METHOD AND SYSTEM FOR PRODUCING FOAM COMPOSITE ELEMENTS

Abstract

The present disclosure relates to a method and a system for applying a foamable reaction mixture to a moving outerlayer, the reaction mixture being applied from discharge openings on the outerlayer, and the outerlayer moves at a speed of 15 meters per minute relative to the discharge openings. The system also comprises 7 discharge openings.

Claims

1. A process for applying a foamable reaction mixture onto a moving outerlayer, wherein the reaction mixture is applied onto the outerlayer from discharge openings and the outerlayer moves at a speed of 15 meters per minute relative to the discharge openings, wherein the reaction mixture is applied onto the outerlayer from 7 discharge openings simultaneously, and wherein the process further comprises the steps of: providing a plurality of mixing heads, wherein each mixing head is adapted for mixing two or more reactant streams to afford one product stream; providing a plurality of distributors, wherein the number of distributors corresponds to the number of mixing heads, wherein each distributor is connected to the product stream of one of the mixing heads, wherein each distributor comprises 2 flexible discharge conduits, each of which terminates in a discharge opening, and wherein each distributor is adapted for distributing the product stream from the mixing head assigned thereto to its discharge conduits in a homogeneous material composition; mixing two or more reactant streams in each of the mixing heads to obtain the product stream exiting each of the mixing heads, wherein the product stream comprises a portion of the reaction mixture; distributing the respective product streams to the respective discharge conduits in the respective distributor; applying the reaction mixture from the discharge openings of the discharge conduits onto the outerlayer.

2. The process as claimed in claim 1, wherein the reaction mixture comprises a polyol, a polyisocyanate and a blowing agent.

3. The process as claimed in claim 2, wherein the reaction mixture has a cream time of the reaction of <5 s and a fiber time of <25 s.

4. The process as claimed in claim 2, wherein the reaction mixture further comprises a catalyst component comprising D1) aminic catalysts and D2) carboxylates of alkali metals or alkaline earth metals in a D2/D1 ratio of between 0.1 and 80.

5. An apparatus for applying a foamable reaction mixture onto a moving outerlayer, wherein the reaction mixture is applied onto the outerlayer from discharge openings, wherein the system comprises 7 discharge openings, and wherein the system further comprises: a plurality of mixing heads, wherein each mixing head is adapted for mixing two or more reactant streams to afford one product stream; a plurality of distributors, wherein the number of distributors corresponds to the number of mixing heads, wherein each distributor is connected to the product stream of one of the mixing heads, wherein each distributor comprises 2 flexible discharge conduits, each of which terminates in a discharge opening, and wherein each distributor is adapted for distributing the product stream from the mixing head assigned thereto to its discharge conduits in a homogeneous material composition.

6. The apparatus as claimed in claim 5, wherein the flexible discharge conduits are attached symmetrically to a securing rail at their end facing away from the distributor.

7. The apparatus as claimed in claim 5, wherein the flexible discharge conduits are attached asymmetrically to a securing rail at their end facing away from the distributor.

Description

[0053] The system according to the invention and the process according to the invention shall be elucidated with reference to FIG. 1 and to FIG. 2 without, however, being limited thereto. The system according to the invention further comprises: [0054] a plurality of mixing heads 100, 110, 120, wherein each mixing head is adapted for mixing two or more reactant streams to afford one product stream; [0055] a plurality of distributors 200, 210, 220, wherein the number of distributors corresponds to the number of mixing heads 100, 110, 120, each distributor is connected to a product stream from a mixing head, each distributor comprises 2 flexible discharge conduits 300, each of which terminate in a discharge opening 400, and each distributor is adapted for distributing a product stream from the mixing head assigned thereto to its discharge conduits 300 in homogeneous material composition.

[0056] Shown here is a system comprising three mixing heads 100, 110 and 120. Each of these three mixing heads receives a product stream comprising a polyol-containing component ROH and a product stream comprising an isocyanate component RNCO. It will be appreciated that the designations ROH and RNCO do not represent monoalcohols and monoisocyanates but rather generally polyols and polyisocyanates and blowing agents and other additives also present in these reactant streams.

[0057] The mixing heads 100, 110, 120 combine their reactant streams into product streams which are each supplied to a distributor 200, 210, 220 assigned to the mixing head. The product streams thus contain the foamable reaction mixture. The distributors 200, 210, 220 used according to the invention are preferably those such as are described for example in EP 1 857 248 A2 ([0023], FIG. 1) under the designation distributor head. This is shown in more detail in FIG. 2. The geometry of the distributor is preferably chosen such that the distance covered by the reaction mixture from the inlet of the distributor to the respective outlets to the discharge conduits is of equal length. It is moreover advantageous when the cross section of the distributor head outlets is identical for all distributor head outlets. The cross section of the distributor head inlet may conversely also be larger than the respective distributor head outlets. The material of the distributor may be selected from steel, stainless steel, aluminum and plastics. In each case the selected material must be resistant to the pressures and temperatures prevailing in the mixing head. If distribution takes place into only two discharge conduits, a T-shaped branching of the discharge conduit 310 may also be referred to as the distributor. In this respect, a conduit branching such as a T-piece or a Y-piece may also be regarded as a distributor in this embodiment. The distributors 200, 210, 220 homogenize the product stream so that for example differences in the temporal progress of the reaction or temporal differences in the properties of the reactant streams are compensated. Temporal differences in the properties of the reactant streams may be for example differences as a consequence of density variations or of variations in the conveying power of the reactant streams to the mixing heads.

[0058] The reaction mixture exits the distributors 200, 210, 220 via 2 flexible discharge conduits 300 which each terminate in discharge openings 400.

[0059] In the embodiment shown in FIG. 1 each distributor has five discharge conduits 300, in FIG. 2 four discharge conduits. The discharge conduits 300 may be flexible or rigid. Flexible discharge conduits are particularly preferred which are attached to a securing rail 500 at their end facing away from the distributor, thus allowing the positions of the discharge openings 400 to be flexibly varied and fixed. The flexibility of the discharge conduits can be achieved, for example, through the use of hoses or variable, for example slidable, tubes. This has the advantage that the geometry of the panel can be influenced by the precise positioning of the fixing. In one preferred embodiment, the distances between the hose ends to the rail are all identical. The reaction mixture exits the individual discharge openings 400 and contacts substantially over its entire width an outerlayer 10 which is moving away from the discharge openings and is represented by its dashed outline. Due to the expansion of the foaming reaction mixture the individual stripes of the reaction mixture combine to form the foam layer 600 on the outerlayer 10.

[0060] It is noted that the outerlayer 10 moves away from the discharge openings in each case, i.e. upwards in the drawing in the schematic representation of this figure.

[0061] The embodiment of the process according to the invention performable with the system according to the invention discussed hereinabove further comprises the steps of: [0062] providing a plurality of mixing heads 100, 110, 120, wherein each mixing head is adapted for mixing two or more reactant streams to afford one product stream; [0063] providing a plurality of distributors 200, 210, 220, wherein the number of distributors corresponds to the number of mixing heads 100, 110, 120, each distributor is connected to a product stream from a mixing head, each distributor comprises 2 flexible discharge conduits 300, each of which terminate in a discharge opening 400, and each distributor is adapted for distributing a product stream from the mixing head assigned thereto to its discharge conduits 300 in homogeneous material composition; [0064] mixing two or more reactant streams in each of the mixing heads 100, 110, 120 to obtain a product stream exiting each of the mixing heads, wherein the product stream comprises a foamable reaction mixture; [0065] distributing the respective product streams to the respective discharge conduits 300 in the respective distributor 200, 210, 220; [0066] applying the reaction mixture from the discharge openings 400 of the discharge conduits 300 onto the outerlayer 10.

[0067] The number of mixing heads in these embodiments of the system according to the invention and of the process according to the invention may be 2, 3 (as shown here), 4, 5, 6 or more. The number of distributors may accordingly be 2, 3 (as shown here), 4, 5, 6 or more, wherein the number of distributors also corresponds to the number of mixing heads. The number of discharge conduits per distributor may be 2, 3, 4 (as shown here), 5, 6 or more.

[0068] This embodiment very markedly reduces problems with the running and mingling of the rising reaction mixture. This has the advantage over existing discharging apparatuses that precise positioning of the discharging streams, both symmetrically and also asymmetrically, is achievable through the use of the flexible discharge conduits. This can result in advantages in panel geometry or allows targeted product application, for example into the corrugations of a roofing element. This application methodology may be used for producing metal panel sandwich composite elements, insulation panels and continuous blocks. Discharging may be performed in the direction of the belt or counter to the direction of the belt.