DE102010034159A1 - Apparatus, useful to produce molded fiber article (used e.g. as cushioning material), comprises pneumatic fiber supply device associated with heating device having a heat exchanger, and a mold provided with a flow passage hole on one side - Google Patents

Abstract

Apparatus comprises: a pneumatic fiber supply device (2) associated with a heating device (4) having at least one heat exchanger (6) for heating air; and a mold (12) provided with at least one flow passage hole (14) on one side for the transport of air, where the mold on one side of the flow passage hole is disposed with an exhaust valve in which many closable outlet ports are arranged in succession in the feed direction of the fibers. Independent claims are also included for: (1) producing a molded fiber article from a thermally crosslinkable fiber material, comprising transporting fibers into the mold with an air flow, where the mold is divided and moved apart before filling the fiber material; after filling the fiber material, closing the mold, compressing and heating the fiber material with hot air until the fibers are connected to each other, where the fibers in the mold prior to compression are oriented perpendicular to the supplying direction and in the direction of out flowing air; and (2) the molded fiber article of a thermally crosslinkable fiber material, which has been crosslinked in a mold under supply of thermal energy, comprising a top surface that is substantially perpendicular to the principal loading direction and elastic, and a main fiber orientation aligned in the direction of the principal loading direction.

Description

The invention relates to a device and a method for producing a fiber molded part with a pneumatic fiber feeding device with an associated heating device with at least one heat exchanger for heating the heating air and a mold having on at least one side Durchströmlöcher for the transport air. The invention also relates to a fiber molding of a thermally crosslinkable fiber material, which has been crosslinked in a corresponding form by supplying thermal energy, wherein the fiber molding has an upper surface which is aligned perpendicular to the main loading direction of the fiber molding. The device, the method and the fiber molding itself are particularly suitable for the production of three-dimensional upholstery bodies or components, which in addition to a sufficient stability in a main load direction also have a sufficient dimensional stability.

Fiber molded parts can be manufactured in different ways. A method provides that the fibers to be joined together, which consist of a thermally crosslinkable material, are inserted into a mold and heated. Thermally crosslinkable materials are, for example, natural fibers which are coated with a thermoplastic layer. Hemp, flax, sisal or bamboo, for example, can be used as natural fibers. Also, for example, a polyester fiber or a polyester bicomponent fiber can be used. Via a heat source, in particular a Heizluftgebläse, the fiber material is heated until a connection of the fibers has taken place with each other. Subsequently, the finished fiber molding is removed from the mold.

The problem is the production of molded fiber parts, which should have a spring action perpendicular to the main load direction, especially for relatively flat 3D molded parts such as seat cushions or seat backs.

The object of the present invention is to provide an apparatus and a method for producing a fiber molded part and a molded fiber part as such, with which an improved product can be produced as effectively as possible.

According to the invention this object is achieved by a device having the features of the main claim, a method having the features of the independent claim and a molded fiber article according to the independent product claim. Advantageous embodiments and further developments of the invention are described in the subclaims.

The device according to the invention for producing a fiber molded part with a pneumatic supply device with an associated heating device with at least one heat exchanger for heating heating air and a mold having on at least one side Durchströmlöcher for the transport air, provides that the shape of a on the side of Durchströmlöcher arranged outlet control having a plurality of, in the feed direction of the fibers arranged one behind the other, closable outlet openings. The arrangement of the outlet control makes it possible to achieve alignment of the fibers within the mold. The flow-through holes are preferably arranged over the entire length of the mold, ie along the feed direction of the fibers, so that the fibers can be successively piled up. The Durchströmlöcher are arranged such that a diversion of the transport air flow takes place, so that there is a preferably vertical deflection of the transport air to the feed direction. By the closable outlet openings, it is possible to decouple areas in the form of a flow by the outlet openings are closed or remain. Due to the flow path of the transport air, that region of the mold is preferably filled with fibers, which lies in the region of the opened outlet openings. This makes it possible to achieve a controlled filling of the mold and a directional orientation of the fibers within the mold.

In the flow direction of the transport air behind the outlet control, a suction air connection is preferably arranged, via which the transport air can be sucked out of the mold. As a result, an accelerated filling of the mold can be achieved.

The outlet control may include flaps or sliders as outlet outlet closures for easy, quick-to-use and reliable opening or closing of the outlet openings.

The apparatus may include a fan associated with the heat exchanger that fills the mold with fibers via a compressed air port connected to the pressure side of the fan. The suction air connection of the mold can be connected to the suction side of the blower, so that it is possible to guide the transport and heating air in a circulation process, so that the blown air flowing through the molded part with the residual heat again fed to the heat exchanger and to heat the fiber form or The fiber material can be used within the mold.

The mold preferably has flow-through holes on opposite sides, wherein the Saugluftanschlüsse are arranged on opposite sides of the mold. This makes it possible that the mold is filled evenly with a deflected air flow. The heating air can either be performed as the transport air in the form or be performed separately, for example by a suction air connection is connected to the pressure side of a fan, so that a complete flow through the form can be done without deflecting the air flow. By arranging the Durchströmlöcher and the pressure and Saugluftanschlüsse in this way, it is possible to influence the air flow, so that the most uniform and uniform heating of the fiber material can be done. The same applies to a cooling of the mold and the molding after heating.

Sieve plates may be arranged with orifices on or in the mold, in order to retain the fibers of the fiber material in the mold on the one hand, and to allow a flow of the forced air on the other hand.

In order to achieve the fastest possible uniform heating even in the case of complex shapes of a fiber molded article, it is provided that regions with different fiber densities or fiber thicknesses are present in the mold and that the free flow cross section of the throughflow holes is greater in regions of high fiber density or fiber thickness than in FIG Areas of low fiber density or fiber thickness is formed. In other words, very large or very many through-holes are arranged in those regions of the mold which form particularly thick fiber-molded part regions or in which a high compression of the fiber material is present. In areas of the mold in which only a few fibers or fibers with a low compression and thus a low fiber density are present, smaller through-holes or fewer through-holes per unit area may be present. The fiber thickness or fiber molding thickness is to be assessed with regard to the flow direction of the hot air flow. The longer the path to be flowed through in the mold, the greater the fiber thickness.

A variant of the invention provides that the mold is divided and the mold parts are mounted displaceable to each other. By dividing and opening the mold, it is possible that the filling volume can be substantially increased. By opening and filling the fibers, the compression strength of the fibers can be controlled, so that the density of the end product can be influenced among other things by the degree of movement of the molded parts to each other. In addition, there is an influence by the amount of fiber supplied, that is, over the amount of fiber introduced into the mold.

Preferably, the shape is arranged such that the feeding direction of the fibers substantially corresponds to the direction of gravity. In the usual orientation, this means that in the case of flat fiber molded parts, the large-space-like surfaces of the main load directions, for example the surfaces of seat cushions or seat backs, are arranged essentially vertically.

In order to ensure a better allocation of the outlet openings to the closure devices, louvers are arranged between the mold and the outlet control, wherein the louvers separate the outlet openings from each other. The separation of the outlet openings from one another can be carried out completely in terms of flow, that is to say in such a way that there is no fluidic communication between the individual outlet openings, or by a predominant reduction of the overflow from the louvers to other outlet openings. So there must be no hermetic foreclosure between the individual outlet openings. Via the louvers, ventilation ducts or ventilation ducts are provided within the mold, which guide the transport air or the heating air from the molded body through the outlet openings to the suction air connections.

Preferably, a fiber bunker is coupled to the fan, so that the fibers are blown or sucked out of the fiber bunker into the mold via a fiber transport line. For this purpose, it may be provided that the heating air circuit is disconnected from the fan, so that the suction and blowing of the fibers into the mold does not take place with hot air, but over normal ambient air. The decoupling can be done via slide.

In order to enable a faster removal of the finished fiber moldings, a cooling air duct is coupled to the blower, which is arranged separately from the heat exchanger and connected to the mold. By a separate design of the hot air duct and the cooling air duct, it is possible, for example by moving a slider or an air guide flap, instead of passing hot air cooling air through the mold, so that a rapid cooling of the fiber molding can be done. As a result, short cycle times can be achieved, which increases the overall productivity of the plant. The mold may have separate, closable outflow openings for the cooling air, which are independent of the throughflow openings for the hot air, so that it is possible that cooling air can be blown into the mold both through the pressure-side and through the suction-side throughflow openings for the hot air. The outflow openings are then opened separately, so that the cooling air flows into the environment or is discharged, so that no circuit for the Cooling air is present. Otherwise, the forced air can be circulated to minimize energy losses and not consume the resource air unnecessarily.

Preferably, the mold is formed divided along the feeding direction of the fibers. Especially in the production of large and flat parts, it is provided in the prior art that they are laid flat in molds, to then heat them by a hot air oven. In particular, in the case of seat covers or mattresses, no good result could be achieved because the production times were too long and the fibers were not oriented in the correct direction. The hot air has taken the path of least resistance, so that the fibers have not been melted evenly. As a result, thin portions of the mold were heated faster than the thicker portions of the fiber molding, resulting in uneven bonding of the fibers. However, when the mold is longitudinally split in the feeding direction of the fibers, it is possible to orient the fibers in a standing orientation of the finished fiber molding. A standing fiber can withstand a compressive load better than a lying fiber and behaves like a brush, providing improved elasticity and some memory effect.

The inventive method for producing a fiber molding of a thermally crosslinkable fiber material in which the fibers are transported in a mold via an air flow, provides that the mold is formed divided and is moved apart before filling, after filling the fiber material by closing compressed the mold and then the fiber material is heated by hot air until the fibers have joined together, wherein the fibers are oriented in the mold prior to compression perpendicular to the feed direction and in the direction of the outgoing air from the mold. By opening the mold, the filling volume can be substantially increased, a mechanical compression by closing the mold allows a high degree of compression, which is much greater than that which can be achieved by a suction fan in an economically acceptable form.

The hot air is preferably passed through the mold and may be circulated through the blower, the heat exchanger and the mold.

It is further provided that the form in the feed direction of the fibers are assigned to one another arranged louvers, the closure means and the closure means for filling the mold from the feed opening for the fibers away begin to be opened in the direction of the feed opening. By opening the closure device furthest from the feed opening, the mold slowly begins to fill up without congestion or clogging. Advantageously, the mold is arranged upright, so that first the lowermost closure device is opened, then the closing devices located closer to the feed opening are wholly or partially opened in order to completely fill the mold with the fiber material. Advantageously, the closure devices will be opened one after the other, wherein after opening during the filling process also closing devices can be closed again in order to be able to control the filling process and influence the orientation and the filling density. The controlled opening and the controlled closing of the closure means different density zones and thus different hardness zones of the fiber molding can be realized.

After connecting the fibers together by supplying thermal energy, in particular hot air, the mold parts of the mold can be moved to the final dimension of the fiber molded part and held there for cooling. The molding of the molded parts to the final dimension is preferably carried out in the heated state of the fibers, in which a postformability or deformability of the fibers is still possible.

The fiber molding of a thermally crosslinkable fiber material according to the invention, which has been crosslinked in a mold with supply of thermal energy, wherein the fiber molding has an upper surface which is aligned perpendicular to the main loading direction of the fiber molding, provides that the fiber molding is formed elastically in the direction of the main load direction and a fiber main orientation aligned in the direction of the main load direction. This makes it possible to provide an increased dimensional stability with simultaneous elasticity for the fiber molding, so that it is particularly well suited for use in upholstered furniture and vehicle seats.

Preferably, at least 50% of the fibers are oriented longitudinally to the main loading direction, ie perpendicular to the upper side of the surface of a flat fiber molded part.

Hereinafter, an embodiment of the invention will be explained in more detail with reference to the accompanying figures. Show it:

1 a basic structure of the device in sectional view; such as

2 a sectional view of the molding.

In the 1 is an apparatus for producing a fiber molding 10 shown in a schematic sectional view. The device has a fiber feed device 2 in the form of a filling nozzle, which has a heating device and a heat exchanger 6 assigned. In the filler of the fiber feeder 2 be in the form 12 provided fibers and pneumatically into the mold 12 through the schematic in the area of the parting line of the mold 12 indicated insertion opening 8th introduced. Form 12 consists of two moldings 121 . 122 , which are arranged on tool holders. There may also be more than two moldings. The left molding 121 and the associated tool holder are slidable on a frame 40 on a sledge 30 stored. About the sled 30 For example, a compressive force P may be applied to the left molding 121 towards the right molding 122 to relocate. It is also possible, the moldings 121 . 122 move away from each other to increase the volume of the cavity within the mold 12 so that the fiber material can be introduced more easily. Subsequently, by moving the carriage 30 towards the fixed part of the mold 12 a mechanical compression can be achieved.

Within the form 12 and the moldings 121 . 122 are flow holes 14 arranged, which are only schematically indicated. The flow holes 14 extend over the entire height of the mold 12 and allow outflow of the transport air or the heating air laterally from the mold 12 , In the shape 12 or at the shape 12 can perforated sheets 16 be arranged to prevent fiber material from the mold 12 is discharged.

Of the 1 It can be seen that the longitudinal extent of the cavity of the mold 12 essentially follows the direction of gravity, so that the shape 12 is aligned. Accordingly, the feeding direction S of both the fibers and the conveying air is perpendicular from above along the direction of gravity. Laterally from the moldings 121 . 122 go louvers 28 off, which is directly attached to the mold 12 connect. The louvers 28 form shafts or channels in fluid communication with the passage openings 14 stand. Again 1 it can be seen, are the louvers 28 formed in the form of sheets or partitions. The through the louvers 28 formed shafts or channels are substantially separated from each other, so that no transport air or heating air from the respective channels associated passage openings 14 can flow through other channels. The channels open into outlet openings 22 passing through closure devices 24 can be closed in the form of flaps or sliders. The outlet openings 22 open into suction air connections 26 in the illustrated embodiment, on both sides of the longitudinal extension of the mold 12 and are arranged on both sides of the parting line. As a result, the transport air stream, which is initially oriented from top to bottom, branches off into two suction air streams which are discharged laterally and essentially at right angles to the feed direction of the fibers and thus substantially horizontally.

The suction air connections 26 can be arranged on a common fan, the pressure side with the fiber feed device 2 can be coupled, so that a circulation of the working air is possible.

In the device is an outlet control 20 for each side of the locking devices 24 provided so that the opposing closure devices 24 can be opened and closed individually.

In the illustrated embodiment, the lower closure means are open, so that the areas of the lower two louvers 28 be separated, can be flowed through by the transport air or the heating air. Fibers from the fiber bunker are then guided vertically downwards over the transport air and stacked on top of each other, as the fibers are sucked down. Due to the deflection of the flow by 90 ° in opposite directions, the fibers align with their longitudinal extent substantially parallel to the flow direction in order to oppose the lowest possible air resistance of the suction flow. This results in a stacking and orientation of the air fibers such that they are perpendicular to the parting plane of the two moldings 121 . 122 are oriented. A majority of the fibers is thus substantially perpendicular to the parting plane and thus substantially perpendicular to the large-area surfaces of the fiber molding 10 ,

For further loading successively more closure devices 24 open, leaving from the most distant louver 28 up to the louver 28 , the insertion opening 8th closest is the locking devices 24 be opened one after the other. There is also the possibility of individual closure devices 24 to close in the course of filling in order to realize different density profile within the fiber molding component can.

After filling the mold 12 it is possible and provided through the insertion opening 8th also hot air through the mold 12 to lead. Alternatively, a suction air connection 26 be connected to a hot air blower on the pressure side, so that a substantially horizontal flow of hot air through the precompressed fiber molding can be passed through to activate the adhesive or to effect a cohesive or cohesive networking of the fibers. Such an air guide has the advantage that a uniform flow through the mold with the hot air is realized, at the same time a uniform connection of the fibers is ensured with each other. The hot air flows through the mold 12 in a very short way, so that a uniform heating of the fibers and the fiber molding is achieved very quickly.

In the 2 is a schematic sectional view of a fiber molding 10 shown in the form of a seat upholstery. The fiber molding 10 is designed as a three-dimensional, flat component and has a surface 51 which is oriented substantially perpendicular to the main loading direction H. Due to the perpendicular to the surface 51 and fiber orientation oriented substantially parallel to the main loading direction H is the fiber molding 10 elastic and also has a high recovery factor, so that a high dimensional stability is guaranteed.

The fiber molding 10 consists essentially of a thermally crosslinkable fiber material 55 which has been introduced into a mold and oriented so that the fiber material 55 substantially parallel to the main loading direction H and thus substantially perpendicular to the top 51 of the fiber molding 10 is oriented. Not all fibers of the fiber material 55 are oriented parallel to each other, but it comes in a manufactured by thermal crosslinking fiber molding 10 , which is pressed under the supply of pressure and heat in a mold, to different fiber orientations, which are also wanted, because by the different orientations, the overall stability, overall strength and dimensional stability of the fiber molding 10 is guaranteed. However, targeted elasticity in the fiber molding 10 to provide the elasticities substantially in the main loading direction H, is a majority of the fiber materials 55 oriented so that the longitudinal extent of the fibers is oriented substantially parallel to the main loading direction H. Density differences can be different strengths in individual areas of the fiber molding 10 be achieved. Also by different orientations in individual areas of the fiber component 10 it is possible to achieve different strengths or elasticities.

The fiber moldings 10 For example, they can be used as upholstery materials, interior trim parts for motor vehicles, floor coverings, insulation materials or supports for chairs or seats.

Claims (15)

Device for producing a fiber molding ( 10 ) with a pneumatic fiber feed device ( 2 ) with an associated heating device ( 4 ) with at least one heat exchanger ( 6 ) for heating hot air and a mold ( 12 ), which at at least one side Durchströmlöcher ( 14 ) for the transport air, characterized in that the shape ( 12 ) one on the side of the flow holes ( 14 ) arranged outlet control ( 20 ), the plurality, in the feed direction of the fibers successively arranged, closable outlet openings ( 22 ) having. Apparatus according to claim 1, characterized in that in the flow direction of the transport air behind the outlet control ( 20 ) a suction air connection ( 26 ) is arranged. Device according to claim 1 or 2, characterized in that the outlet control ( 20 ) Flaps or slides as closure devices ( 24 ) for the outlet openings ( 22 ) having Device according to one of the preceding claims, characterized in that in the form ( 12 ) Regions for different fiber densities or fiber thicknesses are present and the free flow cross-section of the flow-through holes ( 14 ) is formed in areas of high fiber density or fiber thickness greater than in areas of low fiber density or fiber thickness. Device according to one of the preceding claims, characterized in that the shape ( 12 ) and the mold parts ( 121 . 122 ) are mounted displaceable to each other. Device according to one of the preceding claims, characterized in that the shape ( 12 ) is arranged such that the feeding direction (S) of the fibers substantially corresponds to the direction of gravity. Device according to one of the preceding claims, characterized in that air guiding devices ( 28 ) between the form ( 12 ) and the outlet control ( 20 ) are arranged, which the outlet openings ( 22 ) separate each other. Device according to one of the preceding claims, characterized in that the shape ( 12 ) along the feed direction (S) of the fibers is formed divided. Process for the production of a fiber molded part from a thermally crosslinkable fiber material, in which the fibers are conveyed into a throughflow ( 14 ) provided form ( 12 ) are transported via an air stream, wherein the shape ( 12 ) is divided and is moved apart before filling, after filling the fiber material by closing the mold ( 12 ) and then the fibrous material is heated by hot air until the fibers have bonded together, the fibers being in the form ( 12 ) before compression perpendicular to the feed direction (S) and in the direction of the mold ( 12 ) are directed outward air. Method according to claim 9, characterized in that the shape ( 12 ) in the feed direction (S) of the fibers one behind the other arranged louvers ( 28 ), the closure devices ( 24 ) and the closure devices ( 24 ) for filling the mold ( 12 ) from the feed opening ( 8th ) for the fibers, starting in the direction of the feed opening ( 8th ). Method according to claim 10, characterized in that the closure devices ( 24 ) are opened one after the other. Method according to claim 10 or 11, characterized in that closure devices ( 24 ) are closed again after opening during the filling process. Method according to one of claims 9 to 12, characterized in that after joining the fibers together, the molded parts ( 121 . 122 ) to the final size of the fiber molding ( 10 ) and kept there to cool. Fiber molding of a thermally crosslinkable fiber material ( 55 ), which was crosslinked in a mold with the supply of thermal energy, wherein the fiber molded part ( 10 ) an upper side ( 51 ) substantially perpendicular to the main loading direction (H) of the fiber molding ( 10 ), the fiber molding ( 10 ) in the direction of the main loading direction (H) is elastic and has a fiber main orientation, which is aligned in the direction of the main load direction (H). Fiber molding according to claim 14, characterized in that at least 50% of the fibers are oriented longitudinally to the main loading direction (H).

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