DE10119809A1 - Extrusion of elastic door seal sections includes cross-linking or polymerization immediately after emerging from die by near infra-red radiation - Google Patents

Abstract

Irregular profiles, especially door seals, are treated immediately after emerging from the extruder die (6) by near infra-red radiation with a wave length between 0.8 and 1.5 mu m at an energy level above 150 kW/m<2>, preferably between 400 and 600 kW/m<2>. The radiation is produced by halogen lamps running above 2500 K, preferably above 2900 K. An Independent claim is also included for an extrusion plant (5) incorporating a tunnel (1) immediately after the extrusion die (6) to provide all-round radiation from halogen lamps. The lamps are divided into segments and controlled singly or in groups to provide the required conditions. The extruded strand (7) is treated in an unsupported condition.

Description

The invention relates to a method for producing a irregularly shaped profile and a device for Execution of the method according to the preamble of the patent claim 1 and claim 9.

Sealing and butt profiles can be found, for example, as door profiles file in motor vehicles, but also in household appliances etc., multiple Application. Such profiles are usually used Sound and temperature insulation or isolation between two Buttocks used. To this end, the profiles are more common have a structure that is on at least one side on an object, for example on a bodywork or other sheet metal part, can be attached while the Ge subject pointing away side of the profile more or less ger flexible area, which is a second Ge object that comes into contact with the profile.

Such sealing or butt profiles are usually made of two or several different hard components, in particular Rubber components, built up or have a stabilizing metal or plastic insert.

According to the prior art, such profiles become main actually manufactured with an extrusion process, the Profile according to its later form as an elongated strand  is pressed out of an extrusion die. Since the fresh ex strand immediately after the extrusion die he has plasticity and is not inherently stable, be is a manufacturing problem that should not be underestimated the profiles in it, the outer shape, but also if necessary to get necessary cavities in the profile or a Zu to prevent them from collapsing. Usually the Production of the profile a cross-linkable or polymerizable Plastic or natural material used, immediately after the Extrude a cross-linking or polymerisation of the material than is initiated. For this, the freshly extruded, pla tical strand on a transport device, for example applied a belt conveyor, which then for Initiation of the crosslinking or polymerization by a heated salt bath or conveyed through a hot air duct. However, this approach has numerous disadvantages, which one tries to eliminate with complex measures.

On the one hand, this is due to the support on the belt conveyor which in combination with that on the plastic strand acting gravity a sagging of the strand under Fear of losing its shape. The problem will be solved time z. B. by blowing support air directly on Mouthpiece of the extruder encountered. However, this procedure is very complex and requires extensive trials for every new extrusion or profile shape carried out again the need, in particular, intricately shaped cavities to be able to receive efficiently.

At least as problematic is cantilevered corners or to get edges until one for a structure maintaining adequate crosslinking or polymerization of the ma terials has taken place. At this point, therefore often a metal or textile insert inserted into the profile brings or the plastic strand around a metal insert  extruded, which in turn is a cumbersome technique calls.

Another problem that arises from the need for one If a plastic strand is placed on a conveyor, is that bumps or impurities, Erhe exercises, but also deepenings that exist on the conveyor those are to memorize themselves directly in the profile and to egg on an uneven surface. Especially at visible surfaces, such as on door profiles in the Household and automotive, this is extremely undesirable since the overall picture suffers and an impairment occurs.

In the past, therefore, this problem has been tried with the help of a microwave-based shock vulcanizer solve, after the extrusion a crosslinking or polyme rization of the plastic used by microwave heating mung was tried. A disadvantage of this method is egg on the other hand, however, the high space requirement of the microwave irradiation device of two to three meters in length, while de rer the microwave radiation on the measure to be polymerized must act in order to achieve a usable result and the high price of microwaves location. In particular, the high space requirement requires everything Usually a new design or a new building of the extruder because a suitable microwave system cannot be integrates existing system. Beyond that, there is a need due to the long processing distance also with this Sy stem u. U. a support of the plastic strand, what turn to the problem already described above leads to the look of the finished profile. Even with one polymerization or crosslinking initiated by microwaves accordingly, surface defects are to be feared.  

It is therefore the object of the invention, a method of generic type and a device for this available with the risk of collapse encountered a plastic strand and at the same time a ver improved surface appearance of the finished profile is achieved.

This object is achieved by a method according to claim 1 or solved by a device according to claim 9.

An essential idea of the invention is that with a very fast or shock crosslinking by means of NIR radiation or shock polymerization of the plastic or natural material (in referred to as the starting material). here it is essential that electromagnetic radiation in the Wavelength range of the NIR is used because its on depth of penetration in the manufacture of the profiles mentioned in Question materials depending on wavelength and beam intensity is up to five millimeters.

This way it is essentially when using one All-round radiation possible, vulcanization over the in essentially the entire cross section of a profile is almost the same initiate early, which leads to a very quick self- Stabilization of the plastic strand leads. Mostly All-round radiation can alternatively be used for flat profiles carried out by one or two-sided radiation become. (At this point it should be noted that in the white vulcanization as a generic term for cross-linking and po is used and includes these.)

The profile material is preferably immit in the direction of movement can be placed behind the extruder die with NIR radiation shines, so that initiation and extensive volcano nization of the profile material immediately behind the Extruder mouthpiece takes place. A sagging of the plastic  Strand is thus when using the invention Procedure not to be feared. Likewise, on the use who does not need to carry out cumbersome support air experiments because of the high penetration depth of the NIR radiation deeper layers, for example inner walls of cavities in which the profile is vulcanized and thus solidified.

Essentially all extrusion materials come as profile materials cross-linkable or polymerizable art and / or nature substances in question. In particular, artificial and natural rubbers such as EPTM and others Ter polymer rubbers, especially on ethylene and propy called len basis, the double bonds or vulcanizable Contain sulfur groups. Other suitable materials are, for example, latex, silicone and the like thermopla plastic materials, such as polyethylene, polyamide, polypropylene, Polyvinyl chloride, polyarylate or polycarbonate.

According to a further development of the method, the NIR Radiation essentially the radiation from at least one halogen lamp operated with increased operating temperature uses an emitter temperature above 2500 K, be preferably above 2900 K.

A radiation power acting on the plastic strand is preferably used, which is above 150 kW / m ² , preferably in the range from 300 kW / m ² to 800 kW / m ² and particularly preferably in the range from 400 kW / m ² to 600 kW / m ² lies. This high radiation power makes it possible to greatly increase the vulcanization and solidification speed of the plastic strand. The profile strand already starts to solidify immediately behind the mouthpiece of the extruder and is "in flight", ie without the support required in the prior art, so solidified that it, or the profile, when it hits a subsequent supporting belt conveyor is insensitive to bumps and dirt on the belt conveyor. These therefore no longer lead to an optical impairment of the surface of the profile. Direct winding onto a roll is already conceivable at this point.

According to a further development of the invention, the radiation is used of the profile to the special system and the con Customized arrangement of individual and / or groups halogen lamps used. This has the advantage that an individual, adapted to the profile shape Radiation or radiation power can be used. It are, for example, rod-shaped halogen lamps as a line heater zer or line emitters or halogen arranged in groups lamps of this type visible, which are preferably each in ih rer radiation intensity are controllable. But it should be mentioned that ring-shaped halogen lamps can also be used. This is particularly advantageous when an approximately rotation symmetrical profile, such as a hose shall be.

According to a further embodiment of the method, the Irradiation in at least one essentially tunnel-shaped trained steel room. The green here Dete advantage is that due to the tunnel-shaped Training a comprehensive all-round and on the respective Profile shape adjustable radiation of the plastic strand can be done with very low radiation losses.

The tunnel-shaped radiation beam is advantageously used mainly consists of preconfigured segments volume sets. In this way it is possible to comprehensively essentially triangular, rectangular, pentagonal, right to form an irregularly or irregularly shaped tunnel, whereby  the respective shape individually to the desired one Profile shape can be matched. The respective segments have assembly facilities for this purpose that enable attach them to each other or to a carrier device. They are as active emitters or counter or side reflectors configured.

According to another development of the invention, the Radiation flux density in the irradiation area in tunnels in the longitudinal direction and / or in the circumferential direction of the tunnel by rules the emitter power, especially individual or grouped Halogen lamps, regulated and to a material to be irradiated customized.

Through the use of NIR radiation to effect the vulka The effect of a ver sintering of the profile surface can be avoided. Beyond that the vulcanization can be controlled so that a de Finished structure of an outer or inner surface - in the case of voids in the profile - can be obtained. By the one It is set of suitable materials and radiation parameters possible to create a porous or open-pored profile structure testify by means of which a desired damping behavior of the Profile is adjustable.

According to a further embodiment, the plastic Strand made of a multi-component material that in particular built up or composed of several layers is. This should be understood to mean that ver differentiated hard materials, with different chemical Structure, processed, the different functions have similarities. So it is possible to have one side of the profile made of a harder rubber-like material than load-bearing ele ment to extrude while another side of the profile a softer material, such as foam rubber, or a  other porous, optimal damping behavior has performing material.

As it is usually desirable, these are different Materials with different radiation powers radiate, it proves to be an essential advantage that a Regulation of the radiation flux density in the radiation area is provided and an adaptation to the respective material is possible.

The profile is expediently produced in con tinuous way, so that with the procedure according to the invention high productivity can be achieved.

In a first structurally simple version, stab shaped halogen lamps aligned in the longitudinal direction of the extruder. They are each in an alternative embodiment perpendicular to the longitudinal direction of the extruder (and transport direction of the material strand or profile) arranged. This leaves advantageously in the transport direction generate fender radiation gradient, so that depending on the requirements high intensity at the beginning of the tunnel End of the tunnel decreases, or a low at the beginning of the tunnel intensity that decreases towards the end of the tunnel can be. This is useful, for example, if the extruded plastic strand in multi-layer core-shell type is built up. In this way, a "layered Control of the vulcanization possible.

The radiation sources preferably have one or more, for example parabolic reflectors for radiation concentration tration on.

Furthermore, the device according to the invention shows in part of a control device for controlling a  Radiation field with predetermined, in particular spatial and temporally constant irradiation parameters that spe target according to a given spatial or temporal Chen power density of the radiation can be adjusted. Of course, with the control device also targeted an inhomogeneous radiation field within the Be set the radiation range. At this point be further noted that to measure the surface temperature a non-contact of the plastic strand to be irradiated Temperature measuring device (pyrometer) can be used, the z. B. is integrated in a control loop. That way it is possible, the optimal temperature for a vulcanization, re spective radiation power, on the plastic strand to work without excessive heating of the profile fear of aterials that can cause burns could.

Further advantages and advantages of the invention result itself from the subclaims and from exemplary embodiments, which are explained in more detail using the illustrations. in this connection demonstrate:

Fig. 1 is a schematic representation of an inventive SEN tunnel shaped irradiation means,

Fig. 2 shows a segment of the irradiation device having arranged in doing nellängsrichtung radiation emitters,

Fig. 3 shows another embodiment of an inventive SEN segment having arranged perpendicular to the tunnel longitudinal direction of radiation emitters, and

Fig. 4 is a schematic representation to illustrate the method according to the invention.

In the following description, the same and Identical parts of the invention have the same reference numerals used.

In Fig. 1, a tunnel-shaped irradiation device 1 according to the invention is shown schematically. Elongated halogen lamps 3 for generating a radiation field are arranged on the same segments 4 and form a cuboid radiation area, the open end face 3 of which serves to supply the strand of material to be irradiated. The irradiation device 1 is thus designed as an elongated tunnel. It has a further opening on the side lying in the longitudinal direction in FIG. 1 through which the irradiated material is removed from the irradiation device.

It is possible to use several such radiation devices to be arranged one behind the other in the direction of movement, in order to achieve this Way to get a longer radiation path. Furthermore it is possible to switch between individual radiation devices For example, to arrange support rollers, on which a short one timely support of the plastic to be irradiated Strands or pre-consolidated profile takes place. If the If the strand comes into the area of the support roller, it is already so solidified that an influence on the surface by the support roller no longer affects the upper surface quality of the profile leads.

A not shown in Fig. 1 feature of the invention is that the feed and outlet opening 3 , 3 'of the tunnelför shaped irradiation device 1 to avoid radiation losses with apertures, which can also be formed as reflectors, as far as can be covered that the plastic strand can be introduced into and out of the radiation area without any problems, but energy losses can be practically completely avoided. The diaphragms can be either plate-shaped or designed as an iris.

In Fig. 2 and Fig. 3 shows a segment 4 is in each case schematically shown, wherein FIG. 2 shows in angeord designated to the tunnel longitudinal direction halogen lamps 2, by means of which a peripheral side gradient can be generated with respect to the radiation intensity in the tunnelför-shaped irradiation device 1. By means of the arrangement of the halogen lamps 2 in the segment 4 shown in FIG. 3, the radiation gradient can be set in the longitudinal direction of the tunnel.

In FIG. 4, an irradiation device 1 in combination with an extruder 5 and a belt conveyor 8 is shown. An elastomer strand 7 is extruded through an extrusion mouthpiece 6 and speed due to the quasi shot Extrusionsgeschwin by the irradiation device 1, in which the strand is vulcanized 7 and solidified. As the movement progresses, the strand, which is at least on the periphery already solidified and thus dimensionally stable, reaches the belt conveyor 8 after the radiation device, on which it is transported further, for example to a winding device. Between the extruder die 6 and the conveyor 8 , the plastic strand moves without support, so that it is irradiated from all sides uniformly in the irradiation device 1 by the NIR radiation and solidified evenly from all sides.

At this point, it should be emphasized that the term "solidified" does not mean complete hardening here, but rather, as a result of the irradiation, a profile which is possibly still plastic, but at least dimensionally stable, is produced on the inside. With the aid of suitable starting materials, however, curing of the initially plastic strand is also possible, so that, for example, a hard plastic part can be produced. The "flight path" lying between the extruder die 6 and the conveyor 8 can range from a few centimeters up to 1.5 meters, up to a maximum of 2 meters. The flight path can be vertical, for example for the manufacture of tubes, or horizontal.

At this point it should be noted that all of the above be Written parts seen alone and in each comm combination, especially those shown in the drawings Details are claimed as essential to the invention. Abände Experts are familiar with this.  

LIST OF REFERENCE NUMBERS

1

irradiation device

2

Means for generating a radiation field (halogen lamp)

3

.

3

'Inlet, outlet opening

4

segment

5

extruder

6

Extruder die

7

Plastic strand

8th

(Belt) conveyors

Claims (17)

1. A method for producing an irregularly shaped profile, in particular elastic sealing profile, from egg nem cross-linkable and / or polymerizable starting material, wherein one, in particular by extrusion, is thermally solidified before forming plastic material strand to form the profile, characterized in that immediately after the preforming a crosslinking and / or polymerization is initiated by all-round irradiation with electromagnetic radiation, which has a substantial active component in the near infrared range, in particular in the wavelength range between 0.8 μm and 1.5 μm and a power density above 150 kW / m ² , preferably in the range from 300 kW / m ² to 800 kW / m ² and particularly preferably in the range from 400 kW / m ² to 600 kW / m ² . 2. The method according to claim 1, characterized in that essentially the radiation of at least one halogen lamp ( 2 ) is used as electromagnetic radiation, which is operated substantially at a temperature above half of 2500 K, preferably above 2900 K, ben. 3. The method according to claim 1 or 2, characterized in that for irradiation with electromagnetic radiation, halogen lamps ( 2 ) are used, which are arranged on at least one segment ( 4 ) of a tunnel-shaped radiation device ( 1 ). 4. The method according to claim 3, characterized in that the radiation flux density in the radiation region in the longitudinal direction of the tunnel and / or in the tunnel circumferential direction by regulating an emitter power, in particular individual ner and / or group-controllable radiation sources, in particular halogen lamps ( 2 ), adapted to a material to be irradiated becomes. 5. The method according to any one of the preceding claims, characterized in that the plastic strand an irradiation area in the we goes through substantial support-free. 6. The method according to any one of the preceding claims, characterized in that the plastic strand made of a multi-component material, in particular multilayered. 7. The method according to any one of the preceding claims, characterized in that as the starting material thermoplastic materials, ins special polymers based on ethylene and / or propylene, such as EPTM, polyacrylate, polycarbonate, polyamide, polyvi nyl chloride can be used.   8. The method according to any one of the preceding claims, characterized in that the radiation is carried out so that a porous, in particular an open-pored profile is retained. 9. Device for producing an irregularly shaped profile, in particular elastic sealing profile from a crosslinkable and / or polymerizable starting material, wherein a, in particular by extrusion, preformed plastic material strand is thermally solidified to form a profile, characterized in that immediately adjacent to an extrusion device ( 5 ) an all-round irradiation device ( 1 ) is provided which has at least one radiator for generating an elec tromagnetic radiation field, the essential radiation component of which is red in the region of the near infrared, in particular in the wavelength range between 0.8 μm and 1.5 μm , and the a power density above 150 kW / m ² , preferably in the range from 300 kW / m ² to 800 kW / m ² and particularly preferably in the range from 400 kW / m ² to 600 kW / m ² on the profile surface. 10. The device according to claim 9, characterized in that the irradiation device ( 1 ) has one and / or more, in particular tubular elongated, Halogenlam pe (s) ( 2 ) with a radiator temperature of over 2500 K, in particular over 2900 K, which have one or more reflectors for focusing and aligning the radiation. 11. Device according to one of claims 9 or 10, characterized in that the irradiation device ( 1 ) is substantially tunnel-shaped. 12. Device according to one of claims 9 to 11, characterized in that the irradiation device ( 1 ) has at least two segments ( 4 ) equipped with radiation sources ( 2 ). 13. The apparatus according to claim 10, characterized in that the halogen lamps ( 2 ) are arranged in groups and are aligned substantially axially to each other. 14. Device according to one of claims 9 to 13, characterized in that a control device for generating a beam development field with predetermined, in particular constant Irradiation parameters, especially a given lei density of radiation is provided. 15. The apparatus according to claim 14, characterized in that the halogen lamps arranged in the longitudinal direction of the tunnel and can be controlled individually or in groups. 16. The apparatus of claim 14, characterized in that the halogen lamps perpendicular to the longitudinal direction of the tunnel orderly and controllable individually or in groups. 17. The device according to one of claims 14 to 16, characterized in that a measuring device for non-contact temperature measurement solution, in particular a pyrometer, is provided.