WO1997004265A1 - Conduite en acier pourvue d'une gaine formee solidairement et son mode de fabrication - Google Patents

Conduite en acier pourvue d'une gaine formee solidairement et son mode de fabrication Download PDF

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Publication number
WO1997004265A1
WO1997004265A1 PCT/US1996/011933 US9611933W WO9704265A1 WO 1997004265 A1 WO1997004265 A1 WO 1997004265A1 US 9611933 W US9611933 W US 9611933W WO 9704265 A1 WO9704265 A1 WO 9704265A1
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WO
WIPO (PCT)
Prior art keywords
polymer layer
pipe
polymer
layer
metal pipe
Prior art date
Application number
PCT/US1996/011933
Other languages
English (en)
Inventor
James R. Andre
Original Assignee
W.E. Hall Company
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 W.E. Hall Company filed Critical W.E. Hall Company
Priority to EP96924615A priority Critical patent/EP0836692A4/fr
Priority to AU65018/96A priority patent/AU712762B2/en
Priority to MX9800485A priority patent/MX9800485A/es
Priority to BR9609777-9A priority patent/BR9609777A/pt
Publication of WO1997004265A1 publication Critical patent/WO1997004265A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L9/00—Rigid pipes
    • F16L9/16—Rigid pipes wound from sheets or strips, with or without reinforcement
    • F16L9/165—Rigid pipes wound from sheets or strips, with or without reinforcement of metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/12—Making tubes or metal hoses with helically arranged seams
    • B21C37/123—Making tubes or metal hoses with helically arranged seams of coated strip material; Making multi-wall tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
    • B29C53/56—Winding and joining, e.g. winding spirally
    • B29C53/58—Winding and joining, e.g. winding spirally helically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L11/00—Hoses, i.e. flexible pipes
    • F16L11/14—Hoses, i.e. flexible pipes made of rigid material, e.g. metal or hard plastics
    • F16L11/16—Hoses, i.e. flexible pipes made of rigid material, e.g. metal or hard plastics wound from profiled strips or bands
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2009/00—Layered products
    • B29L2009/003—Layered products comprising a metal layer

Definitions

  • the present invention relates generally to buried pipe for use in sewers, storm drains, pen stocks, culverts and other low head applications, and more particularly to metal pipe with an integrally formed liner for use in corrosive and abrasive environments and a method of fabricating the same.
  • Metal pipe of both corrugated and spiral rib design is widely used for drainage, culverts and other similar fluid conduits.
  • steel pipe Although susceptible to abrasion, steel pipe has advantages over concrete pipe and the like due to its comparatively high strength and low weight. These characteristics render metal pipe comparatively inexpensive to manufacture, ship and handle while permitting it ⁇ use in applications requiring it to support substantial soil overburden.
  • a particular spiral ribbed steel pipe has been introduced by W.E. Hall Co., of Newport Beach, California, the assignee of the subject application, that possesses hydraulic efficiency comparable to more costly concrete pipe as well as possesses superior structural capabilities for prolonged use in buried storm drain applications.
  • metal pipe Since metal pipe is susceptible to corrosion and excessive abrasion, its use has heretofore been restricted primarily to culvert and storm drain applications. In sanitary applications, i.e. sewer systems, corrosion causing sulfuric acid is formed from hydrogen sulfide gas generated by waste products. Such waste products and/or acid has rendered the use of steel pipe in sanitary applications impractical since it rapidly deteriorates in the corrosive environment. As such, much heavier and more expensive concrete, lined concrete and/or vitreous clay pipe has traditionally been utilized for sanitary applications. Thus, although metal pipe is generally preferred because of its high strength and comparatively low weight and cost, metal pipe has heretofore not been widely used in sanitary applications due to its susceptibility to corrosion.
  • such metal pipe In storm drain applications, such metal pipe is particularly susceptible to extensive abrasion caused by the movement of gravel, dirt, sand, etc. therethrough. Such excessive abrasion frequently degrades metal pipe to a point where leakage of the contents of the pipe therefrom becomes a major concern. Additionally, such abrasion may, in some instances be sufficient to adversely affect the structural integrity of the pipe, and consequently result in structural failure of the pipe wherein the overburden crushes a portion of the pipe, thereby effectively plugging the pipe and substantially reducing or eliminating flow therethrough.
  • Such prior art corrosion-resistant liners typically comprise plastic inserts sized to be received within each concrete pipe section. Such liners are commonly cast within each pipe section. Subsequently after the pipe sections have been laid in place, adjacent liners are bonded together with the intention of forming a seal to prevent corrosive fluids and gases from contacting the concrete pipe.
  • Such prior art concrete pipe/plastic liner solutions have proven generally suitable for large size sewer applications, the inherent high cost of such solutions has posed a severe impediment in construction products and projects. Further the useful life of such prior art sacrificial concrete pipe solutions is finite, which requires widespread rehabilitation over time thereby mandating tremendous expense in down line rehabilitation costs.
  • plastic pipe In recognition of the general inability of metal pipe and concrete pipe for sewer applications, in recent years plastic pipe has been introduced into the marketplace. Although such plastic pipe withstands degradation caused by the corrosive environment found in sewer applications, its use has heretofore been primarily limited to small size sewer applications. In this regard, the structural integrity of plastic pipe is extremely limited such that in large size applications, the sidewall of such plastic pipe must be fabricated extremely thick or profiled to enable such plastic pipe to withstand compressive forces exerted in burial applications. Due to the high cost of such plastic material, the use of such plastic pipe in large scale sewer applications has been economically impractical.
  • metal pipe utilized for burial storm drain applications additionally encounters substantial problems associated with its operational environment.
  • long term exposure of the exterior of the metal pipe within the burial environment serves to corrode the exterior of the pipe while water and debris flowing through the interior of the metal pipe degrades the pipe through abrasion.
  • the present invention specifically addresses and alleviates the above referenced deficiencies associated in the prior art. More particularly, the present invention comprises a metal pipe with an integrally formed polymer liner for use in corrosive and abrasive environments.
  • the polymer liner is comprised of .050 to .125 inch thick polyethylene, preferably a low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or a blend of both which is securely bonded to the metal pipe during fabrication of the metal pipe.
  • LDPE low density polyethylene
  • LLDPE linear low density polyethylene
  • the term "low density polyethylene/linear low density polyethylene blend is defined to include a blend having from 0 to 100% low density polyethylene and from 0 to 100% linear low density polyethylene. Thus, this term includes low density polyethylene with no linear low density polyethylene added and also includes linear low density polyethylene with no low density polyethylene added.
  • other polymers having corrosion resistant properties similar to polyethylene are likewise contemplated herein.
  • the liner is formed by first applying a comparatively thin monolayer or multilayer polymer/adhesive film to the metal pipe surface during a pre-treatment process in order to facilitate bonding of the subsequently extruded, comparatively thick, layer of low density polyethylene/ linear low density polyethylene blend.
  • the thin film is formed as a multilayer film, the sublayers are preferably co-extruded. However, the sublayers of the thin film may alternatively be formed completely independent of one another, i.e., at different times.
  • the comparatively thin film is preferably applied via extrusion or co-extrusion, those skilled in the art will appreciate that the comparatively thin film may be applied via various different well known techniques, including cast and blown-film techniques.
  • the thin film is preferably applied in a pre-treatment process to the sheet metal, preferably prior to roll forming corrugations or ribs in the sheet steel.
  • the comparatively thick low density polyethylene/linear low density polyethylene layer blend is preferably applied after the corrugations or ribs are formed in the sheet metal, preferably subsequent to helically winding and forming the sheet steel into a pipe product.
  • the thin film is specifically formed to securely adhere to the surface of the sheet metal and provide a polymer constituent layer suitable for subsequent thermal/chemical bonding of the comparatively thick layer of polyethylene, preferably a low density polyethylene/linear low density polyethylene blend.
  • the thin film serves as a strong bonding agent or interface which adhesively bonds to the metal pipe and additionally forms a base material suitable to enable the subsequent application of the comparatively thick layer of polyethylene, preferably low density polyethylene/linear low density polyethylene blend thereto.
  • the present invention provides a smooth, hydraulically efficient interior surface which is resistent to the corrosive action of sulfuric acid and the like as is typically encountered in sanitary applications. It is also highly resistant to abrasion caused by the flow of water-born debris such as dirt and gravel as is encountered in culvert and storm drain applications.
  • the comparatively thin film applied in the pre- treatment process to facilitate bonding of the later applied comparatively thick layer of low density polyethylene/linear low density polyethylene blend comprises either a monolayer or multilayer film.
  • the monolayer film defines a single layer and the multilayer film defines two sublayers.
  • the monolayer is preferably comprised of polyolefin/maleic anhydride (MA) , ethylene acrylic acid (EAA), ethylene methacrylic acid (EMAA), or a blend of these polymers, or another metal adhesive.
  • MA polyolefin/maleic anhydride
  • EAA ethylene acrylic acid
  • EEMAA ethylene methacrylic acid
  • the monolayer may be corona treated prior to applying the comparatively thick layer of low density polyethylene/linear low density polyethylene blend.
  • the concentration of maleic anhydride is preferably maintained between approximately 0-10%, preferably less than 1%, by weight.
  • the monolayer adhesively bonds to the metal surface, thereby providing a securely attached substrate to which the later applied comparatively thick low density polyethylene/linear low density polyethylene blend bonds, so as to provide secure and reliable attachment of the low density polyethylene/linear low density polyethylene blend to the metal pipe.
  • the first sublayer i.e., that sublayer next to the metal pipe wall, is preferably formed the same as the monolayer discussed above, i.e., polyolefin/maleic anhydride, ethylene acrylic acid, ethylene methacrylic acid, a blend of these polymers, or another metal adhesive.
  • the second sublayer of the multilayer thin film i.e., that sublayer formed on top of the first sublayer, to which the later applied layer of low density polyethylene/linear low density polyethylene blend is bonded, preferably comprises a polymer adhesive/polyethylene blend, i.e., a carboxy-modified polyethylene such as either ethylene acrylic acid, ethylene methacrylic acid, low density polyethylene with a 0-10% concentration, by weight, of maleic anhydride, linear low density polyethylene with a 0-10% concentration, by weight, of maleic anhydride, high density polyethylene with a 0-10% concentration, by weight, of maleic anhydride, or some combination of these materials.
  • a polymer adhesive/polyethylene blend i.e., a carboxy-modified polyethylene such as either ethylene acrylic acid, ethylene methacrylic acid, low density polyethylene with a 0-10% concentration, by weight, of maleic anhydride, linear low density polyethylene with a 0-10% concentration, by
  • metal adhesives are likewise suitable.
  • additives such as antiblocks, antioxidants, pigments, ultraviolet stabilizers, etc., may be added to the second sublayer, as desired.
  • Corona treatment may also be utilized to facilitate application of the first and second sublayers, as desired.
  • the process of forming the metal pipe of the present invention commences with the steps of pre-washing G-210 (2 oz.) galvanized coil strip in the gauge range of 0.048 inches thick thru 0.138 inches thick to initially remove any residual oil and dirt.
  • the metal is subsequently processed in a high pressure hot alkaline spray bath to remove any residual dirt or oils and then rinsed with high pressure hot water sprayed upon both surfaces of the metal.
  • An optional mechanical brushing device may be employed to further condition the surfaces or to remove any residual chromates or surface oxides.
  • a secondary high pressure hot alkaline spray and hot, fresh water rinse is then repeated.
  • the strip is then treated with a suitable etchant and then dried.
  • An optional oxygen barrier primer may be applied to the strip or the strip may be prime coated with an adhesive and then heated to the appropriate temperature to cure the coating with the subsequent lamination of the monolayer or multilayer film. Subsequently, this laminated strip is then water quenched and cooled to the appropriate ambient temperature and then recoiled into coil form again. Subsequently, the laminated coil may then be formed by conventional techniques to include corrugations or ribs and formed into a pipe length via a conventional pipe mill.
  • the pre-treated and corrugated/profiled sheet metal strip is optionally heated and a comparatively thick, typically having a thickness of approximately .050 to .125 of an inch, molten layer of polyethylene preferably a low density polyethylene/linear low density polyethylene blend, for example, is extruded unto the interior of the pipe length. Due to the comparatively thick layer being applied at an elevated plasticized temperature, it securely thermally and chemically bonds to the monolayer or multilayer thin film previously applied to the sheet metal to provide a composite corrosion and abrasive resistant pipe.
  • the comparatively thick, low density polyethylene/linear low density polyethylene blend occurs subsequent to forming the sheet metal into a pipe product. After this, the pipe sections are cooled and cut into desired lengths using conventional techniques.
  • the comparatively thick, low density polyethylene/linear low density polyethylene blend may optionally be further secured to the sheet metal via extruding the same polyethylene material into the ribs or channels of the pipe to form anchors which attach to the low density polyethylene/liner low density polyethylene blend layer.
  • the anchor is extruded directly into the channel.
  • the comparatively thick, low density poly- ethylene/linear low density polyethylene blend is then immediately applied thereover such that the anchor and the low density polyethylene/linear low density polyethylene blend layer firmly bond to one another.
  • Such thermal/ chemical bonding is facilitated by positioning both the anchor extruder die and the low density polyethylene/linear low density polyethylene blend layer extruder die in close proximity to one another and in close proximity to the formed pipe.
  • the anchor conforms precisely to the configuration of the channel, i.e., substantially fills the channel, and additionally thermally bonds thereto.
  • Extrusion of the anchor into the channel preferably occurs after the pipe has been formed, i.e., after interlocking of the seams attaching adjacent wall sections to one another.
  • Extrusion of the anchor into the channels may occur as a single extrusion, or alternatively, may comprise a plurality of extrusions. For example, in a double extrusion process approximately one half of the anchor is first formed by extruding into the lower portion of the channel and the remainder of the anchor is subsequently formed by applying a second extrusion upon the previously extruded portion of the anchor.
  • a plurality of channels may be filled simultaneously or each channel may be filled individually, as desired.
  • the anchor and the low density polyethylene/linear low density polyethylene blend layer may be commonly extruded from a single extruder such that the channel is filled so as to form the anchor and the low density polyethylene/linear low density polyethylene blend layer applied upon the inner surface of the pipe simultaneously.
  • the extruder is thus configured such that a quantity of low density polyethylene/linear low density polyethylene blend is initially provided in those areas of the pipe where the channel is formed and a further layered quantity of low density polyethylene/linear low density polyethylene blend is provided on the inner surface of the pipe, and extending over the channels.
  • the fabrication process is simplified by reducing the number of extruders required and by eliminating the requirement for bonding between the anchor and the low density polyethylene/linear low density polyethylene blend layer since the two are integrally extruded.
  • the present invention is additionally applicable to other metal forming applications wherein chemical resistance of the fabricated metal product is required.
  • Figure 1 is a perspective view of the exterior of a length of pipe constructed in accordance to the present invention
  • Figure 2 is an enlarged cross-sectional view of the pipe wall of Figure 1 taken about lines 2-2 of Figure 1;
  • Figure 3 is a flow diagram of the method of forming metal pipe with an integral liner of the present invention
  • Figure 4 is a perspective view of the apparatus for forming the metal pipe with an integrally formed liner for the present invention
  • Figure 5 is an enlarged perspective view of the pipe mill former of Figure 4;
  • Figure 6 is an enlarged sectional view of the sheet metal after the ribs and edge portions have been cold formed but prior to crimping;
  • Figure 7 is a sectional view depicting the crimping lock seam process
  • Figure 8 is a sectional side view depicting the optional roller blending of the monolayer/co-extruded layer over the crimped lock seam
  • Figure 9 is a flow chart of the pre-treatment, pre ⁇ coating process for bonding the thin mono/multi-film layer to the sheet metal
  • Figure 10 is an enlarged cross-sectional view of a portion of the liner and steel pipe showing the resultant thin film layer and the comparatively thick low density polyethylene layer formed on the interior of the pipe layer.
  • Figure 11 is a perspective view of an apparatus for applying both the integral liner to the inner surface of the metal pipe and forming the anchor within a channel thereof;
  • Figure 13 is an enlarged perspective view of the liner extruder and anchor extruder of Figures 11 and 12;
  • Figure 14 is an enlarged cross sectional side view of a tapered channel having an anchor extruded directly therein and also having the integral liner formed upon the inner surface of the pipe.
  • the improved spiral ribbed pipe of the present invention is depicted as being generally comprised of a metal pipe wall material, preferably steel.
  • Spiral ribbed pipe 10 has externally extending ribs 12 and lock seams 14 formed thereon, and also has an integrally formed polyethylene liner 16 formed upon the inner surface thereof.
  • Spiral channels 18 are preferably formed in the sheet steel 11 of which the pipe 10 is formed, and are preferably filled with a polymer such as polyethylene, as will be explained in more detail infra.
  • the process generally comprises pre-treating sheet metal such as steel to have a comparatively thin, polymer/adhesive layer formed thereon and coiling the same for later pipe fabrication.
  • the pre-treated sheet metal 11 is then subsequently uncoiled via an uncoiler 20, and ribs and/or corrugations and seams 14 (as shown in Figures 1 and 2) are formed thereon with a profile roll former 22 (as shown in Figure 4).
  • the pretreated and preformed sheet metal 11 may be cleaned and optionally heated 24.
  • a seam roller and pipe mill former 30 forms the preformed sheet metal into a helical pipe section and crimps the lock seams 14 together to form a pipe product.
  • a sheet extruder with a suitable die and laminator 31 provides hot extrudate polymer such as polyethylene and preferably low density and/or linear low density polyethylene or a blend thereof, to the upper or inside surface of the sheet metal.
  • the laminator applies presses the hot extrudate into contact with the upper pre-treated surface of the sheet metal, thermally and chemically bonding it to the comparatively thin polymer/adhesive film layer.
  • the pipe and liner are preferably cooled 32 after the extrusion process and cutter 33 then cuts sections of pipe to a desired length.
  • the metal pipe having an integrally formed liner of the present invention includes a channeled wall defining a plurality of outwardly projecting structural ribs 12 and a hydraulically efficient interior surface.
  • the ribs 12 are preferably formed in a helical configuration.
  • the channels 14, which are formed interiorly thereof, are generally fabricated having either a square, rectangular or deltoid configuration, and are open along the interior surface of the pipe.
  • the channels 14 are tapered to define a deltoid shape so as to mechanically capture an anchor therein, as shown in Figure 14.
  • the pre-treatment process 19 utilized prior to forming the sheet metal 11 into pipe sections 10 is described.
  • the sheet metal 11 is fabricated in elongate lengths that are coiled for ease in subsequent forming processes.
  • the initial pre-treatment process 19 is initiated by un-coiling the coiled galvanized metal strip 61 and then pre-washing 62 the strip to remove any residual oil and/or dirt from the upper and lower surfaces of the strip 11. This step may consist of processes well known in the art such as the application of a detergent solution.
  • the sheet metal 11 is then preferably subjected to a high pressure hot alkaline spray bath 64 to further loosen and remove any oil and dirt remaining upon the surfaces.
  • the alkaline spray 64 is followed by a high pressure hot water/fresh water rinse 66.
  • the strip 11 may optionally be brushed with a mechanical rotary brushing device 67 to remove any residual chromates and to further condition the surfaces of the metal or to remove any oxides
  • the strip 11 is then further conditioned and cleaned with another high pressure hot alkaline wash 68 to ensure adequate removal of any residual chromates or surface contaminants.
  • Strip 11 is then rinsed with a buffered high pressure hot water/fresh water rinse to neutralize the surface and prepare same for the application of the etchant.
  • the sheet metal is subsequently subjected to a chemical treatment or etchant 72, such as Parker Bonderite 1303, or Betz Metchem Permatreat 1500 etchant to roughen the surface and prepare it for the optional application of a primer or adhesive.
  • a chemical treatment or etchant 72 such as Parker Bonderite 1303, or Betz Metchem Permatreat 1500 etchant to roughen the surface and prepare it for the optional application of a primer or adhesive.
  • an optional oxygen barrier primer or adhesive 76 may be applied to the etched strip 11. In most instances however, the oxygen barrier primer or adhesive may be eliminated.
  • the etched strip 11 is cured or heated 78, to an exit metal temperature of approximately 400°F and a comparatively thin, continuous, planar, preferably co-extruded polymer/adhesive layer is laminated to the sheet metal 11.
  • the polymer/adhesive layer 80 is applied to the sheet metal to have a laminated thicknes ⁇ of 10 mils min. and is preferably manufactured as a monolayer or alternatively as a multilayer film having two distinct layers, i.e., the lower laminate layer 81 and upper laminate layer 82.
  • the comparatively thin layer preferably comprises a polymer/adhesive material such as polyolefin/maleic anhydride, ethylene acrylic acid, ethylene methacrylic acid, or a blend of these.
  • a polymer/adhesive material such as polyolefin/maleic anhydride, ethylene acrylic acid, ethylene methacrylic acid, or a blend of these.
  • corona treatment may be utilized prior to application of the comparatively thin layer so as to enhance a fusion thereof.
  • the first sublayer thereof i.e., that layer immediately adjacent the metal surface, i ⁇ preferably formed a ⁇ the same polymer/adhesive material as the monolayer discussed above and the second sublayer, is preferably formed upon the first layer, and comprises a carboxy-modified polyethylene such as an ethylene acrylic acid, low density polyethylene blend having a 0-10% concentration, by weight, of maleic anhydride, linear low density polyethylene having a 0-10% concentration, by weight, of maleic anhydride, high density polyethylene having a 0-10% concentration, by weight, of maleic anhydride, or ethylene methacrylic acid.
  • a carboxy-modified polyethylene such as an ethylene acrylic acid, low density polyethylene blend having a 0-10% concentration, by weight, of maleic anhydride, linear low density polyethylene having a 0-10% concentration, by weight, of maleic anhydride, high density polyethylene having a 0-10% concentration, by weight, of maleic anhydride, or ethylene meth
  • the first and second sublayers of the comparatively thin film are fabricated by any of the various techniques well known in the art, including cast and blown film techniques.
  • the first sublayer of the thin film comprises ethylene acrylic acid and the second layer of the thin film comprises linear low density polyethylene having a 0-10% concentration of maleic anhydride, by weight.
  • the lower laminant 81 is formed of an ethylene acrylic acid which comprises an adhesive which securely bonds the co ⁇ extruded laminant 80 to the sheet metal 11 via direct contact with the sheet metal 11 or contact with the prime coat 76 applied to the sheet metal 11.
  • the monolayer or multilayer co-extruded film 80 therefore provides a lower adhesive/polymer layer 81 adapted to securely bond the co-extruded layer 80 to the sheet metal 11 and an upper polymer containing layer 82 which serves as a base material to allow thermal bonding of a subsequent polymer to the upper layer 82 of the co-extruded layer 80.
  • the preferably co- extruded polymer layer 80 is applied to the sheet metal 11 at an elevated temperature of approximately 425° to 630 C F, and is pressed tightly thereupon by way of a conventional roller 316. Subsequently, the sheet metal 11 having the co-extruded polymer layer 80 applied thereto is cooled 84 and subsequently recoiled 85 for later use in the pipe fabrication process.
  • the pre- treatment process is facilitated on both the upper and lower surfaces of the sheet metal 11 with the lower surface treatment providing additional corrosion protection for the soil side of the resultant pipe.
  • the lower side may alternatively be coated with conventional thermoplastic films such as vinyls or acrylics.
  • the pre-treated sheet metal 11 previously disposed in a coil 30 is mounted upon a conventional uncoiler 20.
  • the uncoiler 20 facilitates the uncoiling of the pre-treated sheet metal 11, having the polymer/adhesive layer 80 disposed upon the upper surface thereof.
  • the pre-treated sheet metal 11 passes through a profile roll former 22 having a plurality of form rolls 32 which progressively form the ribs 12 (as shown in Figure 1) and edge seam members 54 and 56 (as shown in Figure 6) within the sheet metal 11.
  • the formation of the ribs 12 comprises the major cold forming procedures for the pipe 10 and is facilitated on the pre-treated sheet metal.
  • the substantial tensile and compressive forces exerted in the cold forming process are accommodated by the comparatively thin, preferably co ⁇ extruded, polymer/adhesive layer 80 without cracking and/or blistering.
  • the sheet metal 11 may optionally be subjected to a cleaner/heater 24 which prepares the upper polymer/adhesive surface of the sheet metal 11 for the subsequent pipe length forming process and the thermal/ chemical bonding of the comparatively thick polymer layer, preferably low density polyethylene thereto.
  • the thermally bonded metal/ polyethylene sheet 44 is then passed into a conventional pipe mill having a crimp/forming roller 50 which helically winds and crimps the male and female edge seams 56 and 54 into a lock seam which forms the resultant pipe length 46.
  • the action of the crimping/forming roller 50 is depicted in Figure 7.
  • the crimping/forming rollers 50 crimps adjacent edge seam members 56 of the polymer/adhesive laminated sheet metal 44 together by forcing male seam members 56 into the adjacent female seam member 54 as the sheet steel '44 is rolled helically and then bending both male 56 and female 54 seam members into laminar juxtaposition with the adjacent laminated steel sheet 11.
  • the comparatively thick polymer layer preferably formed of a low density polyethylene is subsequently applied within the interior of the pipe length 46 by way of an extrusion process.
  • the extrusion process is utilized to simultaneously fill the interior of the channel or rib 18 formed on the pipe wall while simultaneously applying the comparatively thick polymer layer over the interior of the pipe section.
  • a mechanical anchor is provided which further secures the resultant polymer layer 16 to the interior of the pipe length 46.
  • the apparatus preferably comprises a hopper 300 containing a granular polymer preferably polyethylene 302.
  • a lead screw assembly 304 extends from the bottom of the hopper 300 and into the interior of the pipe 46 axially downline of crimping roller 50 by way of an extension 303.
  • the re ⁇ ultant pipe 46 extends axially away from the roller 50, i.e., from left to right as viewed in Figure 11.
  • a lead screw as ⁇ embly 304 heat ⁇ and pla ⁇ ticizes the granular polymer 302 as it travels via lead screw 308 throughout the length of the lead screw a ⁇ embly 304.
  • the lead screw assembly 304 transports the polymer 302 to an extrusion head as ⁇ embly or die 310 located axially down line from the crimp roller 50 which both fill ⁇ the channel 18 to form an anchor 200 ( Figure 14) of the pipe ⁇ ection 46 and applie ⁇ a liner 16 to the inner surface thereof.
  • the extrusion assembly die 310 comprises an anchor extruder die 312 and a liner extruder die 314.
  • the anchor extruder die 312 deposits a quantity of polymer material directly into the channel 18 such that the channel 18 is sub ⁇ tantially filled with polymer material, thereby forming an anchor 200 directly therein. Due to the interior of the channel 18 having the comparatively thin polymer/adhesive layer 80 previously applied thereto, the quantity of polymer firmly bonds to the polymer con ⁇ tituent of the previou ⁇ ly applied comparatively thin layer.
  • the liner extruder die 314 subsequently lays down a sheet of polymer material over the anchor 200 as well as upon the interior of the pipe wall such that the heated polymer material of the anchor 200 and the hot polymer material of the liner 16 adhere to one another, as well as to the previously applied comparatively thin polymer/adhesive layer 80 upon the pipe wall.
  • each newly added section of liner 16 slightly overlaps the previously applied layer thereof, so a ⁇ to assure adequate bonding thereto a ⁇ well a ⁇ desired coverage of the interior of the pipe 46.
  • a roller 316 is preferably utilized to firmly press the extruded sheet 16 of polymer material into contact with the inner polymer/adhesive surface layer 80 of the pipe 46, thereby assuring adequate contact pressure to bond the layer 16 to the polymer/adhesive layer of the pipe wall. It has been found that a roller 316 compri ⁇ ed of aluminum and cooled with air allows the liner 16 to be firmly pressed into place while inhibiting adhesion of the liner 16 to the roller 316 itself.
  • the roller 316 is preferably adjustable in height so as to vary the thickness of the liner 16 applied to the interior of the pipe section 46, as well as the application pressure. Those skilled in the art will recognize that alternative roller configurations are contemplated herein.
  • a preferred material candidate for the comparatively thick polymer layer is a low density/ linear low density polyethylene material known as DOWLEX 3010 or DPT 1450 (trademarks of Dow Chemical Company, Midland, Michigan), which are known to exhibit superior abrasion resi ⁇ tance.
  • DOWLEX 3010 or DPT 1450 trademarks of Dow Chemical Company, Midland, Michigan
  • the cleaner/heater 24 elevates the temperature of the sheet metal 11 and the polymer/adhesive layer 80 di ⁇ posed thereon to approximately 100-225° F. and not to exceed 300° F. such that the polyethylene layer 16 will more readily thermally bond thereto.
  • the extruder head or die 310 forms the polyethylene into a continuous planar layer 40 (shown in Figure 10) having a thickness of approximately .050 to .125 of an inch, and preferably approximately .100 inch, which is applied to the upper surface of the comparatively thin polymer/adhesive layer 80 disposed upon the sheet steel 11.
  • the polyethylene layer 40 is extruded onto the comparatively thin polymer layer 80 at a temperature between approximately 425°- 630°F, preferably approximately 525°F.
  • the preferred process and temperature for extruding DOWLEX 3010 is approximately 500°F.
  • the resultant metal/polyethylene laminate possesses a cross-sectional configuration depicted in Figure 14.
  • the low density polyethylene layer 40 extends in a thermally/chemically bonded generally contiguous orientation over the upper surface of the sheet metal 11 and preferably overlaps at the rib or channel 18 to maintain a consistently smooth diameter through the pipe length.
  • the pipe 10 includes an integrally formed substantially pure low density polyethylene liner 16 having sufficient thicknes ⁇ (i.e. approximately .100 of an inch) which is capable of withstanding corrosion caused by contaminant acids encountered in sewer applications. Additionally, since the low den ⁇ ity polyethylene liner 16 is applied integrally to the pipe during the fabrication process and thermally bonded to the polymer/adhesive layer 80 adhered to the steel pipe 11, delamination, blistering or cracking of the low density polyethylene layer 16 is eli inated.
  • adjacent pipe sections may be easily abutted and joined at their interfaces by utilizing high density polyethylene wraps which may be thermally welded/bonded to the low density polyethylene liner affixed to the interior of the pipe.
  • a cross ⁇ ection of the anchor 200 formed within a channel 18 and a liner 16, 40 formed upon the interior of a pipe section 46 is provided.
  • the anchor 200 bonds to the liner 16 at the interface 320 thereof.
  • the anchor 200 is both mechanically captured and chemically bonded to the previously applied comparatively thin polymer/adhesive layer 80 within the channel 18.
  • the anchor 200 is bonded within the channel 18 since it is applied thereon while in the plastic state and thu ⁇ bonds to the previously applied comparatively thin layer 80 disposed within the channel 18.
  • the anchor 200 is mechanically captured within the channel 18 due to the deltoid or upwardly tapered construction thereof, which mechanically prevents the anchor from being pulled therefrom.
  • the liner 16 adhesively bonds to the previously applied comparatively thin layer 80 applied on the interior of the pipe 46 since it is likewise applied in a heated or molten state.
  • the helical shape of the anchor 200 itself tends to prevent its being pulled from the channel 18, since such pulling from the channel would require that the helical anchor be twisted to facilitate its removal.
  • the present invention provides both an adhesive/chemical bond of the liner to the metal pipe as well as a mechanical bond via the deltoid shape anchor. Thu ⁇ , if for any reason the adhesive/chemical bond should fail over time, the mechanical bond positively insures maintenance of the liner within the interior of the pipe.
  • the present invention facilitates the u ⁇ e of a relatively thick polymer liner to be disposed upon a metal surface, which polymer is adhered to the metal surface by way of a previously applied comparatively thin layer having an adhesive component and a polymer/adhesive component which enable ⁇ the ⁇ ubsequent thermal bonding of the comparatively thick substantially pure similar polymer layer via the constituent polymer layer found in the previously applied comparatively thin layer.
  • the present invention contemplates the use of affixing a protective polymer layer to a fabricated product after pre-forming and/or completely forming the fabricated product by pre-treatment of the metal utilized in the fabricated product for subsequent deposition of the polymer layer thereto.
  • various metals and alloys having sufficient structural strength may be utilized as the pipe metal.
  • the polymer laminated metal and method for forming the same need not be limited to the fabrication of pipe, but rather may find application in many diverse areas such as automotive body sheet metal applications and the like.
  • these and other modifications and additions may be obvious to those skilled in the art and may be implemented to adapt the pre ⁇ ent invention for u ⁇ e in a variety of different application ⁇ .

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)

Abstract

L'invention se rapporte à une conduite (11) en acier pourvue d'une gaine formée solidairement et à son mode de formation. La gaine est conçue pour un usage dans des milieux corrosifs et abrasifs et est constituée d'un polymère relativement épais (16) qui est collé à chaud à la conduite (11) en métal. On applique une couche de polymère/adhésif intermédiaire (80) à la conduite (11) en métal pour faciliter la liaison thermique/chimique. On applique la couche intermédiaire (80) à la tôle (11) de préférence lors d'un traitement préalable avant le profilage des nervures (12) dans la tôle. On applique la gaine de protection en polyéthylène (16) une fois que le tuyau a été profilé pour lui conférer une surface lisse, hydrauliquement efficace, pouvant résister à l'action corrosive de l'acide sulfurique et des autres acides de même type que l'on trouve dans les installations sanitaires, ainsi qu'à l'abrasion provoquée par l'écoulement de débris transportés par les eaux tels que la terre et le gravier comme on en trouve dans les installations de drainage.
PCT/US1996/011933 1995-07-20 1996-07-18 Conduite en acier pourvue d'une gaine formee solidairement et son mode de fabrication WO1997004265A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP96924615A EP0836692A4 (fr) 1995-07-20 1996-07-18 Conduite en acier pourvue d'une gaine formee solidairement et son mode de fabrication
AU65018/96A AU712762B2 (en) 1995-07-20 1996-07-18 Steel pipe with integrally formed liner and method of fabricating the same
MX9800485A MX9800485A (es) 1995-07-20 1996-07-18 Tuberia de acero con revestimiento formado integralmente y metodo de fabricacion de la misma.
BR9609777-9A BR9609777A (pt) 1995-07-20 1996-07-18 Tubo de metal laminado, e, processo para formar tubo de metal laminado.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US50477495A 1995-07-20 1995-07-20
US08/504,774 1995-07-20

Publications (1)

Publication Number Publication Date
WO1997004265A1 true WO1997004265A1 (fr) 1997-02-06

Family

ID=24007683

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1996/011933 WO1997004265A1 (fr) 1995-07-20 1996-07-18 Conduite en acier pourvue d'une gaine formee solidairement et son mode de fabrication

Country Status (7)

Country Link
EP (1) EP0836692A4 (fr)
KR (1) KR19990035756A (fr)
AU (1) AU712762B2 (fr)
BR (1) BR9609777A (fr)
CA (1) CA2225854A1 (fr)
MX (1) MX9800485A (fr)
WO (1) WO1997004265A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0875712A3 (fr) * 1997-04-30 1999-02-03 Witzenmann GmbH Metallschlauch-Fabrik Pforzheim Tuyau souple agrafé pour systèmes de gaz d'échappement

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20000053698A (ko) * 1999-12-23 2000-09-05 김한곤 강관 성형기
KR101040971B1 (ko) * 2010-10-13 2011-06-16 백용석 파형강관 제조방법
EP2868719A1 (fr) * 2013-10-31 2015-05-06 PPG Coatings Europe B.V. Réservoir ou tuyau ayant un système de revêtement
KR101700350B1 (ko) * 2016-08-10 2017-01-31 주식회사 픽슨 고 내식성 나선형 리브강관의 제조방법

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4169906A (en) * 1975-09-15 1979-10-02 Rexnord Inc. Wear resistant coated pipe and method of making it
US4254165A (en) * 1977-11-30 1981-03-03 American Cast Iron Pipe Company Method of forming a filled polymer coating on an internal cylindrical surface and article produced thereby
US4319610A (en) * 1979-10-05 1982-03-16 Hoechst Aktiengesellschaft Process for coating metal tubes and use of the coated tubes
US4630650A (en) * 1984-10-15 1986-12-23 Pacific Roller Die Co., Inc. Spiral ribbed pipe
US4838317A (en) * 1980-10-14 1989-06-13 Andre James R Hydraulically efficient ribbed pipe
US5300336A (en) * 1990-12-21 1994-04-05 Shaw Industries Ltd. High performance composite coating

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB820121A (en) * 1956-05-02 1959-09-16 Ti Group Services Ltd Method of lining pipes and vessels with polymer plastics
US3348995A (en) * 1964-03-09 1967-10-24 American Cast Iron Pipe Co Method of coating metal surfaces with polyethylene utilizing a polyethylene primer and articles produced thereby
GB1310915A (en) * 1969-12-16 1973-03-21 Dunlop Holdings Ltd Lined pipes
DE3628670A1 (de) * 1986-08-23 1988-02-25 Volkmar Eigenbrod Verfahren zum kunststoffbeschichten und nach dem verfahren hergestellte beschichtung
WO1995013917A1 (fr) * 1991-07-26 1995-05-26 W.E. Hall Company Conduite metallique avec une chemise integree et procede de fabrication d'une telle conduite
US5316606A (en) * 1991-07-26 1994-05-31 W. E. Hall Company Method of fabricating a metal pipe with an integrally formed liner
CA2187331C (fr) * 1994-04-08 2004-06-22 James R. Andre Fabrication d'un conduit d'acier dote d'un revetement solidaire

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4169906A (en) * 1975-09-15 1979-10-02 Rexnord Inc. Wear resistant coated pipe and method of making it
US4254165A (en) * 1977-11-30 1981-03-03 American Cast Iron Pipe Company Method of forming a filled polymer coating on an internal cylindrical surface and article produced thereby
US4319610A (en) * 1979-10-05 1982-03-16 Hoechst Aktiengesellschaft Process for coating metal tubes and use of the coated tubes
US4838317A (en) * 1980-10-14 1989-06-13 Andre James R Hydraulically efficient ribbed pipe
US4630650A (en) * 1984-10-15 1986-12-23 Pacific Roller Die Co., Inc. Spiral ribbed pipe
US5300336A (en) * 1990-12-21 1994-04-05 Shaw Industries Ltd. High performance composite coating

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0836692A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0875712A3 (fr) * 1997-04-30 1999-02-03 Witzenmann GmbH Metallschlauch-Fabrik Pforzheim Tuyau souple agrafé pour systèmes de gaz d'échappement

Also Published As

Publication number Publication date
MX9800485A (es) 1998-04-30
AU712762B2 (en) 1999-11-18
BR9609777A (pt) 1999-12-21
KR19990035756A (ko) 1999-05-25
EP0836692A1 (fr) 1998-04-22
EP0836692A4 (fr) 1998-10-21
AU6501896A (en) 1997-02-18
CA2225854A1 (fr) 1997-02-06

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