GB2244448A - Method and apparatus for continuous centrifugal deposition of a tubular layer of material - Google Patents

Method and apparatus for continuous centrifugal deposition of a tubular layer of material Download PDF

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Publication number
GB2244448A
GB2244448A GB9012121A GB9012121A GB2244448A GB 2244448 A GB2244448 A GB 2244448A GB 9012121 A GB9012121 A GB 9012121A GB 9012121 A GB9012121 A GB 9012121A GB 2244448 A GB2244448 A GB 2244448A
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GB
United Kingdom
Prior art keywords
former
material
mould
end
axis
Prior art date
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.)
Withdrawn
Application number
GB9012121A
Other versions
GB9012121D0 (en
Inventor
John Briggs
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Research Development Corp UK
Original Assignee
National Research Development Corp UK
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by National Research Development Corp UK filed Critical National Research Development Corp UK
Priority to GB9012121A priority Critical patent/GB2244448A/en
Publication of GB9012121D0 publication Critical patent/GB9012121D0/en
Publication of GB2244448A publication Critical patent/GB2244448A/en
Application status is Withdrawn legal-status Critical

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B28WORKING CEMENT, CLAY, OR STONE
    • B28BSHAPING CLAY OR OTHER CERAMIC COMPOSITIONS, SLAG, OR MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00Producing shaped prefabricated articles from the material
    • B28B1/30Producing shaped prefabricated articles from the material by applying the material on to a core or other moulding surface to form a layer thereon
    • B28B1/32Producing shaped prefabricated articles from the material by applying the material on to a core or other moulding surface to form a layer thereon by projecting, e.g. spraying
    • B28B1/34Producing shaped prefabricated articles from the material by applying the material on to a core or other moulding surface to form a layer thereon by projecting, e.g. spraying by centrifugal force
    • AHUMAN NECESSITIES
    • A23FOODS OR FOODSTUFFS; THEIR TREATMENT, NOT COVERED BY OTHER CLASSES
    • A23GCOCOA; COCOA PRODUCTS, e.g. CHOCOLATE; SUBSTITUTES FOR COCOA OR COCOA PRODUCTS; CONFECTIONERY; CHEWING GUM; ICE-CREAM; PREPARATION THEREOF
    • A23G3/00Sweetmeats; Confectionery; Marzipan; Coated or filled products
    • A23G3/02Apparatus specially adapted for manufacture or treatment of sweetmeats or confectionery; Accessories therefor
    • A23G3/0236Shaping of liquid, paste, powder; Manufacture of moulded articles, e.g. modelling, moulding, calendering
    • AHUMAN NECESSITIES
    • A23FOODS OR FOODSTUFFS; THEIR TREATMENT, NOT COVERED BY OTHER CLASSES
    • A23GCOCOA; COCOA PRODUCTS, e.g. CHOCOLATE; SUBSTITUTES FOR COCOA OR COCOA PRODUCTS; CONFECTIONERY; CHEWING GUM; ICE-CREAM; PREPARATION THEREOF
    • A23G3/00Sweetmeats; Confectionery; Marzipan; Coated or filled products
    • A23G3/02Apparatus specially adapted for manufacture or treatment of sweetmeats or confectionery; Accessories therefor
    • A23G3/0236Shaping of liquid, paste, powder; Manufacture of moulded articles, e.g. modelling, moulding, calendering
    • A23G3/0252Apparatus in which the material is shaped at least partially in a mould, in the hollows of a surface, a drum, an endless band, or by a drop-by-drop casting or dispensing of the material on a surface, e.g. injection moulding, transfer moulding
    • AHUMAN NECESSITIES
    • A23FOODS OR FOODSTUFFS; THEIR TREATMENT, NOT COVERED BY OTHER CLASSES
    • A23PSHAPING OR WORKING OF FOODSTUFFS, NOT FULLY COVERED BY A SINGLE OTHER SUBCLASS
    • A23P30/00Shaping or working of foodstuffs characterised by the process or apparatus
    • A23P30/10Moulding
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/006Continuous casting of metals, i.e. casting in indefinite lengths of tubes
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B28WORKING CEMENT, CLAY, OR STONE
    • B28BSHAPING CLAY OR OTHER CERAMIC COMPOSITIONS, SLAG, OR MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00Producing shaped prefabricated articles from the material
    • B28B1/20Producing shaped prefabricated articles from the material by centrifugal or rotational casting
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B28WORKING CEMENT, CLAY, OR STONE
    • B28BSHAPING CLAY OR OTHER CERAMIC COMPOSITIONS, SLAG, OR MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B11/00Apparatus or processes for treating or working the shaped or preshaped articles
    • B28B11/003Apparatus or processes for treating or working the shaped or preshaped articles the shaping of preshaped articles, e.g. by bending
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/02Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
    • B29C41/04Rotational or centrifugal casting, i.e. coating the inside of a mould by rotating the mould
    • B29C41/042Rotational or centrifugal casting, i.e. coating the inside of a mould by rotating the mould by rotating a mould around its axis of symmetry
    • B29C41/045Rotational or centrifugal casting, i.e. coating the inside of a mould by rotating the mould by rotating a mould around its axis of symmetry the axis being placed vertically, e.g. spin casting
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C41/00Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
    • B29C41/24Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of indefinite length
    • B29C41/26Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of indefinite length by depositing flowable material on a rotating drum
    • B29C41/265Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of indefinite length by depositing flowable material on a rotating drum on the inside of the drum
    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21FPAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F9/00Complete machines for making continuous webs of paper
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29LINDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2023/00Tubular articles
    • B29L2023/22Tubes or pipes, i.e. rigid

Abstract

A continuous seamless tube is produced by feeding material into the top end of a cylindrical former (3) e.g. a mould whose axis (6) gyrates over a cylindrical, frusto-conical, or conical surface, preferably without rotating about its axis (6). The centrifugal force set up by the gyration holds the material to the former wall along which it travels to be continuously withdrawn from the bottom end of the former. The material may be cooled, heated, thickened e.g. dewatered, or compressed in passing along the former, or may be hardened, cured, or solidified to be withdrawn as a moulded tube from the former. The casting of a steel tube is described, but the material may also comprise non-ferrous metal, cellulose fibre, mineral fibre, cementitous, polymeric, or foodstuff materials, and may incorporate a reinforcing mesh to prevent tube breakage as it is being withdrawn. The tube may be slit and opened up into a sheet. <IMAGE>

Description

CONTINUOUS PRODUCTION OF LAMINAR MATERIALS SUCH AS TUBES The invention relates to a method of and apparatus for handling matter, such as for continuous production of laminar materials, normally tubes, but also flat sheets and profiles.

Compared with batch production or treatment, continuous operation offers important advantages of speed, consistency and susceptibility to automatic control.

Continuous production of tubes such as pipes is known for materials which can show a high degree of plasticity or 'formability', as typified by plastic clay bodies or organic polymeric 'plastic' materials having a viscosity characteristic of approximately 104 poises at shear rates of 10'2sec'l. Such materials can be advantageously extruded continuously through a die. It is also known to draw glass tubing continuously from a bath of molten glass, but again very careful control of the drawing rate, cooling rate, and viscosity characteristics of the melt are necessary.

Production of tubes from materials which do not have the correct plastic rheological response for the above extrusion or drawing processes can be carried out by a variety of methods, almost all of which involve discontinuous, (i.e. batch production) methods. An example is production of concrete pipes by centrifugal casting of a wet concrete mix in a tubular mould which is spun about its axis at a suitable speed for a suitable time to give a tubular concrete shape which is defined in length and in outer diameter by the dimensions of the mould itself. The intern#l.!diameter of the tube is determined by the quantity of material introduced into the mould.The production of shapes by centrifugal force is also known in the metal foundry industries, especially for cast iron, and is similar to the above cited case of concrete pipes or pipes based on cementitious materials.

In all these cases, however, the mould body rotates about an axis to generate centrifugal force to transfer the material being formed to the wall of the mould cavity. Since the tube thus formed is rotating at high speed during the forming process, it is difficult to handle in a continuous manner.

A method of production of tubes has nonetheless been developed (UK Patent Application GB 2004784A) comprising continuous centrifugal casting of solid round steel bars, which are cooled rapidly and have highly desirable microstructures and good properties. The bars are subsequently transformed into tubes by extrusion with a central mandrel. Although that gives some of the benefits of continuous production, the mandrel still has to be periodically withdrawn in the extrusion operation, which therefore cannot itself be made continuous.

According to the present invention, a method of handling matter comprises applying the matter to one end of and inside a generally tubular former, causing the axis of the former to gyrate describing the surface of a cylinder, frustum or cone (the frustum or cone preferably converging away from the said one end), the former optionally also rotating about its axis, and withdrawing or collecting matter from the other end of the former. The handling may take the form of heating or cooling the matter by heat transfer via the former, to which the matter is centrifugally held, or thickening (e.g. dewatering) or compression.

Further according to the present invention, a method of continuously producing a laminar material comprises continuously feeding material into one end of a generally tubular mould, causing the axis of the mould to gyrate describing the surface of a cylinder, frustum or cone (the frustum or cone preferably converging away from said one end), (the mould preferably not itself rotating about its axis) and continuously withdrawing the material, which has been centrifugally pressed to the wall of the mould (to a generally tubular form), from the other end of the mould. Preferably the material is fluid when entering the method and is treated (e.g. dewatered, cooled, reacted or cured) to solidify it by the time it is withdrawn. Optionally, the withdrawn material can be axially or helically slit and opened to form a continuous sheet, or, if a tube, it can be used in that form directly.

Also according to the present invention, a gyratory handling (e.g. moulding) apparatus comprises a generally tubular former, means for gyrating the axis of the former such that (preferably without rotating the former about its axis) the axis describes a cylinder, frustum or cone, means for applying matter to be handled to one end of and inside the former, and means for withdrawing or collecting matter which has been handled from the other end of the former. The notional frustum or cone preferably converges towards said other end. Optionally, a slitter (which may be axial or helical) is provided to modify the handled matter.

The apparatus may be used to mould material or merely to compress it, thicken (e.g. dewater) it or heat or cool it by conductive heat transfer via the former, or a combination of these.

The method uses centrifugal force to compress the feed material against the inside of a cylindrical mould. The centrifugal force is generated by gyratory rather than rotational movement of the mould. The continuous tube which is initially produced can subsequently be cut as it comes off the gyratory tube-making machine in different lengths of tube to suit the application envisaged. Furthermore by cutting the tube continuously, parallel to the length of the tube or helically around the tube as mentioned, the material can, for example while in the plastic state, be opened out to give a continuous flat sheet, as was formerly done for making large pieces of flat glass from tubular elements.

The -gyrated mould which gives form to the stiffening or solidifying mass of material is held rigidly in a typical embodiment, but its axis is caused to trace out a cylindrical surface (or preferably a conical surface) in space by an externally applied eccentric movement. The radius of the imaginary cylindrical or conical surface traced out by the mould axis is preferably from 0.1 to 0.8 time the inner radius of the mould itself.

Preferably, the mould axis is at such an angle to the vertical that the feed material in falling under gravity impinges on the mould wall and is caused to be thrown around the mould wall by the gyration of the mould.

Note that tube can be produced continuously, since the product tube does not rotate but simply gyrates, and not even that if the mould axis gyration locus is the surface of a cone.

The optimum angle or range of angles of this cone, and angles and diameters if the gyration describes a frustum, depend on the speed of rotation of the mould, the speed at which the tubular product is drawn off and the mechanical limitations of the freshly formed product, as may be found by calculation or trial and error.

The centrifugal force on the feed material generated by such a conical gyration has a component along the mould axis which can, in extreme cases, interfere with the progressive movement of feed material resulting in discontinuities or tearing within the tube being made. This problem may be overcome in various ways, for example: choice of speeds and geometries to give an acceptable balance of forces on the material during forming; or incorporation of reinforcing mesh or grids of fibre or wire which can transmit an externally applied downward force to all parts of the material shape; or use of a composite cylindrical mould which provides for continuous downward movement of the inner surface of the tubular mould simultaneously with the gyratory action.

The invention will now be described by way of example with reference to the accompanying drawings, in which Figure 1 shows apparatus according to the present invention in schematic cross-section for performing a method according to the invention, and Figure 2 shows an optional supplementary apparatus, in schematic elevation. Turning to Figure 1, in use, liquid or viscous matter 1 is introduced into the top end 2 of a gyrating cylinder 3 which, by centrifugal force, presses the matter against the inner surface of the cylinder 3, where the matter is caused to stiffen or strengthen either by a change in temperature, or a chemical reaction, or by extraction of a fluid such as water. The speed of gyration is chosen to provide the best compaction or contact at the cylinder wall, which acts as a mould.

The stiffening or strengthening proceeds progressively as the matter or material moves continuously down the mould, so that by the time it reaches the lower end 4 of the mould it is sufficiently strong to be drawn down continuously, without fracturing, into the next stage of the process.

In the case of continuous production of tubes, the material will be cut off to the desired length of tube by a cutting device which; travels in step with the material being produced, as already known in continuous production of metal bars and billets.

Turning to Figure 2, which applies where continuous production of flat sheet is desired, the tube emanating from the end 3 of the cylinder 3 is slit continuously parallel to the direction of motion of the tube by a slitter 20, which also starts to open the tube, and the opened tube then flattened down using rollers 22 to produce continuous sheet. One surface of the sheet corresponds to what was the outer surface of the tube and the other surface to the inner surface of the tube. When more complex cross-sections other than flat sheet are required, then more complex roller profiles may b needed.

The technique as described may be beneficially applied to a wide variety of manufacturing fields, from ferrous and non-ferrous metals to thick cellulose fibre (cardboard) products, to mineral fibre products, cement-based composite materials, polymer-based composite materials, and even foodstuffs and other biological materials.

The various advantages which the technique offers will differ according to the material being manufactured, but will usually include some or all of the following: high speed of throughput good consistency good uniformity no edge effects high density when required high energy efficiency less critical specification for the feedstock the possibility of composite structures having different assemblage of materials through the thickness lower capital cost lower factory floorspace less labour intensive more flexible in terms of thickness and length of product, therefore less wastage.

The requirements for starting up the continuous process differ depending on the material to be produced. In the case of materials such as metals or thermosetting materials which solidify to give strong tubes, the simple priming of the cylindrical mould with a starter blank cylinder which is somewhat thinner in wall thickness than the tube to be produced is inserted in the mould and drawn out as the liquid feed and gyratory motion are started.

In the case of the less strong products, such as cellulose fibre boards or cylinders, mineral fibre boards, gypsum boards, or cement-based products, it is necessary in some cases to introduce a strengthening grid or woven textile-like material which is metallic, or glass fibre, or polymeric. The latter serves to transmit the drawing forces through into the stiffening mass.

Example 1 The gyratory mould 3 is a water-cooled cooper hollow cylinder. Into the mould is introduced a constant .stream of molten steel 1. The mould is 4 metres long and 600mm in diameter. The movement of the mould's axis 6 over a frusto-conical surface measuring 300mm at the top end 2 and 20mm at the lower end 4 projects the steel 1 against the cooled wall where it solidifies continuously to produce a steel tube. The mould 3 does not rotate about its axis 6; only the axis 6 gyrates about a vertical origin 7. Gyration speeds of 500 rpm are used in this case. A tube with 35mm wall thickness is produced at a rate of 300 metres per hour. A seamless tube results which can be of any length, a product impossible to make by conventional extrusion over a mandrel.

Claims (12)

1. A method of handling matter, comprising applying the matter to one end of and inside a generally tubular former, causing the axis of the former to gyrate describing the surface of a cylinder, frustum or cone, and withdrawing or collecting matter from the other end of the former.
2. A method according to claim 1, wherein the handling takes the form of heating, cooling, thickening or compression.
3. A method of continuously producing a laminar material, comprising continuously feeding material into one end of a generally tubular mould, causing the axis of the mould to gyrate describing the surface of a cylinder, frustum or cone, and continuously withdrawing the material, which has been centrifugally pressed to the wall of the mould, from the other end of the mould.
4. A method according to claim 3, wherein the material is fluid when entering the method and is treated to solidify it by the time it is withdrawn.
5. A method according to claim 3 or 4, further comprising slitting the withdrawn material to form a continuous sheet.
6. A method according to any preceding claim, wherein the mould or former does not rotate about its axis.
7. A method according to any preceding claim, wherein the said frustum or cone converges towards said other end.
8. A gyratory handling apparatus, comprising a generally tubular former, means for gyrating the axis of the former to describe a cylinder, frustum or cone, means for applying matter to be handled to one end of and inside the former, and means for collecting or withdrawing matter which has been handled from the other end of the former.
9. Apparatus according to claim 8, wherein the former is not rotated about its axis.
10. Apparatus according to claim 8 or 9, wherein the frustum or cone converges towards said other end.
11. Apparatus according to claim 8, 9 or 10, further comprising a slitter for modifying the handled matter.
12. Use of apparatus according to claim 8, 9, 10 or 11 for moulding, compressing, thickening, heating or cooling material or a combination of these.
GB9012121A 1990-05-31 1990-05-31 Method and apparatus for continuous centrifugal deposition of a tubular layer of material Withdrawn GB2244448A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9012121A GB2244448A (en) 1990-05-31 1990-05-31 Method and apparatus for continuous centrifugal deposition of a tubular layer of material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9012121A GB2244448A (en) 1990-05-31 1990-05-31 Method and apparatus for continuous centrifugal deposition of a tubular layer of material

Publications (2)

Publication Number Publication Date
GB9012121D0 GB9012121D0 (en) 1990-07-18
GB2244448A true GB2244448A (en) 1991-12-04

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GB9012121A Withdrawn GB2244448A (en) 1990-05-31 1990-05-31 Method and apparatus for continuous centrifugal deposition of a tubular layer of material

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0651613A4 (en) * 1992-04-16 1995-01-11 John M Zevlakis Apparatus and method for dispensing defined portions of ice cream, or the like.

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1112471A (en) * 1964-11-13 1968-05-08 Monsanto Co Device and process for casting plastic pipe
GB1536447A (en) * 1975-05-30 1978-12-20 Nippon Carbon Co Ltd Carbon article manufacturing methods and apparatus
GB2033828A (en) * 1978-10-27 1980-05-29 Universal Optical Rotationally moulded articles of epoxy resin
GB2075910A (en) * 1978-06-30 1981-11-25 Safilo Spa Apparatus for moulding articles
EP0266100A2 (en) * 1986-10-15 1988-05-04 Dalily Limited Rotational moulding apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1112471A (en) * 1964-11-13 1968-05-08 Monsanto Co Device and process for casting plastic pipe
GB1536447A (en) * 1975-05-30 1978-12-20 Nippon Carbon Co Ltd Carbon article manufacturing methods and apparatus
GB2075910A (en) * 1978-06-30 1981-11-25 Safilo Spa Apparatus for moulding articles
GB2033828A (en) * 1978-10-27 1980-05-29 Universal Optical Rotationally moulded articles of epoxy resin
EP0266100A2 (en) * 1986-10-15 1988-05-04 Dalily Limited Rotational moulding apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0651613A4 (en) * 1992-04-16 1995-01-11 John M Zevlakis Apparatus and method for dispensing defined portions of ice cream, or the like.
EP0651613A1 (en) * 1992-04-16 1995-05-10 ZEVLAKIS, John M. Apparatus and method for dispensing defined portions of ice cream, or the like

Also Published As

Publication number Publication date
GB9012121D0 (en) 1990-07-18

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