Back to results
US 5,378,878 AGranted
Heat resistant and light weight container for materials to be heated, and process for manufacture thereof
AssigneeCEM Corporation
InventorRobert N. Revesz
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeCEM Corporation
InventorRobert N. Revesz
Estimating the term…
A highly preferred container for ashable material, which material is to be ashed by heat in an ashing furnace, while it is in such container, especially when such container is to be heated by microwave radiation onto microwave absorptive elements of the furnace, which thereby heat the container, is a heat resistant, walled container which is light weight, microwave transmissive, porous and air transmissive, which is of quartz microfibers that are held in desired walled container form, preferably in substantially flat cylindrical form. Such a container may be made by shaping a heat resistant, light weight, microwave transmissive and porous non-woven sheet of quartz microfibers to container form and heating and curing such sheet in such form, preferably after moistening it with water, whereby a form-retaining container results that can be successfully employed to hold ashable samples to be ashed for analysis during microwave powered ashings of such samples. The described containers may also be made by formation directly from the quartz microfibers, followed by sintering thereof to a form retaining article. Although pure quartz microfibers are preferred for the described containers they may contain or may be made of borosiliate glass, in which case their microwave transmission and high temperature stability can be decreased.
A container for a material which is to be heated therein, which container is microwave transmissive and heat resistant during such heating operation, light in weight and porous, and includes integral bottom and side wall portions made of quartz fibers, borosilicate glass fibers or a mixture of quartz fibers and borosilicate;
A container for a material which is to be heated therein, which container is heat resistant during such a heating operation, light in weight and of integral thin walled bottom and side wall portions which are porous to air flow through them during ashings of ashable analytical samples, which bottom and side wall portions are of non-woven microfibers which are quartz microfibers, borosilicate glass microfibers or a mixture of quartz microfibers and borosilicate glass microfibers, which non-woven microfibers are sintered together so as to be in integral walled and bottomed container form, wherein the container wall and bottom portions are resistant to a temperature of 500.degree. C., are of a thickness in the range of 0.2 to 5 mm, are of a weight in the range of 50 to 500 g/m.sup.2, are retentive of micron size particles and are of such a porosity that the pressure drop across them is in the range of 0 to 10 mm of mercury at a face velocity of air in the range of 1 to 10 cm per second.
A process for manufacturing a container which is suitable for use as a container for ashable material to be ashed in an ashing furnace, which container is heat resistant during such an ashing operation, light in weight and of integral thin walled bottom and side portions which are porous to air flow through them during ashings of ashable analytical samples, which bottom and side wall portions are of non-woven microfibers which are quartz microfibers, borosilicate glass microfibers or a mixture of quartz microfibers and borosilicate glass microfibers, which non-woven microfibers are sintered together so as to be in integral walled and bottomed container form, wherein the container wall and bottom portions are resistant to a temperature of 500.degree. C., are of a thickness in the range of 0.2 to 5 mm, are of a weight in the range of 50 to 500 g/m.sup.2, are retentive of micron size particles and are of such a porosity that pressure drop across them is in the range of 0 to 10 mm of mercury at a face velocity of air in the range of 1 to 10 cm per second, which process comprises shaping a light weight, microwave transmissive and porous sheet of non-woven microfibers, which are quartz microfibers, borosilicate glass microfibers or a mixture of quartz microfibers and borosilicate glass microfibers, to integral walled and bottomed container form, wetting material of such sheet or form before heating, heating said wetted and shaped form to a sintering temperature in the range of 800.degree. to 1,000.degree. C. for 1 to 20 minutes, and cooling it to room temperature in room temperature air.
A process according to claim 13 wherein the light weight, microwave transmissive and porous sheet of non-woven microfibers is of quartz microfibers containing 0 to 10% of borosilicate glass microfibers and said sheet is wet with water before being shaped to container form.
A process of manufacturing a container for a material which is to be heated therein, which comprises shaping a light weight microwave transmissive, heat resistant and porous sheet of quartz fibers, borosilicate glass fibers or a mixture of quartz fibers and borosilicate glass fibers, to container form, including integral bottom and side wall portions, heating said sheet in said form to a sintering temperature and cooling said container form, so that a form retaining integral porous container results, through the bottom and side wall partions of which air can pass and in which container micron size particles are retained.
Dependencies are inferred from the claim text.