PROTECTION PROCESS AND APPARATUS

Abstract: The exposed surfaces of objects are protected by an absorbent sheet of woven cloth material impregnated on at least one of its sides with a solution containing an instrumescent substance, and an adhesive including an instrument substance for adhering the sheet to the object to be protected.

Description: PROTECTION PROCESS AND APPARATUS This invention relates to a process for protecting objects in the event inter alia of a fire and apparatus for use in this process. In many countries there is a growing recognition of the need to conserve objects of historical significance and especially to protect such objects against outbreaks of fire. The importance of protecting historical objects against the adverse effects of inclement weather and general decay is also both appreciated and recognised. Examples of these objects include painted or otherwise coated wooden facades, pillars, columns, roof beams and the like of historic buildings, particularly in Far Eastern countries where, to date, only limited resources have been employed to protect the fabric and contents of temples and other historic buildings, many of these objects being of timber to which paint or other material has been applied. These objects include tree trunks typically of 30 to 40 feet in height which, some thousands of years ago, were covered with cloth and plaster and then painted. Such pillars and columns have remained essentially untouched to the present time. Many of the external surfaces are cracked and, with ever increasing pollution, require urgent renovation. At the present time attempts to conserve such objects have included the removal of the outer surface of an object together with any paint or coating thereon and the application of fresh coatings of paint or the like. These attempts have in many cases been found seriously to damage the objects to be conserved and, in any event, do not provide protection against fire. The' present invention sets out to provide an economic and effective process for protecting and conserving such objects; the invention also sets out to provide apparatus for use in this process. According to the present invention in one aspect, there is provided apparatus for protecting the exposed surfaces of objects, the apparatus comprising an absorbent sheet of woven cloth material impregnated on at least one of its sides with a solution containing an intumescent substance, and an adhesive including an intumescent substance for adhering the sheet to the object to be protected. The apparatus may also comprise an intumescent containing filler for effecting repairs to cracks and the like. The apparatus may also include an intumescent containing coating and/or intumescent containing masonry paint. The intumescent substance for both the solution and the adhesive may comprise an alkaline metal silicate or exfoliating graphite. The intumescent content of the filler, coating and/or masonry paint may also comprise an alkaline metal silicate or exfoliating graphite. A preferred alkaline metal silicate is sodium silicate and the solution may, for example, contain up to about 50% by weight of the intumescent substance. In a preferred embodiment, the solution contains up to about 30% by weight, more especially up to about 20% by weight of the intumescent substance. The precise concentration of intumescent substance employed will depend inter alia upon the degree of intumescence and longevity of fire protection required. The liquid carrier of the solution may be aqueous or non-aqueous. If aqueous, the liquid carrier may additionally contain one or more volatile organic solvents in order to reduce the drying time of the solution. The liquid carrier of the solution may contain thickening agents, suspending agents and stabilising agents, and may be in the form of an emulsion or suspension. The absorbent sheet may comprise woven cloth produced from, for example, glass fibres. In a preferred embodiment both sides of the sheet are impregnated with the intumescent containing solution. The intumescent containing solution may be applied to the sheet with, for example, a brush or spray. Alternatively, the sheet may be immersed in a quantity of the solution. The sheet may be pre-coated with a layer of adhesive on one of its surfaces, the layer being protected by a removable sheet of, for example, cloth, paper or card. Alternatively, the adhesive may be sprayed onto the sheet and/or onto the object to be protected just prior to application of the cloth sheet to the object's surface. In another aspect, the invention provides a process for protecting the exposed surfaces of objects of historical significance which comprises applying to the exposed surface of the object a coating of a clear washable solution comprising a quantity of intumescent material. In a further aspect the invention provides a process for protecting an object against fire, inclement weather or general decay by applying to the object's surface a sheet of woven cloth coated on at least one of its surfaces with a solution of an intumescent containing substance, the cloth being adhered to the object's surface by an adhesive which includes an intumescent substance. The surface of the object may be cleaned or stripped prior to the application of the cloth. Alternatively, the cloth may be applied to the object surface without prior cleaning or stripping. Prior to the application of the cloth, cracks or other unwanted indentations may be filled with an intumescent containing filler. After adherence of the cloth to the object surface, a protective coating containing an intumescent substance may be applied to the exposed cloth surface. Once dried, one or more coatings of an intumescent containing masonry paint may be applied to the covered object surface. In one example of a process in accordance with the invention, each surface of a woven cloth sheet was impregnated with an intumescent containing solution marketed by the applicants under the trading style FB56. The cloth was allowed to dry and is then wrapped around and adhered to the surface of the object (for example a pillar or column comprising a tree trunk) to be protected using an adhesive marketed by the applicants under the trading designation 1A Intumescent Adhesive (Product 46). Once applied the cloth surface was coated with Applicants' intumescent coating product HW01 (Product 42) and, once dry, painted using a suitable masonry or other paint which may or may not include a quantity of intumescent material. Cracks or other unwanted indentations in the object surface were filled using the Applicants' intumescent filler material (Product 63) may be employed. The intumescent substance for both the solution and the adhesive comprised an alkaline metal silicate or exfoliating graphite. The intumescent content of the filter, coating and masonry paint also included an alkaline metal silicate or exfoliating graphite. A preferred alkaline metal silicate is sodium silicate and the solution may, for example, contain up to about 50% by weight of the intumescent substance. In a preferred embodiment, the solution contains up to about 30% by weight, more especially up to about 20% by weight of the intumescent substance. The precise concentration of intumescent substance employed will depend inter alia upon the degree of intumescence required. In another example of the process, roof beams which in their unpreserved form comprised timber beams wrapped in a type of cloth weave hessian on the surface of which were water based paintings were initially sprayed with a washable intumescent containing coating material marketed by the Applicants under their trading style 321 (Product 66). In some cases, where the hessian wrapping was damaged, the beams were treated as mentioned above using a covering of woven cloth sheet impregnated with an intumescent containing solution and an adhesive containing an intumescent material. The applied cloth and coatings provide protection for the respective object against general wear and tear, inclement weather and decay. One advantage of the invention is that no or limited preparation of the object surface is required. There is, for example, no need to remove from the object surface paint or other decorations applied to the surface. In the event of fire, the intumescent contents of the impregnated cloth and other coating material expands rapidly to protect the covered object for periods of an hour or more. It will be appreciated that the foregoing is merely exemplary of fire protection processes and apparatus in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention.

Claims: CLAIMS 1. Apparatus for protecting the exposed surfaces of objects, the apparatus comprising an absorbent sheet of woven cloth material impregnated on at least one of its sides with a solution containing an intumescent substance, and an adhesive including an intumescent substance for adhering the sheet to the object to be protected. 2. Apparatus as claimed in claim 1 further comprising an intumescent containing filler for effecting repairs to cracks and the like. 3. Apparatus as claimed in claim 1 or claim 2 further comprising an intumescent containing coating and/or intumescent containing masonry paint. 4. Apparatus as claimed in any one of the preceding claims wherein the intumescent substance for both the solution and the adhesive comprises an alkaline metal silicate or exfoliating graphite. 5. Apparatus as claimed in any one of claims 2 to 4 wherem the intumescent content of the filler, coating and/or masonry paint comprises an alkaline metal silicate or exfoliating graphite. 6. Apparatus as claimed in claim 5 wherein the alkaline metal silicate is sodium silicate. 7. Apparatus as claimed in any one of the preceding claims wherein the solution contains up to about 30% by weight. 8. Apparatus as claimed in claim 7 wherein the solution contains up to about 20% by weight of the intumescent substance. 9. Apparatus as claimed in any one of the preceding claims wherein the liquid carrier of the solution is aqueous. 10. Apparatus as claimed in claim 9 wherein the liquid carrier additionally contains one or more volatile organic solvents in order to reduce the drying time of the solution. 11. Apparatus as claimed in any one of the preceding claims wherein the absorbent sheet comprises woven cloth. 12. Apparatus as claimed in claim 11 wherein the cloth is produced from glass fibres. 13. Apparatus as claimed in any one of the preceding claims wherein the sheet is pre- coated with a layer of adhesive on one of its surfaces. 14. A process for protecting the exposed surfaces of objects of historical significance which comprises applying to the exposed surface of the object a coating of a clear washable solution comprising a quantity of intumescent material. 15. A process for protecting an object against fire, inclement weather or general decay by applying to the object's surface a sheet of woven cloth coated on at least one of its surfaces with a solution of an intumescent containing substance, the cloth being adhered to the object's surface by an adhesive which includes an intumescent substance. 16. A process as claimed in claim 15 wherein the surface of the object is cleaned or stripped prior to the application of the cloth. 17. A process as claimed in claim 15 or claim 16 wherein after adherence of the cloth to the object surface, a protective coating containing an intumescent substance is applied to the exposed cloth surface.

Inventors: WARD DEREK ALFRED, WARD, DEREK, ALFRED
Applicants: ENVIRONMENTAL SEALS LTD, WARD DEREK ALFRED, WARD, DEREK, ALFRED
Application year: 2001
Main classification: E04B1
IPC codes: E04B1, E04G23