DE2742934A1 - ORIENTED THERMOPLASTIC POLYMER MATERIAL TUBE - Google Patents

Description

TlEDTKE - Bühling 'KlNNE - group Dipl.-Chem. Q. Bunting

- 3 - Dipl.-Ing; R. Kinne

2742934 Dipl.-Ing. P. Grope

Bavarlaring 4, P.O. Box 20240S 8000 HOnchMi 2

Tel .: (089) 5396 53

Telex: 5-24845 tipat

cable: Germaniapatent Munich

23rd September 1977

B 8473

ICI case M.29072

Yorkshire Imperial Plastics Limited Leeds / Great Britain

Oriented thermo tube

plastic polymer material

The invention relates to pipes made from oriented thermoplastic polymer material.

In British Patent No. 14 32 539 there is described a method and apparatus for forming a tube of orientable thermoplastic polymer material which comprises radially expanding a tubular blank into a mold at a temperature at which the expansion of the tube causes an orientation of the Polymer molecules causes. In this way, the finished pipe has an oriented structure, which is able to withstand a greater hoop stress at a given wall thickness than one made of the same material tube, which has not been oriented. In this way , the pipe is also provided with an expanded, oriented socket, which provides a sealing

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Dresdner Bank (Munich) Account 393 «844 PostaclMwk (MOiMlMn) Account ITIMMM

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ring can accommodate. Hence it is possible to use a pipe an integrated sleeve at one end which has a prescribed burst strength with a thinner wall thickness than previously possible ge essence, creating the volume of plastic that is needed for one given pipe diameter and a given strength was used, is reduced, so that the cost of required materials are kept as small as possible. Such pipes are typically made of PVC, chlorinated tem PVC, high or low density polyethylene, polypropylene, or ABS, although others are suitable orientable polymers can be used. Every material has a specific reversion temperature, at which the molded pipe and the molded socket auto matically tend to return to the original shape of the pipe blank. The reversion temperature for PVC is typically on the order of 60 ⁰ C and it has been found that higher temperatures under storage conditions in hot, sunny weather, in particular can be obtained in drier equatorial countries. The reason for this is that the oriented Pipes usually contain black or dark gray pigments incorporated, which increase the absorption of solar energy.

According to the invention, a tube of oriented, thermoplastic polymer material has a light-reflecting outer surface. The light-reflecting outer surface is preferably supplied by a light colored pigment that is incorporated into the polymeric material that forms the tube blank prior to orientation. The light-colored pigment can be incorporated into the outer surface of the tubular blank alone. Alternatively, a light-reflecting outer surface can be created by applying a light- reflective material on the outer surface of the tubular

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shaped blank can be provided prior to orientation or on the outer surface of the tube after orientation. Alternatively, the light-reflecting outer surface can be created by an outer film made of thermoplastic polymer material in which a light-colored pigment is incorporated. This outer layer can be used in the same way, as described in British Patent Application No. 39 506/76.

The invention will now be explained in more detail with reference to the drawings, in which

Fig. 1 is a side view of a pipe with an integral sleeve, which is partially shown in Section is shown and according to GB-PS

14 32 539 is manufactured;

Fig. 2 is an enlarged section of the sleeve shown in Fig. 1 showing one embodiment the invention explained and

FIG. 3 shows a section similar to that in FIG. 2, which explains a second embodiment.
25th

In Fig. 1, a tube of oriented thermoplastic material 10 with an integrated sleeve 11 has been shown formed, which contains an annular groove 12 which has a sealing ring 13 made of elastic material, for example synthetic rubber. The opposite end 14 of the tube 10 has a smooth cylindrical surface. In this way, a second tube 15, similar to the tube 10, is sealed with its cylindrical end 16 encircled by the sealing ring 13 within the sleeve 11 of the first tube 10. The tubes 10 and 15

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are prepared according to GB-PS 14 32 539, so that the polymer material by radial expansion to a complementary Molding was oriented. In this way, the wall thickness of the tubes 10 and 15 and their corresponding Sleeves 11 are considerable for a given burst strength lower than for unoriented tubes made from the same material, reducing the cost the required material can be reduced. The tubes 10 and 15 were made from blanks that passed through Manufacturers of standard extruded plastic products and these blanks have black and white Dark gray pigments invariably contain.

As shown in Fig. 2, the outer surface of the tubes 10 and 15 contains a light colored pigment incorporated therein, such as indicated by dotting so that the pipes 10 and 15 and the sleeve 11 will reflect solar energy, thereby reducing the heat absorbed when stored in hot, sunny weather or direct Exposed to sunlight. A white or light yellow pigment is preferred and is used in the tubular blank incorporated before it is oriented. The pigment can be incorporated anywhere in the thermoplastic polymer material or it can only be incorporated into an outer layer.

Referring to Figure 3, tubes 10 and 15 are provided with a separate layer 17 of light reflective Material created. The layer 17 can be applied to the outer surface of the tubes 10 and 15 after them have been oriented, for example by spraying on or vacuum deposition of a reflective material, for example Aluminum. On the other hand, according to the teaching of British Patent Application No. 39 506 / 76 by radial expansion of concentric tubular

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Blanks are applied, the outer blank of which is made of light-reflecting material or a light-reflecting Incorporated pigment contains. From Fig. 3 it can be seen that the layer 17 also the sleeve 11 and the groove 12 is covered.

Alternative methods of applying a light reflective material are to spread it on or immerses the object while absorbing the material,

The invention is mainly used in connection with a pipe that is designed to be pressure-resistant is, for example, a main water pipe. Although such a pipe is often buried in use, it is also stored open before installation, and Problems can arise during such storage; PVC is commonly used as the material for such piping is used, but this is not necessary.

Dark colored and light colored pipes exposed to hot sun conditions were tested. In summer conditions in England with ambient temperatures sometimes reach 36 ⁰ C, the maximum temperature recorded was for a white-pigmented pipe 49 ° C; in comparison, the temperature for a pipe with conventional dark gray color was 71 ^° C. The white pipe retained its original dimensions for 2 months, while the dark gray pipe suffered a deformation of approximately 0.5%.

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Claims (9)

TLEOTKE - BOHLING - KlNNE "GRUPE Dipl.-Ing. H. Tiedtke Dipl.-Chem. G. Bühling Dipl.-Ing. R. Kinne 11 ? QΊ L ^Dip '" ^lng · ^P - ^Gmpe / 4 ^ J * ♦ Bavarlaring 4, PO Box 202403 8000 Munich2 Tel .: (089) 539653 Telex: 5-24845 ti pat cable: Germaniapatent Munich 23rd September 1977 B 8473 ICI case M.29072 Claims / 1. \ Tube made of oriented, thermoplastic polymer material with an outer surface which is exposed to direct sunlight, characterized in that the outer 4g surface is provided with a light-reflecting agent (10, 17) to reduce the absorption of solar energy. 2. Tube according to claim 1, characterized in that the light reflective agent is a light colored pigment (Fig. 2) which is present in the polymer material prior to orientation is incorporated. 3. Tube according to claim 2, characterized in that the light-colored pigment is incorporated into the outer surface alone is. 4. Tube according to claim 1, characterized in that the light-reflecting means is a light-reflecting rende material that is applied to the outer surface before the thermoplastic polymer material orients will. 5. Tube according to claim 2, characterized in that the light reflecting agent is a light reflecting agent viii /, 7 809813/0963 DmdMf BMIk (MOnehwi) Kto. 3β3β 844 Post «*« * (MOnctwn) KIo. - 2 - B 847, Is material that is applied to the outer surface after the thermoplastic polymer material is oriented became. 6. Tube according to claim 5, characterized in that the light reflective material on the outer surface of the Pipe was deposited by spraying or vacuum deposition. 7. Tube according to claim 6, characterized in that the light-reflecting material is a reflective material, is preferably aluminum. 8. Tube according to claim 1, characterized in that the light-reflecting means has an outer layer (17) is made of thermoplastic polymer material, which is a
light colored pigment incorporated. 9. Tube according to claim 8, characterized in that the outer layer of thermoplastic polymer material is also oriented. 13/0063