JPH02229012A - Foam member, its structural unit, and device and manufacture thereof - Google Patents

Abstract

PURPOSE: To prevent a foamed member from being collapsed by inserting reinforcing mats into an open mold to be disposed adjacent to an entangled strip and to open a gate of the mold, charging a foamed component in the mold, and closing to hold the moild at least to an end of a foaming step. CONSTITUTION: A strip 11 is formed of a continuous tangle of many threads 12, 13, 14. The thread is, for example, a thermosetting or thermoplastic synthetic resin monofilament with smooth surface and a thickness of 0.6 mm. A component to be foamed is injection charged from a gate 38, but glass fiber mats 43, 47 remain as they are, and are, accordingly, disposed at a maximum distance from a neutral zone passing a dividing line 36. That is, a main operation of the strip 11 is to particularly hold the mats 43, 47 at the time of injecting. The strip 11 has, on one hand, excellent openability and, on the other hand, a rigidity sufficient to hold themselves at extremely many positions such as round heads 27, 28 in a cavity 39 and its lateral and longitudinal sections or the like, and hence melted liquid to be foamed can be distributed into the cavity 39 without being disturbed in fact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a foamed member according to the preamble of the main claim, namely a small-cell foamed member having a light weight and a certain stiffness, the member having at least 3 The invention relates to a foam member that is at least the dimension of the recessed area in one of the two coordinate directions. "Elements" are understood to mean elements in the form of rods, ribs, timbers, tubes, plates.

The invention also relates to a structural unit using the foamed member, an apparatus for manufacturing the foamed member, and a method for manufacturing the foamed member.

[Prior Art] The above-mentioned foam member has the advantage that it can be manufactured as a mass-produced product, is lightweight, yet has a volume, can be easily processed in subsequent steps, and has a high pressure resistance. It is tensile resistant even at the boundary, and has thermal or soundproofing properties.

[Problems to be Solved by the Invention] However, the above-mentioned foam member has disadvantages in that it can be broken relatively easily, crumbles into tatters, and has low bending rigidity.

The main object of the invention is to provide a foam component which maintains the positive properties of components of this kind mentioned at the outset, but which has a substantially improved retention within the foam. In doing so, it is necessary to be able to maintain traditional manufacturing techniques. This means that there is no need to change the chemical composition forming the foamed volume, that work can be continued, for example with the well-known two-part mold, that no special provisions are required for the subsequent processing of the parts, and that no special requirements for the manufacturing operator are required. No retraining is required, no changes to the mechanical equipment are required, no special calculations are required, and no life losses appear in other ways.

Another object of the invention is to provide a structural unit of the foamed member.

Still another object of the invention is to provide an apparatus and method for manufacturing the above-mentioned foamed member.

[Means for Solving the Problems] A foamed member according to the invention that achieves the above main object has at least one tangled body strip having a very open mesh inside the foam, and the volume of the threads of the tangled body strip is equal to that of the tangled body strip. the foam contacts the threads of the tangle strip over at least a majority of the thread surface, the net volume occupied by the tangle strip corresponds to at least a majority of the foam, and the tangle strip The textured yarn section is characterized in that it is neither substantially rigid nor substantially unstable in its longitudinal direction with respect to the forces generated during foaming.

The structural unit according to the invention is also characterized in that a layer is formed around the component, which is integrally connected to the component.

Further, in the foam member manufacturing apparatus according to the invention, a tangle strip with a reinforcing mat placed on one side is inserted into a two-split mold, and a gate of the mold is placed in front of the tangled strip at a location where there is no reinforcing mat. It is characterized by the presence of

Further, the method of manufacturing a foamed member according to the invention includes inserting a tangled body strip into an open mold of a two-part mold, at least substantially filling the mold with the tangled body strip, and applying a reinforcing mat to the open mold with the tangled body strip. The foam-forming component is inserted into the mold so that it is adjacent to the gate of the mold and the gate of the mold is open, and the mold is kept closed at least until the end of the foaming process.

[Function] Entanglement strips in foam components constructed as described above are currently already found on the market as mass-produced products, albeit for other fields of use.

It provides extremely strong reinforcement of the component and prevents it from splintering. The foam still forms the main body.

From the appearance, the member according to the present invention is the same as the conventional member and appears to have the same properties such as paintability and workability. Nevertheless, the distance between each thread and the parts directly surrounding it is small. If the thread section has sufficient stiffness, the entangled strip will not be blown away into the mold even in injection molding processes. On the other hand, however, the threads are sufficiently unstable that they can be tensioned during the final stage of the foaming process and do not shred the foam during this stage. Although the contributions of the individual thread sections are small, the large number of thread sections adds up to a significant overall effect.

With the structural unit according to the invention, the possibility of color printing is improved, the softness is increased and damage is no longer possible.

With the device for manufacturing foamed parts according to the invention, the parts can be manufactured in a single mold, optionally together with attachment means. The device does not require any changes to the conventional structure.

The method for producing foamed parts according to the invention provides a particularly simple method for producing the parts according to the invention. This eliminates the need to hold the reinforcing mat in any special way. If the function of the tangle strip is not emphasized and only the retention function for the reinforcing mat(s) is assigned to it, the tangle strip may be changed during the foaming process or at its final stage, for example to completely or partially release it. There's no harm in that either.

[Example] The present invention will be explained below based on preferred embodiments.

As shown in FIG. 1, the strip 11 includes a number of threads 12,
13. It consists of 14 entangled bodies. The thread is, for example, a thermosetting or thermoplastic synthetic resin monofilament with a smooth surface and a thickness of 0.6 mm. The rigidity of the strip 11 is such that it can be easily bent in the longitudinal direction.
It is gender. The strip 11 can be manually compressed laterally to its original height of about 273 cm, but will return to its initial state again under the force of the spring. The threads 12, 13, 1, 4... form numerous meshes 16.

The volume of the threads 12, 13, 14... is significantly smaller than the volume of the strip 11. The threads 12, 13, 14... are joined at the contact points at various stages of fusion. In the complete fusion section 17 shown in FIG. 4, the yarn 12.1-3 is
The whole is integrated. At the fused portion 18, the bent portion 19
is fusion welded to thread 12 in the elbow area. Between the fused portion 17 and the fused portion 18, the thread 12 has a thread portion 21. The thread 13 also has such a thread section between the fusion section 17 and the point of contact/intersection of another thread. The same applies to yarn ] 4 and other yarns. Fusions can be formed in which the threads become adjacent in the contact direction, where three or four threads intersect each other in a more or less strongly fused manner. Thread 1
2. ↑3, 14..., the mesh 16... and the fused parts 17, 18 are arranged at random (statis), if not completely by chance.
ti, 5ch). In any case, FIG. 1 shows the degree of opening of the mesh 16 in this direction, and FIGS. 2 and 3 show it in another direction.

Threads 12, 13, 14..., mesh 16..., and fused portion 17.1
8 is evenly distributed overall, even if this is not the case in individual cases. The free length of thread portion] 2 is one area and is also randomly distributed. According to FIG. 2, a dense portion 22 appears in the yarn 1.2.13.degree. 14 in this figure, and becomes denser toward the top and bottom. As can already be seen in the view of FIG. 2, the strip 11 has downwardly directed conical ridges 23, between which there is an air gap 24. In the 45 DEG view of FIG. 3, these conical elevations 23 are directly one behind the other.

That is, on the lower surface of the strip 11, the conical ridges 23 are arranged not at random but in a grid pattern, so that the gaps 24 and 26 are visible, as when passing a propped vineyard. You will end up doing something like this.

According to FIG. 2.3, the strip 11 has randomly distributed leading edges 27 on its two sides and leading edges 28 on its lower side.

The tops are not all at the same height. However, an average plane 29 can be drawn at the top 27 and an average plane 31 can be drawn at the top 28. These planes 29, 31 are parallel when it comes to the product to be manufactured, but they may diverge or form two- or three-dimensional planes when producing other products. Plane 29 if it concerns the production of spoilers.
．． 31 is approximately 1.5 m apart.

The strip 11 is available on the market as a finished product and is sold under the name Enkamat 7020/1 by Industrial Systems BV Belpaave-Quarnchem, The Netherlands.

Objects manufactured in other ways, such as those with tangled bodies similar to plastic pot scrapers, can also be used in strips 1.
It can be used as a first class object.

According to FIGS. 5 and 6, a schematically illustrated injection mold 3
2 has a lower mold 33 and an upper mold 34 separated by a dividing line 36. Gate nozzle 37 with gate 38 on the left side in FIG.
is the provision. A cavity 39 is provided in the injection mold 32 to match the shape of the product to be manufactured. The upper mold 33 has a sealed through hole 41 for a threaded bolt 42 in a manner not shown. Cut glass fiber mat 4 on the bottom of the lower mold 33
There are 3. Its left-hand region is bent upwards by a width 44 that does not reach the gate 38. On the second side of the glass fiber mat 43 is a strip 11, which is only shown schematically here. In the center of the strip 11 is a locking head 46 of a screw bolt 42. The second glass fiber mat 47 placed on the top surface of the strip 11 contacts only the inner lower wall of the upper mold 34 and is pressed there;
That is, the height of the strip 11 in the untensioned state is somewhat greater than in the closed state of the injection mold 32, and the cavity 39 is at the height of the glass fiber mat 43.
1 and the height of the glass fiber mat 47. Holes 48 are provided in the fiberglass mat 47 in alignment with the through holes 41, through which threaded bolts 42 are passed. On the left, the glass fiber mat 47 is bent downwards by a width 49, but its end lies in front of the gate 38.

As FIG. 5 shows, the leading edge 27.28 (here exaggerated) is pushed (statistically) into the glass fiber mat 43.47. The components to be foamed are injected through the gate 38, and the glass fiber mat 43.
47 remains the same and is therefore at the maximum distance from the neutral zone passing through the dividing line 36 in the figure. The main function of the strip 11 is thus to hold the glass fiber mat 43, 47 firmly, especially during pouring.

The strip 11 has excellent openness on the one hand;
On the other hand, since it has sufficient rigidity to support itself in many places within the cavity 39, such as the leading edge 27, 28 and its longitudinal and cross sections, the foamed melt can flow inside the cavity 39 virtually unhindered. can be distributed in As a result, prestressing occurs statistically during the foaming process. Many thread sections 21 are in fact located more or less perpendicular to the expansion movement of the foaming volume. This foam becomes increasingly viscous towards the end of the foaming process, becomes pasty and entrains the thread section 21, which becomes more elongated. Even if the contribution provided by each individual thread section 21 is small in itself, the overall contribution is still significant because of the large number of thread sections. Tangle body strip 11. ．． 71
The net volume occupied by the foam 6 injected as described above is
9 (see FIG. 8).

As FIG. 6 shows, the framework 44,49 is provided with a cutout 51,52 around the gate 38, so that the gate 38 never sees the glass fiber mat 27 in front of it. In the left and right areas 53 and 54, the width part (
Bahn) 44.49 may touch or even overlap.

However, as shown on the right side of FIG. Such constant width sections 44,49 can also be omitted since little or no stiffness is essential. When the plate 56 manufactured in the mold shown in FIGS. 5 and 6 is cut, the cut surface has a randomly distributed cross section 58 of threads 12.13° 14, a randomly formed cross section 58, a warped portion 59, and a longitudinal cross section. 6
1 appears. This plate 56 is inserted into a second injection mold 62 of known shape as shown in FIG. This mold has a dividing surface 63, a sealed through hole 64 for the threaded bolt 42, and a gate nozzle 66. Since the plate 56 has a gap 67 which is smaller in size than the cavity 68 of the injection mold 62, the plate 56 may be coated with further layers, such as softer foam material, other colored substances, printable materials, etc. It can be coated with a substance or the like. Vehicle wind guide device Qinleitv
Orrichtung fur Fahrzeuge)
In this case, the layer is preferably made of hard foam rubber. With these layers, the foam 69 can be attached to the glass fiber mat 43.
．． Both 47 and 47 are coated.

Experiments have shown that the strip 11 does not have to be fixed in any way between the mold halves 33,34. Rather, it is sufficient here that there still be a considerable distance to the underside of the upper die 34. The glass fiber mat 47 can simply be placed on the strip 11, in which case the leading edges 27, 28 will naturally not dig in. Nevertheless, contrary to all expectations, in this case the glass fiber mat 43.47
They are not blown away into corners and form flocks there. Rather, this arrangement remains within the cavity 39.

Through the foaming process the glass fiber mat 47 can (as it turns out) be raised above half of its original height. The only condition is that the gate 38 be free from the area of the glass fiber mat.

The cylindrical strip 71 obtained according to FIG. 9 is again made of a number of threads, is also open, has sufficient but not excessively high stiffness, and has a glass fiber pine door 2 around it. Vacant location 7 where the injection jet 73 flows in
4 is a provision. Naturally, one mold surrounds the whole thing.

It is clear that other articles such as boat skins, tubing, T-beams, U-beams, channel formations, etc. can also be produced in this way.

The foam 69 is made of strips 1.171 of threads 1.2.13.
14... over at least a large part of the yarn surface 76 (see FIG. 7). If emphasis is not placed on the reinforcing properties provided by the strip 1171 by appropriate material selection, it may be advantageous for the yarn surface to have a baking area 76 between it and the foam 69, for example as shown for the yarn 12 in FIG. be. Depending on the selection of method and material parameters such as fusing characteristics, chemical melting capabilities, temperature, etc., baking region 76 can be more or less intensive.

[Advantageous Effects of the Invention] According to claim 1, the member is reinforced very strongly by the tangled body strip and is prevented from breaking. Judging from the appearance, the members are the same as conventional members, and their properties such as repaintability and workability appear to be the same. If the thread section has sufficient stiffness, the entangled strip will not be blown away into the mold even in injection molding processes. On the other hand, the threads are sufficiently unstable that they can be taut during the final stage of the foaming process and do not shred the foam during this stage.

According to claim 2, the tangling body strip is positioned itself within the entire mold, in which case only the tips of the conical elevations touch the part of the part that will later become the outer skin.

According to claim 3, the weight is reduced. Furthermore, unlike metal-based threads, this thread does not corrode. Although it is lightweight, it can also be made thicker, so it does not cut into the foam as much. Furthermore, in terms of material, the synthetic resin of the thread is compatible with the synthetic resin of the foam. Monofilament yarn is particularly good in light of its various problem characteristics.

According to claim 4, the thread is better fixed in the foam.

According to claim 5, the retention of the tangle strip itself is improved, so that it is substantially oriented in the member.

According to claim 6, it is possible to obtain an excellent opening property of the entangled body strip, and on the other hand, it is possible to satisfactorily pour the various components into the mold used. On the other hand, the distances between the points of intersection are relatively small, and the points of intersection, due to their crossing characteristics, form small locking points.

Claim 7 has proven its value particularly in the case of small-cell rigid foams.

According to claim 8, the tangle body strip can be manually reshaped into the correct shape.

According to claim 9, it is possible to manufacture components whose dimensions are as small as the mouth area.

According to claim TO, the starting points of each prefecture can be arranged particularly firmly.

According to claim 1-1, the production of the tangled body strip is simplified, while it can nevertheless be produced with sufficient tangles and a good statistical distribution of the threads in the volume.

According to claim 12, the member is used in the vehicle manufacturing field, such as a vehicle spoiler, a pull-in prevention plate for a truck, a surfboard,
It is especially suitable for the outer panels of boats, etc.

According to claims 1 to 3, a member that is particularly hardly affected by heat can be obtained.

According to claim 14, the component can still be bent subsequently, provided that the foam is also thermoplastic.

According to claim 15, in this case the tangle body strip is such that the reinforcing mat is forced far away from the central axis.
The stiffness of the component and the load-bearing capacity of its skin are further increased substantially.

According to claim 16, the characteristics can be obtained with high accuracy at low cost. However, if price is not an issue, expensive reinforcing mats, such as carbon fiber mats, can be used.

According to claim 17, the member has an equal bending stiffness in both directions.

The invention is particularly suited to the dimensions defined in claim 18.

The plate has the property that it is thin compared to its width and its length is at least comparable to its width.

According to claim ]-9, the attachment means is fixed very well,
The shear forces generated can be well absorbed in the root region.

This provides a substantially better result than simply fixing the attachment means within the foam.

According to claim 20, these advantages are again enhanced and it is possible now possibly to make the attachment means thinner.

According to claim 21, the member can be easily connected to another structural group.

According to claim 22, a structural unit is obtained in which the possibility of color printing is improved, the softness is increased and damage is no longer possible.

According to claim 23, the component can be further processed, for example as an air guide device for a motor vehicle, and all that is required here is to work with two molds.

The invention is particularly suitable for the subject matter defined in claim 24.

According to claim 25, the foamed part can be produced in a single mold, optionally together with the attachment means. The device does not require any changes to the conventional structure.

According to the feature of claim 26, it is possible to prevent the jet of the injected melt mixture from colliding with the reinforcing mat at all or hardly.

According to claim 27, a particularly simple method for producing foamed parts is obtained. This eliminates the need to hold the reinforcing mat in any special way.

[Brief explanation of the drawing]

Figure 1 is a plan view of a full-size tangled body strip. Figure 2 is a view of Figure 1 seen in the two directions of the arrows. Figure 3 is an actual size view of Figure 1 viewed in the three directions of the arrows. FIG. 4 is a cutaway partial view in which the thread portion and the intersection point are significantly enlarged. Figure 5 is a cross-sectional schematic diagram of the two-split type. FIG. 6 is a view seen in the direction of arrow 6 in FIG. 5. FIG. 7 is a cross-sectional cutaway with a significantly enlarged baking area between the thread and the foam volume. Figure 8 is a cross-sectional view of a two-split mold for continued processing of the product taken out from the first mold. FIG. 9 is a schematic cross-sectional view showing a tangled body of threads around which a reinforcing mat is wound for manufacturing a rod-shaped member. 11, 71... Entanglement body strip 12, 13. 14... Yarn 16... Mesh 17, 18... Intersection 21... Thread portion 22... Central region 23... Conical raised portion 32... Mold 33... Upper mold (two-piece mold) 34... Lower mold (two-piece mold) 38...Gate 42...Threaded bolt (attachment means) 43, 72...Glass fiber mat (reinforced mat) 46...Locking head (root area) 69...Foam 76...Year surface

Claims (27)

[Claims] (1) In a small-cell foam member of light weight and specific stiffness, the member having dimensions in the at least mm range in one of at least three coordinate directions, a mesh 16 that is very open in the foam body 69; , the volume of the threads 12, 13, 14, ... of the tangled body strip 11 is sufficiently smaller than the volume of the tangled body strip 11, and the foam 6
9 is the thread 12, 13, 1 of the entangled body strip 11, 71
4,... over at least a large part of the yarn surface 76, the net volume occupied by the tangled body strips 11, 71 corresponds to at least a large part of the foam 69, and is organized into tangled body strips 11, 71. A foamed member characterized in that the filament portion 21 is neither substantially rigid nor substantially unstable in its longitudinal direction with respect to the forces generated during foaming. (2) At least one side of the tangled body strips 11, 71 has a conical ridge 23 which stands out statistically from the central area 22 of the net volume of the tangled body strips 11, 71. 1 foam member. (3) The foamed member according to claim 1, wherein the threads 12, 13, 14... are made of synthetic resin. (4) The surface 76 of the threads 12, 13, 14...
3. At least a large part of the foam 6 is baked with the adjacent surface of the foam 69.
foam material. (5) A foamed member according to claim 1, characterized in that the threads 12, 13, 14, . . . are firmly connected to each other at intersections 17, 18. (6) The foamed member according to claim 5, characterized in that the intersection points 17 and 18 have an interval in the cm range. (7) The foamed member according to claim 6, wherein the distance is statistically the lowest cm region. (8) The foamed member according to claim 1, wherein the thickness of the threads 12, 13, 14, etc. is at least cm. (9) The foamed member according to claim 8, wherein the thickness is in the 1/10 mm range. (10) A foamed member according to claims 3 and 5, characterized in that the threads 12, 13, 14... are baked until they fuse together at their intersection points. 11. The foam member of claim 1, wherein the tangled strips 11, 71 are produced at least in part by random operations. (12) A foam member characterized in that at least the outer skin region of the foam member 69 has reinforcing mats 43 and 72 that absorb tension. (13) The foamed member according to claim 3, wherein the threads 12, 13, 14... are made of a thermosetting material. (14) The foamed member according to claim 3, wherein the threads 12, 13, 14... are made of a thermoplastic material. (15) The foamed member according to claim 1, characterized in that at least the outer skin region of the foamed body 69 has reinforcing mats 43, 72 for absorbing tension. (16) The reinforcing mats 43 and 72 are the glass fiber mats 4
16. The foam member of claim 15, wherein the foam member is a glass fiber mat substantially thinner than the thickness of the member 56 perpendicular to 3,47. (17) Reinforcement mats 43 on two opposing outer skin areas,
17. The foamed member according to claim 15 or 16, wherein the reinforcing mats 43 and 47 are provided with a spacing sufficiently smaller than the horizontal dimension of the reinforcing mats. (18) The foam member according to claim 17, wherein the member is in the shape of a plate 56. (19) A foam member according to any one or more of the preceding claims, characterized in that the root region 46 of the attachment means 42 is fixed within the member 56. 20. The foam member of claim 19, wherein the root region is within the tangle strip. (21) The foamed member according to claim 19, wherein the attachment means 42 is a pin-like means such as a threaded bolt. (22) A structural unit according to any one or more of the preceding claims, characterized in that a layer integrally connected to the member 56 is formed around the member 56. (23) Structural unit according to claim 22, characterized in that the layer is made of hard foam rubber. (24) Structural unit according to claim 23, characterized in that it is a wind guide device for a vehicle. (25) In the apparatus for manufacturing a foamed member according to any one or more of claims 1 to 21, the bislit mold 34
The tangled body strips 11, 71 with a reinforcing mat placed on one side thereof are arranged, and the gate 38 of the mold is placed in front of the tangled body strips 11, 71 and the reinforcing mats 43, 47, 7.
1. An apparatus for manufacturing a foamed member, characterized in that the apparatus is disposed at a location where no. (26) The foam member manufacturing apparatus according to claim 25, wherein the gate 38 is tangential to the direction of the reinforcing mats 43, 47. (27) In the method for manufacturing a foamed member according to any one or more of the preceding claims, the tangled body strips 11, 71 are inserted into the open mold 32 of the two-split molds 33, 34, and the mold is closed. At least substantially filled and open mold 32 is provided with reinforcing mats 43, 47, 72 adjacent entanglement strips 11, 71 and at gate opening 38 of the mold.
, 74 are inserted so that they are open, the foam-forming components are charged into the mold 32, and the mold 32 is kept closed at least until the end of the foaming process.