US1033756A - Manufacture of cardboard. - Google Patents

Description

' air, particularly damp air,

WILLIAM GRANT 'FISKE, QF PURFLEET, ENGLAND.

MANUFACTURE OF CARDBOARD.

No Drawing.

To all "whom it may concern:

Be it known that I, WILLIAM GRANT FISKE. a citizen of the United States of America, and resident of Purflee-t, Essex, England, have invented a certain new and useful Improvement in and in the Manufacture of Cardboard, of which the following is a specification.

My invention has for its object the production of cardboard which shall possess the quality of complete impermeability to but which, while sufiiciently rigid to be self-supporting, shall yet be pliable to the extent necessary for permitting of its being bent without detriment to its capability of serving as a means of opposing the infiltration of moistureladen air; the improved cardboard being designed more especially to serve as a material for the manufacture of boxes or containers for goods (such as tea, biscuits, etc.) which have hitherto required to be inclosed in tins in order that they may be effectually protected from atmospheric influences.

The cardboard made in accordance with the present invention consists of not less than three distinct layers or thicknesses each of cardboard, together with intervening films or layers consisting solely of pitch adapted to serve not only as the non-hygroscopic air-excluding medium but also as the adhesive between the several card-layers. The improved cardboard may thus be described as a triplex or multiplex pliableboard constituted by a pile of alternate layers of card and pitch, the external layers being of card.

The improved cardboard may be made by drawing each internal layer continuously through a container wherein the pitch is kept in a fluid state by means of heat, so that a card-layer thus treated becomes coated on both surfaces with a film of pitch, and on leaving the container, superposing the coated card-layers (if more than one) ,one upon another and at the same time applying the two external card-layers to the internal card-layer or layers, the whole (2". e., the three or more card-layers) being thereupon passed between a pair or pairs of Specification of Letters .Patent. Application filed March 18, 1912. Serial No. 68,614.

Patented July 23, 1912.

pressure-rollers whereby the several juxtaposed layers compr" to adhere closely together while any excess of pitch is squeezed .out from between the card-layers.

Especially in cold weather, it is desirable. either to co duct the operation in a warm room or to subject the several layers of card to a preliminary heating so as to obviate the pitch becoming cooled too-rapidly by contact with the card material.

, From the above description'it is apparent that the substance employed to unite the three or more layers of fabric is one which shall be sufficiently viscous and of a character that when spread in a thin layer shall be practically impermeable by air and 'especlally damp air. It must, however, also be asubst-ance which will not either in itself, or by reason of incorporated oils'or other not strongly coherent ingredients, tend to penetrate or permeate the card, it being the essence of this invention that the outer surfaces of the board shall be to all effects and purposes, card layers, having the usual or normal card qualities, whereas interposed between them are one or more sheets or layers of a viscous material impervious, when spread out into a thin layer, to air, and having the property of not sinking deeply into or penetrating the outer layers of the card, so that the board as'a whole will be relatively air proof without yielding up its properties as a flexible, bendable cardboard suitable to be used as a container for merchandise. Pitch, of course, is an ideal material for this purpose, but it will be readily recognized that other substances having similar qualities would be the equivalent of pitch for the purposes of this invention.-

Claimed 1n the pile are caused The herein described improved cardboard pheric or thermal conditions, the said layers being pressed together so that any excess ture, and also as the medium to prevent the is removed and the pitch appears therein as passage of moist air through the cardboard a very thin but uninterrupted film anchored as a whole, substantially as described. on both sides in the layers of the inclosin WILLIAM GRANT FISKE.

5 sheets but not penetratin said sheets, said 'Witnesses: I

film of pitch serving bot as the adhesive HAROLD JOHN PUT, to unite the layers into single unitary struc- HARRY WILFRED QUINNELL.