US2972378A

US2972378A - Treatment by compression of fibrocement wet sheet material and the like

Info

Publication number: US2972378A
Application number: US596378A
Authority: US
Inventors: Josephu Augustinus Fr Henricus
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-06-23
Filing date: 1956-06-20
Publication date: 1961-02-21
Anticipated expiration: 1978-02-21
Also published as: FR1155883A; BE539244A; NL199865A; DE1116588B; CH339552A; LU34446A1; NL94211C

Description

Feb. 21, 1961 A. F. H. J. M. NUYENS 2,972,378

TREATMENT BY COMPRESSION 0F FIBRO-CEMENT WET SHEET MATERIAL AND THE LIKE 4 Sheets-Sheet 1 Filed June 20, 1956 531, 1951 A. F. H. J. M. NUYENS 2,972,378

I TREATMENT BY COMPRESSION OF FIBRO-CEMENT wET SHEET MATERIAL AND THE LIKE Filed June 20, 1956 4 Sheets-Sheet 2 ,Feb. 21, 1 A. F. H. J. M. NUYENS 2,972,373

TREATMENT BY COMPRESSION OF FIBROCEMENT WET SHEET MATERIAL AND THE LIKE 4 Sheets-Sheet 5 Filed June 20, 1956 F. H. J. M. NUYENS TREATMENT BY COMPRESSION OF FIBRO-CEMENT WET SHEET MATERIAL AND THE LIKE Feb. 21, 1961 4 Sheets-Sheet 4 Filed June 20, 1956 TREATMENT BY COMPRESSION OF FIBRO- CEKREENT WET SHEET MATERIAL AND THE LI Augustinus Franciscus Henricus Josephus Maria Nuyeus, '162 Ave. de Merode, Turnhout, Belgium My invention relates to apparatus for treating, by compression, the fibrous wet sheet material produced by pulp gathering or wet machines of the Hatcheck or Fourdrinier type as used in the manufacturing of asbestos-cement or fibro-cement products, paper card'or mill-board and the like.

Generally speaking, this apparatus can be applied in a terminal operation following the one performed by the wet machine or even during the formulation of the sheet on the accumulator cylinder of this machine.

An object of my invention is to provide continuity in the operations and to eliminate the expensive, slow working and very cumbersome static hydraulic presses as well as some of the costly conventional dehydrating processes.

The principal object, however, is to improve substantially the quality of the products, not only by squeezing out, under a tremenduous pressure, the free water and the air retained in the sheet and thus rendering the ma terial considerably more dense, but alsothrough lamination, stressing its'fiber structure, and so forth.

The compression, with calenders, of wet fibrous sheets or layers of wet fibrous material has always been a problem, the compression depending on the relationship of different factors such as: the pressure applied and its duration the diameter of the cylinders aswell as the hardness of the contact faces, the rotating speed of the cylinders and sine qua non condition, the ability of the fluids, imprisoned in the material, to migrate.

The calender of the invention is equipped, in principle, with two superposed work cylinders maintained at the required spacing by means of set screws and powerful hydraulic buffers and between which the wet sheet, formerly produced by the wet machine, is progressively subjected to a slowly increasing linear pressure or lamination. In order to allow the fluids imprisoned in the material to migrate, which isessential, the lower cylinder is provided on its surface, with a multitude of duly spaced grooves, and is covered by a. hard and easilyremovable element such as a perforated sheet metal which has a filtering function. a

The fluids forced through the perforations migrat freely in the grooves, which constitute a drain. In order to accelerate the flow of the water in the grooves, the center line of the two cylinders is at approx. 15 from vertical.

Fibrous wet sheets produced by pulp gathering or wet machines and passing subsequently between-those two slowly revolving cylinders are progressively compressed, strained and stretched. They will thus be transformed into dehydrated rigid mats, extremely dense and outstandingly tough.

This remarkable toughness results from the milling.

action which laminates the material and stretches the fibres. These fibres are thus put under a stress which tates Patent Fig. 3 illustrates in broken away section a detail of a roller of the press of Figs. 1 and 2;

Figs. 4-7 show further details; I

Figs. 8 and 9 relate to a special embodiment in which, the wet machine is employed for the production of sheets bearing relief drawings on one side.

In the treatment according to Figs. 1 and 2, which relate to the subsequent treatment of the sheet delivered by the wet machine, the calender is composed of the tw Work cylinders 1 and 2 of large diameter and with a.

circumference larger than the full length of the sheet to be treated. 1

The frame of the structure includes beams 3 connected and spaced by bolts 5. i

At the top of the beams are movable heads 6 attached to the beam 3 by bolts 9.

In each head 6 which is supplied with oil'under pressure moves a piston 10 which acts as a hydraulic buffer and reacts. on the bearing 11 of the upper cylinder 1.

Beneath each bearing 11 a 'set screw'12 engages in a cross-beam 13 which rests by means of superposed vertical members at the bottom of the slide 15 of the beam.

Screw 12, provided at its lower end with a locknut,

acts as a set screw to avoid close contact between cylinders 1 and 2 or their covers, which contact could damage them.

The lower cylinder 2 is driven by a variable speed reducer motor (not shown), acting by means of a pinion on a gear 17, thus driving this cylinder at'a speed,-

for example, of 6 to 1.0 feet per minute corresponding to the average output of a normal wet machine. I

Grooves 20 spaced at 0.055 inch, for instance, by crests 21' (Figs. 3-6) are provided on the circumference of the lower cylinder 2, concentric with the axis thereof. 7

This cylinder 2 is covered by a removable sheet metal 21 provided with perforations 22, the diameter of which is larger (0.075"inch, for example) than'the width of the crests '21 in such a way that each of the perforations 22 always communicates with one or two grooves 20 whatever the position of the sheet metal may be on cylinder 2.

The removable sheet metal 21 must be free to elon-,

pivoting on a cam (not shown).

The lower cylinder 2 which is inder. The lower cylinder provides, moreoverjtor the straining of the sheet.

Patented vFeb. 21, 1961 Rod, 24 is retained at each end projecting beyond the cylinder by a through bolt.

7 the driving cylinder; drives the fibrous sheet which becomes squeezed be-f tween the two cylinders and thus drivesthe upper cyl The upper cylinder can also be covered by an easily removed element such as a sheet of metal or any suitable lining, which is provided with whatever relief drawings may be desired, but this cylinder is not provided with perforations as is the lower cylinder. This lining will be attached in the same way as the perforated sheet metal covering the lower cylinder.

The upper cylinder 1 provides then for the impression of the surface of the sheet, impressions which are effected at the same time as the compression.

The upper cylinder may also be smooth, the lower cylinder being covered as above by a hard and removablefiltering element.

The two cylinders can be provided with corrugations, the lower cylinder being grooved and covered by a removable filter element also corrugated.

In this way, there are various alternatives as follows:

(a) The lower cylinder is covered. The upper cylinder is not covered (smooth).

(b) The two cylinders are covered.

(c) The lower cylinder, which is corrugated, is covered. The upper cylinder, which is corrugated, is not covered.

In these three alternatives, the pressure may be exerted on one or the other cylinder, according to the planning of the machine.

A removable spray pipe 80 can be provided which will prevent clogging up of the perforations of the removable element.

As shown in Fig. 7,

gears

33 and 34, connected by means of a chain 35 are mounted on the ends of the

shafts

30 and 31 of the cylinders 1 and 2. These shafts are located in

bearings

11 and 32. The chain 35 is mounted such as to invert rotation and passes around a guiding wheel 36 and is stressed by means of a lever 37 provided with a counter weight 38.

Lever 37 rests on an adjustable support 39 or hydraulic shock absorber.

The main function of this device is to bring both cylinders back to their initial positions, with the joints of the respective linings facing each other, after passage of each sheet which impulses the upper cylinder. By starting from another position, the sheets would be marked by the joints.

Since the thickness of a lining increases the circumference of the upper cylinder, the rotation of this cylinder will be slower than the lower cylinder. Therefore, the chain 35 will loosen in section 46 directly conmeeting the two

gears

33 and 34. On the other hand, the lever 37 Will move upwards.

At the time the treated sheet comes from between the cylinders, the upper cylinder, by the action of the counter weight 38 will be timed again with the lower cylinder.

Figure 8 shows an application of the calender of a wet machine (Hatcheck process) intended for the manufacturing of fibro-cement products composed of fibres and hydraulic binders.

According to this well known process, one or more layers of an aqueous slurry of fibers and hydraulic binders are conveyed by an endless felt between the two cylinders of this calender.

These thin layers accumulate a number of times on the upper cylinder until a laminated material of the desired thickness has been obtained which is then slitted lengthwise of this cylinder and removed therefrom.

In accordance with the invention, a similar machine is used composed of two

cylinders

41 and 42 of unequal diameter, the upper cylinder having the largest diameter and having a circumference corresponding with the theoretical length of the sheet.

The functions of the lower cylinder 42 are as follows:

(a) To support and drive the conveying felt 43 carrying the thin layer of wet fibrous material and which is guided by

rollers

44 and 45. One of these rollers is located in such a way that the felt 43 contacts a part of the circumference of cylinder 41. The felt drives the upper cylinder.

(b) To contribute to the straining of the felt and of the depot of the fibrous material adhering to the upper cylinder.

This upper cylinder 41 is covered by a removable element 46, for instance sheet metal or any suitable lining of which the length is slightly less than the circumference of the cylinder.

To this element, a rod 48 is attached, for instance by screws 47, the rod being located in the cylinder 41 and being wedged therein by means of a conical key (not shown). This rod 48 has, at a place where it is not covered by the movable element 46, a groove 49, the purpose of' which will be explained further on.

The functions of the upper cylinder are as follows:

(A) To gather at each rotation the thin layer of material carried by felt 43. At each rotation, a layer will be superposed on the preceding layers to form finally a fibrous sheet by these subsequent additions.

(B) To exert, by means of gravity a slight pres sure on the conveying felt 43 which thus is strained as well as the material. This pressure also ascertains the integration of the superposed layers of material on the cylinder.

As a result of the invention, the slight pressure exerted at each rotation of the upper cylinder on a part of the layers already gathered is used to produce an embossing which is effected on the plastic material from the very moment of its formulation.

This modeling is obtained by means of cover or lining 46 carrying a pattern in negative relief corresponding to the one which must be obtained on the sheet.

When the desired number of layers is reached, the fibrous sheet is removed from cylinder 41 through a cutting operation by means of a tool introduced in groove 49.

It is clear that the advantage obtained is that only one die plate must be provided for each pattern to be executed whereas heretofore an engraved cylinder was required for each different design.

In this way the use of a machine is extended simply by removal of a die 46 and its replacement by another one having another design.

The position of roller 44 can be adjusted by means of a screw 50 provided with a handwheel 51 and acting on an iron 52 provided at its end with a fork 53 supporting the shaft 54 on the roller 44.

The shaft 55 of cylinder 41 is located in a movable bearing 56 and attached to the same by a screw 57 or by another device.

A sleeve 58 is provided around bearing '56 in which sleeve a groove 59 allows the passage of shaft 55 when a cylinder 41 must be replaced by another one.

A pressure is exerted on sleeve 58 by a screw rod 60 engaging in a member 61 allowing an adjustment of the length; this rod is provided with a handwheel 62 and goes through a stationary sleeve 63 on supporting column 64.

A certain pressure can be exerted on felt 43 by means of a counterweight 65 mounted on lever 66 articulated at 67 on the frame 68; on this lever 66 an arm 69 of adjustable length extending upwards is pivoted and arm 69 is attached at its upper end to an arm 70 articulated at 71 to column 64.

What is claimed is:

1. Apparatus comprising a source of fibro-cement sheet, superposed cylinders adjacent said source the lowermost of which is provided with peripheral grooves concentric with the axis of the lowermost cylinder, means adjustably supporting the cylinders to accommodate the sheet therebetween, means operatively cou pled to and driving the lower of the cylinders and,

through the intermediary of said sheet, the upper of the cylinders, and a perforated cover on the lower roller having perforations in communication with said grooves.

2. Apparatus as claimed in claim 1 comprising gears on said cylinders and rotatable therewith, a lever, means fixed relative to said cylinders and pivotallysupporting said lever, a pulley on said lever, an endless chain engaging said gears and pulley, and a weight on the lever whereby the cylinders are maintained in predetermined registration when idle.

3. Apparatus as claimed in claim 1, wherein said cover is a cylindrical sheet having adjacent ends and the lowermost cylinder is provided with an axially disposed dovetail peripheral groove and with a second groove parallel to but spaced from the first said groove, comprising a rod connected to said cover at one end thereof and accommodated within said dovetail groove, a wedge in said dovetail groove for locking the rod therein, and a second rod displaceable in said second groove and connected with said cover at the other end thereof whereby said ends are freely displaceable relative to one another.

References Cited in the file of this patent UNITED STATES PATENTS Thom Mar. 15, Hofmeir Dec. 13, Sinclair May 25, Tveden July 15, Haug May 13, Lorenz Apr. 27, Doerr Oct. 11, MacLachlan Oct. 11, MacMenigall June 11, Boyer June 14, Kane June 6, Hornbostel Feb. 25, Cavagnaro Aug. 18, Ireland et a1. Feb. 2, Schmitz Jan. 12, Walter Apr. 27, Wood July 20, Zesbaugh June 28,

Cohn ct a1. Jan. 3,