US2395703A - Laminated sheet pulp container and method of forming same - Google Patents

Description

L. M. WILEY Feb. 26, 1946;

LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME 7 Sheets-Sheet 1 Filed Dec.

7 INVENTOR.

L. M. WILEY Feb. 26, 1946.

LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME Filed DC.

7 Sheets-Sheet 2 INVENTOR. 7 LEE /7. l V/Lfh BY I Feb. 26, 1946.

L. M. WILEY LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME 7 Sheets-Sheet 5 Filed Dec. 3, 1942 l O y O l/wmro/z 45s mew/5r WWW Feb. 26,1946. 7 1... M. WILEY 2,395,703

LAMINATED SHEET PULP CONTAINER AND METHOD 0F FORMING SAME Filed Dec. 3, 1942 7 Sheets-Sheet 4 ff'fln gi nu &\\\\\\\ 1.. M. WILEY 2,395,703 LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME Feb. 25, 1946.

' 7 Sheetls-Sheet 5 Filed Dec. 3, 1942 uwm/ra/a, LEE M. WILEY Feb. 26, 1946. M. WILEY LAMINATED SHEET PULP 2,395,703 0F FORMING SAME L.' M. WILEY Feb. 26; 194 6 LAMINATED SHEET PULP CONTAINER AND METHOD OF FORMING SAME 7 Sheets-Sheet '7.

Filed Dec; 3, 1942 Patented eb. .26, 194.6

I I 2,395,103- I j LAMINATED snna'r PULP CONTAINER METHOD OF FORMING SAME Lee M. Wiley, Marlon, Ind assignor of one-third to Julian Wiley '1. Lett and one-third to Reeley B.

I Applicatlon'Dec embei- 1942, Serlal'No. 467,715 1 Claim. (c'l. 154-2) invention relates to a deep drawn seamless container formed primarily of sheet pulp stock.

The present invention also is directed to the means for and method of laminating such stock to produce a composite, laminated sheet prior] to formation therefrom oi the aforesaid container.

'Ihelaminated-sheet comprises the stock which is first passed through impregnating tanks, andthen through a wringer structure to form a moistened lmpreg'nat ed loop which is then fed to blanking dies to form blanlm. These blanks are then precreased anddrawn through tubular die extensions by plungers that subsequently eject the partially formed article into a receiver mold wherein the container side wall precreased stock is consolidated and distributed bythe plunger dated May 16, 1944; No. 2,348,272, dated May 9, 1944; No. 2,296,889, dated Sept. 29, 1942; No. 2,354,564, dated July 25, 1944; and allowed application Serial No. 444,671, now Patent No. 7 3 2, dated June 5, 1945.

Since these patents are readily available for a detailed disclosure of complete article formation,

and since thersum hereinbefore briefly summarizes said disclosuresyno further reference to form 'an article that approximates final form.

The receiver molds are turret mounted and suceessively presented in indexed turret rotation to successive pressure stations and a final discharge station. Here the articles are sultably transferred to a conveyor for transportation to and through a heater.

This heater evaporates the remaining moisture not mechanically extruded from the article. These articles are then pressure formed and .in oversize relation and then shrunk to size in a second heater that operates at a temperature high enough to cause dispersion and distribution of the residual impregnate or size. Final pressure forming and decorating then may be elTected if desired.

An alternate method or processing is for the conveyor supported, turret mold ejected articles to pass through a unitary two stage heater, in the first stage (of longer duration) being subjected to drying and in the second stage (shorter duration) being subjected to furtherdrying but at a higher temperature sulficient to thermally condition the article carried impregnate or size, so that it can be consolidated in afinal pressure formation. 5

The latter may occur in a turret type mechanism, there being included between the receiv- I ing molds of the same and'the conveyor beyond the heater, a suitable stripper.

The turret die consolidated and formed article may then be printed, decorated or the like, as desired, and finally ejected.

Illustrative ofapparatus and methods for practicing parts of the present invention reference may be had to the following copending patents:

No. 2,337,581, dated Dec. 28, 1943; N0.'2,348,871,

thereto is believed necessary if it be distinctly understood that the present disclosure is directed to laminated sheet formation for laminated article formation. I

The subsequent disclosure is confined, to minimize descriptive matter only.- However, it, is amplified by a disclosure of the article, or rather parts and sections thereof when including the laminated sheet pulp stock of this invention.

The chief object of thisinvention is to provide a laminated pulp sheet including outer layers or plies of sheet pulp and an intermediate layer or ply of plastic for reenforcement purposes, for hermetic sealing purposes, and for non-tacky handling of the subsequent-laminated sheet in the several processes and apparatuses summarized hereinbefore and also illustrated and described in said patents.

. The chief feature of the present invention condesired, of tacky plastic, water repellent and/or thermal and/or pressure setting in character.

Other objects and features of this invention will be set forth more fully hereinafter.

The full nature of the invention will be understood from the accompanying drawings and the following description and claim:

.In the drawings,

Fig. 1 is a diagrammatic elevation outline of the prelaminating formation of a laminated paper board pulp sheet including the inclusion of a sheet of plastic for laminating purposes.

Fig. 2 is a similar view of a modified formof the invention and represents plastic lamination inclusion when the plastic is in liquid form.

Fig. 3 is a similar view of a further. modified form of the invention and when the plastic lamination is initially in powder form.

Fig. 4 is a top plan viewof an article including the laminated sheet and prior to final consolidation steps disclosed in the copending applications.

Fig. 5 is a similar view on an enlarged scale of a small section thereof.

Fig. 6 is a view similar to Fig. 5 andwith the parts of the article in final wall consolidated repulp sheets I and it when presented thereto.

lotion. This occurs at or immediately prior to the sheets Fig. 'l 'is a vertical sectional view taken on line passing through the booster and squeezing rolls 1-1 of Fig. 4 and in the direction oi the arrows and on a scale approximately four times Fig. 4 scale. which may, for illustration purposes, be considered substantially full size.

Fig. 8A is a longitudinal sectional view of one apparatus illustrating the blanking, pre-creasing,

creasing and initial formation of the article.

Fig. BB is a similar view of the dehydrator through which the article passes.

Fig. 8C is a similar view of an. intermediate forming press and a second oven through which the article passes.

ing die shown in Fig. 8A.

Fig. 10 is a face view of the stationary precreas- 45 adjacent tank II.

In passing through these rolls, or a similar pressure roll set ahead of same, the three sheets are caused to adhere together. The plastic layer being water repellant thus prevents water passage through the laminated sheet; Since the plastic ply is flexible, it will conform with the two outerplies of the sheet to whatever deformation the laminated sheet is thereafter subjected.

Reference will now be had to Fig. 2. In this disclosure the plasticintermediate ply initially .is

Fig. 9 is a face view of the movable precreas-' ing corrugated and tubular die shown in Fig. 8A.

Figs. lla, 11b and 110 are sectional views showing successive relative positions of the movable pre-creasing die and stationary pre-creasing die, immediately prior to pre-creasing, intermediate pre-creasing and final pre-creasing of the blank.

Fig. 12 is a side elevation of a modified form of apparatus to which the conveyor shown in Fig. 8A may connect and which may replace the apparatus shown in Figs. 8B and 8C and is distinguished by an oven with superposed communicatin: chambers of dehydrating and presetting character anda turret type final former.

In each of the Figs. 1 to 3, i0 indicates a roll support and il a second roll support, the former supporting a roll i2 of prime pulp sheeting (bleached or unbleached) and the latter supporting a similar roll i3. From the same are drawn the sheets ll and i5 respectively.

Following suitable plastic inclusion therebetween. as hereinafter more fully set forth, the resuiting laminated sheet it passes into an impregnating tank I! below an impregnating solution immersed roll 18 suitably suspended in the tank t as at IS. The sheet then passes Tbelow roll 20 similarly suspended as at 2i and thence passes upwardly between wringer rolls 22.

The impregnating solution in the tank I1 is of the desired character, but is intended primarily for surface treatment of the finished article.

The sheet i6 extends upwardly from the wringer rolls 22 and passes over an elevated support roll 23 supported as at 24. A gravity reof liquid character, being contained'in a tank 50, the-same being automatically or manually suppliedwith the'liquid and the temperature of which'may be automatically or manually controlled if. necessary.

In said tank 50 is a doctor roll 5i for transferring the liquid to the applicationr'oll 52 over which passes the sheet i4. Sheet l5 passes over roll 53 and engagzs the plastic covered lower face of sheet i4. Upper squeeze roll 54 cooperates with lower roll 53 to cause adherence of the now plastic inner layer to both liner plies. The resultant is a laminated pulp sheet similar to that previously described.

In Fig. 3 a third method of plastic lamination application is illustrated. Herein the plastic is in powder form. The two sheets 14 and i5 pass between booster rolls B0 and then into tank 6| through inlet 610. It then passes below roll 62 in the tank and out through outlet 6117. This tank contains vapor for softening the two sheets.

Steam supply lines, etc., 63- are provided.

The softened sheets then pass between squeeze rolls 64 and surplus softening material, if condensed, is squeezed out and runs back on the sheets and into the tank. The sheets, after passing between the squeeze rolls 6!, separate and the lower sheet (ply I5) passes over approach I roller' 65 and platen '66. The upper sheet passes tained light roll 25 ,with shaft 26 seated in slots 21 of support 24 overlies and bears on the sheet The sheet i6 leaving roll 23-45 forms a loop or festoon 28 and the other end thereof passes over roll 29 of the block diagrammed forming machine 30, see Figs. 1 to '3. Herein one or more impregnating tanks H and associated mechanism' may be utilized as desired or required.

Reference will now be had to Fig. 1 herein.

Between rolls i2 and i3 and upon a roll support 40 there is supported a 'roll ll of plastic in sheet form. A separating sheet of non-adhering material such as holland cloth may be included when necessary, but is stripped as the roll is stripped leavingonly the plastic sheet 42. The separating strip disclosure is omitted for clarity as well as any rewind structure therefor if utilized.

The water repellant, normally non-tacky flexible sheet 42 is then subjected to a suitable solvent spray 43 obtained by passing the sheet between oppositely directed solvent discharging spray nozzles 44. This solvent tempers the plastic sheet 42 surfaces so same will adhere to the over ' overhead roller 61 and 68.

Between the two sheets is a supply container 69 containing powdered plastic. The discharge therefrom may be regulated in the throat Ill.

The powder P drops or is forced under pressure onto the upper face of sheet l5, while on the platen 66. A gauge ii, of adjustable character, determines the thickness of the powder -layer. This gauge may be of scraper type.

A pair of squeeze roll l2 and 13 are positioned adjacent the discharge end of the platen 66. Sheet 14 passing over roll 68 passes under roll 12. Sheet l 5, covered with powdered plastic to the desired depth, passes directly from the platen to roller 13. The two sheets with the included powdered plastic are then consolidated in their passage through rolls 12-13 into a laminated sheet similar to each of the aforesaid sheets.

As previously stated, each of the laminated sheets i6 then passes between boosterand squeeze rolls 45 and then through tank i1 and wringer 22-22 forming loop 28 prior to introduction to the forming machine 30.

Reference will now :be had to Figs. 4 to '7 inclusive. The composite sheet as stated is initially blanked, see left-hand portion of Fig 8A. and the blanks precreased, see same portion of Figs. 8A, 11a, 11b and then drawn through a die, see Figs. 8A and 10, and seated in-a female mold, see Fig. 8A, and pressure molded to approximate form (see central portion of Fig. 8A).

Figs. 83 and 8C disclose respectively a dehyasearos drator and a forming press and second oven. The movable precreasing die is illustrated in Fig. 9 as well as Fig. 8A. Fig. 12 illustrates an alternative composite dehydrating and tempering oven and another form of final finishing press, same being of the turret type.

Fig. 8A corresponds to Fig. 1 of Patent 2,348,272.

Fig. 83 corresponds to Fig. 2 thereof and Fig. 86' corresponds to Fig. 3 thereof.

Figs. 9 audio correspond to Figs. 9 and- 10 of Patent No. 2,337,581.

Figs. 11a, 11b and lie correspond respectively to Figs. 12, 13 and 14 .of the aforesaid last mentioned patent.

Fig. 12 corresponds to Fig. 1 of Patent No.- 2,377,392.

In Figs. 4 and 7, 80 indicates the bottom of the article initially formed, 8| the sidewall portion immediately contiguous thereto, 82 indicates the initially pleated portion and 83 the upper fully pleated portion. Fig. illustrates the upper fully pleated portion 83 priorto full consolidation.

Each pleat in cross section is substantially U- shaped with inturned arm portions, see Fig. 5.

The successive pleats are reversed in position and are continuations of each other. When the pleats are finally consolidated, see Fig. 6, the interior and exterior surfaces of the container or article are of continuous wood pulp type. The plastic layer is therebetween and also pleated. This obviously constitutes a stifi ribbed reenforcement for the container sidewall. No external or internal ribbing or creases appear in. the finished product. The pulp sheets due to impregnation have the desired finish.

The intermediate layer of plastic or ribbed reenforcement between the pulp sheets, so far as the side wall is concerned, adds considerable strength to the molded container over one of pellency, heat resistance and the like and by surthe same wall thickness, but made of a single pulp sheet, or a plurality of pulp sheets. The present invention forms a homogeneous wall between the two fibre walls so that hermetically sealed packaging can be accomplished where pulp d only might fail.

It will also be apparent that by laminating in i any oi the manners illustrated and described practically any thermoplastic material can be used for the laminated board due to the fact so either or both may be treated for water reface treatment only. Difierent colored sheets also may be employed with the present invention, so that either interior or exterior or both can 'be of the desired color or colors.

The critical feature of the present invention is the formation of a multiply sheet with an included plastic bond between adjacent pulp sheets and coextensive therewith, the plastic being homogeneously united to the confronting surfaces of the plastic-bonded sheets. v

Desirable characteristics are strengthening of the article, possible hermetical sealing of the article, subsequent formation, without dimculties enumerated, of multi-plyblanks into containers.

While the invention has been illustrated and described in great detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character.

The several modifications described herein, as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to'the appended claim.

The invention claimed is;

A method of forming a deep drawn. seamless, laminated wall container of substantially uniform wall thickness in transverse section and with an inner surface forming pulp layer, an outer surface forming pulp layer and an intermediate imperforate plastic layer therebetween comprising initially assembling two water and size absorbing pulp plies with a water repellant, 'teinperature and pressure settable bonding plastic layer therebetween and coextensive therewith. consolidating by pressurethe plies and layer into 'a unitary laminated sheetimpregnating the pulp piles of the sheet with moisture. the'impregnation being with or without size as desired, wringingthe sheet to the desired moisture content for subsequent working of the sheet in blank form such as initially precreasing the'blank and then forming side wall flutes or pleats in the blank in registration with the creasing. compressing. consolidating and distributingthe fluted material to form an article with an imbedded imperforate plastic reinforcement of concentric circumferential and radial type in the wall. and of approximately final form, pressure consolidating the 31".

ticle to nearly finalform, subjecting the article between the sheets to successive heatingsfor drying and setting purposes. and finally pressure finishing the article to final container form.

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