IMPROVED INSULATING PANEL AND PROCESS FOR MANUFACTURING SUCH PANEL

The present invention refers to an improved insulating panel, in particular for making isothermal refrigerated vans, and to a process for manufacturing such panel.

As known, refrigerated vans are refurbished on motor vehicles or trucks to allow transporting and distributing particularly heat-sensitive products inside a suitably refrigerated environment and at a substantially constant temperature.

According to the known prior art, such vans are made with layers of foamed polyurethane injected between two layers of polyester reinforced with fibre glass.

Such known panels however suffer some inconveniences: in fact, due to possible thermal shocks created by the presence of a high temperature difference between the environment inside the van and the outside environment, they can be subjected to high de-laminations between the component layers .

Moreover, existing panels are subjected to 45 distortions created by the presence of possible remaining bubbles of styrene inside the layer of foamed polyurethane, such distortions being sometimes such as to impair the planarity of external layers and decrease their aesthetic and functional qualities.

Moreover, existing panels cannot reach thicknesses that are greater than a certain value, due to the low structural resistance offered by the layer of foamed polyurethane only.

Moreover, the processes for manufacturing existing panels create, with related problems of scavenging and removal, obnoxious gases, such as styrene.

Therefore, object of the present invention is solving the above prior art problems by providing an improved insulating panel, in particular for making isothermal refrigerated vans, subjected to less de- lamination problems with respect to prior art panels.

Another object of the present invention is providing an improved insulating panel, in particular for making isothermal refrigerated vans, that has a better planarity of external layers with respect to prior art panels.

Moreover, an object of the present invention is providing an improved insulating panel, in particular for making isothermal refrigerated vans, that can be made through a more ecologic process for manufacturing, in particular that does not provide for the creation of obnoxious gases such as styrene, with respect to prior art panels.

Another object of the present invention is providing an improved insulating panel, in particular for making isothermal refrigerated vans, that can be made with substantially greater thicknesses with respect to prior art panels.

Moreover, an object of the present invention is providing a more ecologic process for manufacturing an improved insulating panel, in particular free from the creation of obnoxious gases such as styrene, with respect to processes for manufacturing prior art panels.

The above and other objects and advantages of the invention, as will result from the following description, are obtained with an improved insulating panel as claimed in claim 1.

Moreover, the above and other objects and advantages of the invention, as will result from the following description, are obtained with a process for manufacturing an improved insulating panel as claimed in claim 16.

Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims. It will be immediately obvious that numerous variations and modifications (for example related to shape, sizes, arrangements and parts with equivalent functionality) can be made to what is described, without departing from the scope of the invention as appears from the enclosed claims.

The present invention will be better described by some preferred embodiment thereof, provided as a non- limiting example, with reference to the enclosed drawings, in which:

- Figure 1 shows a perspective and partially sectioned view of a van made with a preferred embodiment of theimproved insulating panel according to the present invention; and

- Figure 2 shows a partially sectioned view of another van made with different further preferred embodiments of the improved insulating panel according to the present invention .

With reference to the Figures, it is possible to note that the improved insulating panel la, lb, lc according to the present invention, in particular for making isothermal refrigerated vans, is composed of a composite sandwich-type structure composed of:

at least one first external layer 3;

at least one layer composed of at least . one reinforcing panel 5 adhering to such first external layer 3;

at least one insulating layer 7; and

at least one second external layer 9.

Preferably, the first 3 and the second 9 external layer are composed of a polyester reinforced with fibre glass (plastic reinforced by fibre glass) shaped as a sheet, preferably superficially treated with GELCOAT.

Moreover, always preferably, the reinforcing panel 5 is made adhering to the first external layer 3 by interposing at least one layer of adhesive 11, such layer of adhesive 11 being still more preferably composed of a two-component polyurethane glue like the one marketed with denomination DUNAPOL AD 1563/V2. .

Preferably, the insulating layer 7 is composed of foamed polyurethane, preferably of a closed-cell type, suitably injected between the first 3, and the related reinforcing panel 5, and the second 9 external layer. Still more preferably, the foamed polyurethane composing the insulating layer 7 comprises formic acid suitable to increase the adhesion of such layer 7 to the external layers 3, 9 composed of plastic reinforced by fibre glass .

In particular, in the. preferred embodiments of the insulating panel according to the present invention, shown in the Figures with numeric references la and lb, the reinforcing panel 5 is composed of a rigid polyurethane panel, preferably of a closed-cell type: in this case, preferably, the polyurethane composing such panel 5 has a greater density of the foamed polyurethane possibly composing the insulating layer 7.

Alternatively, in the preferred embodiment of the insulating panel according to the present invention, shown in particular in Figure 1 with numeric reference lc, the reinforcing panel 5 is composed of a panel made of marine plywood, preferably of a multilayer type, .

As further alternative, in the preferred embodiments of the _. insulating panel according to the present invention, shown in particular in Figure 2 with numeric references lb and lc, such improved insulating panel can comprise at least one reinforcing section bar 13, having preferably a substantially "Ω''-shaped section, immersed inside the insulating layer 7.

The present invention further refers to a process for manufacturing an improved insulating panel la, lb, lc as previously described. In particular, the process according to the present invention comprises the steps of:

a) cutting a sheet, preferably composed of a polyester reinforce with fibre glass, to make such external layers 3 , 9 and paper-sanding such layers 3 , 9 ;

b) cutting and providing such reinforcing panel 5 whose sizes are compatible with the sizes of such external layers 3 , 9 : preferably, such reinforcing panel 5 has such sizes that each one of the edges of the panel 5 has a distance from a respective edge of the external panel 3 included between 50 mm and 90 mm;

c) laying at least one layer of adhesive 1 1 onto such first external layer 3 and possibly performing the normalisation of the thickness of such layer 1 1 ;

d) arranging the reinforcing panel 5 onto such layer of adhesive 11 and pressing such layers 3 , 5 , 1 1 ;

e) placing the external layer 9 and the pressed. layers 3 , 5 , 11 to form the structure of the insulating panel la, lb, lc, making such structure integral, for example with frames, templates, adhesive bands, etc., and placing possible reinforcing profiles 13 between such external ±ayex ^{~ "} and ^~ suc hr-presssxi—.layers— 3— 5-— Hr ;

f) sealing the perimeter junctions between such layers 3 , 5 , 9 , 11 and making inspection holes and air-exiting holes; and

g) injecting, preferably by means of a high-pressure foamer, the foam of foamed polyurethane between the external layer 9 and the layers 3 , 5 , 1 1 .