A SHUTTERING PANEL, CONTACT LAYER AND A METHOD FOR PRODUCING SHUTTERING PANELS

Abstract: A mould-form shuttering board against which concrete is intended to be cast. The shuttering board is preferably wood-based, such as so-called plywood, and is mainly characterized in that the side of the shuttering panel intended to lie in contact with the concrete includes an elastic layer which will not adhere to the concrete to any significant extent. The invention also relates to a contact layer and a method for manufacturing shuttering panels.

Description: A Shuttering Panel. Oαπtact Layer and a Method for Producing Shuttering Panels The present invention relates to a concrete-form shuttering panel against which concrete is intended to be cast. The invention also relates to a shuttering-panel contact layer and to a method for manufacturing shuttering panels. Shuttering panels of this general kind are known. One problem ex¬ perienced when concreting in this way resides in the difficulty of releasing the shuttering panels f om the setting concrete after concreting. It is known to apply so-called farm oil to the panel surface facing towards the concrete, prior to casting the concrete. This is expensive, however, owing to the time consumed in applying the oil and also due to the cost of the material consumed, and is also undesirable from an environmental aspect. Rresent-day shuttering panels are normally mod based, for instance plywood panels, among other things for reasons of cost and mechanical strength. Another advantage afforded by the use of wood-based panels is that they can be nailed. Ihe kncwn panels often have a surface coating, e.g. a plastic film coating, which is baked on the wood surface, or a plastic laminate which is glued onto the wood surface, or a plastic material reinforced with fibre glass. Hcwever, despite the presence of this surface coating, it is necessary to apply large quantities of form oil in order to enable the panel to be released from the concrete. One serious drawback with known wood-based panels is that the nail holes are permanent and allow moisture to enter the wooden panel, causing the panel to rot quickly. The present invention relates to a shuttering panel and to a contact layer which solves the above-related problems. Accordingly, the invention relates to a concrete-form shuttering panel against which concrete is intended to be cast and vftiich is preferably wood-based, such as plywood, and therewith nailable. The shuttering panel is mainly characterized in that the side of the panel which is intended to lie in contact with the concrete includes an elastic layer which will not adhere to the concrete to any sig¬ nificant extent. The invention also relates to a contact layer for concrete-form shuttering panels, said contact layer being intended to lie against the cast concrete. Ihe contact layer is mainly characterized by an elastic layer which is intended not to adhere to the concrete to any significant extent. The invention also relates to a method for manufacturing a concrete- form shuttering panel against vdiich concrete is intended to be laid and which is preferably wood-based, such as so-called plywood, and vdiich is provided on the side thereof intended for contact with the concrete an elastic layer which will not adhere to the concrete to any significant extent. The method is mainly characterized by applying liquid elastic-layer forming material to one surface of a shuttering panel, preferably with the aid of one or more spray nozzles, and rolling the layer material to a desired thickness with the aid of a roller, such as a steel roller, vfoerein a release agent, such as a layer of Teflon^ is preferably applied between the roller and the liquid contact-layer forming material. The invention will new be described in more detail with reference to an exemplifying eπfoodύnerrt thereof. The inventive shuttering panel is thus preferably wood-based, i.e. is comprised mainly of wood, such as so-called plywood, and the side of the panel v ch is intended to lie in contact with the concrete is provided with an elastic layer vftiich will not adhere to the concrete to any significant extent, the layer material being chosen against this background. It has been found that some plastic materials possess properties vdiich enable concrete to be laid in contact with these materials without the materials binding or adhering to the concrete. This enables the material to be quickly and easily separated from the concrete when the concrete has set. According to preferred embodiments, the layer is formed from a polymer- based material, a rubber-based material or the like. Preferred materials are those which are able to withstand temperatures considerably beneath 0 β C, i.e. materials which will not freeze. Examples of such materials which, in addition to the aforesaid properties, will not adhere to hardened concrete but can be readily loosened therefrom, is a polymer-based material retailed under the trademark BAXTEC, designated 0308 and manufactured by Bayer Chemie, Germany, and a similar polymer-based material which is retailed under the trademark ADHKENE, designated REA and manufactured by du Pont, U.S.A. Suitable elastic materials have a Shore-hardness A of 60-90, preferably 70-80. The surface of the shuttering panel onto which the elastic layer, or coating, is to be applied is preferably treated with a so-called primer before applying the elastic layer, this primer functioning to seal the wood and to prevent air from exiting from the wood during application of the layer. According to one such embodiment, the primer used is a material retailed under the trademark ELIO GRIP, designated 6036, and manufactured by Achland Chemicals Corp., U.S.A. According to one entoodimsπt, which is preferred in some instances, the elastic material from which the contact layer is formed includes a εo- called plasticizer, such as essentially dioctyl phthalate, which provides the contact layer with a surface having further improved release properties with regard to concrete. According to one method for manufacturing shuttering panels provided with elastic cxsncrete-σontaσt layers, the material from which the elastic layer is formed is applied in a liquid state, preferably by means of one or more spray nozzles, onto a primer-treated panel surface and is rolled to a desired layer thickness with the aid of a roller, such as a steel roller, wherein a release agent, such as a Teflor coating, is preferably applied between the roller and the applied liquid layer-forming material, whereafter the Teflon^coating is then preferably removed. Preferably, at least seme of the edge surfaces of the panel, such as the surfaces located at right angles to the roller axis, are provided with frame parts vrtiich extend above the panel surface to be coated through a distance whicii corresponds to the desired thickness of the contact layer, said frame work forming roller spacing means during a rolling operation. The panel will also preferably slope downwards in the direction in which, the contact layer is rolled out, for instance at an angle from 1-2° in relation to the horizontal plane. According to one esixxϋmeπt, the layer has a thickness of about 1-5 nm, preferbly from 2-4 raα. According to one embodiment, the contact layer is glued to a suppo ing panel body. The function of an inventive shuttering panel and an inventive contact layer, and also the inventive method will be understood in all essen¬ tials from the aforegoing. The elasticity of the layer and its surface properties ensure that the shuttering panel can be released relatively easily from the concrete. The layer is pressed against the panel by the pressure exerted by the concrete as it expands, as a result of its elastic resilience of the layer when the concrete has set and the form is stripped. It will also be obvious from the aforegoing that the invention affords important advantages over the kncwn prior art. A large number of concrete constrictions can be laid while using one and the same layered shuttering panel, thereby achieving considerable savings in material (farm oil) and working time. In addition, the time taken to strip the form is reduced by the fact that the form can be readily removed frcm the concrete structure. In addition, the shuttering panel can be nailed and the contact layer is "self-healing", i.e. the nail holes are "healed" automatically when the nails are withdrawn, due to the elastic resilience of the contact layer. The invention has been described in the aforegoing with reference to exenplifying e_πfcodiments thereof. It will be understood, hcwever, that other eπbodimeπts and minor modificatiαns are conceivable within the concept of the iπveπticn. For instance, the term shuttering panel as used here shall be given a wide interpretation and not considered limited to straightforward panels, but can also be considered to include, for instance, cylindri- cal configurations and form elements in which more elements than a shuttering panel are integrated to form an assembly. It is preferred to -treat the panel surface that has not been provided with a contact layer, thus the surface remote from the concrete, with a preservative substance, such as Cuprinol (registered trademark) which will allcw moisture to depart from the panel. It will also be understood that materials other than the above-men¬ tioned BAYTBC, ADHRENE, PLIO OOP and dioctyl phthalate, having generally cxsrresponding properties can be used when applying the invention, where BAYTEC and ADIHENE are mouldable, polymer-based materials of synthetic rubber type. Ωie invention is thus not restricted to the afaredescribed exemplifying eπbodimeπts thereof, since modifications and variations can be made within the scope of the following Claims.

Claims: Claims 1. A concrete-form shuttering panel against whicii concrete is intended to be laid and whic is preferably wood-based, such as so- called plywood and therewith nailable, cha ract e r i z e d in that the side of the panel which is intended to lie against the concrete is provided with an elastic contact layer of such nature as not to adhere to the concrete to any significant extent. 2. A panel according to Claim 1, characteri z ed in that the elastic layer is comprised generally of an elastic, polymer- based material having a lew freezing point such as not to freeze at teπperaturs considerably below 0°C. 3. A panel according to Claim l or 2, ch aracte r i z e d in that the panel surface inwardly of the elastic layer is treated with a so-called primer in order, among other things, to prevent air from exiting from the panel material during the manufacture of said panel. 4. A panel according to Claim 1, 2 or 3, c haracteri z e d in that the elastic material includes a so-called plasticizer, suc±t as dioctyl phthalate for further iπprσving the release properties of the panel with regard to concrete. 5. A panel according to Claim 1, 2, 3 αr 4, chara c ¬ teri z ed in that the contact layer has a thickness of 1-5 itm, preferably 2-4 nm. 6. A panel according to Claim 1, 2, 3, 4 or 5, cha r ac¬ ter i z ed in that the elastic material has a Shore-hardness A of 60-90, preferably 70-80. 7. A contact layer for concrete-form shuttering panels against which layer concrete is intended to be cast, character i z ed by an elastic layer of such nature as not to adhere to the concrete to any significant extent. 8. A contact layer according to Claim 7, c h a r a c t e r i z e d in that the elastic layer comprises substantially an elastic, polymer- based material having a freezing point which is so low that the material will not freeze at temperatures considerably beneath 0°C. 9. A contact layer according to Claim 7 or 8, c h a r a c ¬ t e r i z e d in that the contact layer includes a so-called primer with which the panel surface is treated inwardly of the elastic layer, said primer being intended, among other things, to prevent aid exiting from the panel material during manufacture of the panel. 10. A contact layer according to Claim 7, 8 αr 9, c h a r a c ¬ t e r i z e d in that the elastic material includes a so-called plas- ticizer, such as dioctyl phthalate for further improving the release properties for further improving the release properties of the layer with regard to concrete. 11. A contact layer according to Claim 7, 8, 9 or 10, c h a r a c - t e r i z e d in that the layer has a thickness of 1-5 nm, preferably 2—4 n . 12. A contact layer acx∞rding to Claim 7, 8, 9, 10 or 11, char¬ acteri z ed in that the elastic material has a Shore-hardness A of 60-90, preferably 70-80. 13. A method for manufacturing σoncrete-fαrm shuttering boards against which concrete is intended to be cast and which is preferably wood- based, such as so-called plywood, and which is provided on the side thereof intended for contact with concrete with an elastic layer which will not adhere to the concrete to any significant extent, c h a r a c t e r i z e d by applying the elastic layer material in a liquid state to a panel surface, preferably with the aid of one or more spray nozzles, and rolling the liquid layer to a desired thickness with the aid of a roller, such as a steel roller, wherein a release agent, such as a eflonlayer, is preferably applied betoreen the roller and the applied liquid contact-layer material. 14. A method according to Claim 13, ch a r ac te r i z e d by treating the panel surface with a so-called primer prior to applying the liquid, elastic layer material. 15. A method according to Claim 13 or 14, chara cteri z ed in that the desired thickness of the contact layer is achieved with the aid of roller spacers in the farm of frame parts arranged on at least some of the sides of said panel, said frame parts extending from the panel surface to an extent corresponding to the desired layer thickness.

Inventors: TARALDSSON LEIF BOERJE, TARALDSSON, LEIF, BOERJE
Applicants: TARALDSSON LEIF B, TARALDSSON, LEIF, BOERJE
Application year: 1992
Main classification: E04G9
IPC codes: E04G9