WO2016042468A1

WO2016042468A1 - Thermal break section and method for manufacturing such a thermal break section

Info

Publication number: WO2016042468A1
Application number: PCT/IB2015/057074
Authority: WO
Inventors: Christian DAMPIERRE
Original assignee: Mazzer Materie Plastiche S.N.C.
Priority date: 2014-09-17
Filing date: 2015-09-15
Publication date: 2016-03-24

Abstract

It is disclosed a thermal break section comprising a first half-shell, a second half-shell, a rigid heat-insulating element and a thermal break chamber, - wherein a layer of a non-expanded compound comprising a thermosetting resin resistant to high temperatures is provided on at least one surface of the thermal break chamber, - wherein the layer of compound has a thickness of between about 0.5 mm and about 5.0 mm, - wherein the compound is configured so as to expand when subjected to an activating heat treatment and form an expanded heat- insulating filling body inside the thermal break chamber, - wherein the volume of the expanded heat-insulating filling body is at least twice the volume of the layer of non-expanded compound.

Description

"Thermal break section and method for manufacturing such a thermal break section"

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DESCRIPTION

The present invention relates to the sector of sections, preferably metal sections made of aluminium or aluminium alloy, for constructing window and door frames or the like. In particular, it relates to a thermal break section with an expanded heat-insulating filling body. The invention also relates to a method for manufacturing a thermal break section with an expanded heat-insulating filling body.

Although the present invention will be described with specific reference to door and window frames made of aluminium or aluminium alloy, the present invention is applicable also to door and window frames made of other materials such as wood, resin (optionally with fibreglass or carbon fillers), PVC or any combination thereof (for example wood and aluminium).

In the present description and in the claims, the term "half-shell" will be used to indicate an element extending longitudinally and substantially with a rectilinear axis having any cross-sectional form, which element, when assembled together with another corresponding half-shell and a heat-insulating element, forms a thermal break section.

Each half-shell is typically made of aluminium or aluminium alloy and is typically obtained by means of extrusion. As regards that stated above, in the present description and in the claims the term "section" will be used to indicate the assembly consisting of two half-shells and a heat-insulating element.

The heat-insulating element is a body also extending longitudinally having any cross-sectional form. Typically, this heat-insulating element is an element obtained by means of extrusion and made of a heat- insulating material, for example a plastic material. A material suitable for forming a heat-insulating element for a thermal break section is polyamide with a filler (for example fibreglass) or without filler.

Thermal break sections have been known for many years. A thermal break section reduces significantly the thermal bridge, between inside and outside, of windows, doors or continuous facades. As mentioned above, in thermal break sections, the externally exposed part is separated from the internal part by means of heat-insulating elements. A thermal break chamber (or cavity) with walls made of heat-insulating material is formed in these sections. This chamber, which is made partially of plastic, interrupts the transmission of heat, due to conduction, between inside and outside and provides the window or door frame with a high heat-insulating power.

In the currently known thermal break sections, the thermal break chamber is formed by inserting the end of two polyamide bars inside special seats provided in the two half-shells of the section. Alternatively, tubular shaped heat-insulating bodies are used.

Generally, each of the aforementioned seats is defined by a pair of foldable longitudinal teeth or by a foldable longitudinal tooth and a fixed shoulder. After inserting the bars or the tubular body inside the respective seats rolling is performed. The rolling machine compresses the teeth of both seats and rigidly joins together the bars or the tubular body of heat-insulating material and the half-shells.

In order to improve the insulation inside the thermal break chamber, it is at least partially filled with a heat-insulating material, which is typically expanded. The heat-insulating filling material is introduced inside the chamber when the section is completely assembled.

The Applicant has considered that the step of introducing the heat- insulating material inside the thermal break chamber is relatively awkward to perform and involves a considerable cost in terms of time and machinery. The Applicant has therefore established the aim of providing an alternative and more efficient way of manufacturing thermal break sections with a thermal break chamber at least partially filled with a heat-insulating material.

According to the present invention, a compound configured so as to expand when subjected to an activating heat treatment and form a heat- insulating filling body is applied onto a surface of at least one structural element of a thermal break section.

For the purposes of the present description and the claims, the expressions "structural element of a thermal break section" and "structural element" (or similar expressions) are understood as meaning a half-shell, a heat-insulating element (made of polyamide, PVC, ABS, Tefanyl ® or the like) in the form of a bar or tubular element, a dividing element provided inside the thermal break chamber (for example between two heat-insulating elements) or a connecting element provided inside the thermal break chamber (for example for connecting together two heat-insulating elements).

According to a first aspect, the invention relates to a thermal break section comprising a first half-shell, a second half-shell, a rigid heat- insulating element and a thermal break chamber defined at least partly by the first half-shell, the second half-shell and the rigid heat-insulating element,

wherein a layer of a non-expanded compound comprising a thermosetting resin resistant to high temperatures is provided on at least one surface of the thermal break chamber, wherein the layer of compound has a thickness of between about

0.5 mm and about 5 mm.

wherein said compound is configured so as to expand when subjected to an activating heat treatment and form an expanded heat-insulating filling body inside the thermal break chamber, wherein the volume of the expanded heat-insulating filling body is at least twice the volume of the layer of non-expanded compound. Preferably, the volume of the expanded heat-insulating filling body is at least four times the volume of the layer of the non-expanded compound.

Preferably, the density of the expanded heat-insulating filling body is less than at least half of the density of the non-expanded compound.

The compound preferably also comprises inorganic fillers.

Preferably, the percentage of thermosetting resin ranges between 70% and 90%.

Preferably, the layer of non-expanded compound is a layer of a compound applied in a liquid, semi-liquid or gel state and dried before assembling the section.

The surface on which the compound may be applied may be a surface of the first half-shell, a surface of the second half-shell, a surface of the rigid heat-insulating element, a surface of a dividing element provided inside the thermal break chamber and/or a surface of a connecting element provided inside the thermal break chamber.

The application of the aforementioned compound may be performed using any known means, for example by means of spraying, spreading casting, injection or using a roller or brush.

The application of the aforementioned material may be performed continuously in the longitudinal direction or discontinuously, for example along regular or irregular sections.

The compound is configured so as to pass from this form to an expanded form (for example a foamed or sponge-like form) where the volume is at least doubled with respect to its volume upon application. Preferably, the volume of the compound after expansion is at least twice, but preferably at least four or five times, the initial volume.

The quantity of compound applied may depend, among other things, on the volume which is to be obtained after expansion. The compound thickness may be about 1 mm or more. According to embodiments, a layer of non-expanded compound of about 1 -4 mm, for example about 2-3 mm, is applied.

After application of the compound it is preferably left to dry naturally or force-dried (for example inside a ventilated or static oven). Drying or desiccation may also be performed using infrared rays. In any case, in order to be able to store the structural element according to the present invention or be able to assemble it quickly it is preferable to accelerate drying.

The activating heat treatment comprises a step for performing heating to an activation temperature. Preferably, this activation temperature is greater than or equal to about 150 °C, for example between about 180 °C and 190 °C.

The activation heat treatment may be a heat treatment substantially designed to activate the compound so as to stimulate the expansion thereof and form a heat-insulating filling body. Alternatively, preferably, the activation temperature may be reached during the painting step. For example, powder painting of an aluminium section is generally performed using powder and involves heating the section to a temperature higher than 150 °C. This is obviously very advantageous since painting is performed only when the section is assembled. The heat-insulating filling body therefore expands only when the section is assembled and without further additional processing steps.

For the purposes of the present description and the claims, the expression "heat-insulating filling body" will be understood as meaning a body, with a regular or irregular shape, which has a density lower than at least half the initial density of the compound. More preferably, the density of the heat-insulating filling body is less than a fourth of the initial density of the compound. According to one embodiment, the density of the compound when applied is equal to about 1 .5 g/cm³ and after expansion is equal to about 0.24 g/cm³.

A compound suitable for implementing the present invention preferably comprises a thermosetting resin which is resistant to high temperatures. The maximum operating temperature of the compound after expansion is for example 250 °C. Preferably the compound also comprises inorganic fillers.

Preferably, the percentage of thermosetting resin ranges between 70% and 90%. In a preferred embodiment, said percentage is equal to about 80%. The remaining part may consist, at least partly, of inorganic fillers.

According to one embodiment, the viscosity of the compound (at 20 °C) is about 15000 cps.

According to one embodiment, the expansion thickness is about 200%.

Unlike the known methods in which an expanded insulating material (for example in the form of a pre-formed bar 3-4 m long) is inserted inside the thermal break chamber, the present invention involves applying material onto a surface in a non-expanded state in such a way that this material is transformed into the expanded state only if subjected to a predetermined heat treatment.

According to another aspect the invention relates to a method for manufacturing a thermal break section, comprising the steps of

• providing a first half-shell, a second half-shell, a rigid heat-insulating element and a thermal break chamber defined at least partly by the first half-shell, the second half-shell and the rigid heat-insulating element,

• applying a layer of a non-expanded compound comprising a thermosetting resin resistant to high temperatures on at least one surface of the thermal break chamber, wherein said layer of compound has a thickness of between about 0.5 mm and about 5 mm and wherein the compound is configured to expand when subjected to an activating heat treatment;

• subjecting the thermal break section to an activating heat treatment so that the compound expands and forms an expanded heat- insulating filling body inside the thermal break chamber, wherein the volume of the expanded heat-insulating filling body is at least twice the volume of the layer of non-expanded compound.

Preferably, the volume of the expanded heat-insulating filling body is at least four times the volume of the layer of non-expanded compound. Preferably, the density of the expanded heat-insulating filling body is less than at least half the density of the non-expanded compound.

The compound preferably also comprises inorganic fillers.

Preferably, the percentage of thermosetting resin ranges between 70% and 90%.

Preferably the step of applying a layer of non-expanded compound comprises the step of applying the compound in a liquid, semi-liquid or gel state and the step of leaving the compound to dry in a natural or forced manner before assembling the section.

The non-expanded compound is preferably applied onto a surface of the first half-shell, a surface of the second half-shell, a surface of the rigid heat-insulating element, a surface of a dividing element provided inside the thermal break chamber and/or a surface of a connecting element provided inside the thermal break chamber.

The step of subjecting the thermal break section to an activating heat treatment preferably comprises the step of heating the assembled thermal break section to a temperature higher than 150 °C, for example during a step for painting the thermal break section.

A detailed description of the invention now follows, being provided purely by way of a non-limiting example, to be read with reference to attached sets of drawings in which:

- Figure 1 is a cross-section through a thermal break section with material expanded so as to form a heat-insulating filling body according to a first variant;

- Figure 2 is a cross-section through a second variant;

- Figure 3 is a cross-section through a third variant;

- Figure 4 is a cross-section through a fourth variant;

- Figure 5 is a cross-section through a fifth variant;

- Figure 6 is a cross-section through a sixth variant;

- Figure 7 is a cross-section through a seventh variant;

- Figure 8 is a cross-section through an eighth variant;

- Figure 9 is a cross-section through a ninth variant;

- Figure 10 is a cross-section through a tenth variant;

- Figure 1 1 is a cross-section through an eleventh variant;

- Figure 12 is a cross-section through a twelfth variant;

- Figure 13 is a cross-section through a thirteenth variant;

- Figure 14 is a cross-section through a fourteenth variant;

- Figure 15 is a cross-section through a fifteenth variant;

- Figure 16 is a cross-section through a sixteenth variant;

- Figure 17 is a cross-section through a seventeenth variant; and

- Figure 18 is a cross-section through an eighteenth variant.

According to the invention a compound having a thickness according to needs is deposited on a surface which is smooth, rough and/or has lugs, both on plastic and metallic materials. Application may be performed manually or using automated means with a natural or forced drying period so that the surface may be totally dry, allowing easy logistic handling thereof.

The compound has the characteristic feature that, at a predetermined temperature, it expands and solidifies immediately after natural cooling. The elements on which the compound may be applied may have different shapes. The compound may be applied on a surface of the thermal break chamber or on the outside thereof, with the aim of improving the thermo-acoustic and mechanical performance. The compound, after reaching the expansion activation temperature, helps improve, once dried, joining together of the components.

The compound may also be applied inside the cells of tubular (or cellular) heat-insulating elements in order to maintain the continuity of the insulation inside the cavity and improve considerably the thermo- acoustic and mechanical performance thereof.

Advantageously, the heat-insulating body obtained after expansion of the compound improves the heat insulation, the sound insulation and the robustness of the section. In addition, it has proved to be very advantageous for improving the resistance to pulling forces (or resistance to extraction) of the heat-insulating elements.

Figure 1 shows, merely by way of a example, a thermal break section with two half-shells 1 and 2 and two heat-insulating elements 3 in the form of bars of polyamide, PVC, ABS, Tefanyl ® or the like. The half- shells 1 and 2 are shown with a roughly square cross-section and have teeth for seals or accessories. The cross-section of the half-shells must not in any way be understood as limiting for the present invention.

Each of the half-shells has teeth which form seats for the ends of the heat-insulating elements (in this example, in the form of substantially Ύ-shaped bars).

In this first example, the compound is applied to the internal surface of the two heat-insulating structural elements 3. After activation (obtained by heating the section to an activation temperature) the compound expands and forms two heat-insulating bodies 5, as schematically shown in Figure 1 . The shape of the heat-insulating bodies 5 shown in Figure 5 is schematic and does not necessarily correspond to a real situation. The shape of the compound, following expansion, may vary significantly depending on many factors including the type of material, the temperature and the heating time, the thickness of the layer applied and the position of the section during the expansion step. The two heat-insulating bodies 5 could also expand until they touch and form a single expanded heat-insulating body which occupies substantially the entire volume of the thermal break chamber.

As mentioned above, the expanded heat-insulating bodies 5 improve the thermal, acoustic and structural performance of a thermal break section.

The example shown in Figure 2 is similar to that of Figure 1 . The difference lies in the fact the compound is applied to a surface of only one heat-insulating structural element 3 (the left-hand one). On the other element no compound is applied. Therefore, when the section is subject to a predetermined heat treatment, only a single expanded heat-insulating body 5 will be formed. All the other observations made in connection with Figure 1 are applicable.

The example shown in Figure 3 is similar to that of Figure 1 . The difference lies in the fact that the internal surfaces 6 of the heat- insulating structural elements 3 are shaped so as to form a slight concavity. During application of the compound, this concavity allows a greater quantity of compound to be retained. This in turn results in the possibility of forming expanded heat-insulating bodies 5 which are larger in volume and fill more the chamber 4. Obviously, in the same way as for Figure 2, the compound may be provided on only one of the internal surfaces 6. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 4 is similar to that of Figure 1 . The difference lies in the fact that the internal surfaces 6 of the heat- insulating structural elements 3 are shaped so as to form projections 7 which form shoulders for confining the compound between them. The compound is then applied, where necessary in a relatively large amount, in a predetermined zone. This in turn results in the possibility of forming expanded heat-insulating bodies 5 which have a larger volume and/or are denser in the centre. Obviously, in the same way as for Figure 2, the compound may be provided only on one of the heat- insulating elements. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 5 is similar to that of Figure 1 . The difference lies in the fact that the internal surfaces 8 of the heat- insulating structural elements 3 are formed with a surface which is knurled, rough or machined stepwise so as to improve the adhesion and drying of the compound during production. Obviously, in the same way as for Figure 2, the compound may be provided only on one of the internal surfaces 8. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 6 is similar to that of Figure 1 . The difference lies in the fact that the internal surfaces of the heat-insulating structural elements 3 are provided with two or more projections 9 on round surfaces 10 (as in Figure 3) or on smooth or rough surfaces (as in Figure 5) in order to improve the adhesion and drying of the compound during production. Obviously, in the same way as for Figure 2, the compound may be provided only on one of the heat-insulating elements. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 7 is similar to that of Figure 1 . The difference lies in the fact that the heat-insulating structural elements 3 are tubular elements and not bars with an open cross-section. According to this example, the compound is applied, for each tubular element, on the internal surface of the chamber 4, but not inside the cells of the heat-insulating elements. Obviously, in the same way as for Figure 2, the compound may be provided on only one of the heat- insulating elements. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 8 is similar to that of Figure 7. In this case also, the heat-insulating structural elements 3 are tubular elements and not bars with an open cross-section. According to this example, the compound is applied, for at least one of the tubular elements, inside at least one of the cells 1 1 of the heat-insulating elements. Obviously, in the same way as for Figure 2, the compound may be provided only in one of the heat-insulating elements. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 9 is similar to that of Figure 1 . The difference lies in the fact that the heat-insulating structural elements 3 are joined together by means of one or more structural connecting elements 12. The compound is applied on at least one of the structural connecting elements 12. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 10 is similar to that of Figure 1 . The difference lies in the fact that the heat-insulating structural elements 3 are provided with two more vertical projections 10 suitable for improving seating of the compound, during production, allowing drying thereof on said heat-insulating structural elements 3. Obviously, in the same way as for Figure 2, the compound may be provided on only one of the heat- insulating elements 3. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 1 1 is similar to that of Figure 1 . The difference lies in the fact that heat-insulating structural elements 3 are provided with a flange 14 which is normally used for thermal improvements or other purposes. According to this example, the compound is applied on both the heat-insulating structural elements, on either side of the flange 14. In this case also, after application, the compound may be dried directly on the heat-insulating structural elements 3 before assembly. Obviously, in the same way as for Figure 2, the compound may be provided only on one of the heat-insulating elements 3. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 12 is similar to that of Figure 1 1 . According to this example, the compound is applied on both the heat- insulating structural elements 3, only on one side of the flange 14. Preferably the flange in this example is not centred with respect to the heat-insulating structural element 3. In this case also, after application the compound is dried directly on the heat-insulating structural elements 3 before assembly. Obviously, in the same way as for Figure 2, the compound may be provided only on one of the heat-insulating elements 3. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 13 is similar to that of Figure 1 . According to this example, however, the compound is not applied directly onto the heat-insulating structural elements 3, but onto a film 15. The film, in turn, is applied onto the internal surface of the heat- insulating structural elements 3 after the compound has dried or before it becomes completely dry. Obviously, in the same way as for Figure 2, the compound may be provided only on one of the heat-insulating elements 3. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 14 is similar to that of Figure 10. According to this example, the compound is applied to a support structure 16 which can be combined, once the compound has dried (or also in some cases before the compound has dried), with the two heat- insulating structural elements 3 or only one of them. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 15 is similar to that of Figure 1 . According to this example, the compound is not applied to the heat- insulating structural elements 3, but to the surfaces 18 and 19 of the half-shells 1 and 2 which define the chamber 4. The compound is applied preferably before assembly of the section. Assembly may be performed before the compound is completely dried, but preferably occurs after complete drying of the compound. According to this example, after the expansion caused by a specific heat treatment, two bodies 5 of heat-insulating material which fill at least partly the chamber 4 are formed. Obviously, the compound may be provided only on the surface of one of the half-shells. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 16 is similar to that of Figure 1 . According to this example, the compound is not applied to the heat- insulating structural elements 3, but to a structural connecting element 20 which is separate from the heat-insulating structural elements 3, but which can be associated therewith. The compound may be associated with one or both the sides of the element 20. Assembly may be performed before the compound is completely dry, but preferably takes place after complete drying of the compound. According to this example, after the expansion caused by a specific heat treatment, two bodies 5 of heat-insulating material which fill at least partly the chamber 4 (divided by the element 20) are formed. Obviously the compound may also be provided on one side only of the element 20. All the other observations made in connection with Figure 1 are also applicable.

The example shown in Figure 17 is similar to that of Figure 16. The difference lies in the fact that the two heat-insulating structural elements 3 are also joined together by a connection 12 which further defines the chamber. All the other observations made in connection with Figure 16 are also applicable.

The example shown in Figure 18 is similar to that of Figure 1 . The difference lies in the fact that the compound is applied both on the internal surface and on the external surface 21 of the two heat- insulating structural elements 3 (or also only one of them). Assembly may be performed before the compound is completely dry, but preferably occurs after complete drying of the compound. According to this example, after the expansion caused by a specific heat treatment, two bodies 5 of heat-insulating material which fill at least partly the chamber 4 and extend also outside the chamber are formed (for each heat-insulating element 3).

Claims

1 . A thermal break section comprising a first half-shell (1 ), a second half-shell (2), a rigid heat-insulating element (3) and a thermal break chamber (4) defined at least partly by said first half-shell (1 ), said second half-shell (2) and said rigid heat-insulating element (3), wherein a layer of a non-expanded compound comprising a thermosetting resin resistant to high temperatures is provided on at least one surface of said thermal break chamber (4), wherein said layer of compound has a thickness of between about 0.5 mm and about 5 mm,

wherein said compound is configured so as to expand when subjected to an activating heat treatment and form an expanded heat-insulating filling body (5) inside said thermal break chamber (4),

wherein the volume of the expanded heat-insulating filling body (5) is at least twice the volume of the layer of non-expanded compound.

2. The thermal break section according to claim 1 , wherein the volume of the expanded heat-insulating filling body (5) is at least four times the volume of the layer of non-expanded compound.

3. The thermal break section according to claim 1 or 2, wherein the density of the expanded heat-insulating filling body is less than at least half the density of the non-expanded compound.

4. The thermal break section according to claim 1 , wherein the compound also comprises inorganic fillers.

5. The thermal break section according to claim 5, wherein the percentage of thermosetting resin is between 70% and 90%.

6. The thermal break section according to claim 1 , wherein said layer of non-expanded compound is a layer of a compound applied in a liquid, semi-liquid or gel state and dried before assembling the section.

7. The thermal break section according to claim 1 , wherein said surface is a surface of the first half-shell (1 ), a surface of the second half-shell (2), a surface of the rigid heat-insulating element (3), a surface of a dividing element (14, 15, 16) provided inside the thermal break chamber (4) and/or a surface of a connecting element (1 2, 20) provided inside the thermal break chamber (4).

8. A method for manufacturing a thermal break section, comprising the steps of

i. providing a first half-shell (1 ), a second half-shell (2), a rigid heat-insulating element (3) and a thermal break chamber (4) defined at least partly by said first half-shell (1 ), said second half-shell (2) and said rigid heat-insulating element (3), ii. applying a layer of a non-expanded compound comprising a thermosetting resin resistant to high temperatures on at least one surface of said thermal break chamber (4), wherein said layer of compound has a thickness of between about 0.5 mm and about 5 mm and wherein said compound is configured to expand when subjected to an activating heat treatment;

iii. subjecting the thermal break section to an activating heat treatment so that said compound expands and forms an expanded heat-insulating filling body (5) inside said thermal break chamber (4), wherein the volume of the expanded heat- insulating filling body (5) is at least twice the volume of the layer of non-expanded compound.

9. The method according to claim 8, wherein the volume of the expanded heat-insulating filling body (5) is at least four times the volume of the layer of the non-expanded compound.

10. The method according to claim 8 or 9, wherein a density of the expanded heat-insulating filling body is less than at least half of a density of the non-expanded compound.

1 1 . The method according to claim 8, wherein the compound also comprises inorganic fillers.

12. The method according to claim 1 1 , wherein the percentage of thermosetting resin ranges between 70% and 90%.

13. The method according to claim 8, wherein the step of applying a layer of non-expanded compound comprises the step of applying the compound in a liquid, semi-liquid or gel state and the step of leaving the compound to dry in a natural or forced manner before assembling the section.

14. The method according to claim 8, wherein said non-expanded compound is applied on a surface of the first half-shell (1 ), a surface of the second half-shell (2), a surface of the rigid heat-insulating element (3), a surface of a dividing element (14, 15, 16) provided inside the thermal break chamber (4) and/or a surface of a connecting element (12, 20) provided inside the thermal break chamber (4).

15. The method according to claim 8, wherein said step of subjecting the thermal break section to an activating heat treatment comprises the step of heating said assembled thermal break section to a temperature higher than 150 °C during a step for painting the thermal break section.