US1792382A - Paper product and method of producing the same - Google Patents

Description

Patented Feb. 10, 1931 PATENT OFFICE WILLIAM CLARENCE. LODGE, OF FULTON, NEW YORK, ASSIGNOR T0 OSWEGO FALLS CORPORATION, OF FULTON, NEW YORK, A CORPORATION OF NEW YORK PAPER PRODUCT AND METHOD OF PRODUCING THE SAME No Drawing.

view, I have discovered that paper products where sizing is added during the paper making process, attain economy in production combined with approximately maximum (at) strengtl'i, and (6) water resistance qualities, when the product contains not more than approximately one percent wax or its equivalent, and not more than approximately three percent rosin or its equivalent; and that the preferred method of producing such paper product is to add to the pulp in the beater during the paper making process, as a sizing, (1) an emulsion or suspension of rosin or equivalent ingredient equal by weight to approximately three percent of the pulp and then (2) an emulsion or suspension of paraffin or equivanent water resisting agent or ingredient equal by weight to approximately one percent of the pulp, and thereafter add to the pulp in the beater a proportion of suitable fixing or precipitating agent, such as alum or its equivalent, equal by weight to approximately three percent of the pulp.

By the term paper products, I include paper or paper board in the sheet or roll, and also paper articles, such as paper containers of various forms, and paper closures,

such as paper closure disks and paper hood caps, for bottles and other containers.

While it is highly 'desirable to provide paper containers and paper closures, the paper or paper board of which is approximately water proof or of good Water resistant qualities, yet it is exceedingly disadvantageous to provide paper products of substantially weak paper material, wherein the strength of the paper is substantially weakened as the water resistant quality of the paper is increased, and it is also objectionable to substantially increase paper production costs by reason of the attainment of substantial water resistant qualities in the paper product.

Applicationfiled January 28, 1927. Serial No. 164,382.

It is highly desirable that paper hood caps (paper caps of skirted form designed to cover and protect the heads of containers, 'mrticul'arly milk bottles) be of more or less high tensile strength, and possess substantial water resistant qualities, and where such hood caps carry a binder rendering the caps moldable when heated and quick setting to rigid securing form, it is particularly desirable that the caps possess the qualities of strength as well as resistance against the entrance of moisture and consequent swelling of the paper material with a tendency to expand and unduly loosen the binder carrying skirt molded on the bottle neck.

In making my tests under this invention, I have followed sizing methods in the production of paper or paper board, particularly that gradelof paper board commonly known as manilla sulphite or oyster pail, and hood caps for bottles, made from such board.

It is known to those skilled in the art, that waxes and fats generally, and parafiin specifically, materially improve the water resistance of paper and paper products when incorporated intothe sheet of paper either by the process commonly known as engine sizing in which process a solution, emulsion or finely dispersed suspension of wax or waxes alone or in combination with rosin and/or other ingredients, is added to the paper pulp in the heaters; or when the wax is applied to a.

surface of the finished sheet of paper by immersion in a bath of molten wax, or by any other convenient method.

However, I find that the addition of any of these sizing materials and/or compounds to the paper pulp in the beater, has a marked weakening effect on the tensile strength of the finished sheet or paper product.

I have tested paper products the pulp for which was subjected to various engine sizing treatments during the paper making process, and in the following tables I have tabulated various results attained and compared the same with the results attained with paper products of andproduced according to, 'my invention.

In the following tables, and explanations, the percentage or proportion of size added to ion the pulp, indicates approximately the amount of sizing material in the finished sheet or paper product independent of the concentration of the emulsion or suspension of the size as introduced.

Parafiin in the following tables means an aqueous emulsion or suspension containing substantially pure parafiin wax as the only sizing agent in the preparation.

50-50 paraffin. and rosin, hereinafter means that approximately equal weights of rosin and parafiin wax were fused and then emulsified or finely dispersed in water.

Rosin hereinafter means the ordinary rosin size of commerce, that is a solution of sodium resinate containing more or less free or unsaponified rosin, (in this instance 30% of the total rosin present).

As to the tensile strength of variously sized finished paper, my tests show as follows, an unsized sheet of paper board being used as a standard:

Decrease (1) Size added Strength n Strength 90% 10% 75% 25% 40% 50% 50% 1% paraffin and 2% lOS1I1 85% 16% 1% paraffin and 3% rosin 80% 20% 2% parafiln and 2 rosin 75% 25% I find that paraifin wax has a weakening effect on the strength of the sheet, that this effect increases with the amount added, although not in exact proportion to it. I also find by blending wax and rosintogether and then emulsifying the resultant mixture that a compound is formed which exerts proportionately a greater effect on the strength of 'the finished sheet than paraflin alone.

(2) I find the sizing efiiciency of the various mixtures is not 1n plroportion to their amount or composition. he effect of these various mixtures on the water resistance of the paper in whiohthey are used is tabulated below and the results are expressed as percent of water absorbed by sheets of uniform thickness when submerged in distilled water at a temperature plus or minus Fahrenheit for exactly twenty minutes.

Percent Size added moisture absorbed 1% paraffin"... 35 (1% paraifln 24 2% 5050 paramn and rosin 38 5% 50-50flparaflln and rosin 26 1% para ti and 2% rosln 28 1% parafiln and 17 r0sln 32 1% paraffin and 3 a realm. 24 2% pamflin and 2% rosin 28 3% n in I find that while rosin of itself is very inferior to wax alone, that the combination of the rosin with the wax materially improves the sizing properties of the rosin, so much so that approximately 1% of wax in the finished sheet is suliicient for all practical purposes and may be taken as the optimum amount.

I find that greater efliciency is obtained by the use of separately prepared emulsions or suspensions of rosin and wax. It is also ob served that this method produces a stronger finished product than any of the others enumerated. i

(3) I find that when wax and rosin are used in this way, the retention of the rosin is materially improved, for example: To 1000 pounds of pulp in the beater is added 30 pounds of rosin as emulsified size followed after an interval of ten minutes by 30 pounds of alum, the stuff passed through a Jordan englue and formed into board on a cylinder machine.

The finished board contained 2% of resinous material of which 1.2% was present in the original pulp, leaving .8% which has been absorbed in the size, showing a retention of L976 01 These results were obtained in commercial production. The pulp was less than one hour in the heater, and the board made on a six cylinder machine.

Any substance that will form soluble soap with an alkali, for paper sizing purposes, such as stearic acid, stearme, and many vegetable and animal fats, could be used as a substitute for rosin, for the purposes of my invention, in paper sizing, and hence the term sizing soap employed herein to include rosin and its substitutes for sizing purposes within my invention. However, rosin is at this time preferable because it can be readily obtained in the desired quantities at a reasonable price.

Various substances or compounds can be substituted for paraflin to perform the functions of paraflin within my invention. Any substance that will perform the functions of paraflin under my invention and that is susceptible of emulsification, or that will exist in a fine state of subdivision, in an aqueous menstruum, can be substituted for paraffin, for instance, ceresin, Montan, carnauba, and Japan wax, beeswax, asphalt emulsions, and emulsions of oils and/or fats, the latter as distinmoaeea aflim As at present advised by experience and market conditions, I prefer to employ parafin, or mixtures of parafin and carnauba or Montan Waxeswith rosin.

Where the paper product of my invention will be exposed to heat, say above the melting point of parafin, carnauba, or Montan wax or asphalt would be preferable to paraflin, but on the other hand, the color of some of these paraflin substitutes might be objectionable in paper products, for some purposes.

What I claim is 1. In the production of a water resistant paper product, those steps which consist in adding to the pulp in the paper making process, approximately 2% to 3% sizing soap such as rosin, and approximately 1% water resistant ingredient as a sizing, and fixing or precipitating said sizing in the pulp.

2., In the production of a water resistant paper product, those steps which consist in adding to the pulp, sizing in the proportion of three parts rosin or rosin substitute and approximately one partwax or wax substitute, and thereafter fixing or precipitating the same in the pulp, for the final production of paper product containing approximately 1% I wax and not more than 3% rosin.

In testimony whereof I have hereunto set my hand at Fulton, New York, this 27th day of Jan., 1927.

WM. 0. LOIJGE.