FOAM FORMING DEVICE AND FOAM EXTRUSION APPARATUS

Abstract

A foam forming device has an inlet, an outlet and a longitudinal axis that leads from the inlet to the outlet. The foam forming device has a plurality of surface pairs. Each surface pair has two opposing surfaces. The surfaces delimit a foaming space at least to some extent. At least one of the surfaces of the surface pairs is an adjustable surface whose orientation relative to the longitudinal axis can be adjusted. The first surface pair and the second surface pair are off-set from one another along the periphery of the foaming space. Also disclosed is a foam extrusion apparatus having a foam forming device.

Claims

1. A foam forming device having an inlet, an outlet and a longitudinal axis which leads from the inlet to the outlet, and having a large number of face pairs, wherein the face pairs each have two opposite faces and the faces at least partially delimit a foaming space, wherein the large number of face pairs have a first face pair and a second face pair, wherein at least one of the faces of the first face pair is an adjustable face, the positioning of which relative to the longitudinal axis is adjustable, and at least one of the faces of the second face pair is an adjustable face, the positioning of which relative to the longitudinal axis is adjustable, wherein the first face pair and the second face pair are offset relative to each other along the circumference of the foaming space.

2. The foam forming device as claimed in claim 1, wherein the face pairs delimit the foaming space substantially completely circumferentially.

3. The foam forming device as claimed in claim 1, wherein the first face pair and the second face pair together delimit the foaming space circumferentially and the face pairs form a quadrangle, a trapezium, a parallelogram or a rectangle.

4. The foam forming device as claimed in claim 1, wherein the position of the adjustable faces relative to the longitudinal axis and/or a pressure which is applied by the adjustable faces in the direction of the foaming space is adjustable.

5. The foam forming device as claimed in claim 1, wherein the faces of the face pairs are planar or are bent in a direction which leads away from the longitudinal axis.

6. The foam forming device as claimed in claim 1, wherein a plurality of face pairs of the large number of face pairs are arranged beside each other in rows in a direction from the inlet to the outlet.

7. The foam forming device as claimed in claim 6, wherein the faces of the face pairs which are arranged in rows beside each other in the direction from the inlet to the outlet are arranged beside each other in rows in a substantially gap-free or partially overlapping manner.

8. The foam forming device as claimed in claim 1, wherein the spacing between opposite faces of a sub-group or all of the face pairs increases in the direction toward the outlet of the foam forming device.

9. The foam forming device as claimed in claim 1, further comprising actuators which support the adjustable face pairs and which are configured to adjust the inclination and/or the position of the adjustable face pairs.

10. The foam forming device as claimed in claim 9, wherein the actuators support the face pairs resiliently with respect to a counter-bearing.

11. The foam forming device as claimed in claim 9, wherein the actuators are pneumatic actuators.

12. The foam forming device as claimed in claim 9, which further has a control unit which is connected to the actuators in terms of control, and furthermore a plurality of face pairs of the large number of face pairs are arranged in rows beside each other in a direction from the inlet to the outlet, wherein the control unit is configured to adjust faces of the face pairs in a state arranged in rows beside each other without any gaps.

13. The foam forming device as claimed in claim 1, wherein the first face pair is located between the second face pair and is arranged at an angle relative thereto.

14. The foam forming device as claimed in claim 1, wherein first and second face pairs are arranged in rows beside each other in a direction from the inlet to the outlet in several groups, and the first face pairs are offset relative to each other along the circumference of the foaming space with respect to the second face pairs and there is provided at least a first group in which the first face pair is located between the second face pair and there is provided at least one second group which follows the first group in the direction toward the outlet, and wherein the second face pair is located between the first face pair.

15. The foam forming device as claimed in claim 14, wherein there is provided between two successive groups a gap, at which a surface processing apparatus is arranged.

16. The foam forming device as claimed in claim 1, wherein an opening is provided in one of the faces, wherein at the opening a surface processing apparatus is arranged.

17. The foam forming device as claimed in claim 1, wherein the inlet has a die, which the face pairs abut in a substantially gap-free manner or the die is arranged between the face pairs.

18. The foam forming device as claimed in claim 1, wherein at least some of the face pairs are configured in a temperature-controllable manner.

19. A foam extrusion apparatus having a foam forming device as claimed in claim 1 and having an extruder which has an outlet, wherein the inlet of the foam forming device adjoins the outlet of the extruder in a substantially gap-free manner.

20. The foam forming device as claimed in claim 9, wherein the actuators are bellows actuators, electromechanical actuators, or hydraulic actuators.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIGS. 1 to 4 serve to explain in greater detail the foam forming device which is described herein.

DETAILED DESCRIPTION OF THE INVENTION

[0044] FIG. 1 shows a perspective view of an apparatus with an inlet E which follows a die D. The die D is a wide-slot die.

[0045] In order to form the foam which is discharged from the die D, first laterally arranged face pairs are used. The (first) face pair S1, S1 directly adjoins the die, wherein the edge, which faces the die D, of this face pair is part of the inlet. The additional first face pairs S2, S2 and S3, S3 adjoin this first face pair S1, S1 in this sequence. It can be seen that the faces of these face pairs overlap each other. At a transition of a first face pair to the next first face pair (in a direction which is directed away from the inlet E), the edge of the face pair above the next face pair which is located nearer the inlet E is located. When viewed from the surrounded foaming space, the first face pairs merge into each other and form a (virtually) continuous inner face. The faces, which are designated S . . . , of the face pairs are laterally arranged and delimit the foaming space laterally. The relevant face pairs extend laterally (and substantially in the conveying direction) and have faces which are spaced apart transversely relative to the conveying direction and between which the foaming space R is located.

[0046] Furthermore, there are second face pairs H1-H3 which extend substantially in the conveying direction and transversely relative to the first face pairs. In cross section, faces of the first face pairs and faces of the second face pairs alternate with each other in a circumferential direction. The upper faces of the second face pairs can be seen. The second face pair H1 directly adjoins the die D (or forms a portion of the inlet E), with the additional second face pairs H2, H3 adjoining in this sequence. The second face pairs also form a continuous inner face (when viewed from the foaming space).

[0047] The face pairs H1 and S1, S1 form a first group and surround the foaming space. This also applies to the face pairs H2 and S2, S2 which form a second group and to the face pairs H3 and S3, S3 which form a third group. Each group completely surrounds the foaming space in a circumferential direction. The first group is located directly at the inlet, wherein the second and third groups adjoin it in this sequence (in an overlapping manner). A circumferential inner face which is continuous in the conveying direction (a direction directed away from the inlet) and which is formed by the face pairs is produced.

[0048] It can be seen that, for the face pairs which are illustrated in FIG. 1, the transversely extending (horizontal) face pairs H1-H3 are enclosed by the lateral face pairs S1, S1-S3, S3. Additional groups can follow, wherein this is transposed. The first and second face pairs of the same group are arranged at the same height in a direction directed away from the inlet E. In particular, the centers of the first and second face pairs of the same group can substantially be provided in the same cross sectional plane (that is to say, at the same distance from the inlet E). A transition between first successive face pairs is provided at the distance from the inlet at which the transition between second successive face pairs is also provided. The transitions between the successive groups are at the same location, that is to say, at the same spacing from the inlet, for the relevant first and second face pairs.

[0049] FIG. 1 illustrates that the lateral face pairs are provided in a frame T and are supported with respect to the frame T by bellows elements B. The bellows elements can be acted on with an adjustable internal pressure so that the position and/or the pressing pressure of the relevant face pairs can be adjusted with respect to the foam in the inner space. The foaming process can thereby be adjusted. The face pairs H1-H3 can also be adjusted in terms of their position.

[0050] The first face pairs S1, S1-S3, S3 initially extend, when viewed from the inlet E, at a greater angle apart from each other than in the subsequent extent in a direction directed away from the inlet E. While the faces of the face pair S3, S3 (further away from the inlet E than S1, S1) have only a comparatively small opening angle and are virtually parallel with each other, the faces of the fac pair S1, S1 (at the inlet E) have a substantially greater opening angle in comparison with S3, S3. With the distance from the inlet, the opening angle (which is open relative to the outlet) decreases between the faces of the face pairs.

[0051] FIG. 1 shows a foam forming device, in which the face H3/the face pairs S3, S3 is/are followed by the outlet. However, one embodiment of the foam forming device provides for a first portion which is constructed similarly to the arrangement illustrated in FIG. 1 and which is followed by a second portion. This is explained in greater detail with reference to the additional Figures.

[0052] FIG. 2 shows a plan view of a foam forming device having first face pairs S1, S1-S3, S3 as illustrated in FIG. 1, and having additional successive first face pairs S4, S5. The second face pairs H1-H3 (that is to say, the three face pairs which are closest to the inlet E/the die) are laterally surrounded by the first face pairs S1, S1-S3, S3. This changes with the successive first and second face pairs H4, H4 and S4, S4; S5, S5 (in the direction away from the inlet), in which the first (lateral or vertically orientated) face pairs S4, S4 and S5, S5 are provided between the second face pairs H4, H5 (that is to say, the transversely extending or horizontally orientated face pairs). This allows without substantial unused structural space selective control of the foaming in the first region at the inlet A and in a subsequent second region at the outlet A. The dot-dash arrow F indicates the conveying direction which extends from the inlet and which leads in the direction of the outlet. The mentioned portions and groups are arranged in rows beside each other in this conveying direction; the successive groups have faces which overlap each other.

[0053] The first group is formed by the first face pair S1, S1 and the second face pair H1. The second group is formed by the first face pair S2, S2 and the second face pair H2. The third group is formed by the first face pair S3, S3 and the second face pair H3. These groups are arranged in rows beside each other in the direction of the arrow F (conveying direction) and all have the property that the first face pairs H1-H3 are arranged between the second face pairs (S1, S1 and S2, S2 and S3, S3). These three groups can be referred to as the first portion. It can be seen that the groups of the first portion can also be provided in numbers different from three, for instance in the form of only one group or two groups or more than three groups. This is dependent on the application, in particular the intended size of the foam product and the foaming behavior thereof.

[0054] There follows a second portion, in which the property which is mentioned in the preceding paragraph is transposed. The second portion has a fourth and a fifth group. The fourth group is formed by the first face pair S4, S4 and the second face pair H4. The fifth group is formed by the first face pair S5, S5 and the second face pair H5. These groups are arranged in rows beside each other in the direction of the arrow F (conveying direction) and follow the groups of the first portion. The fourth and fifth groups each have the property that the second face pairs (S4, S5 and S2, S2 and S3, S3) are arranged between the first face pairs H4, H5. These two groups can be referred to as the second portion. It can be seen that the groups of the second portion can also be provided in numbers different from two, for instance, in the form of only one group or three or more than three groups. This is dependent on the application, particularly the intended size of the foam product and the foaming behavior thereof.

[0055] FIG. 3 shows the apparatus of FIG. 2 as a longitudinal section. The first face pairs H1, H1/H2, H2/H3, H3/H4, H4/H5, H57 H6, H6 and H7, H7 which are arranged in rows beside each other in the conveying direction can be seen. There are further shown actuators G, by means of which the position and/or the pressure which is applied by the face pairs can be adjusted in the direction of the foaming space R. The actuators G may be different from the bellows elements B which are used to adjust the second face pairs. In particular, the actuators G may be spindle drives.

[0056] The spacings of the first face pairs (that is to say, between the faces of the face pairs) of FIG. 3 increase from the inlet E in the direction A. This corresponds to the thickness increase of the foam member in the course of the foaming process. In at least one longitudinal portion of the illustrated apparatus, the first (horizontal) face pairs can be arranged between the second (lateral) face pairs. In at least one additional longitudinal portion of the illustrated apparatus, the second (lateral) face pairs can be arranged between the first (horizontal) face pairs.

[0057] FIG. 4 shows a detail of a foam forming device, as described herein, and corresponds to an inner view which can be seen from the foaming space toward the inner sides of the face pairs. It can be seen that the faces of the second face pairs (only one of the two lateral faces can be seen) are in two pieces (generally: several pieces) and have mutually displaceable and overlapping face elements S4.1, S4.2 and S5.1 and S5.2. Thus, a face of a second face pair is formed by the face elements S4.1 and S4.2 or by the vertical, overlapping juxtaposition thereof. The face, which follows it in the conveying direction, of an additional second face pair is formed by the face elements S5.1 and S5.2 or by the vertical, overlapping juxtaposition thereof. The juxtaposition of the face formed by the face elements S4.1 and S4.2 is located between the first face pair H4, H4. They are part of the same group. The juxtaposition of the face formed by the face elements S5.1 and S5.2 is located between the second face pair H5, H5. They are part of an additional group which follows (in the conveying direction). The face elements of the same face are preferably supported displaceably relative to each other, in particular in a direction perpendicular to the conveying direction, but preferably not displaceably in the conveying direction.

[0058] The first face pairs illustrated in the Figures extend horizontally and can also be described as horizontal face pairs or transversely extending face pairs. The second face pairs which are illustrated in the Figures extend vertically and can also be described as vertical face pairs or laterally extending face pairs. However, this depends on the orientation during the assembly and applications so that this description is preferably used only to explain the embodiments of the Figures.