DE10119809B4 - Method and device for producing a profile - Google Patents

Abstract

Method 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 bonded 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 significant proportion of active in the range of the near infrared, in particular in the wavelength range between 0.8 .mu.m and 1.5 .mu.m and a power density in the range of 400 kW / m ² to 800 kW / m ² , wherein
as electromagnetic radiation substantially the radiation of halogen lamps (2) is used, which are operated substantially at a temperature above 2500 K, preferably above 2900 K, and on at least one segment (4) of a tunnel-shaped irradiation device (1) are arranged ,

Description

The The invention relates to a method for producing an irregularly shaped Profils and an apparatus for performing the method according to the The preamble of claim 1 or claim 7.

Seals and shock profiles for example, as door profiles in car, but also in household appliances, etc., multiple use. As a rule, such profiles for sound and temperature insulation or insulation used between two abutment surfaces. For this purpose, the profiles usually have a structure that is on at least one side of a Article, for example on a body or other sheet metal part, fasten while the side of the profile facing away from the article one more or less flexible area, which is attached to a second object, which comes to the profile to the plant, can adapt.

Such Sealing or shock profiles are usually made of two or more different hard components, especially rubber components, constructed or have a stabilizing metallic or plastic insert.

According to the state In the art, such profiles are mainly using an extrusion process made, the profile according to his later Form is extruded as an elongated strand from an extrusion die. Since the freshly extruded strand immediately after the extrusion die a high plasticity has and is not dimensionally stable in itself, there is no underestimated Problem with manufacturing the profiles in it, the external shape, but also to obtain any necessary cavities in the profile or to prevent them from collapsing. Usually becomes a cross-linkable or polymerizable for the production of the profile Artificial or natural substance used, immediately after the extrusion a crosslinking or polymerization of the material is initiated. For this purpose, the freshly extruded, plastic strand on a transport device, for example, a belt conveyor then applied this to initiate crosslinking or polymerization by a heated salt bath or by a Hot air duct promoted. However, this approach has numerous disadvantages that one with elaborate measures tried to eliminate.

So On the one hand, due to the support on the belt conveyor in Combination with the force acting on the plastic strand gravity to fear a collapse of the strand while losing its shape. This problem is currently z. B. by blowing in support air directly at the mouthpiece encountered by the extruder. However, this method is very expensive and requires extensive testing for each new extrusion or profile shape carried out again Need to become, to be able to efficiently obtain in particular complicated shaped cavities.

At least it is just as problematic, self-supporting corners or edges as long to get until one for a structure preservation sufficient crosslinking or polymerization of the material has taken place. At this point is therefore often a Metal or textile insert introduced into the profile or the plastic Extruded strand around a metal insert, but in turn a complicated one Technology requires.

One Another problem that is due to the need for a circulation of a plastic strand on a conveyor is to that bumps or impurities, surveys, but also depressions on the promoter are present, imprint themselves directly into the profile and to an uneven surface lead the same. Especially on visible surfaces, such as on door profiles in the household and automotive sectors, this is highly undesirable as the overall picture suffers and an impairment occurs.

In The past was therefore attempted to help this problem with help a shock vulcanizer based on microwave, wherein after extrusion, crosslinking or polymerization of the used Plastic by microwave heating was tried. However, a disadvantage of this method is on the one hand the high space requirement of the microwave irradiation device of two to three meters in length, while derer the microwave radiation to the material to be polymerized must act, to lead to a usable result, and on the other hand the high price of a microwave system. In particular, the high space requirement usually requires a new design or a new building the extruder plant, since a suitable microwave system is not can be incorporated into an existing system. In addition, it requires due the long processing distance also in this system u. U. one support of the plastic strand, which in turn is already described above Problem regarding the appearance of the finished profile leads. Also in a microwave initiated polymerization or crosslinking are accordingly surface defects to fear.

The publication DE 199 41 106 A1 discloses a method and an apparatus in which, immediately after exiting an extruder, a profiled strand over a distance of 8 cm, preferably 4 cm, irradiated in a period of 1 s to 3 s from a radiation source whose essential area of action is in the near infrared (NIR), and thus prevents plastic deformation of the extruded material. The disadvantage here, however, with 0.8 m / min to a maximum of 4.8 m / min low production speed, resulting from distance and time. Furthermore, it should be regarded as disadvantageous that only one radiation source with a maximum of two lamps (see 2 ), Whereby the power density is limited to about 200 kW / m ² .

It is therefore the object of the invention, a method of the generic type and a device for this to disposal to provide with those in the production of a profile of danger the plastic deformation with improved surface appearance and higher production speeds and thus an increase in productivity allows becomes.

These The object is achieved by a method according to claim 1 or by a device according to claim 7 solved.

One essential idea of the invention is that by means of NIR radiation a very fast or shock-crosslinking or shock polymerization of the natural or synthetic material (hereinafter referred to as the starting material) is effected. It is essential that electromagnetic radiation in the wavelength range of the NIR is used because of their depth of penetration in the production the mentioned profiles in question depending on the wavelength and radiation intensity in the range of up to five Millimeters.

On this is the case when using substantially all-round irradiation possible, a vulcanization over the substantially entire cross-section of a profile virtually simultaneously to initiate, resulting in a very rapid self-stabilization of the plastic strand leads. For predominantly flat Alternatively, all-round irradiation can be achieved by means of a or two-sided irradiation. (At this point it should be noted that in further vulcanization used as a generic term for crosslinking and polymerization processes is and includes these.)

Prefers The profile material is immediately behind in the direction of movement the extruder mouthpiece irradiated with NIR radiation, so that initiation and extensive Vulcanization of the profile material already immediately behind the extruder mouthpiece takes place. A collapse of plasti rule strand is thus when using the method according to the invention not to be afraid. As well may be due to the use of cumbersome supporting air experiments be waived because of the high penetration depth of the NIR radiation also deeper layers, such as inner walls of cavities, in the profile vulcanized and thus solidified.

When Profile materials come essentially all extrudable cross-linked or polymerizable synthetic and / or natural substances in question. Especially be artificial here and natural Rubbers, such as EPTM and other ter-polymer rubbers, in particular ethylene-based and propylene-based, the double bonds or contain vulcanizable sulfur groups. Other suitable materials For example, latex, silicone and the like are thermoplastics. such as polyethylene, polyamide, polypropylene, polyvinyl chloride, polyarylate or polycarbonate.

According to one Further development of the method is essentially the radiation of NIR radiation at least one with elevated Operating temperature operated halogen lamp that uses a Emitter temperature of above 2500 K, preferably above 2900 K, having.

Preferably, a radiation power acting on the plastic strand is used which is above 150 kW / m ² , preferably in the range of 300 kW / m ² to 800 kW / m ² and particularly preferably in the range of 400 kW / m ² to 600 kW / m ² lies. Due to these high radiant powers, it is possible to greatly increase the vulcanization and solidification rate of the plastic strand. The profile strand already begins to solidify immediately behind the mouthpiece of the extruder and is "in flight", ie without a support required in the prior art, so far solidified that he, respectively, the profile when hitting a support the belt conveyor already Insensitive to unevenness and dirt on the belt conveyor is. These therefore no longer lead to a visual impairment of the surface of the profile. A direct winding on a roll is already conceivable at this point.

According to a further development of the invention, an arrangement of individual and / or grouped halogen lamps adapted to the specific system and the specific profile shapes is used to irradiate the profile. This has the advantage that an individual, according to the profile shape adapted radiation or radiant power can be used. For example, rod-shaped halogen lamps can be used as line heaters or line emitters of the halogen lamps of this type which are arranged in groups and which are preferably controllable in each case in their radiation intensity. But he is suggests that annular halogen lamps are also applicable. This is particularly advantageous if an approximately rotationally symmetrical profile, such as a hose to be generated.

According to one Another embodiment of the method, the irradiation in at least a substantially tunnel-shaped trained steel room carried out. The advantage based on this lies in the fact that due the tunnel-shaped Training a circumferentially versatile and to the respective profile shape tunable irradiation of the plastic Strand can be done with very low radiation losses.

In Advantageously, the tunnel-shaped irradiation area in essentially composed of preconfigured segments. On this way it is possible a perimeter essentially triangular, rectangular, pentagonal, regular or irregular shaped Tunnel form, with each shape individually on each desired Can be matched profile shape. The respective segments have For this purpose, mounting devices that allow it to each other or on a carrier device to fix. They are active spotlights or counter- or side reflectors configured.

According to one Another embodiment of the invention is the Strahlungsflußdichte in the irradiation area in the tunnel longitudinal direction and / or in the tunnel circumferential direction by controlling the emitter power, in particular individual or grouped halogen lamps, regulated and adapted to a material to be irradiated.

By the use of NIR radiation to effect vulcanization can the sooner frequently watched Effect of a sintering of the profile surface can be avoided. Furthermore The vulcanization can be controlled so that a defined structure an outside or inner surface - in the case of cavities in the profile - preserved is. Through the use of suitable materials and irradiation parameters Is it possible, a porous one or open-pore profile structure by means of which a desired damping behavior of the profile is adjustable.

According to one another embodiment the plastic strand is made of a multi-component material, which is constructed or assembled in particular multi-layered. This is to be understood that in the material strand different hard materials, with different chemical structure, which have different functionalities. So it is possible one side of the profile made of a harder rubber-like material as a supporting element to extrude while another side of the Profils a softer material, such as foam rubber, or any other porous, a optimal damping behavior ensuring forming Material has.

There It is usually desirable is, these different materials with different radiation powers to irradiate, it proves to be a significant advantage that a scheme the radiation flux density is provided in the irradiation area and an adaptation to the respective material possible is.

Conveniently, the production of the profile in a continuous manner, so that with the method according to the invention a high productivity is reachable.

In a first structurally simple design are rod-shaped halogen lamps in extruder longitudinal direction aligned. In an alternative embodiment, they are each vertical to the extruder longitudinal direction (And transport direction of the material strand or profile) arranged. This can be in an advantageous manner, a radiation gradient running in the transport direction generate, so that ever after request at the beginning of the tunnel initially a high intensity, the Tunnel end decreases, or even at the beginning of tunnel low Intensity, which decreases towards the tunnel end, can be adjusted. This is For example, it makes sense if the extruded plastic strand in multi-layered core-shell-type. That way is a "layered Control "the Vulcanization possible.

Prefers For example, the radiation sources have one or more Parabolic reflectors on the radiation concentration.

Furthermore, the device according to the invention advantageously has a control device for controlling egg nes radiation field with predetermined, in particular spatially and temporally constant irradiation parameters, which can be adapted specifically according to a given spatial or temporal power density of the radiation. Of course, it is also possible with the control device to set an inhomogeneous radiation field within the irradiation area in a targeted manner. At this point it should be further noted that a non-contact temperature measuring device (pyrometer) can be used to measure the surface temperature of the plastic strand to be irradiated, the z. B. is integrated in a control loop. In this way, it is possible to have the optimal temperature for vulcanization, respectively radiation power, to act on the plastic strand, without fear of excessive heating of the profile material, the could lead to burns.

Further Advantages and expediencies The invention results from the subclaims as well as from exemplary embodiments, the closer to the pictures explained become. Hereby show:

1 a schematic representation of a tunnel-shaped irradiation device according to the invention,

2 a segment of the irradiation device with radiation emitters arranged in the longitudinal direction of the tunnel,

3 a further embodiment of a segment according to the invention with arranged perpendicular to the tunnel longitudinal direction radiation emitters and

4 a schematic representation for illustrating the method according to the invention.

In The following description will be for the same and the same Parts of the invention used the same reference numerals.

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

It is possible, several such irradiation devices in the direction of movement in order to arrange in this way a longer irradiation path to obtain. Furthermore, it is possible between individual irradiation facilities for example, support rollers on which a short-term support of the to be irradiated plastic strand or pre-consolidated profile takes place. When the strand is in the area of the support roll comes, he is already solidified so that an influence on the surface by the support roller no longer an impairment the surface texture of the profile leads.

An in 1 not shown feature of the invention is that the supply and exhaust port 3 . 3 ' the tunnel-shaped irradiation device 1 To avoid radiation losses with diaphragms, which can also be designed as reflectors, as far as can be covered, that the plastic strand can be easily introduced into the irradiation area and executed from it, but energy losses can practically be completely avoided table. The panels can be either plate-shaped or iris.

In 2 and in 3 is each a segment 4 schematically shown, wherein 2 in arranged to the tunnel longitudinal direction halogen lamps 2 shows, by means of which a circumferential gradient with respect to the radiation intensity in the tunnel-shaped irradiation device 1 can be generated. By means of in 3 illustrated arrangement of the halogen lamps 2 in the segment 4 can set a running in the tunnel longitudinal beam gradient.

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

At this point it should be emphasized that the term "solidified" here does not mean complete curing, but rather, as a result of the irradiation, a profile which may still be plastic in the interior, but which is at least dimensionally stable, is produced. With the aid of suitable starting materials, however, hardening of the initially plastic strand is also possible, so that, for example, a hard plastic part can be produced. The between the extruder mouthpiece 6 and the sponsor 8th lying "flight distance" can be 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 hoses, or horizontal.

It should be noted at this point that all the above-described parts, taken alone and in any combination, in particular the details shown in the drawings as invented essential for the training. Variations thereof are familiar to the person skilled in the art.

1

irradiation device

2

medium for generating a radiation field (halogen

lamp)

3, 3 '

Supply, outlet

4

segment

5

extruder

6

Extruder die

7

plastic strand

8th

(Belt) conveyors

Claims (13)

A method for producing an irregularly shaped profile, in particular elastic sealing profile, of a crosslinkable and / or polymerizable starting material, wherein a, in particular by extrusion, preformed plastic material strand is thermally bonded to form the profile, characterized in that immediately after the preforming a cross-linking and / or polymerization is initiated by all-round irradiation with electromagnetic radiation, which has a significant proportion of active in the range of the near infrared, in particular in the wavelength range between 0.8 microns and 1.5 microns and a power density in the range of 400 kW / m ² to 800 kW / m ² , wherein as electromagnetic radiation substantially the radiation of halogen lamps ( 2 ), which are operated essentially at a temperature above 2500 K, preferably above 2900 K, and on at least one segment ( 4 ) of a tunnel-shaped irradiation device ( 1 ) are arranged. A method according to claim 1, characterized in that the Strahlungsflußdichte in the irradiation region in the tunnel longitudinal direction and / or in the tunnel circumferential direction by regulating an emitter, in particular individual and / or groupwise controllable radiation sources, in particular halogen lamps ( 2 ), is adapted to a material to be irradiated. Method according to one of the preceding claims, characterized characterized in that the plastic strand is an irradiation area essentially free of support passes. Method according to one of the preceding claims, characterized characterized in that the plastic strand on a multi-component material, in particular multi-layered, is built. Method according to one of the preceding claims, characterized characterized in that as starting material thermoplastic materials, in particular polymers based on ethylene and / or propylene, such as EPTM, Polyacrylate, polycarbonate, polyamide, polyvinyl chloride used become. Method according to one of the preceding claims, characterized characterized in that the irradiation is carried out so that a porous, in particular open porous, Profile is preserved. Device for producing an irregularly shaped profile, in particular elastic sealing profile made of a crosslinkable and / or polymerizable starting material, wherein a, in particular by extrusion, preformed plastic material strand is thermally bonded to form a profile, characterized in that immediately adjacent to an extrusion ( 5 ) an all-around irradiation device ( 1 ) comprising one or more tubular elongated halogen lamps (n) ( 2 ) having a radiator temperature of over 2500 K, in particular over 2900 K, which have one or more reflectors for focusing and alignment of the radiation and their essential radiation component in the range of the near infrared, in particular in the wavelength range between 0.8 .mu.m and 1.5 μm, and which produces a power density in the range from 300 kW / m ² to 800 kW / m ² on the profile surface, wherein the irradiation device ( 1 ) is formed substantially tunnel-shaped. Apparatus according to claim 7, characterized in that the irradiation device ( 1 ) at least two with radiation sources ( 2 ) equipped segments ( 4 ) having. Device according to claim 7 or 8, characterized in that the halogen lamps ( 2 ) are arranged in groups and aligned substantially parallel to each other axis. Device according to one of claims 7 to 9, characterized that a control device for generating a radiation field with predetermined, in particular constant irradiation parameters, especially a predetermined power density of the radiation is provided. Device according to claim 10, characterized in that that the halogen lamps are arranged in the tunnel longitudinal direction and individually or in groups are controllable. Device according to claim 10, characterized in that that the halogen lamps are arranged perpendicular to the tunnel longitudinal direction and individually or in groups are controllable. Device according to one of claims 10 to 12, characterized that a measuring device for contactless Temperature measurement, in particular a pyrometer, is provided.