NL8202038A - METHOD AND APPARATUS FOR FORMING COLORED MARKING STRIPES ON PLASTIC-COATED STEEL PIPES - Google Patents

Description

- 1 - 22470 / CV / lïï £ ___ 5

Short designation * Method and device for forming colored markings on 5 steel houses with plastic orbital casing.

The invention relates to a method and an apparatus for forming a plurality of circumferentially distributed polyethylene markers on the surface of polyethylene-sheathed steel pipes, the sheathing of which is co-extruded by a heat-adhesive ethylene copolymer and a hose foil. horizontal tubular polyethylene film is formed using an extrusion head with the two annular channels.

Most of the 13 different methods are used for marking pipes, cables and conduits from solid material rails for pipe transfer. For example, labels with technical information or advertising images and brands, waterproof labels with the same texts or license plate data with dyes (water-soluble or solvent-containing) texts applied with soya clones are produced by printing with color in 20 layers, produced by spray-painting and an extrusion with a color giving in a color tone other than the base material can also take place.

Most of these methods do not produce weather-resistant markings or markings. fail when influenced by ultra-23 violet light and temperatures with varying climatic conditions.

A plastic-dismantled article is long-lasting only if it contains additionally strong ultraviolet stabilizers in the form of carbon black, acrylic acid ester admixtures or other ultraviolet-absorbing admixtures.

Multi-applied linear stripes are not known, which are permanent, ultraviolet and heat-resistant, weather-resistant and are produced in extruded form in a continuous process by coloring of the most different kind, if, moreover, an underlying extruded adhesive, which adheres simultaneously. an enveloping object and permanent edging there t.

The object of the invention is to obtain a method and an apparatus with which it is possible during extruding of the tubular adhesive adhesive and sheeting foil colored markings in the length 8202038

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* apply direction to the casing, which indicate the purpose of application of the pipes laid in the ground in any position · Applying the food must be done in such a way that the markings are not completely pressed against the thermoplastic casing and that the 5 physical and chemical properties of the casing are not adversely affected, for example by notch effects, change due to fracture expansion and chemical behavior, by ultraviolet radiation or heat

According to the invention this can be achieved by the features indicated in claims 10 1 and 6, respectively ·

Further embodiments of the method are apparent from subclaims 2-5.

In the double nozzle used according to the invention, an annular side with circumferential outlet openings for the brand polyethylene distributed over the circumference, i.e. in the upper third of the outer annular slit (from which the sheath foil is extruded) is arranged in the vicinity of the ironing zone.

The shape of an extruded mark is limited in width and depth in a casing, which is continuously pressed in the mark bearing layer 20. A raised lenticular or a flat design of the marking can be achieved by a corresponding pressure differential control

The design is only released if the design of the distribution channels prevents deep penetration. · Furthermore, it has been used that «and brand polyethylene (hereinafter referred to as PE) must be in the ig ^ near the casing PE to be marked. Example:

Casing PE 0.4 -0.5

Marking PE 0.6 -0.9

In the extrusion process, the UV and heat-stabilized dyestuff must remain colorfast. This task is all the more convenient the fewer admixtures (mixed polymer of PE) are present.

The possibility is obtained that heat and W-stabilized marking wires can be made phosphorescent as illuminating color not only with coloring, but this measure achieves that the strength properties, elongation, tear strength and fracture expansion are fully retained and can be taken into account with the applicable DIN.

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The embodiments can be supplemented thereby by extruding an index wire attacking the coloring, which perfectly indicates the identity of the article wrapped in plastic.

The intended PE selection of the marking PE over the jacket PE allows the processing and distribution of the signing PE-S without additional heat damping between the extruders, since the extrusion operation can be carried out in a uniform temperature conduction ·

The invention will be explained in more detail below with reference to the accompanying figures.

Hg. 1 shows a section through the extruder head and the pipe to be dismantled

Hg · 2 shows a section on a larger scale over a part of the front neck ring of the extruder head · 15 Hg · 3 shows a section ever Hg · 2, seen along the line A-B.

Hg4 shows a longitudinal section on a larger scale

The extrusion head used for extruding two tubular foils is known per se according to German patent 1,957,078 and consists of three neck rings.A first housing ring is made of one piece with a doom 2. housing ring 1 axially attaches an intermediate ring 3, which forms a ring-shaped gap 3 for the inner heat-adhesive hose 19 with a conically-tapered end portion 4 of the doom 2 · Furthermore, the intermediate ring 3 and the ring-shaped channel 6 are fixed and exchangeable. While the housing ring 1 for the purpose of applying the inner heat-adhesive hose 19 emerging from the annular gap 5 is connected to the pipe 17 to be surrounded and for this purpose is connected to a supply 8, a second housing ring 9 is provided for applying the outer polyhylene hose 18. which is designed in a similar manner to the housing ring 1 and which is closely connected to the intermediate ring 3 with its side facing away from it. The annular slit 5 opens directly in front of the annular opening of a second annular slit 10, which is formed by the beveled outer surface of the intermediate ring 3 and by the inner surface of the housing ring 9 extending parallel thereto. The annular 53 slit 10 communicates with an annular channel 11, which is connected to a feeder 12 for polyethylene, the cross section of which, as with the housing ring 1, can be made with the aid of a strut ring 13 8202038 - 4 - 22470 / CY / liï, * being changed. The housing ring 1, the intermediate ring 3 and the housing ring 9 are just connected with bolts 14. The extrusion head is heated to the operating temperature with adjustable heating elements 13.

A distribution ring 22 is arranged in the front housing wall 9 of the extrusion head. In the region of the ironing zone, that is to say in the region of the upper third of the outer annular gap 18, it has an annular channel 21 (see Hg. 2 and 3). This annular channel 21 is connected to a channel 20. * which extends through the front # house wall 9 and which serves for the supply of the marking PE. As will be apparent from Fig. 3, 3, the manifold ring 22 (in this example) comprises four evenly spaced outflow openings 23 circumferentially extending into the upper third of the annular gap (Fig. 4). Thus, during the extrusion, four marking stripes are simultaneously formed, thereby ensuring that at least one of the stripes is visible in each position of the tube.

8202038

Claims (5)

1 · A method of forming multiple circumferentially distributed polyethylene streaks on the surface of polyethylene-jacketed steel housings, the dismantling of which by simultaneous reefing of an adhesive-bonding ethylene-polymeric hose and an adjacent hose-shaped polyethylene film using is formed from an extrusion head with two annular channels, characterized in that for the outer sheath film a polyethylene with a seam tinder i2 ^ - P, 4 to 0.5 g / 10 min and for the marking line a polyethylene mixed with a dye with the melt-10 index 16 * "to 0.9 g / 10 min is used and that the markings in a width of 8 mm and a thickness of 50 to 100 are extruded simultaneously in the longitudinal direction of the tube forming the sheathing tube, whereby between the extrusion pressure for the jacket film and that for the mark, a pressure difference between 10 and 50 bar is maintained. Method according to claim 1, characterized in that, for a smooth design of the marking strip with a jacket surface, these are extruded at a pressure of about 100 bar and the jacket film at a pressure of about 150 bar. 20 Method according to claim 1, characterized in that to form a lenticular cross-sectional shape of the mark, it is extruded at a pressure between 130 and 140 bar and the jacket foil at a pressure of about 150 bar. turn into. 4. A method according to any one of claims 1 to 3, characterized in that an IV and heat stabilizing dye is added to the polyethylene for the marking stripe. 5. Process according to any one of claims 1-3, characterized in that a phosphorizing dye is added to the polyethylene before the label. 30 é. Device for stirring the method according to any one of the preceding claims with an extrusion head, which has two annular slits arranged concentrically with respect to each other, the outer one of which serves to extrude the jacket film and the inner one to extrude the adhesive film. characterized in that a distribution ring (22) is inserted in the front housing wall (9) of the extrusion head, which is placed in the vicinity of the upper third of the outer annular gap (18). ) has an annular channel (21), which is connected on the one hand to a channel (20) extending for supplying the brand polyethylene, which extends through the front housing wall (9) and which, on the other hand, is at least three circumferences of equal distance from each other has distributed exit openings (23) which open into the upper third of the annular gap (18). 8202038