DE6610408U - FLEXIBLE PLASTIC PROFILE STRIP. - Google Patents

Description

E 27 357/39 a Gbm

0.z. 1210/01771

Flexible plastic profile strip

The invention relates to a flexible plastic profile strip.

Flexible profile strips made of plastic, especially elastic Plastic, have a wide range of applications. They are almost indispensable for sealing doors and windows etc. in vehicles and airplanes, in cooling systems and similar facilities.

So far, mainly flexible profile strips made of rubber have been used. However, rubber has some properties which make it appear unsuitable for these purposes, namely the low resistance to cold - it then becomes brittle and brittle - and the sensitivity to certain chemicals, such as oil, gasoline, etc., which cause it to swell, and the relatively rapid aging, especially in the presence of ozone.

Plastics are known which are superior to rubber in many respects and in particular also at low temperatures retain their good flexibility. Such a plastic is, for example, polyurethane. Nevertheless, profile strips are made Plastic is rarely used because the production costs for rubber are much lower.

The object of the invention is to create a profile strip made of plastic that has all the superior properties of the plastic for the main intended purposes - for Example of polyurethane - can come into its own and still allow great savings in terms of manufacturing costs.

O.Z. 1210/01771

The solution to this task led to a flexible plastic profile strip, which is characterized according to the invention by hose material of the composition: polyaddition products from polyesters, polyester amides, polyethers, polycaprolactone esters with terminal free hydroxyl groups. Diisocyanates and chain extenders as well as by thermal foamable filling plastic of the same composition.

These profile strips are initially not noticeable from the outside, that they are made of two different materials. If you choose a material for the filling plastic that is actually harder is than the hose material, but has a similar mechanical strength in the foamed state, so is the profile material also with regard to its mechanical properties - Flexibility, temperature resistance etc. - one Full profile equivalent., The only (advantageous) difference is the reduced specific weight. There but the costs are essentially determined by the costs of the starting material, they will be in the corresponding May lowered. In addition, waste material can be used for the filler plastic, for example in color for Full profiles would be unsuitable.

Further advantages of the plastic profile strip according to the invention are given by the fact that thermoplastically processable plastics can also be welded later during use.

A further reduction in costs can be achieved by using lower quality starting materials for the filler plastic are usable as for the tube material, depending on the intended use: Since the filling plastic with the external environment does not come into contact because it is completely covered by the homogeneous hose material often lower requirements for its chemical resistance

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to be asked. Very good results can be achieved, for example, by using polyurethane as the hose material and a polyurethane-polyvinyl chloride mixture is processed as the foamable filler plastic, the latter being correct adjusted porosity the profile material an elasticity which is about as large as when the gesarate Solid polyurethane bar.

The calibration of the profile can be done by any known method; however, it is desirable that the material is stretched as it is withdrawn from the extruder.

The plastic profile strip obtained has a tightly pored, uniformly foamed filling when the extrusion temperature is reached of the hose material and the foaming temperature of the filling plastic can be selected to be of the same order of magnitude.

Suitable hose materials are: Polyaddition products made of

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with terminal free hydroxyl groups, diisocyanates and chain extenders; as Füllkunststoff, the same materials may be used where appropriate with addition of polyvinyl chloride, wherein react as a foaming agent, organic compounds which u in a temperature range between 85. 250 ⁰ C with evolution of gas, preferably Azodicarbonaraid is used, are suitable.

In the following a for the production of the plastic profile strip suitable device will be described with reference to the accompanying drawing, many schematically a Shows section through an extrusion tool.

The inlet 10 for the thermoplastically processable tubing material is with a (not shown) common tendon

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O.Z. 1210/01771

press or extrusion press connected; the material becomes continuous supplied at a temperature at which it is plastically deformable. Via a line 12, the inlet is connected to a Annular channel i4 connected, which opens into an annular nozzle 16. Outside of and in front of the ring nozzle there is a conventional pulling and calibrating device, both of which are not shown.

Approximately opposite the inlet 10 is a second inlet 18 for the foamable filler plastic material, the inlet from a second, for the processing of foamable plastic designed extruder is fed, also continuously at such a temperature that the Foaming agent gas evolved. However, the material must not relax yet, but should only after it has entered the Foam the hose. For this reason, the pressure must be maintained close to the ring nozzle 16, and therefore have the Lines 20 from the inlet l8 to the distribution channel 22 and this itself each have a flow cross-section which is larger than that Cross section at the passage opening 24 through which the now foaming material is pressed into the plastic tube. the The temperature in this area of the tool should be set so that the filling plastic foams completely, but that Tubing material already has a decreasing plasticity, so that it is pulled off well, but also stretched and can be calibrated. A heating device surrounding the lower part 26 of the tool can be used to stabilize this temperature (not shown) may be provided, which is preferably controllable.

The tool shown has a central punch 28 which extends into the passage opening, so that this is annular. As a result, a cavity is created in the interior of the profile, which, however, is filled with the filling plastic will. However, by raising or lowering the punch

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ο.ζ. 1210/01771

the cross-section of the passage opening can be varied. Furthermore, the punch can in turn be pierced in order to jointly insert a core with the filling plastic into the hose to give the profile strips a greater rigidity to give against buckling stress while at the same time maintaining almost the same compressibility as without Soul: A spring steel wire, for example, can be used as the material for this soul.

The external dimensions (cross-sectional dimensions) of the hose are determined by the interaction of the pull-off and calibration device with a cross-sectional constriction just before the mouth of the annular nozzle to the outside.

The expressions "ring nozzle", "ring-shaped" selected for explanation are by no means intended to indicate circular formations alone; of course you can with accordingly adapted nozzle and passage opening forines also extrude oval, rectangular etc. profile cross-sections.

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6610488 it 1.74

Claims (2)

-6- CZ. 1210/01771 protection claims 1. Flexible plastic profile strip, characterized by hose material of the composition: polyadducts of polyesters, polyester amides, polyethers, polycaprolactone esters with terminal free hydroxyl groups, diisocyanates and chain extensions, as well as thermally foamable plastic fillers of the same composition. 2. Flexible plastic profile strip according to claim 1, characterized ge flag ze ic nne t that a core made of homogeneous material is embedded in the filling plastic. 651040810 i. 74