KR20050016761A - Method and device for producing a hollow body by rotation and resulting products - Google Patents

Abstract

The present invention includes the steps of introducing one or more first heated composite webs into one or more dies; Introducing at least one melt in contact with the first composite web to the die to obtain at least one second composite web; And at least a step of winding the second composite web around a support that rotates about an axis. The invention also relates to a device for carrying out the method and to a product obtained.

Description

METHOD AND DEVICE FOR PRODUCING A HOLLOW BODY BY ROTATION AND RESULTING PRODUCTS}

The present invention relates to a rotating body formed of at least one organic thermoplastic compound reinforced with continuous glass strands wound around an axis of the rotating body.

Although not limited to this use, the invention will be described in more detail with reference to the manufacture of all types of pipes, especially pipes used for transporting fluids under pressure.

Another advantageous use is the manufacture of reservoirs intended to contain fluids, especially under pressure.

The production of rotary bodies based on at least one organic flammable compound reinforced with continuous glass strands wound around the axis of the rotary body is already disclosed in WO 00/24566. In this application, a heated ribbon based on an organic thermoplastic compound and continuous glass strand is wound around a rotating tube while simultaneously heating a portion of the surface of the tube covered with the ribbon and downstream of this heating portion. Apply pressure. Ribbons are generally obtained from co-mixed continuous strands consisting of glass filaments, filaments of closely mixed organic thermoplastic compounds, the most common versions of which are SAINT-GOBAIN VETROTEX Which is sold under the trade name TWINTEX ^® and has a weight ratio of 60 or 75% by weight of glass and 40 or 25% by weight of organic thermoplastic compound.

Although the method and the product obtained perform well, the additional action of heating and pressing the tube to achieve certain limitations or constraints, ie constant deposition of the ribbon; The necessary addition of liners or outer coatings for better wear resistance for food grade applications, and constraints on the resulting products in a rather narrow and very variable range arises in use.

1 is a schematic view of a device for manufacturing a rotating body according to the invention.

It is an object of the present invention to mitigate the above disadvantages, and in particular can exhibit different reinforcing contents over the same product and the content can be "customized" without significant confusion in terms of the method or device used in particular. It is to suggest a wider range of products.

This purpose,

Introducing one or more first heating composite strips into one or more dies;

Introducing at least one melt in contact with said first composite strip into said die to obtain at least one second composite strip at the same time; And

Winding the second composite strip around a support that rotates about an axis

It is achieved by a method according to the invention comprising at least.

The invention also relates to a device for manufacturing a rotating body,

At least one means for producing at least one first heated composite strip;

At least one die for simultaneously receiving at least one first composite strip and at least one melt in contact with the first composite strip to obtain at least one second composite strip; And

At least one means for winding the second composite strip around a support that rotates about an axis;

It relates to a device for manufacturing a rotating body comprising a.

Another object of the invention is a composite rotary body, in particular a composite rotary body obtained by the above method. Such bodies have at least one region formed only by winding of the composite strip, which region is optionally variable stiffener content (or distinct, adjustable or variable stiffener content), in particular along the axis of rotation and / or of the rotating body Have a reinforcement content that varies with thickness, and / or the region has a low reinforcement content (eg, a reinforcement content of 75%) relative to the reinforcement content in the starting composite product (s), or the first composite strip used. Reinforcement content less than 75% for the first strip, or less than 60% reinforcement content for the first strip with 60% reinforcement content), and / or reinforcement regions obtained by winding in the current rotating body. Have a low reinforcement content relative to the reinforcement content (e.g., reinforcement content representing the area below 60% by weight), and / or Some of the reinforcements have an off-center position in the organic material into which the area is embedded, and / or the reinforcement (s) in the area may contain two or more different materials, The region is a fluid or solid body in the case of a hollow body of revolution intended to contain a fluid (e.g. without a functional coating, for example a protective or aesthetic coating). Filler foam) and / or direct contact with the outside.

In the present invention, the sheathing of the composite strip by the second material, known as the diluent material, has a number of advantages: by reducing the ratio of reinforcement to organic material in the strip wound on the rotating support, this results in a deposited stream. Allows for more uniform deposition and better integrity of the strip without the need for additional heating or application of additional pressure; By appropriately selecting the sheath, this eliminates the subsequent addition of an inner sheath (liner) (e.g., for food use) or an outer sheath (e.g., an anti-corrosion sheath) and, more generally, selects the sheath. Thereby giving the rotating body additional properties (such as UV protection, sealing, corrosion protection, etc.), which can be changed by changing the amount of exterior material delivered on-line (during the manufacture of the body). It is possible to continuously control and thus obtain a body having a reinforcement content different from the starting product which cannot itself advantageously change.

Thus, the method and the product according to the invention have the advantage of being variable, which is achieved without changing the starting product. In addition, the method according to the invention is easy to carry out, quick and economical. The body according to the invention also has an optimum bonding force (or optimum continuity of the organic component) between the various elements from which it is produced, at least in its region obtained by winding, and the bonding between the various components is particularly satisfactory. Adjacent enough to ensure lifetime and strength / resistant.

In the process according to the invention, the first composite strip comprises at least one reinforcing material (glass, carbon, aramid, etc.) and at least one organic thermoplastic compound. The reinforcement (preferably glass) is preferably in the form of strands and / or filaments that are continuous at least in the longitudinal direction of the strip. The strands or filaments of the reinforcement material are advantageously by means of organic thermoplastic compounds, as such are preferably in the form of strands and / or filaments, and / or in other reinforcing strands and / or filaments (in the case of fabric or cross reinforcement strips). Are joined together by. For reference, the strip is obtained from a composite strand formed from a reinforced filament (preferably glass filament) and a filament of one or more organic thermoplastic compounds, wherein these various filaments are advantageously intimately mixed and the close structure of these strands is thermoplastic It facilitates the injection of glass fibers by the compound, and in particular makes it possible to form very uniform consolidated strips (ie strips with bonding and integrity that can be processed without damage). Advantageous composite strands can be obtained according to direct methods such as those described in European Patent Application EP 0 367 661, International Publication No. WO 98/01751 or European Patent Application EP 0 599 695. The resulting strands have the advantage of having a good comingling index which leads to a good distribution of the glass strands in the thermoplastic compound, as described in WO 00/24566.

The first composite strips generally have a width of about 1 to 10 cm and can be in the form of more complex cross sections that are essentially flat or whose portions are similar to the strips. The strip can be flexible and can be wound up, especially if the strip is substantially flat or somewhat rigid. The use of composite ribbons rather than composite strands has many advantages, particularly in terms of the distribution of glass filaments through the thermoplastic compounds in the product, and the ease of use. Preferably, the first strip has not only longitudinal continuity as it enters the die, but also transverse continuity, in particular of less than 5% (or even less than 3%, or more preferably less than 0.5%). Void volumetric ratio. The void volume ratio can be measured by a known method using a micrographic method of the image analysis type or calculated using an equation as described in WO 00/24566. Can be.

The first composite strip comprises at least one free thermoplastic compound, referred to herein as the first material, which material is for example polyolefin, in particular polyethylene (PE), polypropylene (PP), polyether, in particular polyethylene Terephthalate, polybutylene terephthalate, elastomers, in particular ethylene propylene polymers (EPDM) or polyvinyl chloride (PVC), or polyamides and the like, and some of these materials (particularly polyethylene) are chemically inert It has the advantage of being compatible in terms of foodstuff, the ability to withstand very low temperatures, and the low cost.

The first strip generally consists of continuous composite strands extracted from the winding (s) and is assembled in parallel (or approximately parallel) in one or more layers (or sheets or webs), and / or possibly in fabric or crossover. Assembled from layers of composite strands. In order to obtain one or more composite strips according to the invention, the layers of strands (or, if appropriate, one or more of these layers) are at a temperature at which they reach at least the melting point of the first thermoplastic compound (and below the temperature at which the material deteriorates). And into a region heated to below the temperature at which the reinforcing fibers are softened, followed by a layer of heated strands (usually continuous strands) in which the first molten thermoplastic compound is uniformly distributed and the reinforcing fibers are injected therein Pass through.

This, in turn, yields a strip with longitudinal continuity, which may possibly undergo a forming step in addition to or concurrent with the injection to obtain the desired profile.

Some separate layers may be formed, as in some separate strips, and it is not mentioned that one or more of these strips are introduced into one or more dies according to the method according to the invention.

Advantageously, steps are provided to adjust the tension in the strands (eg, as they gather together in a layer (s) or bundle, or before they gather together) and / or the strands are, for example, web The static electricity can be removed before the) passes through the heating zone.

The method according to the invention may comprise the step of forming a first strip as described above, may utilize one or more strips already formed, in the latter case the strip or strips before the first thermoplastic compound enters the die. It is heated (and possibly shaped into a specific profile) at an initial stage of heating to a temperature at least reaching the melting point of. Preferably, the method according to the invention uses the composite strand only through the starting product and thus comprises the previous step of forming a strip as can be seen above. The first composite strip, or strip obtained at the outlet from the injection device as described above, advantageously reaches the die at a temperature close to the melting point of the first thermoplastic compound (or the temperature at which the first thermoplastic compound is malleable), Or up to a single or a plurality of winding means (for example a laying head) of the second strip mentioned in the present invention.

According to the method according to the invention, the first strip is introduced into one or more die to which also a molten material (or diluent material or facer), referred to herein as a second material, is also fed. The first material may be the same or different than the first organic material from which the strip is formed. It may also be a complex. It may have specific properties, or additives or fillers which give it specific properties (for example sawdust for imparting wood appearance, additives to improve the resistance to hydrocarbons, and also they may be talc, long or short glass It may be filled with fibers). Preferably, the second material comprises at least one organic or plastic material, advantageously a thermoplastic material, for example polyolefin (particularly polyethylene or polypropylene) or polyvinyl chloride, or possibly a thermosetting material such as polyurethane Or elastomers such as SEBS (styrene ethylene butadiene styrene) modified polypropylene. Advantageously, the second material is chosen to be the same, similar or chemically compatible with the first material on which the first strip is formed (in order to have a good binding force or even continuity between the first material and the second material) and In this case, the second material may be filled with an additive (sawdust, glass fiber, activity, etc.), possibly as described above.

Depending on the material selected, the second material may act to dilute or additionally impart additional properties on the formed second strip. The second strip thus formed preferably has a reinforcement content (strand itself used) of 0 to 74% by weight, preferably 1 to 60% by weight and even 5 to 55% by weight of the strip, at least for a particular portion of its length. Generally has a reinforcement content of 60 to 75% by weight), which may also vary depending on the length of the strip.

In addition, the application of the second material allows for better consolidation of the first strip, and the obtained second strip is formed of at least one second material which is slightly reinforced with at least one first composite strip. If the first strip is obtained from a strand which is itself a composite, the second material adheres to the first strip in a particularly satisfactory manner (or even fuses with the first material of the first strip, especially in the case of the same material). ), Which is an example of various substances. Thus, the second strip is advantageously arranged at about parallel, continuous and at least one first strip of continuous reinforcing fibers fixed together by at least one first thermoplastic compound, and at least one agent in intimate contact with the first strip. Contains 2 substances. As mentioned above, when the first material and the second material are the same, the two materials are perfectly fused in the obtained rotating body.

In the method and the device according to the invention, the second material introduced into the die can be derived from an extrusion device, for example. The amount of material to be added, and the shape shown in the second strip, can be perfectly controlled, which shape can in particular be imparted by a die (and possibly an additional molding device). According to this embodiment, the first strip can be deformed, coated with a second material, or to complete the shape imparted by the die as the first strip subsequently enters the die acting as a forming device. It can simply be coated with a second material (possibly through an additional forming device). Preferably, the die allows both the placement of the first strip and the sizing (or shaping) of the cross section of the second strip.

The first strip (or first strips if there are several strips introduced into one or several dies) is a plurality of identical or different feeds to the die (or several dies in series or parallel where appropriate). It can be coated with materials and this method allows for further expansion of the range of products obtained. If multiple second strips are obtained in parallel, the sheath can be changed from one strip to the other, as well as to each strip, and then the various strips are wound onto the rotating support. In the process according to the invention, it is possible to obtain a mixture of materials varying along the axis of rotation and / or thickness as well as bodies having different reinforcement contents by varying the supply of various materials.

The second strip (or second strips in the case of several strips) formed according to the method according to the invention can advantageously be wound directly on a mandrel (if necessary, the winding strip according to the invention The desired properties per se), winding the second strip on a tube or liner intended to form part of the interior of the rotating body, or on a support such as a compartment of the foam, and / or sheathing the windings obtained. The addition of an outer covering is not excluded, and this sheath may be applied in the form of a film or wound strip, for example. The second strip according to the invention may be wound on a support (eg in the form of an organic strip) already covered with the first winding. Incidentally, even if this is not excluded, the second strip does not need to be heated and / or pressure need not be applied to it while the second strip is being wound.

The second strip is wound to form a continuous winding, which windings are spaced apart or at least partially overlap each other. The winding of the strip or strips can be carried out somewhat transversely, generally this is done helically, and the angle of the strip with respect to the axis of the body can vary depending on the position along the axis, as mentioned later, in particular It is dictated by the laying head based on the desired mechanical properties. It can be seen that each winding of the support is deposited with one or more strips of windings for all or some of the length of the support, with the next rotation possibly changing the orientation of the next winding (s) of the strip. It can be seen that. Thus, a structure with an open wound similar to a very dense winding, lapping, or screw flight can be obtained.

As described above, the present invention also relates to a device for performing the method described above. Such devices in particular comprise one or more means for forming a composite strip or one or more means for delivering (and / or driving) and heating (possibly injecting and / or forming) already formed layers or strips. do. When the rotating body according to the invention is produced continuously from the winding of the composite strands, these means,

One or more means for driving and assembling the strands in the form of one or more bundles (or layers) of parallel strands;

At least one means for heating the bundle;

At least one device for injecting heated bundles to obtain strips, for example densified and laminated flat strips; And

At least one means for maintaining the strip at least at a temperature up to the die.

The device also includes a creel in which the reel of the strand is not wound, and one or more rollers guiding the direction of the strand.

Means for assembling the strands in the form of one or more bundles of parallel strands may include, for example, a holed plate, and / or a comb that allows the strands to be arranged evenly spaced in parallel. comb).

One or more means for adjusting the tension of the strand may possibly be provided upstream of the assembly means, for example.

The antistatic device may also be provided upstream of the heating means, for example.

In general, the device comprises one or more heating means, in particular consisting of one or more ovens of the infrared type, powered by a lamp, the power of which is set according to the temperature of the strip, which oven Both have advantages of high performance in terms of ease of use and adjustment.

By way of example, the injection device may comprise three members arranged in a triangle with the bundle passing therebetween, the separation height of which is adapted to establish an appropriate pressure on the surface of the bundle. The member can be a heated roll (or bar) that can be moved or fixed. Advantageously, each roll may comprise a blade for scraping the molten thermoplastic compound deposited on the roll after the bundle has passed.

The injection device may also act as a shaping device, followed by one or more additional shaping devices to convert the formed strands or strips of strips into one or more strips of the selected cross section. Such forming devices may include, for example, heated dies and / or rollers through which the bundles of strands or strips respectively pass.

The device, for example a shaping device, may also be concentrated in the web, in particular before the strip is formed, for example having an appropriate shape (eg hyperbolic shape, or a shape having a rim). And a lower roller and an upper roller that rotate in opposite directions, the layers of strand being concentrated about a moving center axis passing between the two rollers to deliver the bundle of continuous strands.

The device according to the invention is also referred to herein as an external die and preferably comprises at least one die sized in the cross section of the second strip to be obtained, at least one first strip therein, and said first It can be introduced into one or more first molten materials in contact with one strip, resulting in a second strip of one or more second materials reinforced with one or more first strips.

The device according to the invention possibly comprises means for positioning and / or forming one or more strips for contact with one or more second materials upstream of the die or on the die itself.

The die may also include means for contacting the second material with the strip and applying additional pressure thereto. The second material (or second materials if there are a plurality of them) may be in contact with the first strip through various ports of the die. Depending on the cross section of the die and / or the presence of the various ports and / or the application of additional pressure (s) and / or the location of the first strip in the die, the amount of second material (s) delivered varies with the cross section of the strip. At different points in time, for example, more material may be deposited on one side of the first strip than on the other strip, such that the reinforcement in the formed second strip may be eccentric.

Preferably, the device according to the invention comprises at least one extruder for applying at least one molten second material to the outer die or dies.

The device according to the invention also comprises at least one winding means, which means comprises a laying head, for example, to position the strip and to facilitate its placement. The laying head can move and rotate, but it can be formed, for example, with a rotating or stationary self-cleaning roller that concentrates the strip as described later with reference to the drawings.

Preferably, the sheathing die (one or more sheathing dies in the case of a plurality of them) mentioned in accordance with the invention is at the outlet from the already mentioned laying head and in front of the support on which the second strip is to be wound.

Although not required, the device also includes one or more means (eg, hot air) for heating the strip at least on the surface in the region around the support that rotates about an axis, or downstream of the contact area between the strip and the support. Hot air blowing nozzles, and / or one or more means for applying local pressure to a portion of the outer peripheral surface of the support covered with the strip, for example in an area located immediately downstream of the heated area. (Eg in the form of one or more rotating rollers). As indicated above, the rotating support can be, for example, a mandrel (such a mandrel may or may not be heated), or a tube (or inert solid or consolidation) which may or may not form part of the resulting rotating body. To be added).

The various components of the device according to the invention can be fixed or can be translated (translation or rotation).

The rotating body according to the invention is generally hollow, its walls are of continuous form, and generally at least one reinforcing material wound spirally around the (longitudinal) axis of rotation of the body, and at least one organic thermoplastic compound, wherein Reinforcement is generally inserted). Continuously reinforcing strands embedded in an organic material, for example at least in some cases, have an angle of about 15 ° to the axis of the body, or 50 to 55 ° to the axis of the body according to another advantageous embodiment. This arrangement allows for increased axial and circumferential strength resistance of the body to pressure exerted by fluids contained within or flowing in the same amount of continuous glass strands used. In another advantageous variant, at least some of the continuous strengthening strands inserted into the organic thermoplastic compound are at an angle close to 90 ° to the axis of the body, while the other continuous strengthening strands are inserted into the organic material, while longitudinally along the axis of the body. Are arranged.

The choice between these deformations, the combination thereof, or the choice of other variants that favor different angles of winding of the continuous reinforcing strands, and the choice of the individual amounts of reinforcing strands in the direction in which they are arranged, is resistant to pressure, elliptical It is based on specific constraints associated with each use, such as resistance to ovalization, bending strength, tensile strength, and the like.

According to an advantageous embodiment, the wall of the rotating body according to the invention is formed essentially or even entirely by a second winding strip.

In addition, the present invention is formed from the rotating body described herein above, and is covered, for example, with one or more finishing layers (e.g., by winding or extruding), in particular composed of organic thermoplastic compounds, and / or additional components (eg For example, it relates to a structure, for example a composite pipe, mounted on an end, such as a fitting secured by welding or bonding, or one or more liners, etc.).

The body or structure according to the invention is particularly suitable for containing and / or delivering pressurized fluids.

At present, other advantages and features will be described with reference to the accompanying drawings, which show a schematic diagram of a device for manufacturing a rotating body according to the invention. For clarity, the various parts are not necessarily drawn to scale.

The device shown is formed by winding the composite strip 3 around the mandrel 2 formed of a first strip 4 formed of a reinforcement arranged in parallel and in succession and held together by a first thermoplastic compound. Production of the rotating body 1 according to the invention, which strip is inserted into a second plastic compound in intimate contact with the strip.

The strips are sold by SAINT GOBAIN VETROTEX FRANCE under the trade name TWINTEX ^® and are prepared from composite strands such as, for example, strands produced using the method disclosed in European patent application EP 0 599 695. Formed from 5), these strands consist of glass filaments, filaments of organic thermoplastic compounds, and filaments of closely co-mixed polyolefin or polyester type.

These strands are released from the windings 6 located on the krill (not shown). Such krill can be, for example, those disclosed in WO 00/24566. These strands may then be used using one or more combs (s) and / or perforated plate (s) and / or grooved rollers and / or bar sets, etc., using one or more devices (denoted by reference number 7). Are assembled in parallel. One or more means for adjusting tension, detecting movement and / or removing static electricity may be provided to the krill and / or at various points in the pre-forming path of the strip, for example. For example, the device according to the invention may comprise a series of means disclosed under reference number 75 in WO 00/24566 between krill and first oven 8. The strands are assembled in parallel, successively passing through a first oven or a series of first infrared ovens 8 where they are heated to a temperature that reaches at least the melting point of the first thermoplastic compound, followed by layers of the heated strands, Injecting device 9 by flattening (or bundles), removing the air contained between the strands to make the material more dense and inserting the glass filaments into the thermoplastic compound to obtain a first strip or ribbon Pass through. The injection device 9 consists of, for example, three mutually parallel heated rolls arranged in a triangle, the upper roll being in relation to the height so that the strip can be flattened to a greater or lesser extent. It is adjustable.

The first heating strip thus formed is maintained in temperature by passing through the second oven or series of second ovens 10 up to the laying head 11, which head advantageously alters the lay angle of the ribbon. May be pivoted. Such a head may be described, for example, as reference number 71 disclosed in WO 00/24566. Upon leaving the laying head and just before contacting the mandrel, the first strip is introduced into the die 12, where the first strip is coated with a second material, and the molten second material is removed from the extruder 13. And fed to the die via, for example, a flexible pipe 14. The second material is the same as or different from the first material and is introduced into the extruder in the form of granules 15 and / or strands or the like. The second strip 3 thus formed by enclosing the first strip is then wound around a mandrel that rotates around its side (eg in the direction indicated by the arrow here), and the roller 16 adjacent the mandrel is It also possibly assists in the application of the second strip (such a roller may or may not be regarded as a forming part of the laying device).

Rotating bodies obtained in accordance with the present invention can be used in a variety of applications such as transporting or storing fluids.

Claims (15)

As a method for producing a body of revolution, Introducing one or more first heating composite strips into one or more dies; Simultaneously introducing one or more melts in contact with the first composite strip to the die to obtain one or more second composite strips; And Winding the second composite strip around a support that rotates about an axis A method for producing a body by rotation, which includes at least. The body according to claim 1, characterized in that the first composite strip is formed from continuous strands formed of filaments of glass filaments and organic thermoplastic compounds, preferably filaments intimately mixed. method of manufacturing the body). 3. Method according to claim 1 or 2, characterized in that the first strip has a void volumetric ratio of less than 5%. The method of claim 1, wherein the first strip assembles parallel continuous composite strands into one or more layers and is heated to a temperature that at least meets the melting point of the first thermoplastic compound. Rotation, characterized in that it is obtained by introducing into a zone and passing a layer of such heating strands through an impregnation device to uniformly distribute the first molten thermoplastic compound and inject the reinforcing fiber therein. Method for producing a body by 5. The method of any of claims 1 to 4, wherein the first strip is heated and / or maintained at a temperature up to a die or up to one or more means for winding the second strip. , Manufacturing method of a body by rotation. The method of claim 1, wherein the second strip has a reinforcement content of 0 to 60% by weight of the strip relative to at least a particular portion of its length, wherein the content may vary along the length of the strip. A method for producing a body by rotation, which can be characterized by the above-mentioned. 7. A method according to any one of the preceding claims, wherein the second material is introduced into the die when conditioned by an extrusion device. A device for manufacturing a rotating body, At least one means for producing at least one first heated composite strip; At least one first composite strip and at least one die for simultaneously receiving at least one molten material in contact with said first composite strip to obtain at least one second composite strip; And At least one means for winding the second composite strip around a support that rotates about an axis; A device for manufacturing a rotating body, comprising. 9. A rotating body as claimed in claim 8 wherein said single or plurality of winding means comprises at least one laying head, said die located at an outlet from said laying head. device. The method according to claim 8 or 9, One or more means for driving and assembling the strands in the form of one or more bundles of parallel strands; At least one means for heating the bundle; At least one device for injecting a heated bundle to obtain a strip; And At least one means for maintaining the temperature of the strip to at least the die; A device for manufacturing a rotating body, comprising. The device as claimed in claim 8, wherein the extruder feeds the second molten material into a die sized in the cross section of the second strip. A composite rotating body having one or more regions formed only by winding of a strip, wherein the strip is formed from a composite strip on which diluent material is deposited. A composite rotating body having one or more regions formed solely by winding of a composite strip, the regions having varying and / or decreasing reinforcement (s) content, wherein at least some of the reinforcements in the region are embedded in the region. Have an off-center position in the organic material, and / or reinforcement (s) in said region are inserted in at least two different materials, and / or said region is inside and / or inside said rotating body. Composite rotating body for direct contact with the outside. Composite rotating body with variable reinforcement (s) content. A composite structure, such as a pipe or reservoir, comprising one or more rotating bodies according to claim 12.