., that sold under the Mark XC 72 by Cabot Carbon, is incorporated in the stencil tissue after manufacture, e.g., by treating the tissue in a size press with a slurry of the carbon in dilute carboxymethyl cellulose solution (or a solution of similar viscosity) containing to of the above-mentioned carbon, the preferred amount being about 7%.
  • the ink-impervious material in the stencil tissue is applied in the conventional way by impregnating with a solution of nitro-cellulose composition plasticized to render it capable of being cut on a typewriter and incorporating electrically conductive particles to render it electrically conductive.
  • the resistance of the stencil sheet measured using electrodes of 1 sq. cm., 1 cm. apart under a load of 2 kg. is preferably 5,000-l00,000 ohms, the preferred figure being about 30,000 ohms.
  • the electrically conductive particles incorporated in the ink-impervious material may be of a highly conductive carbon, e.g., Vulcan XXX Black, or metallic particles, in amount preferably about 10% by weight.
  • highly conductive carbon particles have an electric resistivity of 0.03 to 0.1 ohm-inch at an apparent density of 44 lbs. per cubic foot while particles of relatively low conductivity have a resistivity greater than 2 ohm-inches at the same density.
  • the mounting of the stencil sheet on the backing sheet and the coating of the highly conductive layer on the backing sheet is carried out in conventional manner.
  • the highly conductive layer may be obtained by roller coating onto the backing sheet a solution of a plasticised polyvinyl resin, e.g., polyvinyl chloride, containing highly conductive carbon black.
  • the electrical resistance of this layer measured in the manner described above will ordinarily be 1,000-2,000 ohms.
  • EXAMPLE A sheet of stencil tissue weighing 6-7 grams per square metre and 0.0013-0.0014 inch thick is wet strengthened with Kymene 557 (Hercules Powder Company) and then 4 optionally treated on a size press with a slurry containing 7% carbon black (XC 72 Cabot).
  • the sheet is then impregnated to a weight (dry) of 45 grams per square metre with a nitrocellulose solution containing:
  • This stencil sheet is mounted on a backing sheet, weighing 60-90 grams per square metre, coated to a coating weight (dry) of 6 grams per square metre, with a P.V.C. solution containing:
  • FIGURE 1 of the accompanying drawings A partial cross-section of a duplicating stencil in accordance with this invention is shown diagrammatically in FIGURE 1 of the accompanying drawings which is self-explanatory.
  • the thickness of the two sheets and of the layer on the backing sheet as well as the size of the kozo fibres have been much exaggerated for purposes of clarity.
  • a duplicating stencil comprising a stencil sheet made of stencil tissue weighing less than 8 grams per square meter, being less than 0.0015 inch thick, having a void area of at least about 30%, and being strengthened by a modified polyamide resin, said tissue being impregnated with an ink-impervious material including electrically conductive particles, but of relatively low electrical conductivity, the resistance of said stencil sheet being in the range of 5,000-100,000 ohms, said stencil sheet being capable of being cut mechanically, a backing sheet attached to the stencil sheet along one edge and a relatively highly electrically conductive layer coated on the backing sheet and located between the stencil sheet and the backing sheet, the resistance of the highly conductive layer being in the range of 1,000 to 2,000 ohms, said resistances being measured using electrodes of 1 sq. cm., 1 cm. apart under a load of 2 kg.
  • a stencil according to claim 1 in which the tissue incorporates a highly conductive carbon in addition to the electrically conductive particles included in the ink-impervious material.
  • a stencil according to claim 1 in which the stencil tissue weighs 6-7 grams per square metre and is 0.0013 to 0.0.014 inch thick.
  • a stencil according to claim 1 in which the tissue is rendered electrically conductive by treatment in a size press with a slurry containing 5-15 by weight of conductive carbon particles so that the said tissue has a resistance of 5,000 to 100,000 ohms as measured using electrodes of 1 sq. cm., 1 cm. apart, in contact with the said tissue and under a load of 2 kg.

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  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Dispersion Chemistry (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Printing Plates And Materials Therefor (AREA)
US588426A 1963-06-21 1966-10-21 Duplicating stencils Expired - Lifetime US3376810A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB24890/63A GB1042585A (en) 1963-06-21 1963-06-21 Improvements in or relating to duplicating stencils
BE651881A BE651881A (xx) 1963-06-21 1964-08-14
NL6409403A NL6409403A (xx) 1963-06-21 1964-08-14

Publications (1)

Publication Number Publication Date
US3376810A true US3376810A (en) 1968-04-09

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Family Applications (1)

Application Number Title Priority Date Filing Date
US588426A Expired - Lifetime US3376810A (en) 1963-06-21 1966-10-21 Duplicating stencils

Country Status (5)

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US (1) US3376810A (xx)
BE (1) BE651881A (xx)
CH (1) CH454186A (xx)
GB (1) GB1042585A (xx)
NL (2) NL6409403A (xx)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3593660A (en) * 1962-12-27 1971-07-20 Tomoegawa Paper Mfg Co Ltd Stencil paper an electric recording and method of producing the same
US3595166A (en) * 1969-02-20 1971-07-27 Bell & Howell Co Three-layer stencil assembly having plastic overlay sheet
US3619345A (en) * 1968-06-28 1971-11-09 Ricoh Kk Heat-sensitive stencil paper
US3661621A (en) * 1968-06-08 1972-05-09 Wolff & Co Ag Process for producing tubular structures coated on both sides
US3777661A (en) * 1970-06-29 1973-12-11 Shinko Electric Co Ltd Method and device for marking sheets through stencils
US4188880A (en) * 1978-01-25 1980-02-19 Vickers Limited Blank for conversion into a perforated stencil by spark erosion
US4718340A (en) * 1982-08-09 1988-01-12 Milliken Research Corporation Printing method
US20090056577A1 (en) * 2007-08-20 2009-03-05 Hook Kevin J Compositions compatible with jet printing and methods therefor
US9701120B2 (en) 2007-08-20 2017-07-11 R.R. Donnelley & Sons Company Compositions compatible with jet printing and methods therefor

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500617A (en) * 1942-08-04 1950-03-14 Western Union Telegraph Co Electrosensitive stencil blank
US3151548A (en) * 1963-04-29 1964-10-06 Gestetner Ltd Duplicating stencils

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500617A (en) * 1942-08-04 1950-03-14 Western Union Telegraph Co Electrosensitive stencil blank
US3151548A (en) * 1963-04-29 1964-10-06 Gestetner Ltd Duplicating stencils

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3593660A (en) * 1962-12-27 1971-07-20 Tomoegawa Paper Mfg Co Ltd Stencil paper an electric recording and method of producing the same
US3661621A (en) * 1968-06-08 1972-05-09 Wolff & Co Ag Process for producing tubular structures coated on both sides
US3619345A (en) * 1968-06-28 1971-11-09 Ricoh Kk Heat-sensitive stencil paper
US3595166A (en) * 1969-02-20 1971-07-27 Bell & Howell Co Three-layer stencil assembly having plastic overlay sheet
US3777661A (en) * 1970-06-29 1973-12-11 Shinko Electric Co Ltd Method and device for marking sheets through stencils
US4188880A (en) * 1978-01-25 1980-02-19 Vickers Limited Blank for conversion into a perforated stencil by spark erosion
US4718340A (en) * 1982-08-09 1988-01-12 Milliken Research Corporation Printing method
US20090056577A1 (en) * 2007-08-20 2009-03-05 Hook Kevin J Compositions compatible with jet printing and methods therefor
US20090064884A1 (en) * 2007-08-20 2009-03-12 Hook Kevin J Nanoparticle-based compositions compatible with jet printing and methods therefor
US8136936B2 (en) 2007-08-20 2012-03-20 Moore Wallace North America, Inc. Apparatus and methods for controlling application of a substance to a substrate
US8328349B2 (en) 2007-08-20 2012-12-11 Moore Wallace North America, Inc. Compositions compatible with jet printing and methods therefor
US8434860B2 (en) 2007-08-20 2013-05-07 Moore Wallace North America, Inc. Method for jet printing using nanoparticle-based compositions
US8496326B2 (en) 2007-08-20 2013-07-30 Moore Wallace North America, Inc. Apparatus and methods for controlling application of a substance to a substrate
US8894198B2 (en) 2007-08-20 2014-11-25 R.R. Donnelley & Sons Company Compositions compatible with jet printing and methods therefor
US9701120B2 (en) 2007-08-20 2017-07-11 R.R. Donnelley & Sons Company Compositions compatible with jet printing and methods therefor

Also Published As

Publication number Publication date
CH454186A (de) 1968-04-15
GB1042585A (en) 1966-09-14
NL134077C (xx)
BE651881A (xx) 1964-12-01
NL6409403A (xx) 1966-02-15

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