MXPA99007806A - Lamina composed of insulation / foundation and metodode forming the mi - Google Patents

Abstract

A composite sheet of insulation and / or foundation is provided by continuously rocking a pair of cover sheets comprising a styrenic polymer, and simultaneously cracking between the freshly extruded cover sheets an inner sheet of a material selected from the group consisting of high polystyrene. impact, styrene butadiene, metallocene catalyzed polymers, and ethylene copolymers, formed with or without discontinuities, the cover sheets being immediately bonded to the interlayer

Description

COMPOSITE SHEET OF INSULATION / FOUNDATION AND METHOD OF FORMING THE SAME Background of the Invention Field of the Invention This invention relates to a composite sheet of insulation and / or foundation and, more particularly, to a laminated sheet having a pair of outer layers or sheets of foamed plastic cover, such as polymeric foam. styrenic, housing an inner layer or sheet of a relatively tough and flexible material such as high impact polystyrene, styrene butadiene, metallocene catalyzed polymers, or the like. The invention also relates to a method of manufacturing such sheets. Related Technology Relatively rigid, laminated foam panels are widely used in building construction for thermal and acoustic insulation and as non-load bearing structural members, due to their smooth surfaces and wind barrier properties. They are usually provided in a sheet of considerable length in relation to its width. The sheet is perforated transversely to its long dimension at equal intervals to define the panels. The sheet is then folded with bellows around the perforation lines to provide a stack of a wide panel for shipping and for transportation to the construction site. Foamed plastic is notoriously brittle, and therefore measures must be taken to prevent the sheet from fracturing and separating in the perforated lines when bending, and to prevent it from crumbling, tearing and breaking at the construction site during handling and when it sticks or staples in place. Sheet and / or foundation insulation known in the state of the art are shown in Figure 1. The known sheet 10 comprises a substrate or first sheet 11 of virgin or recycled styrenic polymer foam. A thinner liner or second sheet 12 is permanently adhered or bonded to one side of the first sheet 11 throughout its entire length. The second sheet 12 comprises a material that is much more tenacious and much more flexible than the styrenic polymer foam-high impact polystyrene or acid polyethylene copolymers, for example-thereby maintaining the integrity of the sheet during bending, handling, nailing or stapled. Styrenic polymeric foam structure sheets are conventionally formed by extrusion, such as continuously extruding a cylinder or styrenic polymer tube, expanding the tube under the internal pressure of gas, and slotting the expanded tube or "balloon" on one side and rolling it to form a sheet of a single thickness, or by spreading it on opposite sides to form a pair of sheets. It is also known to form a laminate of styrenic polymeric foam structure by simply introducing the extruded tube between a pair of rollers for flat pressing, and then continuously cutting the side edges of the flattened tube. Such a technique is disclosed in German Patent 2,946,867, published October 27, 1983, in the name of T. Komori et al. Although plastics, and in particular foamed plastics, are used in large quantities for insulation purposes, more and more efforts are being made to reuse these materials; that is, to recycle them, in view of environmental concerns. Plastics are particularly suitable for general re-use. With these considerations as a starting point, the invention is directed to the problem of providing insulation and / or sheet foundations that meet or exceed the thermal and resistance requirements, that provide an improved ease of handling and, when desired, the use of recycled materials, and that can be manufactured by a simple, effective and economical method. SUMMARY OF THE INVENTION The invention provides a composite sheet of insulation and / or foundation comprising a pair of cover sheets formed of a styrenic polymer foam that houses a relatively tough and flexible inner sheet of a material selected from the group consisting of polystyrene high impact, styrene butadiene, metallocene catalyzed polymers, and ethylene acid copolymers. Such a sheet is brittle and easily fractured in the cover sheets, but the tenacious and flexible internal sheet acts to maintain the integrity of the sheet in a construction analogous to the laminated window glass, resistant to shattering, commonly employed in automotive vehicles. The invention also provides a method of forming a composite sheet of insulation and / or foundation by extruding a pair of styrenic polymer sheeting sheets to form a styrenic polymer foam structure, simultaneously extruding a relatively tough and flexible inner sheet of a material selected from the group consisting of high impact polystyrene, styrene butadiene, metallocene-catalyzed polymers, and ethylene-acid copolymers, rapidly stretching and housing the inner sheet between the newly extruded sheeting sheets, and immediately bonding the sheeting sheets to the sheet internal To form a good bond, the cover sheets are kept as close to the melting point as possible, preferably by joining them to the inner sheet as soon as possible after they are formed, or alternatively heating them before they are joined together. with the inner blade. The preferred technique for doing this is to control the distance of the extruder dies in which the lamination occurs. More particularly, the method is carried out by continuously extruding a styrenic polymer tube to form a styrenic polymer foam structure, and slotting the tube on its opposite sides to provide the freshly extruded cover sheets. The sheets in this way have external surfaces and internal surfaces in confrontation in spaced relation to each other, and the inner sheet is inserted between the faces in confrontation and driven by them in the direction of displacement of the cover sheets. The inner sheet is soon linked between the freshly extruded cover sheets, and the confronting surfaces are immediately bonded around and with the inner sheet. Styrenic polymer foam may be used either recycled or virgin. Other objects, features and advantages of the invention will be apparent from the following description, in conjunction with the accompanying drawings. The Drawings In the drawings: Figure 1 is a partial cross-sectional view, amplified, of the sheet insulation and / or foundations known in the state of the art; Figure 2 is a partial, cross-sectional, amplified view of insulation sheet and / or foundation formed in accordance with the invention; and Figure 3 is a schematic representation of a manufacturing method according to the invention, which is adapted to form the insulation and / or foundation sheet of Figure 2. Detailed Description Figure 2 shows insulation sheet and / or laminated foundation, formed in accordance with the invention, and suitable for use in the construction or rehabilitation of buildings. The outer or cover sheets of the sheet comprise foamed plastic, specifically styrenic polymer foam, adjacent to an inner sheet of support material, the thickness of which is greatly exaggerated in Figure 2 for purposes of illustration. Ideally, the support material should be tough, strong and flexible, but adhere well to the styrenic polymer foam that forms the cover sheets, and should offer low resistance to moisture passage, largely as it happens in styrenic polymer foam. Then, a preferred material is high impact polystyrene, which is tenacious and flexible at room temperatures. It has a melting point in the range of about 70 to 150 ° C. In addition, high impact polystyrene is preferred because it is a good electrical insulator. Other suitable materials include butadiene styrene, metallocene catalyzed polymers, and ethylene acid copolymers. More particularly, a three layer insulation and / or foundation material 13 is shown in Figure 2, and includes a thin inner sheet 14 between two thicker cover sheets 15 and 16, to form the laminate. The cover sheets 15, 16 are formed of foamed, virgin or recycled plastic, while the inner sheet 14, which provides a bonding and support layer, preferably comprises high impact polystyrene, but may comprise any of the other materials of support identified above. If the sheets 15, 16 are formed from recycled styrenic polymer foam or a mixture of virgin and recycled styrenic polymer foam, resources can be conserved and the overall cost of production reduced. The inner sheet 14, coated on both sides by the cover sheets 15 and 16, the insulation sheet and / or foundation 13, is more resistant to tearing, making it more durable and easy to use. For example, either side of the sheet can be placed in contact with a concrete wall or a screw wall. As shown in Figure 2, the cover sheets 15 and 16 of the insulation and / or foundation sheet 13 are approximately equal in thickness and are bonded to the inner sheet 14 through the entire width thereof. Each cover sheet 15, 16 is approximately 100 to 250 thousandths of an inch thick, while the inner sheet 14 is preferably 0.5 to 3.0 thousandths of an inch thick, and most preferably approximately 1.0 thousandths of an inch thick. thickness. Of course, these thicknesses can be increased or reduced as required for a particular application. In addition, it is not essential that any two or more of the sheets be of the same thickness. Figure 3 shows a method of manufacturing the insulation sheet and / or foundation 13 of Figure 2. The two cover sheets 15 and 16 are continuously and simultaneously formed by extrusion. More particularly, a film balloon 23 is created from an extruder by means of an extruder die 22, the balloon being led to a cooling mandrel 24 and then slotted on opposite sides to be separated into two halves. Each of these halves, initially still rounded or dome-shaped in the balloon configuration, is rolled or flattened in order to form the two flat cover sheets 15 and 16. The method is up to this conventional time. The inner sheet 14, in the form of extruded viscoelastic melt, is continuously introduced from an extruder via an extruder die 25 directly between the cover sheets 15 and 16 formed from the balloon, to which it adheres and it stretches with them in their common direction of displacement. The inner sheet is fed from the die of the extruder at a rate which will cause it to be stretched to the desired thickness between the cover sheets.

The connection of the cover sheets 15 and 16 with the inner sheet 14 is carried out through the total widths of the three sheets. As stated above, the cover sheets are kept as close to the melting point as possible, preferably by joining them to the inner sheet as soon as possible after they are formed or, alternatively, heating them before they are brought together with the internal blade The inner sheet 14 leaves the die of the extruder 25 in the form of a hot melt at a temperature in the range of about 180 to 230 ° C. It is immediately linked by the confronting surfaces of the cover sheets and stretched with them. When this happens, the hot melt releases heat to the roof sheets, causing them to melt on the adjacent surfaces since they were already close to their melting temperature. At the same time, this transfer of heat from the inner sheet to the cover sheets causes it to cool and eventually reach its solid state, bonding securely to the melted surfaces of the cover sheets upon cooling and reverting to its solid state. On the other hand, if the cover sheets become overheated, they will blister. In this way, it will be seen that the relative locations of the two extruder dies 22 and 25 with each other and the distance therebetween are of critical importance and should be adjusted as necessary to provide a secure bond without blistering of the cover sheets.

A suitable clearance 27 is formed between a pair of tie rolls 26, which complete the lamination and help determine the thickness of the finished sheet. Although the above method is preferred, other methods of forming the insulation and / or foundation sheet of the invention can be substituted. For example, the sheet has also been formed successfully by co-extruding the sheets. If in the preferred method the residual heat of the extrusion process is inadequate to provide an acceptable bond between the cover sheets 15 and 16 and the inner sheet 14, the confronting surfaces of the cover sheets attached to the inner sheet can be heated before the lamination. Such heating may be provided by heat radiators (not shown), i.e. radiant heat; by heating nozzles (not shown) in contact with the confronting surfaces of the cover sheets 15 and 16, ie conductive heat; or, preferably, by forced convection, ie convective heat. In any case, the heating is carried out through the entire width of the sheet thus treated. Referring to Figure 3, in the preferred form of such heating, just before the cover sheets 15 and 16 are joined to the inner sheet 14, the confronting surfaces to be bonded to the inner sheet are exposed to the heat of two. opposing banks of heaters 35, 35a. These heaters are preferably of a type that continuously discharges heated gases directly onto the surfaces to be heated, the heat source being electric heating elements or gas combustion (none of which is shown), as preferred. Moreover, heater controls are preferably provided and conveniently located for manual adjustment by an operator to regulate the temperature of the heated surfaces. For the sake of simplicity, only one of such controls 36 is represented in Figure 6, although in fact each bank of buffers 35, 35a is provided with individual controls. Again, the link is carried out through all the widths of the adjacent sheets. It is also important to note that if heat is applied in this way, in each case it must be carried out through the entire width of each sheet thus treated. The inner sheet 14 can be formed in a known manner with discontinuities such as perforations or openings of various sizes, thereby achieving a saving of resources and establishing or improving the moisture transmission characteristics in the sheet. This can be carried out on the finished sheet 13 by piercing one or both of the cover sheets 15 and 16 and the inner sheet 14. Alternatively, openings in the inner sheet can be formed in the extruder die in a controlled manner, largely measured in the way that the extruded plastic wefts are manufactured, for example. In any case, moisture transmission can be varied by varying the size and density of the perforations or openings. Although the invention has been specifically described in relation to certain of its specific embodiments, it will be understood that this is by way of illustration and not limitation, and that the scope of the claims should be interpreted as broadly as the state of The technique.

Claims (17)

1. CLAIMS 1. A composite sheet of insulation and / or foundation, having a pair of cover sheets, each of the cover sheets comprising a styrenic polymer foam structure, an inner sheet housed between the cover sheets, the inner sheet comprising a material selected from the group consisting of high impact polystyrene, butadiene styrene, metallocene catalyzed polymers, and acidic ethylene copolymers.
2. 2. A composite sheet of insulation and / or foundation according to claim 1, wherein the cover sheets are bonded to the inner sheet.
3. 3. A composite sheet of insulation and / or foundation according to claim 1, wherein the inner sheet is formed with discontinuities therein.
4. 4. A composite sheet of insulation and / or foundation according to claim 1, wherein the material of the inner sheet comprises high impact polystyrene.
5. 5. A composite sheet of insulation and / or foundation according to claim 1, wherein the material of the inner sheet comprises polystyrene butadiene.
6. 6. A composite insulation and / or foundation sheet according to claim 1, wherein the material of the inner sheet comprises a metallocene catalyzed polymer.
7. 7. An insulation composite sheet according to claim 1, wherein the material of the inner sheet comprises an ethylene acid copolymer.
8. 8. A method of making a composite sheet of insulation and / or foundation, comprising the steps of extruding a pair of styrenic polymer sheeting sheets to form a styrenic polymer foam structure, extruding an inner sheet formed of a selected material of the group consisting of high impact polystyrene, styrene butadiene, metallocene catalyzed polymers, and acidic ethylene copolymers, and promptly housing the inner sheet between the freshly extruded sheeting sheets.
9. A method according to claim 8, including the step of attaching the cover sheets to the inner sheet immediately upon receiving the inner sheet between the cover sheets.
10. A method according to claim 8, including the steps of applying heat to the freshly extruded cover sheets immediately before receiving the inner sheet between the cover sheets thus heated, and attaching the cover sheets to the inner sheet immediately when housing the inner sheet between the cover sheets.
11. 11. A method according to claim 10, wherein the step of applying heat is carried out through all the widths of the cover sheets.
12. 12. A method according to claim 8, including the step of forming discontinuities in the inner sheet material.
13. A method according to claim 12, wherein the step of forming discontinuities in the inner sheet is carried out by piercing at least one of the cover sheets and the inner sheet.
14. A method according to claim 12, wherein the step of forming discontinuities in the inner sheet is carried out during the step of extruding the inner sheet.
15. 15. A method of making a composite sheet of insulation and / or foundation, comprising the steps of continuously extruding a styrenic polymer in a tube from a first extruder die to form a styrenic polymer foam structure, grooving the first tube on its opposite sides to form a spaced pair of cover sheets having confronting surfaces, continuously extruding from a second extruder die a material selected from the group consisting of high impact polystyrene, styrene butadiene, polymers catalyzed by metallocene, and acidic ethylene copolymers, to form an inner sheet, introduce the inner sheet between the confronting surfaces of the spaced cover sheets, quickly bond the freshly extruded sheet between the sheets with confronting surfaces to conduct the inner sheet in the direction of movement of the cover sheets, and immediately link the internal sheets to the confronting surfaces of the cover sheets.
16. 16. A method according to claim 15, including the step of applying heat to at least one of the confronting surfaces immediately before linking the inner sheet between the confronting surfaces of the cover sheets.
17. 17. A method according to claim 15, including the step of applying heat to both faces in confrontation immediately before linking the inner sheet between the confronting surfaces of the cover sheets.