NL1041888B1 - Plastic barrel with reinforced fibers - Google Patents

Abstract

Method for manufacturing a pressure-resistant vessel with pressure-resistant flange configuration, comprising an inner vessel (7) of thermoplastic plastic with an outwardly extending flange part (2), a metal supporting flange (4) provided with an opening (3) with a transition collar ( 5) which partially extends over the inner vessel, and a layer (9) of reinforcing fiber which is arranged over the inner vessel and a part of the transition collar. The layer of reinforcement fiber comprises a displacement-free wrap of reinforcement fiber over the inner vessel and the transition collar. The support flange further comprises an outer edge (10) and a flange plate (11) and / or flange ring (12) with an upright outer edge (18). The support flange and the flange plate and / or flange ring can be connected to each other by means of a bolt connection (13-14) or a screw ring connection (19).

Description

Title: Plastic barrel with reinforcement fibers DESCRIPTION

The invention relates to a pressure-resistant vessel with a plastic inner vessel and a layer of reinforcing fiber, as well as to a method for the manufacture of such a pressure-resistant vessel. In particular, the use of the pressure-resistant vessel as a boiler vessel for hot water is envisaged.

Such a pressure-resistant vessel and its manufacture is known from WO0157429 (based on NL1014290). Therein, a method is disclosed for manufacturing a pressure-resistant vessel which comprises a plastic inner vessel which is manufactured, for example, by blow molding or rotational molding, and which is subsequently wrapped without shifting in a layer of reinforcing fibers, wherein said reinforcing fibers can move freely relative to each other and are wound in such a manner be that they are only loaded in their longitudinal direction at internal pressure in the inner vessel. While the gas or liquid tightness is provided by the thermoplastic inner vessel, the compressive strength of the pressure vessel is mainly provided by the reinforcing fibers.

The present invention has for its object to provide a flange configuration for such a vessel in order to be able to provide a closing element through which the supply and discharge pipes etc. have to be passed. The problem must be solved that there is no room for reinforcement fibers at the location of the flange and its environment, while (also) pressure resistance must be guaranteed there. A further problem arises when the inner vessel is wrapped without displacement: in order to ensure that the inner vessel is completely wrapped with reinforcement fiber opposite the flange without having to apply a separate reinforcement there, it is necessary to adjust the diameter of the passage opening (the neck) of make the flange as small as possible.

In order to meet these and other requirements and wishes, the invention provides a pressure-resistant vessel with pressure-resistant flange configuration, comprising an inner vessel of thermoplastic plastic with an outwardly extending flange part, an opening provided, extending on the side of the inner vessel, metal supporting flange with a transition collar that partially extends over the inner vessel, and a layer of reinforcing fiber that is arranged over the inner vessel and at least a part of the transition collar. Preferably - not exclusively - the layer of reinforcement fiber comprises a displacement-free wrap of reinforcement fiber over the inner vessel and - generally partly - the transition collar, as proposed in said publication WO0157429.

The metal support flange and the transition collar connected thereto preferably form a whole, the support flange supporting and reinforcing the plastic flange part - which is integral with the plastic inner vessel -, while the (metal) transition collar forms a connection to the layer of reinforcement fibers which inner vessel and over (a part of) the transition collar.

The flange configuration preferably also comprises a (metal) flange plate and / or flange ring, on the other side of the plastic flange part, whereby the plastic flange part is received on both sides by components that reinforce the flange part and to absorb the pressure load.

The supporting flange and / or the flange plate resp. flange ring a substantially upright, reinforcing outer edge, which preferably extends around the outside of the plastic flange part. The support flange and the flange plate and / or flange ring can be connected by means of a bolt connection (via bolt openings in the plastic flange part) or by means of a screw ring connection, for example by applying thread to the upstanding outer edge of the support flange and to the raised outer edge of the flange plate resp. flange ring, so that they can be screwed onto each other, whereby the plastic flange part is then enclosed between the two.

The invention will be discussed in more detail below with reference to a few exemplary embodiments, with reference to a few figures. Particular attention will also be paid to the method with which the pressure vessel can be manufactured.

Figures la - le show an illustration of a method for manufacturing a pressure vessel according to a first preferred embodiment of the invention, including the pressure vessel thus manufactured;

Figures 2a - 2e show an illustration of a method for manufacturing a pressure vessel according to a second preferred embodiment of the invention, including the pressure vessel thus manufactured;

Figures 3a - 3c show three exemplary embodiments of flange configurations.

Figures la - le schematically show a method according to the invention for manufacturing a pressure-resistant vessel with pressure-resistant flange configuration and an inner vessel of thermoplastic plastic that is surrounded by a layer of reinforcing fiber, which method comprises: (figure la) the production of a hollow preform 1 for the plastic inner vessel, with a flange part 2 radially outwardly connected thereto, wherein the preform piece, or at least the outwardly extending flange part 2 is manufactured by injection molding; (Figure 1b) manufacturing a metal supporting flange 4 provided with an opening 3 with a transition collar 5 to (in the direction of) the inner vessel to be formed; the support flange 4 is furthermore provided with a substantially upright outer edge 10; (Figure 1c) placing the preform 1 in the opening 3 of the support flange 4, the transition collar 5 extending on the side remote from the flange part 2; (Figure 1d) placing the preform 1 (largely shown in dotted lines) and the transition collar 5 of the support flange 4 in a mold cavity 6, the shape and dimensions of which correspond to the outside of the inner vessel 7 to be formed, providing a plastic deformation temperature of the plastic of the preform and providing it by means of a blow pipe 8, in a positive pressure difference (indicated by the arrows inside the preform 1) between the inside and outside of the preform, such that the outside of the preform 1 under the influence of the pressure difference substantially against the inside of the mold cavity 6 and is partially moved against the transition collar 5 of the support flange 4 (blown and / or optionally sucked towards the inside of the mold cavity 6 by underpressure or vacuum), thus forming the inner vessel 7, which can then be removed from the mold cavity 6 be released by moving that mold cavity apart (see dotted dividing seams 6a); (figure 1) applying the layer 9 of reinforcing fiber over the inner vessel 7 and (a part of) the transition collar 5.

Figures 2a and 2b show that, instead of by injection molding, the outwardly extending flange part can also be manufactured, for example, by initially providing a tubular flange part connected to the hollow preform 1 which serves as the basis for the plastic inner vessel 2 '(ie a tubular part connected to the preform 1, which is intended as the basis for a flange part), and subsequently to provide a temperature suitable for plastic deformation of the plastic of the tubular flange part 2' and the temperature to the outside at that temperature beads or flutes of said flange part 2 ', resulting in a flange part 2 extending radially outwards.

When use is made of the option shown in Figs. 2a and 2b, a change can be made to the method which may have production advantages. According to this alternative method, the support flange 4, as shown in Figure 1c, does not have to be placed in the blow mold 6 before the preform 1 can be inflated to the shape of the inner vessel 7, but the support flange 4 can then be applied, whereafter it ( until then tubular flange part 2 'is then radially turned outwards or radiated outwards, so that it acquires the desired shape of flange part 2.

Figures 2c - 2e, together with Figures 2a and 1b already discussed, illustrate the various steps of the alternative method for manufacturing a pressure-resistant vessel with pressure-resistant flange configuration and an inner vessel of thermoplastic plastic surrounded by a layer of reinforcing fiber, which method comprises: (Figure 2c) providing a hollow preform 1 for the plastic inner vessel, with a substantially tubular flange part 2 'connected thereto; (Figure 1b) manufacturing a metal supporting flange 4 provided with an opening 3 with a transition collar 5 to (in the direction of) the inner vessel to be formed; (Figure 2c) placing the preform 1 (shown largely in dotted lines) in a mold cavity 6 whose shape and dimensions correspond to the outside of the inner vessel 7 to be formed, providing a temperature suitable for plastic deformation of the plastic of the preform and the provision, by a blow pipe 8, in a positive pressure difference (indicated by the arrows inside the preform 1) between the inside and outside of the preform, such that the outside of the preform 1 is moved against the inside of the mold cavity 6 under the influence of the pressure difference (blown and / or optionally sucked towards the inside of the mold cavity 6 by underpressure or vacuum), thus forming the inner vessel 7, which can subsequently be discharged from the mold cavity 6 by moving said mold cavity apart (see dotted part seams 6a ); (Fig. 2d) placing the opening 3 of the metal support flange 4 over the tubular flange part 2 ', the transition collar 5 extending over a part of the outer surface of the inner vessel 7; (figure 2e) providing a temperature suitable for plastic deformation of the plastic of the tubular flange part 2 'and bead-flipping out of said flange part 2' at that temperature around the opening 3 of the supporting flange 4; and (shown in the same figure) applying the layer 9 of reinforcing fiber over the inner vessel 7 and the transition collar 5.

The application of the layer 9 of reinforcing fiber over the inner vessel 7 and the transition collar 5 comprises the shift-free wrapping of said inner vessel 7 and transition collar 5 with reinforcement fibers which can move freely relative to each other and are wound in such a way that, when internal pressure is applied in the inner vessel their longitudinal direction. While the gas or liquid tightness is provided by the thermoplastic inner vessel 7, the compressive strength of the pressure vessel is mainly provided by the reinforcement fibers 9, however, in the vicinity of the flange 2, partly by the (metal) support flange 4 and transition collar 5.

Figures 3a - 3c show some possibilities for providing the passage opening in the flange configuration, formed by the plastic flange part 2 and the support flange 4, with a flange plate 11 and / or flange ring 12. As already indicated in the discussion of figure 1b, the support flange 4 preferably comprises a substantially upright outer edge 10, in the direction of the transition collar 5, such as in Figure 3a (and the preceding figures), or in the opposite direction, as shown in Figures 3b and 3c. This outer edge 10 serves to reinforce the surface abutting the plastic flange 2.

Figure 3a shows a configuration in which the support flange 4 is connected to the flange plate 11 and the flange ring 12 by means of a bolt connection, for which purpose the plastic flange 2, the support flange 4, the flange plate 11 and the flange ring 12 are provided with bolt holes for passage of bolts 13, which together with nuts 14 form the bolt connection with which the plastic flange 2, the support flange 4, the flange plate 11 and the flange ring 12 can be pulled against each other. A good seal between the flange plate 11 and the surface of the plastic flange 2 can be obtained by using an O-ring 15. The flange plate 11 can have passages 16 to resp. from the interior of the plastic vessel 7, for example for, when used as a boiler vessel, the supply of cold water and the discharge of hot water, as well as for installing a temperature sensor in the interior of the vessel 7. Finally, as Figure 3a also shows that the flange plate 11 is provided with an upright outer edge 17. This serves to reinforce the flange plate 11, but can also serve to confine the plastic flange 2 on its outer circumference, which, after all, as a thermoplastic tendency has to "crawl" outwards under pressure (through the bolt connection) and (possibly) increase in temperature, which may reduce the sealing pressure. Instead of the flange plate 11, the outer edge 17 could also be connected to the flange ring 12 for the same purpose and effect.

Alternatively, as Figure 3b shows, the outer circumference of the plastic flange 2 can also be enclosed by the upright reinforcement edge 10 connected to the metal support flange 4, which end then extends along the outer circumference of the flange 2, so that said outer circumference by the edge 10 is completely enclosed and "creep" of the thermoplastic plastic is thus prevented.

Figure 3c shows a configuration in which the support flange 4 is connected to the flange plate 11 and / or flange ring 12 by means of a screw ring connection, in the embodiment shown by means of an upstanding screw edge 18 around the flange ring 12 which, in replacement of the bolt connection in the 3a and 3b, screwed onto the upright reinforcement edge 10 of the metal support flange 4. The screw edge 18 is threaded on its inside, the outside of the reinforcement edge 10 on its outside, thus forming a threaded connection 19 on the outside of the flange configuration, which substantially completely encloses the plastic flange 2. Incidentally, with some simple changes, it is also possible to provide a similar threaded connection 19 by means of a threaded connection 19 which is formed by providing the threaded edge 18 on its outside and the reinforcing edge 10 on its inside with a thread.

Claims (20)

A method for manufacturing a pressure-resistant vessel with a pressure-resistant flange configuration and an inner vessel of thermoplastic plastic surrounded by a layer of reinforcing fiber, which method comprises: manufacturing a hollow preform (1) for the plastic inner vessel, with an associated, outwardly extending flange part (2); manufacturing a metal support flange (4) provided with an opening (3) with a transition collar (5) to the inner vessel to be formed; placing the preform in the opening of the support flange with the transition collar extending on the side remote from the flange part; placing the preform and the transition collar of the support flange in a mold cavity (6) whose shape and dimensions correspond to the outside of the inner vessel to be formed, providing a temperature suitable for plastic deformation of the plastic of the preform and providing in a positive pressure difference between the inside and outside of the preform, such that under the influence of the pressure difference the outside of the preform essentially moves against the inside of the mold cavity and partly against the transition collar of the supporting flange, thus inner vessel (7) is formed which is subsequently released from the mold cavity; applying the layer (9) of reinforcing fiber over the inner vessel and the transition collar. Method according to claim 1, wherein the preform piece or at least the outwardly extending flange part (2) is manufactured by injection molding. Method according to claim 1, wherein the outwardly extending flange part is manufactured by providing a substantially tubular flange part (2 ') connected to the hollow preform for the plastic inner vessel, and then providing a plastic deformation temperature of the plastic of the tubular flange part and beading or flaring out of that flange part at that temperature. A method for manufacturing a pressure-resistant vessel with pressure-resistant flange configuration and an inner vessel of thermoplastic plastic surrounded by a layer of reinforcing fiber, which method comprises: providing a hollow preform (1) for the plastic inner vessel, with an associated substantially tubular flange part (2 '); manufacturing a metal support flange (4) provided with an opening (3) with a transition collar (5) to the inner vessel to be formed; placing the preform in a mold cavity (6) whose shape and dimensions correspond to the outside of the inner vessel to be formed, providing a temperature suitable for plastic deformation of the plastic of the preform and providing a positive pressure difference between the inside and outside of the preform, such that the outside of the preform is moved against the inside of the mold cavity under the influence of the pressure difference, thus forming the inner vessel (7) which is subsequently released from the mold cavity; placing the opening of the support flange over the tubular flange portion, the transition collar extending over a portion of the outer surface of the inner vessel; providing a temperature suitable for plastic deformation of the plastic of the tubular flange part and beading or flicking said flange part (2) outwards at that temperature around the opening of the supporting flange; applying the layer (9) of reinforcing fiber over the inner vessel and the transition collar. 5. Method as claimed in one or more of the foregoing claims, wherein applying the layer of reinforcement fiber over the inner vessel and the transition collar comprises sliding-free wrapping of said inner vessel and transition collar with reinforcement fiber. Method according to one or more of the preceding claims, wherein the support flange is or is provided with a substantially upright outer edge (10). Method according to one or more of the preceding claims, wherein the flange configuration, formed by the plastic flange part and the support flange, is provided with a flange plate (11) and / or flange ring (12) on the side of the plastic flange part remote from the inner vessel ). A method according to claim 7, wherein the flange plate and / or flange ring is or is provided with a substantially upright outer edge (18). Method according to one or more of the preceding claims 7-8, wherein the support flange is connected to the flange plate and / or flange ring by means of a bolt connection (13-14). Method according to one or more of the preceding claims 7-8, wherein the support flange is connected to the flange plate and / or flange ring by means of a screw ring connection (19). A method according to claims 6 and 10, wherein the threaded ring connection is provided by means of applying thread to the upright outer edge (10) of the support flange and to the upright outer edge (18) of the flange plate resp. flange ring. A pressure-resistant vessel with a pressure-resistant flange configuration, comprising an inner vessel (7) of thermoplastic plastic with an outwardly extending flange part (2), a metal supporting flange provided with an opening (3) and extending on the side of the inner vessel (3) 4) with a transition collar (5) which partially extends over the inner vessel, and a layer (9) of reinforcing fiber which is arranged over the inner vessel and at least a part of the transition collar. The pressure-resistant vessel of claim 12, wherein the layer of reinforcement fiber comprises a non-slip wrap of reinforcement fiber over the inner vessel and the transition collar. A pressure-resistant vessel as claimed in one or more of the preceding claims from claim 12, wherein the support flange comprises a substantially upright outer edge (10). 15. Pressure-resistant vessel according to one or more of the preceding claims from claim 12, wherein the flange configuration, formed by the plastic flange part and the support flange, on the side of the plastic flange part remote from the inner vessel, a flange plate (11) and / or flange ring ( 12). A pressure-resistant vessel according to claim 15, wherein the flange plate and / or flange ring comprises a substantially upright outer edge (18). 17. Pressure-tight vessel according to one or more of claims 15-16, wherein the support flange and the flange plate and / or flange ring are or can be connected by means of a bolt connection (13-14). 18. Pressure-resistant vessel according to one or more of the claims 15-16, wherein the support flange and the flange plate and / or flange ring are or can be connected by means of a screw ring connection (19). 19. Pressure-resistant vessel according to claims 14 and 18, wherein the threaded ring connection is provided by means of screw thread on the upright outer edge of the support flange (10) and on the upright outer edge (18) of the flange plate resp. flange ring. A pressure-resistant vessel made according to a method according to one or more of claims 1-11.