United States Patent
`Wood
`
`[19]
`
`[11]
`[45]
`
`4,366,012
`Dec. 28, 1982
`
`[54]
`
`IMPREGNATION PROCESS
`
`[57]
`
`ABSTRACT
`
`Inventor:
`[75]
`[73] Assignee:
`
`Eric Wood, Ossett, England
`Insituform International Inc., Great
`Britain
`,
`
`[21] APPL No.: 231,590
`.
`Feb. 59 1981
`[22] Flled‘
`[51]
`Int. 01.3 ........................... 805D 7/22; 3323 1/08
`
`[52] us. Cl. ............................... 156/93; 156/287;
`427/233
`[58] Field of Search ................ 427/238, 294; 156/287,
`156/93
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`................ 427/238 X
`1/1980 Everson et a1.
`4,182,262
`Primanz Examiner—TJames R. Hoffman
`Attorney, Agent, or Firm—Louis Orenbuch
`
`'A method of impregnating the inner absorbent layer of
`a long flexible tube with a curable resin is begun by
`introducing a mass of the resin into one end of the tube.
`A window is formed in the impermeable outer layer of
`the tube at a distance from the resin mass. A vacuum in
`the interior of the tube is drawn through the window
`and concurrently the resin mass is pushed toward the
`evacuated region by passing the tube between a pair of
`squeezing members When the flowing resin reaches the
`vicinity of the window, the window is sealed. Another
`window is formed in the tube farther downstream of the
`previously formed window. A vacuum is drawn
`through the new window while the squeezing members
`force the resin to flow toward the newly evacuated
`region. The procedure is repeated until the resin has
`spread through the entire inner absorbent layer of the
`tube.
`
`v
`
`3 Claims, 12 Drawing Figures
`
`
`
`(cid:47)(cid:48)(cid:46)(cid:3)(cid:55)(cid:72)(cid:70)(cid:75)(cid:81)(cid:82)(cid:79)(cid:82)(cid:74)(cid:76)(cid:72)(cid:86)(cid:15)(cid:3)(cid:47)(cid:47)(cid:38)(cid:3)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:21)(cid:19)(cid:19)(cid:21)(cid:3)
`LMK Technologies, LLC Ex. 2002
`(cid:37)(cid:47)(cid:39)(cid:3)(cid:54)(cid:72)(cid:85)(cid:89)(cid:76)(cid:70)(cid:72)(cid:86)(cid:15)(cid:3)(cid:47)(cid:47)(cid:38)(cid:3)(cid:89)(cid:17)(cid:3)(cid:47)(cid:48)(cid:46)(cid:3)(cid:55)(cid:72)(cid:70)(cid:75)(cid:81)(cid:82)(cid:79)(cid:82)(cid:74)(cid:76)(cid:72)(cid:86)(cid:15)(cid:3)(cid:44)(cid:81)(cid:70)(cid:17)(cid:3)
`BLD Services, LLC v. LMK Technologies, Inc.
`(cid:44)(cid:51)(cid:53)(cid:21)(cid:19)(cid:20)(cid:23)(cid:16)(cid:19)(cid:19)(cid:26)(cid:26)(cid:19)
`|PR2014-00770
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`(cid:20)
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`US. Patent
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`Dec. 28, 1982
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`Sheet 1 of3
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`4,366,012
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`(cid:21)
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`US. Patent
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`Dec. 28, 1982
`
`Sheet 2 of3
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`4,366,012
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`\\ \‘;
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`

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`U.S. Patent
`
`Dec. 28, 1982
`
`Sheets of3
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`4,366,012
`
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`
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`(cid:23)
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`

`

`1
`
`IMPREGNATION PROCESS
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`4,366,012
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`2
`joint in the lining material tube, and therefore the im-
`pregnation of the tube is of critical importance.
`Additionally, the design and structure of the tube for
`the effective insertion is also important, and this inven—
`tion provides specific constructional forms of tube for
`the INSITUFORM lining process.
`In accordance with a first aspect of the invention, a
`flexible tube comprising an inner layer of resin absor-
`bent material, and an outer layer in the form of an im-
`permeable film, has the resin absorbent layer impreg-
`nated with a curable resin by applying a vacuum to the
`inside of the flexible tube whilst the resin is brought into
`impregnation contact with the resin absorbent material,
`the impermeable film serving as a means to prevent
`ingress of air into the interior of the tube whilst the
`impregnation process is taking place.
`Preferably, the resin is introduced into one end of the
`tube in a quantity calculated effectively to impregnate
`all of the resin absorbent material of the tube, and the
`vacuum is applied to the interior of the tube, down-
`stream of the resin mass, so that the resin will tend to
`flow towards the vacuum appliCation region.
`Preferably,
`the lining tube containing the mass of
`resin is fed through a pressure applying nip, such as may
`be defined by a nip roller, which, together with the
`movement of the tube, squeezes the resin in a direction
`towards the region of application of the vacuum, at the
`same time flattening the tube and assisting in the even
`distribution of the resin.
`,
`The vacuum may be applied through a window in the
`film in the wall of the tube by means of a cup applied to
`said window and connected to a source of vacuum by
`means of a flexible hose, whereby the cup can move
`with the tube during its movement relative to said nip.
`As each section of the tube has its resin absorbent mate-
`rial thus impregnated with resin, the cup may be moved '
`and applied to a position spaced downstream from the
`previous window,
`the said previous window being
`sealed by means of a patch or the like, whereby the
`process is repeated for respective lengths of the tube
`until the entire tube length has been impregnated.
`In order to form an initial air sea] at the end of the
`lining tube into which the resin is introduced, an initial
`slug of resin may be introduced into said end, the end
`subsequently closed, and a vacuum applied to the inte-
`rior of the tube downstream of the slug of resin,
`whereby there will be an initial impregnation of the
`resin absorbent material at the said end at which the
`resin is introduced, to prevent air from being drawn in
`at said end during the subsequent impregnation steps as
`above described.
`- The lining tube may comprise an outer layer defined
`by a felt coated with synthetic resinous material to form
`said film, such outer layer being formed into a tube and
`having theadjacent edges sewn together, and then cov-
`ered by a sealing strip or the like, the one or more inner
`layers of resin absorbent felt formed into tubes with
`their adjacent edges sewn together.
`With such construction, it is possible to construct an
`extremely advantageous end of tube assembly, to make
`the tube particularly suitable for the INSITUFORM
`lining process. In such assembly, the inner layer has
`shoulders cut therein, and the edges of the cut portions
`are bonded together to define a central vent tube. A
`portion of the cut away felt is used to define a strength-
`ening saddle portion having a central aperture through
`which the vent tube passes, and the said saddle portion
`being seated on the formed shoulders. Where appropri-
`
`This invention relates to a process for the impregna—
`tion of a flexible liningrtube comprising or including
`resin absorbent material, for the even and homogeneous
`impregnation of the absorbent material with a resin
`composition.
`.
`In recent years, we have developed what is now
`known in a large number of countries as the Y‘IN-
`SITUFORM” (trade mark) lining process for the lining
`of pipelines and passageways. This process is particu-
`larly suitable for the rehabilitation of underground pipe-
`lines and passageways which have fallen into a state of
`disrepair, or are faulty, and a particularly good applica-
`tion for the INSITUFORM process is the lining of
`underground sewer pipelines and passageways which
`may be suffering from egress or ingress of water.
`The INSITUFORM lining process comprises basi-
`cally the inversion into the pipeline or passageway to be
`lined of a tubular flexible liner which includes a resin
`absorbent material impregnated with curable resin. The
`flexible liner is held against the surface to be lined by
`means of fluid pressure, and the resin allowed or caused
`to cure, so that there is formed a hard resin lining
`against the passageway or pipeline surface, such lining
`being‘free standing and including, embedded therein,
`the resin absorbent material.
`
`The resin absorbent material performs two functions
`in that it provides increased impact strength in the final
`lining as it is totally immersed in the hardened resin, and
`it also serves the purpose of keeping the resin, when in
`fluent state, evenly distributed circumferentially of the
`flexible lining tube until and after the tube is placed in
`position lining the pipeline or passageway.
`The resin absorbent material, which typically may be
`a resin absorbent felt material currently forms an impor-
`tant element in the INSITUFORM lining process, and
`it
`is important
`that
`the resin absorbent material be
`evenly soaked with and impregnated in the resin for the
`formation of an even thickness lining in the pipeline or
`passageway. It is important during the impregnation
`process that air be excluded from the resin absorbent
`material to the maximum possible extent, and the pres-
`ent invention is concerned with the effective impregna-
`tion of the resin absorbent material of a flexible lining
`tube for use especially, but not exclusively in the IN-
`SITUFORM lining process described above.
`In the INSITUFORM lining process,
`the flexible
`tube is also provided with an outer impermeable mem-
`brane, which serves two purposes, the first being to
`retain the wet resin when the resin absorbent material is
`first impregnated, and secondly to permit the eversion
`of the impregnated lining tube into the pipeline or pas-
`sageway using a fluid, usually water. When water is so
`used, it acts on the surface of the lining tube defined by
`the membrane so as to-force the tube to turn‘inside out
`in the passageway, and of course the water is kept out of
`contact with the resin by the membrane.
`In the method of the present invention, use is made of
`the outer impermeable coating, which may be in-the
`form of a loose tubular film, or a coating bonded to a
`layer of resin absorbent material, for the effective and
`even impregnation of the resin absorbent material.
`The INSITUFORM lining process is usedfor the
`lining of pipelines or passageways of considerable
`length e.g. of the order of 100 to 300 meters withoutva
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`4,366,012
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`ate, the contacting surfaces of the felt are flame bonded
`together. The outer layer extends over the vent tube,
`but does not seal same. The end of the outer tube is
`sealed apart from a bleed outlet, by means of flexible
`impermeable material such as polyurethane film. The
`bleed outlet is in line with the vent tube to facilitate the
`charging of the resin into the end of the tube through
`the bleed outlet and vent tube.
`Such an assembly enables the ready insertion of the
`resin into the end of the tube, and also permits the tube
`subsequently to be closed, for example during the appli-
`cation of vacuum for the effective impregnation pro—
`cess.
`
`4
`tube 12 is therefore forced against and moulded to the
`shape of the pipeline inner surface to be lined.
`The lining tube 12 as shoWn in FIG. 2 is in fact made
`up of two tubes, the outer 21 being‘a'resin absorbent
`material such as a felt 22 and an outer membrane 24 in
`the form of a coating or film bonded to felt 22, and the
`inner being a felt tube 26. In use the felts 22, 26 are
`impregnated with a curable synthetic resin. The resin,
`either or with or without fillers, is selected so as to have
`a specific gravity approximating to.that of the liquid
`used to invert the lining, so that the lining as it passes
`along the section 10 will have substantially neutral
`buoyancy and frictional forces between the lined por-
`tion of the section 10, and the section of the lining tube
`moving into that portion, are avoided. The lining tube is
`held position lining the pipeline section until the resin
`cures forming a rigid resin tube which is free standing in
`the tube section 10, and has the resin absorbent material
`embedded therein.
`The outer tube 21 is formed from sheet form into tube
`form, and abutting edges are sewn together as shown at
`25.
`The line of sewing is covered by means of a cutting
`tape, of film, extrudate 27 or the like. The inner tube 26
`is a sheet of felt wrapped to form a tube, and overlap-
`ping edges thereof are sewn together as indicated at 30.
`There may be more than one, or no, inner layer depend-
`ing upon the thickness of lining required.
`The resin absorbent felt material of the inner and
`outer layers is soaked in resin, and in the final lining,
`after curing of the resin,
`the inner and outer layers
`become integral with their felt materials embedded in
`the resin, to form the composite rigid lining pipe.
`As can be appreciated from the structure of the lining
`tube as shown in FIG. 2, the tube prior to impregnation
`will contain a fairly large volume of air and the present
`invention ensures the effective and homogeneous im-
`pregnation of the felt material, utilising the barrier prop-
`erties of the outer membrane 24.
`Prior to the description of the impregnation of the felt
`material however, reference is made to FIGS. 3 to 7 to
`illustrate how a suitable and particularly advantageous
`end structure can be provided on a lining tube con-
`structed as shown in FIG. 2.
`Assuming that the felt material of the inner and outer
`layers of the tube shown in FIG. 2 is a polyester fibre,
`to form the novel end structure, the outer layer 21 is
`folded backwards as shown in FIG. 3, and shoulders 32
`are cut in the inner layer 26, also shown in FIG. 3,
`thereby to define at the end of the inner layer two nar—
`row tongues 34 and 36 and the shoulders 32, the inner
`layer 26 at one side of each shoulder being provided
`with a tab 40.
`As shown in FIG. 4, in order to seal the sides of the
`inner layer together in the region of the cut portions,
`the tabs 40 are folded inwardly as shown and are flame
`bonded to the adjacent inner surface of the inner layer,
`and the opposing edges of the tongues 34, 36 are flame
`bonded together in order to form a vent tube 44 which
`is open at the end 46. As shown in FIG. 5 one of the cut
`away portions 42 (see FIG. 3) created in forming the
`shoulders 32 is cut to define a saddle having a central
`hole 48, and that saddle portion is slipped over the vent
`tube 44,- so that portions of the saddle cover the shoul-
`ders andthe saddle is in fact flame bonded to the outside
`of theinner layer 26 in the region of the shoulders, as
`shown 'in FIG. 6.
`
`the said tube end may be provided with
`Finally,
`straps bonded to the outer surface of the outer layer and
`forming U-shaped loops for the holding back of the tube
`during the insertion process, the said end being the end
`which is last introduced into the pipeline to be lined, as
`will be clear from the description which is given herein.
`The resin which is used for the impregnation of the
`absorbent material, typically may be polyester or epoxy
`resin, but it is not intended that the invention should be
`limited to the use of such materials. Furthermore, the
`resins may or may not include fillers, such as olive stone
`or waste particulate materials from power stations.
`Although the resin absorbent material of the lining
`tube is normally felt in the INSITUFORM lining pro-
`cess, the invention is not to be taken as being limited to
`the use of this material. Woven and knitted materials, or
`flexible foams could be used, either singly or in combi-
`nation and in combination with felt materials.
`For a more detailed explanation of aspects of the
`present invention reference is now made to the accom-
`panying drawings, wherein:
`FIG. 1 illustrates diagrammatically the basic IN-
`SITUFORM lining process;
`FIG. 2 illustrates in perspective, cut away elevation,
`a section of a typical
`lining tube used in the IN-
`SITUFORM lining process;
`FIGS. 3 to 7 illustrate in perspective elevation, the
`steps involved in the construction of the end of the
`lining tube through which the resin is inserted;
`FIG. 8 illustrates in sectional elevation how a slug of
`resin is introduced into one end of the lining tube for the
`initial sealing of same;
`.
`FIG. 9 illustrates how the slug of resin seals the end
`of the tube when a. vacuum is applied thereto;
`FIGS. 10 and 11 illustrate in diagrammatic sectional
`elevation the process of impregnating the absorbent
`material of all of the lining tube; and
`FIG. 11 illustrates in enlarged sectional view how the
`vacuum is applied to the interior of the tube during the
`lining process illustrated in FIGS. 9 and 10.
`Referring to the drawings, in FIG. 1 there is shown
`the basic arrangement of the INSITUFORM lining
`process.
`An underground pipe 10 is to be lined by means of a
`tubular lining 12 (see FIG. 2). There are manholes 14
`and 16 at the ends of the particular length of pipeline 10
`being lined, and a down feed tube 18 is placed in one of
`the manholes 12, so that an elbow at the bottom of the
`tube 18 faces and is in register with the end of the pipe-
`line section 10. The lining tube 12 has one end 20 passed
`down the pipe 18, folded back and anchored to the end
`of the elbow as shown in FIG. 1. The down feed pipe 18
`is filled with water which forces the lining tube 12 to
`evert into and along the pipeline section 10, as shown at
`various stages by the dotted lines in FIG. 1. The lining
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`4,366,012
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`that thevacuum applied to the interior of the cup can be
`applied to theinterior of the lining tube12, whereby air
`is drawn from the inside of the tube 12 to permit the
`effectiveand efficient impregnation of the absorbent
`material withtheresin. The membrane 24Vof course acts
`as a barrier to inflow of air from the atmosphere, so that
`when the vacuum is applied, the tube collapses to a flat
`condition with the withdrawal of air, and the With-
`drawal of air enhances the inflow of the resin material
`into' the interStiCes in the felt material, and therefore the
`effective and even impregnation of the resin absorbent
`material. The nip‘rolle‘r 70 also assists in this regard.
`FIG. 11 shows the impregnation process at a midway
`position, and it should be mentioned that when one
`section of the impregnation of the tube 12 hasbeen
`completed, the suction cup 84 is removed to a down-
`stream location whereat a further window is formed,
`the previous window 86 having been sealed by means of
`a patch of a material compatible to the material of the
`coating, the patch being suitably sealingly bonded to the
`coating material. The vacuum cup 82 is therefore ap-
`plied at intervals during the impregnation process, until
`complete impregnation of the resin absorbent material
`has been achieved.
`FIG. 12 shows a cross sectional View of the suction
`cup 84, and it will be seen to include a filter 88 for the
`prevention of sucking back foreign matter to the vac-
`uum source 80.
`
`The method of the invention provides an extremely
`simple and effective process for the impregnation of a
`tubular structure, including a resin absorbent material
`with resin, especially a tubular structure for the lining of
`pipelines and passageways. Also according to theinven-
`tion, a novel end structure for such lining tubes is pro-
`vided.
`I claim:
`
`1. A method of impregnating with a curable resin an
`inner layer of resin absorbent material disposed in an
`elongate flexible tube having an outer layer formed by
`an impremeable film, the method comprising the steps
`of
`
`(l) introducing into one end of the elongate tube a
`mass of the curable resin sufficient to impregnate
`the entire resin absorbent inner layer of the tube,
`(2) forming a window in the impermeable outer layer
`of the tube at a distance from said one end of the
`tube,
`(3) drawing through the window a vacuum in the
`interior of the tube downstream of said one end by
`disposing over the window a cup connected by a
`flexible hose to a vacuum source which cup pre-
`vents ingress of air into the interior of the tube
`while the tube is being evacuated, the outer layer of
`the tube being substantially impermeable to air,
`(4) beginning at or near the end at which the curable
`resin mass was introduced, passing the tube be-
`tween squeezing members which force the resin to
`flow towards the region of vacuum application as
`the tube progresses through the squeezing mem-
`bers,
`(5) when the resin reaches the vicinity of the region
`of vacuum application, removing the cup and seal-
`ing the window,
`(6) providing another window in the impermeable
`layer of the tube downstream of the previously
`formed window,
`(7) drawing through the new window a vacuum in
`the interior of the tube while progressively moving
`
`5
`Next, as shown in FIG. 7, the outer layer 21 isfblded
`once more to the original position,to cover the vent
`tube 44, and as also shown in FIG.- 7 two similarly
`shaped blanks 50,52 of impermeable film, such as poly-
`urethane film are placed'in register but overlapping the
`end portion of the outer layer 21. These blanks are.
`secured together around their adjacent edges and to the
`coating of the outer layer 21 by means of suitable sol-
`vent, whereby as shownin FIG. 7, the end of the Outer
`layer 21is sealed, apart from a bleed outlet 54, which15
`in register with the vent tube 44In themner layer 26.
`FIG. 7 also shows how a pair of straps 56, which may
`be scrap cuttings of the coated material used for the
`outer layer 21, are bonded to the outer surface of the
`outer layer, to form a hold back means, whereby, by the
`use of ropes looped round said straps 56, the end of the
`lining tube may be restrained from everting too quickly
`into the passageway 10 FIG. 7 furthermore, shows
`how a resin injection nozzle 60 can pass through the
`bleed outlet 54 and the vent tube 44 to enable the injec-
`tion of resin into the interior of the lining tube 12.
`FIG. 8 shows how an initial air seal is formed at the
`end of the lining tube prior to the impregnation proper
`of the entire tube with resin. As shown in FIG. 8, a slug
`of resin 62 is introduced into the end of the tube con-
`structed as shown in FIG. 7, through the bleed outlet 54
`and vent tube 44. After introducing the slug of resin, the
`bleed outlet 54 is closed, and a vacuum is applied to the
`interior of the tube downstream of the slug of resin, that
`is to say at a point more towards the opposite end of the
`tube. This application of vacuum causes the tube to
`collapse in the region of the resin as shown in FIG. 9,
`and the flow of the resin into the felt material of the
`inner and outer layers at top and bottom of the tube,
`thereby to form an effective air seal.
`When the said seal has been effected, the total amount
`of resin required for the effective impregnation of the
`resin absorbent material of the entire tube (obtained by
`calculation), is injected into the end of the tube shown
`in FIG. 7 by means of the nozzle 60 illustrated. A large
`bubble of resin 64 therefore exists inside the tube for
`example as shown in FIG. 10. FIGS. 10 and 11 show
`how the tube is processed for the complete and effective
`impregnation of the resin absorbent material of all lay-
`ers of the tube. The tubeis shown as being supported on
`a conveyor comprising a horizontal section 66, and
`inclined section 68. an nip roller 70 is located in the
`region where the inclined section 68 meets the horizon-
`tal section 66, and the direction of movement of the tube
`on the conveyor is illustrated by arrows 72. The end of
`the tube into which the resin has been introduced is
`indicated by numeral 74 and it will be seen that in the
`position shown in FIG. 10, that end has only just been
`passed under the nip roller 64, and has started its travel
`up the inclined reach 70. The bulk of the lining1s yet to
`be impregnated, and15 containedin a skip 76. An empty
`skip 7615 located adjacent the top end of the inclined
`section 66 of the conveyor, to receive the impregnated
`tube as it is discharged from the upper end of the said
`inclined section 66.
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`A vacuum source 80is provided, and a vacuum cup
`82 is connected to the vacuum source by means of a
`flexible hose 84. The vacuum cap 8218 applied to the
`outside of the lining tube 12, downstream of the mass of
`resin 64 inside the tube 12, by a distance equal to the
`length over which the hose 84 can extend, the vacuum
`cup 82 being in register with a window 86 (see FIG. 11)
`made in the outer membrane 24 of the lining tube 12, so
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`4,366,012
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`7
`the tube through the squeezing members to force
`the resin to flow toward the new region of vacuum
`application, and
`(8) repeating steps 5, 6, and 7, where necessary to
`impregnate the entire resin absorbent inner layer of 5
`the flexible tube.
`2. The method according to claim 1, further including
`the step of
`forming an initial air seal at the end of the flexible
`tube at which the mass of resin was introduced by 10
`closing off that end of the tube after introduction of
`the mass of resin and before vacuum is applied to
`
`8
`the interior of tube to draw the resin toward the
`region of vacuum application.
`3. The method according to claim 1, wherein said
`outer layer of the flexible tube is defined by a felt sheet
`coated with a synthetic resinous material that forms said
`film, the method further including the steps of
`(i) sewing together adjacent edges of the felt sheet to
`form the tube, and
`(ii) covering the resultant seam with a sealing strip
`that is impervious to air.
`*
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