GB1601499A - Process for producing a reinforced flange-shaped connector on plastics pipes - Google Patents
Process for producing a reinforced flange-shaped connector on plastics pipes Download PDFInfo
- Publication number
- GB1601499A GB1601499A GB23919/78A GB2391978A GB1601499A GB 1601499 A GB1601499 A GB 1601499A GB 23919/78 A GB23919/78 A GB 23919/78A GB 2391978 A GB2391978 A GB 2391978A GB 1601499 A GB1601499 A GB 1601499A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pipe
- flange
- plastics
- shaped connector
- die
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims description 40
- 229920003023 plastic Polymers 0.000 title claims description 33
- 239000004033 plastic Substances 0.000 title claims description 33
- 239000011230 binding agent Substances 0.000 claims description 24
- 230000008719 thickening Effects 0.000 claims description 14
- 229920005989 resin Polymers 0.000 claims description 12
- 239000011347 resin Substances 0.000 claims description 12
- 229920001225 polyester resin Polymers 0.000 claims description 11
- 239000004645 polyester resin Substances 0.000 claims description 11
- 230000009172 bursting Effects 0.000 claims description 10
- 230000002787 reinforcement Effects 0.000 claims description 10
- 239000011521 glass Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- 238000000465 moulding Methods 0.000 claims description 8
- 238000007789 sealing Methods 0.000 claims description 8
- 229920002430 Fibre-reinforced plastic Polymers 0.000 claims description 7
- 239000011151 fibre-reinforced plastic Substances 0.000 claims description 7
- 238000003825 pressing Methods 0.000 claims description 7
- 239000000853 adhesive Substances 0.000 claims description 6
- 230000001070 adhesive effect Effects 0.000 claims description 6
- 239000000835 fiber Substances 0.000 claims description 6
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 4
- 238000004140 cleaning Methods 0.000 claims description 4
- 239000003365 glass fiber Substances 0.000 claims description 4
- 239000000126 substance Substances 0.000 claims description 4
- 238000009864 tensile test Methods 0.000 claims description 4
- 239000002657 fibrous material Substances 0.000 claims description 3
- 238000009787 hand lay-up Methods 0.000 claims description 3
- 230000000712 assembly Effects 0.000 claims description 2
- 238000000429 assembly Methods 0.000 claims description 2
- 238000004132 cross linking Methods 0.000 claims description 2
- 238000002474 experimental method Methods 0.000 claims description 2
- 239000003292 glue Substances 0.000 claims description 2
- -1 polyethylene parts Polymers 0.000 claims description 2
- 238000013022 venting Methods 0.000 claims description 2
- 238000003754 machining Methods 0.000 claims 1
- 239000010410 layer Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 4
- 229920000457 chlorinated polyvinyl chloride Polymers 0.000 description 3
- IHPYMWDTONKSCO-UHFFFAOYSA-N 2,2'-piperazine-1,4-diylbisethanesulfonic acid Chemical compound OS(=O)(=O)CCN1CCN(CCS(O)(=O)=O)CC1 IHPYMWDTONKSCO-UHFFFAOYSA-N 0.000 description 2
- 101100495270 Caenorhabditis elegans cdc-26 gene Proteins 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 229920001187 thermosetting polymer Polymers 0.000 description 2
- 229920006305 unsaturated polyester Polymers 0.000 description 2
- 239000007990 PIPES buffer Substances 0.000 description 1
- 229920000034 Plastomer Polymers 0.000 description 1
- 238000006887 Ullmann reaction Methods 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 239000003251 chemically resistant material Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
Classifications
-
- 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
- B29C53/583—Winding and joining, e.g. winding spirally helically for making tubular articles with particular features
- B29C53/585—Winding and joining, e.g. winding spirally helically for making tubular articles with particular features the cross-section varying along their axis, e.g. tapered, with ribs, or threads, with socket-ends
-
- 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
- F16L47/00—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
- F16L47/14—Flanged joints
Description
(54) PROCESS FOR PRODUCING A REINFORCED
FLANGE-SHAPED CONNECTOR ON
PLASTICS PIPES
(71) We, CHEMISCHE WERKE
HULS AKTIENGESELLSCHAFT, a
German Company, of 4370 Marl 1, Federal
Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a process for producing a reinforced flange shaped connector on an end of a plastics pipe which flange-shaped connector is to be detachably connected to an identical flange-shaped connector on another pipe, the process being of the kind wherein a reinforcement consisting of a fibre-reinforced plastics binder, which forms an adhesive bond with the pipe end, is provided in the region of the flange shaped connector, around a flange rim on the pipe end, the external surface of the reinforcement being shaped in accordance with a desired final external contour. The invention also relates to a plastics pipe having a reinforced flangeshaped connector on an end thereof produced by a process of the kind referred to.
A process of the kind referred to for the production of a flange-shaped connector is known from French Patent Specification
No. 1,540,772. In this known process, the end of a pipe without a flange ring is first armoured externally with polyester reinforced by glass fibres and is cut to the desired length. The end of the pipe is then calibrated by means of a special bush. An inner thermoplastic sleeve is pushed into the pipe and is folded over, to the desired width of the flange, by means of a heated tool. The polyester reinforcement is then glued on, with the aid of a press.
Before they are glued in, the inner sleeves are skimmed by turning, in order to ensure a push fit. This relatively complicated method of manufacture whichin addition requires the use of several individual components and of expensive special tools, substantially adds to the cost of production of the pipe ends. There is furthermore the danger that the adhesive layer will be destroyed under extreme chemical and mechanical conditions and thereby produce a break in pipelines employing such flange-shaped connectors.
The aim of the present invention is to provide a process for the production of a reinforced flange-shaped connector which requires less expensive moulds and tools than the known process, ensures high tensile strength of the flange-shaped connection and also makes optimum use of the existing material of the pipe, and which can furthermore be employed in a simple and inexpensive manner and in particular only requires tools which do not have to be heated separately. Using the same mould, the flange-shaped connector thickness can be varied by inserting spacer rings between an ejector plate and the end piece of the pipe, the thickness being varied in accordance with the desired resistance to excess pressure or to under pressure.
According to one aspect of the present invention a process of the kind referred to for producing a reinforced flange-shaped connector on an end of a plastics pipe which flange-shaped connector is to be detachably connected to an identical flange-shaped connector on another pipe, is characterised by the following process steps:
a) wrapping the external surface of the pipe end adjacent to the flange rim with a flexible fibrous material impregnated with a curable plastics binder which binder will form an adhesive bond with the plastics material of the pipe, to form a thickened collar of fibre-reinforced plastics binder extending radially around the pipe end and abutting the flange rim, and
b) pressing the collar against the flange rim and around the pipe in a die before curing of the plastics binder.
Accordingly the process of the invention comprises the step of the so-called hand layup process with subsequent wet moulding at room temperature, for which only simple moulds made from plastomeric materials are used. It is not necessary to employ expensive tools consisting of metal, with heating devices. The flange-shaped connector produced in accordance with the process withstands very high stresses, that is to say high pressures with simultaneously occurring elevated temperatures. By using the wet moulding process it is also possible to build up the flange-shaped connector in its entirety, including the end face of the flange rim from a chemically resistant material.
The step of pressing the thickened collar against the flange rim and around the pipe in a die before curing of the plastics binder causes the flange rim, apart from its end face, to be embedded in the fibre-reinforced plastics binder. Any small amounts of plastics binder forced out during pressing on to the end face of the flange rim may be subsequently removed in a cleaning step when the plastics binder has cured.
In order to achieve a preferred bottleshaped thickening around the pipe end it is proposed, by way of preference, that the pipe end is wrapped with polyesterimpregnated glass staple fibre mats and that first a single mat having a width which exceeds the height of the die is wrapped round, and thereafter further impregnated mats of different widths are wrapped round in succession until an approximately bottleshaped thickening has formed.
Accordingly, as is in itself known, curable polyester resins are preferably used as the plastics binder. Such polyester resins are described in Ullmanns Encyklopadie der
Technischen Chemie (Ullmann's
Encyclopaedia of Industrial Chemistry), volume 14, page 90 et seq. (1963) and in
Kirk-Othmer, Encyclopaedia of Chemical
Technology, volume 20, page 791 et seq.
(1969). Preferably, the glass mat used is a glass staple fibre mat of 450 g/m2, and all plastomers, thermosetting resins and, in the case of linings, also elastomers are used as plastics for the inner pipes. For the thickening above the flange rim, polyester resins of a prescribed viscosity are used, whilst the glass mat used is a glass staple fibre mat (450 g/m2) of varying width, in order to shape the thickening which is (then) to be moulded.
According to another aspect of the invention there is provided a plastics pipe having a reinforced flange-shaped connector on an end thereof, which connector is produced in accordance with the process of the invention and in which the fibrous reinforcement material is embedded in the plastics binder which is firmly bonded to the pipe wall and completely covers the rear face of the flange rim.
Since the plastics binder permeates and/or covers all parts of the pipe end, the end of the pipe with the reinforced binder can be regarded in its entirety as quasiisotropic with respect to the internal distribution of externally applied forces.
Further, the end face of the flange rim can be provided with sealing grooves so that the flange connection can also withstand high pressures if gaskets are appropriately inserted.
Further properties of the flange-shaped connector and of the process according to the invention are illustrated with the aid of the drawing. The figures in the drawing shown the following:
Figure 1: a pipe end of PVC-C, provided with a flange rim and a pre-reinforcement (glass fibre-reinforced unsaturated polyester).
Figure 2: the pipe end with a thickening, shortly before the moulding process.
Figure 3: the pipe end in a die during the moulding process, shortly before the end of the first clamping stage.
Figure 4: a flange-shaped connector, after finishing, on a PVC-C pipe.
Figure 1 shows a plastic pipe 1, consisting of PVC-C. Other plastics pipes, for example of rigid PVC, of polyolefines and of thermosetting resins, preferably glass fibrereinforced unsaturated polyester, can also be used for the process according to the invention. The pipe has a diameter of for example 450 mm, but it is found that the process is suitable for pipes having diameters of from between 20 and 700 mm.
Firstly, a flange rim 2 is secured by means of a weld 3 to the region of an end face of the pipe 1. However, this flange rim can also be drawn round the pipe end thermally by means of a special tool (not shown). The external surface of the pipe end is then wrapped with a first polyester-impregnated glass staple fibre mat 4 and in particular this is wrapped round the neck to such a height that it projects from the subsequently used moulding tool. A gap of 0.2 to 0.6 mm between the external diameter of the prereinforcement comprising the mat 4 and the minimum diameter of the upper part of the moulding tool 13 is maintained. Further layers of glass fibre mat, of different widths (50 and 70 mm in the case of pipes of nominal widths up to 200 mm and 70 and 90 mm in the case of pipes of nominal widths up to 700 mm) are then wrapped round, towards the end of the pipe. In principle, the following wrapping sequence is used: three layers of a narrow tape, then three layers of a broad tape and so on, in this sequence, until a thickening 5 has formed (see Figure 2). Finally, this thickening is additionally covered with two layers of mats of such width that on closing the mould no externally actuated shifting or folding of the strips of mat below the outer layers is possible.
Polyester resin is a plastic which forms a glue bond with the pipe and cures in air. Its viscosity should be adjusted to that required for the hand lay-up process (viscosity value 680 mm2/sec.). Such resins are in themselves known.
After wrapping, the pipe end is introduced into a die according to Figure 3.
The die consists of two polyethylene parts which are suited to the particular requirements, in a manner which is in itself known. The die comprises an ejector plate 7 with an ejector 6 and the pipe end is placed on the ejector plate. The end is surrounded by an annular female mould part 8 which possesses grooves 9, 10, for collecting resin, below the plate 7 and in the region of its side cheeks. A male mould part 13 possesses, on its underside, a pressure ring 11 which is flared and into which are machined eight groove-shaped venting channels 12 (only one of which can be seen in Figure 3). The male mould part 13, is lowered carefully in stages, the pressure not being allowed to exceed a value of 1,000 kp.
The moulding process is terminated after not less than 10 minutes and not more than 15 minutes, in order to guarantee that the strips of mat are embedded in such a way that the moulded thickening subsequently behaves like a quasi-isotropic material with respect to the forces applied. The pressure ring of the male mould part 13 penetrates along the thickening and presses the latter so as to result in a truncated cone outer contour (bottle shape) of the thickening. As a result of the close tolerance between the pipe end section and the male mould, only excess resin is forced out into the resin grooves; this makes it easier to determine the glass fibre content theoretically, and thus permits conclusions regarding the strength characteristics.
Usually, the die remains closed until the polyester resin has cured. After the resin has cured the die is drawn apart and the pipe end removed. As a result of the heat liberated during polymerisation, the pipe end briefly reaches peak temperatures of up to 100"C or above, which results in good crosslinking of the polyester resin. The residual styrene content in the polyester resin is substantially less than 1%, which equates with good chemical resistance and permits high mechanical strength to be achieved. After removal from the die, the pipe end is preferably cleaned to expose the free end face 18 of the flange rim 2. To improve the sealing properties, sealing grooves 19 are preferably additionally formed in the end faces by turning. After cleaning, the flange-shaped connector can be used, and high dimensional accuracy is ensured.
In order to be able to specify approximate values for the mechanical strength of the flange-shaped connector, bursting tests and tensile tests were carried out as follows:
1. Three bursting tests were performed on pipes at about 20"C, using a pipe with a diameter of 500 mm and a flange collar height of 55 mm. Only at 45 to 55 bars excess pressure did the test pipes burst at the flange collar.
2. Three bursting tests were performed on pipes at about 90"C, the pipes having a diameter of 450 mm and a flange collar height of 52.5 mm. At 55 bars excess pressure, the test pipe in each case burst at the flange collar.
3. In a bursting test at 900 C, using a pipe with a diameter of 110 mm, the flat gasket slipped out at 100 bars excess pressure; when using insert rings, with an O-ring as the gasket, bursting pressures of 160 bars were attainable.
4. In the case of a pipe of 160 mm diameter, the flat gasket slipped out at 900C and 100 bars excess pressure. The last two experiments show that at high pressures the flat gasket between two smooth contact surfaces fails. For this reason, sealing grooves were introduced by turning into the end face of the flange connections.
Tensile tests on finished fitted-together assemblies showed that tensile forces of 11,500 kg to 13,500 kg were withstood by pipes of 110 mm diameter. This corresponds to a theoretical tensile strength value of To~1,000 kg/cm2.
WHAT WE CLAIM IS:
1. A process for producing a reinforced flange-shaped connector on an end of a plastics pipe which flange-shaped connector is to be detachably connected to an identical flange-shaped connector on another pipe, wherein a reinforcement consisting of a fibre-reinforced plastics binder, which forms an adhesive bond with the pipe end, is provided in the region of the flange-shaped connector, around a flange rim on the pipe end, the external surface of the reinforcement being shaped in accordance with a desired final external contour, which process is characterised by the following process steps: a) wrapping the external surface of the pipe end adjacent to the flange rim with a flexible fibrous material impregnated with a curable plastics binder which binder will form an adhesive bond with the plastics material of the pipe, to form a thickened collar of fibrereinforced plastics binder extending radially
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (9)
1. A process for producing a reinforced flange-shaped connector on an end of a plastics pipe which flange-shaped connector is to be detachably connected to an identical flange-shaped connector on another pipe, wherein a reinforcement consisting of a fibre-reinforced plastics binder, which forms an adhesive bond with the pipe end, is provided in the region of the flange-shaped connector, around a flange rim on the pipe end, the external surface of the reinforcement being shaped in accordance with a desired final external contour, which process is characterised by the following process steps: a) wrapping the external surface of the pipe end adjacent to the flange rim with a flexible fibrous material impregnated with a curable plastics binder which binder will form an adhesive bond with the plastics material of the pipe, to form a thickened collar of fibrereinforced plastics binder extending radially
around the pipe end and abutting the flange rim, and
b) pressing the collar against the flange rim and around the pipe in a die before curing of the plastics binder.
2. A process according to claim 1, comprising cleaning the exposed end face of the flange rim, after the pressing stage has been completed and the die removed, to remove any plastics binder formed on said exposed end face of the flange rim during the pressing stage.
3. A process according to claim 1 or 2 which also includes the step of machining the exposed end face of the flange rim after the pressing stage has been completed and the die removed.
4. A process according to any of the preceding claims, in which the pipe end is wrapped with polyester-impregnated glass staple fibre mats.
5. A process as claimed in claim 4, in which the first mat wrapped round the pipe has a width which exceeds the height of the die, and thereafter further impregnated mats of different widths are wrapped round in succession until an approximately bottleshaped collar has formed.
6. A process for the nroduction of a reinforced flange-shaped connector on an end of a plastics pipe substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.
7. A plastics pipe having a reinforced flange-shaped connector on an end of the pipe, in which the fibre reinforced connector is produced by the process according to any preceding claim and in which the fibrous reinforcement material is embedded in the plastics binder which is firmly bonded to the pipe wall and completely covers the rear face of the flange rim.
8. A plastics pipe according to claim 7, in which the front face of the flange rim is provided with at least one sealing groove.
9. A plastics pipe having at each end thereof a flange-shaped connector made by the process claimed in any one of claims 1 to 6.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2738982A DE2738982C2 (en) | 1977-08-30 | 1977-08-30 | Method for producing a flange on plastic pipes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1601499A true GB1601499A (en) | 1981-10-28 |
Family
ID=6017637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB23919/78A Expired GB1601499A (en) | 1977-08-30 | 1978-05-30 | Process for producing a reinforced flange-shaped connector on plastics pipes |
Country Status (4)
| Country | Link |
|---|---|
| DE (1) | DE2738982C2 (en) |
| FR (1) | FR2401761A1 (en) |
| GB (1) | GB1601499A (en) |
| IT (1) | IT7850869A0 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107477281A (en) * | 2017-09-16 | 2017-12-15 | 中国海洋大学 | A kind of double limitation connection systems of ocean fiber reinforced composite pipe |
| CN113232329A (en) * | 2021-03-31 | 2021-08-10 | 成都飞机工业（集团）有限责任公司 | Preparation method of integrated composite material conduit with flange plate |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL175755C (en) * | 1978-10-31 | 1984-12-17 | Wavin Bv | FLANGE TUBE PART BOTH OF FIBER-REINFORCED THERMO-CURING RESIN AND METHOD FOR PRODUCING SUCH A FLANGE TUBE PART. |
| AT388425B (en) * | 1987-10-08 | 1989-06-26 | Semperit Ag | PUNCH-RESISTANT CONNECTION OF DIFFERENT RUBBERING QUALITIES IN THE FLANGE AREA OF PIPELINES |
| DE3922335C1 (en) * | 1989-07-07 | 1990-07-05 | Uranit Gmbh, 5170 Juelich, De |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1447820A (en) * | 1965-09-20 | 1966-07-29 | Rapib S A Soc | Reinforced flanged collar |
| DE1276908B (en) * | 1966-03-11 | 1968-09-05 | Licentia Gmbh | Process for the production of rotating bodies preferably provided with flanges |
| FR1540772A (en) * | 1966-10-14 | 1968-09-27 | Bayer Ag | Plastic composite pipe |
| BE794065A (en) * | 1972-01-18 | 1973-07-16 | Bayer Ag | FIBER REINFORCED SYNTHETIC MATERIAL HOSE AND PROCESS AND DEVICE FOR ITS MANUFACTURING |
-
1977
- 1977-08-30 DE DE2738982A patent/DE2738982C2/en not_active Expired
-
1978
- 1978-05-30 GB GB23919/78A patent/GB1601499A/en not_active Expired
- 1978-08-08 FR FR7823328A patent/FR2401761A1/en active Granted
- 1978-08-28 IT IT7850869A patent/IT7850869A0/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107477281A (en) * | 2017-09-16 | 2017-12-15 | 中国海洋大学 | A kind of double limitation connection systems of ocean fiber reinforced composite pipe |
| CN113232329A (en) * | 2021-03-31 | 2021-08-10 | 成都飞机工业（集团）有限责任公司 | Preparation method of integrated composite material conduit with flange plate |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2738982A1 (en) | 1979-03-15 |
| FR2401761B1 (en) | 1983-07-01 |
| FR2401761A1 (en) | 1979-03-30 |
| IT7850869A0 (en) | 1978-08-28 |
| DE2738982C2 (en) | 1983-01-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |