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
  • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
  • B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
  • B29C41/04—Rotational or centrifugal casting, i.e. coating the inside of a mould by rotating the mould
• • 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
  • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
  • B29C41/34—Component parts, details or accessories; Auxiliary operations
  • B29C41/38—Moulds, cores or other substrates
• • 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
  • B29L2023/00—Tubular articles
  • B29L2023/22—Tubes or pipes, i.e. rigid

Definitions

• the invention relates to a die for the production of plastic tubes in a centrifugal process.
• CH 684 326 A5 shows a known form of the matrix.
• the raw materials in particular curable resins, sand, are passed over an arm that can be moved back and forth in the axial direction of a die (so-called “feeder”) Glass fibers and fillers are thrown into the rotating die, which is why it is also called a centrifugal process.
• EP 0 360 758 B1 gives examples of a material selection and the construction of such a tube with different layers.
• the outside of the die is additionally tempered with warm air or warm water in order to accelerate the curing of the plastic material and thus to increase the cycle time.
• these races are arranged at a distance from the respective die end.
• the support rings are arranged on longitudinal ribs which run in the axial direction on the die jacket.
• the object of the invention is to solve this problem, in particular for large-format pipes which are produced using the centrifugal process. No disadvantages should arise for the storage of the die.
• the invention is based on the following finding:
• a pipe with a length> 6.00 and ⁇ 6.50 m is produced via the feeder mentioned, for example 6.30 m to 6.40 m.
• 15 or 20 cm are cut off on the end side after the pipe has been produced in order to form clean pipe ends.
• the ends mentioned, which are cut off, can or should of course be as short as possible, for example only a few cm.
• the idea 'according to the invention' aims to move the races into these areas, i.e. to the end of the die in areas where either no pipe jacket is built up at all or in die areas which are adjacent to the end areas of the tube produced, after manufacture but cut the tube.
• the die jacket is largely homogeneous over the entire, technically relevant length.
• the temperature transfer from outside to inside (to the pipe to be manufactured) is now largely constant over the entire circumference of the die. This enables a tube with very homogeneous material properties to be formed.
• the invention relates to a die for the production of a plastic tube of length X in a centrifugal process, with the following features: - a cylindrical jacket
• the races are arranged on opposite ends of the die outside of a die section corresponding to the tube length X.
• one race is arranged at a free end of the die, the other race at the other free end.
• the shell of the die can be formed at least at one free end with a radially projecting flange to which a race is attached.
• the die need only be a little larger, for example 6.10 m.
• the races are then attached to both flanges at both ends, quasi as an extension of the die.
• the die plus the two races can then have a length of, for example, 6.30 or 6.40 m.
• the races lie outside the die section which is relevant for the tube production (the finished tube).
• At least one race can therefore axially protrude from the front of the jacket. However, it is also possible for at least one race to project radially beyond the casing. This can be set, for example, by arranging the flange mentioned.
• the length of the die can be well over 3, for example> 4 m,> 5 m or even 6 and above.
• the inner diameter can also be> 2 m,> 2.5 m or 3 m or more.
• the cylinders can be welded together at the end. It is also possible to design the cylinder pieces on the end face with (relatively narrow) flanges. Adjacent flanges of adjacent cylinder pieces can thus be screwed together or otherwise connected. At these points there is a material reinforcement compared to adjacent zones of the die shell. However, these material reinforcements are significantly less than those in the area of a race, so that they do not actually interfere with the pipe production.
• At least one race can have a cylindrical U-shaped surface.
• the axes of the associated bearings then run in particular parallel to the axis of the die. Any tolerances can be compensated for by using self-aligning bearings.
• the peripheral surface of at least one race can also be designed differently.
• at least one race has a circumferential surface which has at least a first section which is at an angle> 0 and ⁇ 90 ° to the axial direction of the Matrix runs. This has the advantage that the associated bearings can be “inclined” and not only guide the die in terms of rotation, but also stabilize it in the axial direction.
• the peripheral surface is formed with two inclined surfaces of different inclinations, preferably in a mirror-image version.
• the circumferential surface has a V-shape on average.
• Additional guide rollers can also be provided, which guide the die in the axial direction.
• FIG. 1 a perspective view of a die according to the invention
• FIG. 2 a longitudinal section through the die according to FIG. 1
• FIG. 3 a top view of a bearing end of the die according to FIG. 1.
• FIG. 1 shows a cylindrical die consisting of three cylinder pieces 10, 12, 14 welded together. All cylinder pieces 10, 12, 14 have the same wall thickness w. The inside diameter is 3.00 m. The total length of the three cylinder pieces is 6 m.
• the impeller 22 is screwed onto this flange 20.
• the impeller 22 has a cylindrical peripheral surface 22u.
• a second impeller 24 is screwed onto the flange 18.
• the impeller 24 has a V-shaped circumferential surface 24 u in section.
• the total length of the die including the flanges 18, 20 is approximately 6.10 m; duty unpaid ⁇ Lich of the wheels 22, 24 is the total length of about 6.50 m. It is important to point out once again that the tube to be produced is formed exclusively in the die section which is predetermined by the cylinder pieces 10, 12, 14. As far as the total length of the tube is longer after removal from the die, this does not bother because the tube is then cut to the desired length anyway by trimming the tube on both sides.
• the die is sprayed around the circumference, for example with hot water, as described. This takes place on the entire circumferential surface of the die, in particular thus on the circumferential surface of the cylinder sections 10, 12, 14. But spraying of the races 22, 24 is also harmless because the races are outside the area in which the tube is manufactured. Since the wall thickness w is virtually constant over the entire axial length of the die, there is also a uniform temperature distribution and thus a uniform heating or cooling over the entire die jacket 26.
• the special design of the race 24 creates the in FIG. 3 shown possibility to arrange inclined bearing wheels 30.1, 30.2 or 30.3, 30.4 on opposite sides of the die and thus not only create a rotary bearing for the die, but at the same time also provide axial guidance (in the direction of the central longitudinal axis M-M of the die).

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Moulding By Coating Moulds (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=32087017

Family Applications (1)

Country Status (10)

Cited By (1)

Citations (7)

Family Cites Families (7)

• 2002
  • 2002-10-18 DE DE10248691A patent/DE10248691A1/de not_active Withdrawn
• 2003
  • 2003-08-10 UA UAA200504640A patent/UA78877C2/uk unknown
  • 2003-10-08 RU RU2005115117/12A patent/RU2319610C2/ru not_active IP Right Cessation
  • 2003-10-08 BR BR0315416-5A patent/BR0315416A/pt not_active IP Right Cessation
  • 2003-10-08 TR TR2005/01392T patent/TR200501392T2/tr unknown
  • 2003-10-08 WO PCT/EP2003/011096 patent/WO2004037507A1/de not_active Application Discontinuation
  • 2003-10-08 MX MXPA05004112A patent/MXPA05004112A/es not_active Application Discontinuation
  • 2003-10-08 RO ROA200500347A patent/RO123486B1/ro unknown
  • 2003-10-08 PL PL376972A patent/PL207222B1/pl unknown
  • 2003-10-08 AU AU2003273957A patent/AU2003273957A1/en not_active Abandoned

Patent Citations (7)

Non-Patent Citations (1)

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