Method for the continuous production of an endless string of polyurethane reactive plastic material

Abstract

A method for continuous production of an endless string of polyurethane reactive plastic material including, a) conveying the reactive components to a mixer in a metered manner, b) mixing the reactive components into a reactive mixture, c) subsequently discharging the reactive mixture and d) coating a first sheet section made from a plane, flexible material which is conveyed continuously in a transporting direction with the reactive mixture. Further including: e) guiding the first sheet section across a guiding element, which has a concave section and a flat section which follows the concave section in the transporting direction; f) feeding two lateral sheet sections to the first sheet section, wherein the feeding occurs into the two lateral end sections of the first sheet section; g) merging the two lateral sheet sections and the first sheet section so that a bowl-shaped structure is formed for reception of the reactive mixture.

Claims

1. A method for the continuous production of an endless string of polyurethane reactive plastic material, comprising the steps of: a) at first conveying reactive components polyol and isocyanate to a mixer in a metered manner; b) mixing the reactive components in the mixer to a reactive mixture; c) subsequently discharging the reactive mixture into environmental atmosphere; d) coating a first sheet section made from a planar, flexible material, which is conveyed continuously in a transporting direction, with the reactive mixture; e) guiding the first sheet section across a guiding element, which has a concave section and a flat section which follows the concave section in the transporting direction; f) feeding two lateral sheet sections to the first sheet section, wherein the feeding occurs into two lateral end sections of the first sheet section; and g) merging the two lateral sheet sections and the first sheet section so that the two lateral sheet sections extend upward from a surface of the first sheet section forming a structure for reception of the reactive mixture between the two lateral sheet sections, the two lateral sheet sections and the first sheet section being moved continuously in the transporting direction, wherein the first sheet section is connected with the lateral sheet sections in a sealed manner so that no reactive mixture leaks into the surrounding atmosphere between the sheet sections.

2. The method according to claim 1, wherein the merging of the two lateral sheet sections to the first sheet section occurs in a region of the concave section of the guiding element.

3. The method according to claim 2, wherein the first sheet section and the two lateral sheet sections are formed by folding of a single sheet section made of a planar material.

4. The method according to claim 3, wherein the method further comprises the steps of: h) unwinding a plane sheet of the material from a roll; i) carrying out a first and a second folding of the planar sheet wherein two lateral outer sections of the sheet are folded to an inner side by 180 so that a C-fold is created with a first fold edge between the first sheet section and a first of the lateral sheet sections and with a second fold edge between the first sheet section and a second of the lateral sheet sections; j) guiding the sheet which has the C-fold across the concave section of the guiding element; and k) edging the two lateral sheet sections which are folded to the inner side in the region of the concave section so that at least outer sections of the lateral sheet sections which are at first folded to the inner side by 180 are further folded so that at least the outer sections of the lateral sheet sections are erected vertically to the first sheet section to form the structure for the reception of the reactive mixture together with the first sheet section.

5. The method according to claim 4, wherein the lateral sheet sections after deforming according to step k) are formed in the region of the concave section in the region of the flat section of the guiding element so that each one of the sheet sections is aligned perpendicular to the first sheet section while a respective further sheet section is aligned parallel to the first sheet section.

6. The method according to claim 3, wherein the structure laterally delimited by the lateral sheet sections becomes wider when advancing in the transporting direction in the region of the concave section.

7. The method according to claim 4, wherein a geometrical position of a deformation edge for deformation of the C-fold according to step i) into the edged position according to step k) in the region of the concave section results as a geometrical section of two areas, wherein one of the areas is an area arranged equidistantly above the guiding element by an amount between 0.1 mm and 5 mm and wherein the other area is an area which comprises a line of intersection between the first sheet section and the vertical erected sheet section according to step k), to form a plane inclined relatively to the vertical erected sheet section along the transporting direction by an angle to an interior of the bowl-shaped structure.

8. The method according to claim 7, wherein the angle is 45.

9. The method according to claim 1, wherein the lateral sheet sections are glued with the first sheet section.

10. The method according to claim 5, wherein in a region in the transporting direction behind the concave section of the guiding element, a support for the first sheet section is formed by a revolving band.

11. The method according to claim 10, wherein a folded, flat, sheet-shaped substrate of the parallel further sheet sections as well as sections of the first sheet section, which are arranged between the further sheet sections and the revolving band, are pressed onto the revolving band by rolls so that a sufficient friction is created between the revolving band and the substrate to convey the sheet-like substrate synchronously with the revolving band.

12. The method according to claim 1, including holding the first sheet section of the flat, flexible material by a vacuum on the surface of the guiding element in the region of the concave section of the guiding element.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing:

(2) FIG. 1 shows schematically in a perspective view a part of a device for the production of an endless string made of polyurethane reactive material at which a bowl-shaped reception structure for the reactive mixture is formed from a single material sheet.

(3) FIG. 2 shows in the depiction according to FIG. 1 the device, wherein here lateral regions of a bowl-shaped structure are formed from separate material sheets.

(4) FIG. 3 shows in a perspective view a detail of the device according to FIG. 1.

(5) FIG. 4 shows in a perspective view a further detail of the device according to FIG. 1.

(6) FIG. 5 shows schematically in a side view the device according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(7) In FIG. 1 a perspective view can be seen of a region of a device for the production of an endless string of polyurethane reactive plastic material, wherein a guiding element 2 made from sheet metal forms the ground facing the substrate (i.e. facing the reactive plastic material to be produced). This ground, i.e. the surface of the guiding element 2, has a concave formed section 3 at which a flat section 4 follows in transporting direction T. Specifically the ground consist at first of the guiding element 2 made of sheet metal and merges subsequently in a revolving transport band 5.

(8) Also depicted is a continuously moved, track-like, central first sheet section B.sub.M which runs directly above the sheet metal 2 and the band 5.

(9) Laterally and outwards two lateral sheet sections B.sub.L and B.sub.R are shown which are deformed in the region of the concave formed section 3 in such a manner that in cooperation with the first sheet section B.sub.M a bowl is created which is equipped with continuously moved separation sheets for the reactive mixture. This bowl is delimited against the transporting direction T by said first sheet section B.sub.M; this is in turn delimited transverse to the transporting direction T by means of the two lateral sheet sections B.sub.L and B.sub.R, wherein the first sheet section B.sub.M is connected in a sealed manner with the lateral sheet sections B.sub.L and B.sub.R so that no reactive mixture can leak into the surrounding atmosphere between those sheet sections.

(10) Thereby, the first sheet section B.sub.M and the lateral sheet sections B.sub.L and B.sub.R can be at the one hand originally separate sheets (see FIG. 2 for this) or at the other hand a single connected sheet which was separated by a respective folding in a central and two outer regions. In FIG. 1 the case is depicted that a single sheet is used which is folded to the bowl respectively. After the deformation respectively folding the lateral sheet sections B.sub.L and B.sub.R consist here each of a left lateral sheet section B.sub.L,perp and a right lateral sheet section B.sub.R,perp which each are aligned perpendicular to the first sheet section B.sub.M; furthermore a left parallel sheet section B.sub.L,par and a right parallel sheet section B.sub.R,par are existing which each are aligned parallel to the first sheet section B.sub.M.

(11) Normally, at bloc foam applications additionally a lateral separating sheet 7 is fed from the side which serves as separation sheet between the bloc and the side wall. This is shown in FIG. 1 (due illustration reasons only on the left side).

(12) It is also possible that the lateral sheet sections B.sub.L and B.sub.R are so wide respectively so high that they by themselves already serve as lateral separation substrate for the whole height of the bloc. This is specifically possible for applications in which only small heights of the foam are reached (e. g. less than 300 mm).

(13) In FIG. 2 a variation to FIG. 1 is shown. Here, a solution is shown at which the first sheet section B.sub.M and the lateral sheet sections B.sub.L and B.sub.R are designed at first separately, i.e. they are originally not connected with the first sheet section B.sub.M. Furthermore, they are chosen so wide respectively high that they by themselves can already serve as lateral separation substrate for bloc heights above 1 m for the whole height of the bloc. So that no reactive mixture can leak between those lateral substrate sections and the first, central sheet section it is recommended to glue the in total three sheet section with another.

(14) In FIG. 3 the in transporting direction right forming collar 8 for the deformation of the right sheet section B.sub.R is exemplarily depicted. Also, it can be seen how the forming collar 8 guides the outer part of the sheet section B.sub.M as well as the sheet section B.sub.R,par. To completely and securely guide the sheet section B.sub.M directly on the guiding element 2 (ground sheet metal) it is recommended to use a vacuum in the concave formed section 3 of the guiding element 2 which is not further depicted.

(15) Furthermore, in FIG. 3 a roll 6 (press roll) is shown exemplary by which a frictionally engagement between the substrate and the revolving band 5 can be obtained. Normally, between the roll 6 and the edged sheet section B.sub.R,perp the side wall and if applicable also a further lateral separation sheet (see FIG. 1) runs, which are however not shown in FIG. 3. The rolls 6 are pressed against the band 5 preferably by means of a spring or pneumatically with a defined force.

(16) In FIG. 4 a deformation edge U for the deformation of the in transporting direction T right sheet section B.sub.R is exemplified depicted. The deformation edge U results from the cut contour of the plane E with an imaginary bent plane which runs directly above the guiding element 2 with the concave formed section 3 facing the substrate and parallel to the surface of the guiding element 2. The plane E results when the plane in which the sheet section B.sub.R,perp lies is swivelled by an angle of 45 around the fold edge K.sub.R0. Also the fold edge K.sub.R0 is depicted which results from the above explained C-folding at which the lateral sheet sections B.sub.L and B.sub.R of the sheet section B.sub.M are at first folded by 180 inwardly. Analogue to the shown right hand side fold edges K.sub.R and K.sub.R0 also corresponding left hand side folding edges K.sub.L and K.sub.L0 exist which however are not shown.

(17) In FIG. 5 a schematical side sectional view is shown in which the covering separating sheet 9, the outlet opening 10 of the mixer the bank up reservoir 11 as well as the gap opening 12 at the transition from the bank up reservoir to the rising zone 13 can be seen. The reactive mixture coats in this case at first the covering separating sheet 9, is retained in the bank up reservoir 11 by the gap opening 12 so that a static fluid pressure is created in the bank up reservoir 11 which then compensates the static pressure of the steep raising foam in the rising zone 13 so that the reactive mixture even at very low transporting speeds is not pressed against the transporting direction T.

(18) While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.