Abstract: Method of forming a high-performance, low-cost filter is provided. The filter comprises a housing and a cover. The housing defines a cavity in which one or more rods are disposed, one end of each rod being integrally formed with the housing. The rods function as coaxial resonators. A cover, disposed over the cavity, is securable to the housing. Input and output signal leads are coupled in conventional configurations to the rods. In one embodiment, the housing and cover are formed from a moldable dielectric material, such as plastic, which is then plated with a conductive film. In another embodiment, the housing is formed from a moldable dielectric material which is then plated with a conductive film while the cover is formed from a conductive material. The present invention provides optimal performance by using air as a dielectric separating the rods which function as coaxial resonators.

Abstract: A dielectric substrate is conditioned for subsequent electroless plating thereon by contacting with a catalytic metal salt and then with a reducing agent and with an electroless metal plating bath followed by contacting with a second catalytic metal salt. In addition, a dielectric substrate is conditioned for electroless plating thereon by obtaining a substrate of a dielectric material that contains metal particles therein and contacting with a catalytic metal salt.

Abstract: Addition polymer substrates comprising structural groups derived from olefinic nitriles and conjugated dienes, especially ABS resin substrates, are treated with aqueous tetravalent cerium in a concentration of at least about 0.1 M, preferably with a tetravalent cerium solution, to improve adhesion to metal coatings subsequently deposited non-electrolytically; for example, by electroless deposition. The metallized articles are heat treated following metal deposition. Further metal coatings may be deposited, preferably followed by further heat treatment.

Abstract: Disclosed is a method of drilling, desmearing, and additively circuitizing a printed circuit board. The printed circuit board is drilled under conditions which produce glass and polymer smeared vias and through holes. The particulate debris is removed by vapor blasting the drilled printed circuit board. Next the printed circuit board is soaked in a solvent to swell the drill smear on the circuit interplanes of the printed circuit board. This solvent is then removed by entrainment in a gas, and a stream of an aqueous, acidic, oxidizing solution is passed through the printed circuit board holes to remove swollen smear in the thru holes and produce an etchback of conductors. After a water rinse an aqueous reducing solution is passed through the printed circuit board to reduce and remove aqueous acidic oxidizing solution, e.g., residual aqueous acid oxidizing solution. The printed circuit board is rinsed to remove the aqueous reducing solution.

Abstract: A process for producing a printed wiring board characterized by forming a nickel layer by electroless plating and a copper layer formed thereon by electroless plating, or forming a copper undercoating layer before the nickel layer by electroless plating can produce printed circuit boards excellent in resistance to electrolytic corrosion and suitable for mounting parts in high density.

Abstract: Improved adhesion of electroless metal deposited on an organic dielectric layer with phase separated morphology is accomplished by the spontaneous formation of a morphologically and topographically rough surface. In one embodiment a ternary solution of a polar solvent and two polymer precursors of the same polymer which are separable in two phases of different order are cast in film on a substrate and heated to form two phases of different order to spontaneously produce a rough surface. Upon exposure to an alkaline solution, one phase is etched at a faster rate than the other. Seeding and electroless deposition of a metal on the rough surface results in improved adhesion of the metal to the dielectric layer. In a second embodiment a quaternary solution of a polar solvent, a seeding agent, two polymer precursors of the same polymer which are separable in two phases of different order are cast in a thin film on a substrate and heated to form three phases.

Abstract: An improved method of laminating a metal foil or sheet to a polyimide material is provided. A solution of a precursor of an intractable (i.e. thermosetting) polyimide is applied to a substrate and the solvent is removed to form a dry tack-free film. Thereafter, a solution of a precursor of a thermoplastic polyimide is applied onto the first film of polyimide and the solvent is removed to form a dry tack-free second film. Both films are then cured concomitantly at a sufficiently rapid rate and low temperature to effect substantial imidization of the polyimide precursors of both films without substantial crosslinking or densification of the polyimides in either of the films. Thereafter, a metal sheet or foil is laminated onto the thermoplastic polyimide film according to the following process. The thermoplastic film is contacted with the sheet or foil of metal to be laminated thereto.

Abstract: A process is disclosed for making metal plated PPD-T fibers wherein the plating is durable and highly conductive. The process involves contacting the fibers with an 80 to 90% sulfuric acid solution, neutralizing and washing the fibers with water, and then plating the fibers by an electroless plating process. The acid treatment of the fibers promotes adhesion between the metal and the fiber and high electrical conductivity for the plated metal.

Abstract: A method of manufacturing printed circuit boards is disclosed wherein metallic conductive structures are produced in a desired pattern on a carrier board of isolating material. The method begins with the provision of a carrier board having a metal foil laminated to its surface and thereafter forming conductive traces on the carrier board, deactivating the carrier board to remove substantially all substances deposited on the carrier board other than the conductive traces and forming final conductive structures by electroless chemical metal deposition on the pattern of conductive traces. Circuit boards manufactured in accordance with such a method will have final conductor structures with base layer portions of the original laminated metal foil. In a preferred embodiment, the step of deactivating the carrier board involves rinsing the carrier board with hydrochloric acid.

Abstract: Electroless deposition of copper from solution onto a substrate, particularly a polymeric laminate for use in electronic circuitry, is accomplished by first treating said substrate with a stilbene-based fluorescent brightener to sensitize said substrate and thereafter contacting said substrate with an electroless copper plating solution.

Abstract: Method of producing a polyimide layer having improved adhesion to a metal layer thereon. A halogenated polyamic acid is sprayed, partially cured, degreased and oxidized to form a partially cured polyimide layer, which is then electrolessly plated with a primary metal layer and then final cured into the polyimide layer. Electrolessly or electrolytically applied secondary metal layers are then deposited on the primary layer, until the metal layer of a desired thickness is attained. The present invention further discloses articles such as an EMI shielded enclosure and an insulated mold surface, having metal layers as an EMI shield and an insulating surface, respectively.

Abstract: Method of producing a modified polyimide layer to improve adhesion of a metal layer thereon. A limited quantity of water is added to a halogenated polyamic acid to form a reaction product, which is then sprayed, degreased, oxidized and cured into a modified polyimide layer. The chemically modified surface by the aforementioned method is then electrolessly plated with a primary metal layer followed by one or more electrolessly or electrolytically applied secondary metal layers until the metal layer of a desired thickness is attained. The present invention further discloses articles such as an EMI shielded enclosure and an insulated mold surface, having metal layers as an EMI shield and an insulating surface, respectively.

Abstract: Cyanate ester polymer articles, particularly fiber-reinforced, are metallized by electroless deposition preceded by a series of pretreatment steps which improve adhesion of the metal layer or layers. Said steps include aqueous alkali followed by nitric acid treatment. They preferably also include an initial alkaline permanganate treatment, preferably preceded by aqueous alkali.

Abstract: It is herein disclosed a metallized film having an exhibiting a superior surface gloss, said film comprising a blend of (i) no more than about 10% by weight of low molecular weight, isotactic poly-1-butene with a melt flow in the range, of greater than 20 to about 1500 g/10 min., and (ii) at least about 90% by weight of a propylene polymer.

Abstract: Sulfonated polyamides, e.g. aliphatic polyamides such nylon-6 and nylon-6,6, partially aromatic polyamides and polyaramides such as poly(phenyldiamidoterephthalate), provided with sulfonate radicals chemically bonded as amine pendant groups to nitrogen atoms in the polymer backbone are useful for stainblocking polyamide textile articles and as precursors for providing electrolessly-deposited metal-coatings on palladium sulfonate modified surfaces. Nickel-coated polyaramide textile material have surprisingly exceptional flame resistance.

Abstract: A process for coating a non-conductive substrate, such as glass, ceramic or plastic, which comprises applying to the surface of the substrate a coating of a silylated polyamine-noble metal (SPNM) complex and then optionally bringing the coated substrate so obtained into contact with a solution containing a metal salt, such as a salt of nickel, cobalt or copper, to obtain plating of metal from the latter solution onto the surface of the substrate.

Abstract: The adhesion of metal coatings, such as those produced by electroless or physical vapor deposition, on polypyromellitimide surfaces is improved by prior treatment of the surface with concentrated sulfuric acid, followed by aqueous alkali metal hydroxide of at least about 2M concentration. Further metal may be deposited on the surface, for example by electrolytic or physical vapor deposition, following the original metal deposition.

Abstract: A method of manufacturing a copper-polyimide substrate, includes hydrophilicating the surface(s) of a polyimide film, applying a catalyst thereto, subjecting the film to electroless plating, heat-treating it in an inert atmosphere, and subjecting it to electroless copper plating or to electroless copper plating followed by electrolytic copper plating. The hydrophilication of the surface(s) of the polyimide film is effected with an aqueous solution containing a hydrazine hydrate and an alkali metal hydroxide or with an aqueous solution containing a permanganate and/or a hypochlorite, then a catalyst is applied to the surface(s) by an ordinary way, then the surface(s) is/are subjected to electroless plating with any one of nickel, cobalt nickel alloys or cobalt alloys to form a plated layer thereon having a thickness of from 0.01 to 0.1 .mu.

Abstract: Certain organic polymeric materials are capable of reversibly accepting or donating electrons from a reducing entity. The redox sites in the polymer accept electrons and, as a result, a change in the properties of the polymer occurs. This change is useful in modifying or etching the polymeric material The material can be modified by incorporation of metallic seeds into the material at a controlled depth. The seeds are incorporated by interaction of cations of the metals with the redox sites in the polymer, which cause the reduction of the cations to form the neutral metallic seeds. Subsequent exposure of the polymeric material containing the seeds to an electroless bath causes further deposition of metal having the desirable characteristic of good adhesion to the polymeric material. Etching of the polymeric material can be carried out as a result of an increase in solubility of the polymer in aprotic solvents when its redox sites have accepted electrons.

Abstract: A process for metal plating a resin molded article molded from a resin composition containing as main components, a polyphenylene sulfide resin and a glass-reinforcing agent, which comprises, before the metal plating,(1) treating the resin molded article by immersion in a mixed liquid of nitric acid and a fluoride salt or in a mixed liquid of nitric acid and hydrofluoric acid (A treatment), thentreating the resulting resin molded article by immersion in an organic polar solvent-containing liquid (B treatment), and further, if necessary,treating the resulting resin molded article by immersion in an aqueous floride salt or hydrofluoric acid solution (C treatment).

Abstract: This invention relates to a novel electroless plating method which requires no pre-treatment step for the surface-corrosion on the surface to be plated, wherein a metal layer is formed by applying, onto the surface to be plated, a solution of a composition consisting of a styrene type elastomer used generally as a component for the hot melt type adhesive agent, or the styrene type elastomer and a stickiness imparting resin of a molecular structure similar to that of the elastomer; drying the solution as applied; and effecting the electroless plating on the coated film thus obtained, the method being able to substitute the conventional electroless plating as an advance step of the electrolytic plating for synthetic resin. The particular object of the present invention is to utilize the method in the field of the electroless plating for the purpose of preventing the plating operation from the electromagnetic wave disturbances.

Abstract: The adhesion of metal coatings deposited by electroless deposition on polycarbonate-addition polymer substrates, especially polycarbonate-ABS substrates, containing up to about 85% (by weight) polycarbonate is improved by first contacting the substrate with an alkali metal hydroxide solution for about 1-2 minutes, followed by an alkaline permanganate solution and a reducing agent to remove any manganese residue.

Abstract: Poly(arylene sulfide) articles having plated metal paths thereon are disclosed. A pattern of areas of lesser crystallinity and areas of higher crystallinity is created in the polymer morphology of a surface of the article. The surface is then exposed to a chemical etchant selectively active upon the areas of lesser crystallinity thereby etching those areas of lesser crystallinity while leaving areas of higher crystallinity substantially unaffected. Then a conductive metal is deposited on the etched areas of lesser crystallinity by an electroless plating process. Subsequent electroplating can also be used.

Abstract: The present invention relates to an electroless gold plating solution, a method of plating by using the same, and an electronic device plated with gold by using the same.According to the present electroless gold plating solution, the plating solution components contain no cyanide ions, the amount of a reducing agent used is small, and gold plating can be carried out without causing the gold plating on conducting paths having a fine interval between them to short-circuit the conducting paths.Therefore, according to the method of gold plating by using said electroless gold plating solution, a plating method that is safe in the plating work and in the treatment of its waste liquor can be accomplished. The method has a feature that the method can provide an electronic device on which parts can be mounted highly densely, and wherein the joint reliability to the parts is high.

Abstract: An improved process for depositing strongly adhering metallic coatings on substrate surfaces by wet chemical methods by treating the surfaces with a primer before activation.The materials produced by the process are eminently suitable for the shielding of electromagnetic waves.

Abstract: A method of adhering a polyimide to a substrate includes first placing the substrate in a dilute acid solution. The substrate is then placed in a palladium and tin solution followed by a rinse with water. The rinsed substrate is placed in an accelerator solution to substantially remove the tin from the substrate. The palladium which remains on the substrate surface provides nucleation sites for adhesion promotion and enhanced wetting of polyimide which is applied in a liquid form as by spraying or spinning. Adhesion of polyimide to metals such as gold, ceramics, alumina or polyimide is thereby provided.

Abstract: The present invention provides an electroless gold plating solution comprising essentially gold ions, a complexing agent, and a reducing agent, characterized by further containing a reduction promoter which has a function of giving electrons to an oxidant, the oxidant being produced from oxidation of the reducing agent with the gold ions being reduced, to change the oxidant to the original reducing agent. The present invention also provides a process for conducting electroless gold plating by bringing a substrate into contact with the electroless gold plating solution. The plating solution is excellent in the stability for gold plating of high deposition rate. Thus the present invention allows the electroless gold plating to be performed stably at a higher deposition rate.

Abstract: A process for the surface treatment of moldings based on polyamides by treatment with an aqueous acid, wherein the aqueous acid used is a 30-85% strength solution of H.sub.3 PO.sub.4 yields moldings which are readily metallizable. Metallized moldings obtained by this process are useful in the production of automobiles and in the electronics industry.

Abstract: A method of coating metal on a poly(aryl ether ketone) surface comprises treating the surface with a swelling agent, removing the swelling agent, etchinig the treated surface and then plating the etched surface with a metal using an electroless plating process. The process can be used to metal plate articles of poly(aryl ether ketones) of complex shapes, such as electrical connectors. Exceptional bond strength between the metal and the poly(aryl ether ketone) surface is obtained. Poly(aryl ether ketone) compositions, even those containing little, or no, glass or mineral fillers can be plated with a strongly adherent coating of plated metal using a process of this invention. The poly(aryl ether ketone) may contain additives such as pigments, fillers, stabilizers, reinforcing agents or the like. Blends of poly(aryl ether ketones) with other polymers, such as polyetherimides, fluoroelastomers, or the like, can be treated in accordance with this invention.

Abstract: A method of improving adhesion of a nickel alloy to the surfaces of diamond particles and articles made therefrom. Diamond particles are electrolessly nickel plating with the nickel alloy formed with a transitional metal, such as molybdenum. Electrolessly plated particles are then gradually heated at a steady rate from room temperature to a desired heat treatment temperature in a non-oxidizing atmosphere formed by argon containing 10% hydrogen. Exemplary articles made by the aforementioned process include a grinding wheel having uniformly dispersed abrasive diamond particles having the Ni/Mo alloy coat thereon.

Abstract: A process of pretreatment of metal-plating a resin molded article molded from a resin composition containing as main components a polyphenylene sulfide (PPS) resin, a glass-reinforcing agent and optionally one or more other thermoplastic resins comprises(1) treating the resin molded article by immersion in an oxidative acid solution (A treatment),(2) treatng the resulting resin molded article by immersion in an organic polar solvent-containing liquid (B treatment), and then(3) treating the resulting resin molded article by immersion in a solvent which can dissolve one or both of the glass reinforcing agent and one or more of the other thermoplastic resins (C treatment). The PPS resin contains a paraphenylene sulfide unit ##STR1## in an amount of at least 70 mole % of all recurring units. Total amount of PPS resin and the glass-reinforcing agent is at least 60% by weight of the resin composition, and the ratio of the PPS resin to the glass-reinforcing agent is in the range of 2:8 to 9:1 by weight.

Abstract: A method for producing a coating composed of an electroless metal plate, such as a copper plate, tightly bonded to a polyimide layer comprises a multi-step cure of the polyimide layer carried out in combination with a palladium-catalyzed electroless deposition process. A solution of a polyamic acid compound that is the precursor for the desired polyimide resin in a vaporizable solvent is applied to a substrate and heated preferably to temperature below 250.degree. C., to form a soft-cured polyimide film. The film is immersed in an aqueous palladium-tin colloidal suspension to deposit the colloidal particles thereon, which particles are then activated to form palladium nuclei dspersed on the surface. The soft-cured film is then heated, preferably above about 250.degree. C., to vaporize residual solvent and form a hard-cured polyimide layer having the palladium nuclei dispersed on the surface.

Abstract: A process treats the waste water which accumulates as used activation solution in the one-step activation, on the basis of acidic palladium/tin solutions, of large-surface plastic substrates, in particular of non-woven fabric, needled felt or open-pored foam sheets, for the purpose of a subsequent chemical metallization. A concentrate composed of palladium chloride and sodium chloride and then a solid tin salt in a molar ratio of 1:1.5 to 1:4, based on the palladium, is added to the waste water. After a certain maturing time, a ready-to-use activation solution is again obtained for activating a plastic substrate and reduces the amount of the waste water hitherto accumulating after the activation has taken place.

Abstract: Activator formulations which contain an aromatic polyurethane as binder are highly suitable for the preparation of non-metallic substrate surfaces for currentless metallization.The metal coatings produced are distinguished by good adhesion.

Abstract: A process for promoting the adhesion of metal to thermoplastic substrates such as polyimides. The improvement comprises conditioning the substrate by treating with a lactone and aqueous rinse prior to subsequent steps of etching and deposition of a metal coating. Use of the conditioner promotes increased adhesion between the substrate and the metal without loss of the cohesive integrity of the substrate throughout subsequent processing steps.

Abstract: A method for seeding the surface of a polyimide film which has been generated from a precursor polyamic acid film comprising the steps of: generating a film of polyamic acid on a substance (which may be done by conventional spin coating or by other solution coating techniques well known in the art); then either exposing the polyamic acid film to a solution containing palladium cations; heat-treating the palladium-treated film in a time/temperature schedule that causes imidization of the polymer to occur; exposing the seeded film to an electroless plating bath which causes the deposition of blanket metal film on the surface of the polymer film; or curing the film to the polyimide form; mechanically abrading the film surface, exposing the film to a solution containing palladium cations; exposing the seeded film to an electroless plating bath which causes the deposition of blanket metal film on the surface of the polymer film.

Abstract: A method for electrolessly plating an overcoat metal on a metal conductor disposed on a dielectric surface of a substrate. The method includes removing carbonized film from the dielectric surface by applying a plasma discharge, acid treating the metal conductor by dipping the substrate in a first acid solution in order to clean the surface of the metal conductor, activating the metal conductor to allow electroless plating thereon by dipping the substrate in a metal activator solution, deactivating the dielectric surface to prevent electroless plating thereon without deactivating the metal conductor by dipping the substrate in a second acid solution, and plating an overcoat metal on the metal conductor by dipping the substrate in an electroless plating solution so that the overcoat metal plates on and coats the metal conductor without plating on the dielectric surface.

Abstract: The invention relates to an activating composition for the electroless plating of non-conductive surfaces, in particular electronic printed circuit boards.The composition contains a metal complex in which the ligand consists of a quaternary nitrogen compound, especially a compound in which nitrogen forms part of a heterocyclic system and is quaternarized with a radical comprising an acid residue carrying a negative charge, for example a sulphonated group.The invention also concerns a method for the electroless plating involving the use of such composition, preceded by a preliminary treatment of the substrate and followed by the reduction of activating metal.The activating composition according to the invention allows to fix firmly the activator metal to the substrate.

Abstract: The process of electroless plating of polymers containing units derived from at least one member of the group consisting of acrylonitrile, butadiene and styrene, is carried out in an environment free of chromium ions, by the sequential steps of roughening and activating the surface of the polymer by contacting the same with an aqueous solution of a concentrated sulfur acid, of concentrated nitric acid or of concentrated phosphoric acid, in the presence of noble metal ion and an oxidant selected from the group consisting of nitric acid, hydrogen peroxide and persulfates. This is followed by an aqueous suspension of Pd.sup.0 and then by the conventional chemical metallization.

Abstract: A method of forming at least one electrically conductive path in a plastic substrate comprising providing a thermoplastic substrate having a melting point below 325.degree. C.

Abstract: A process for the manufacture of a multilayer printed circuit board including the step of depositing a noble metal onto an electrically non-conducting substrate. The substrate is first coated with a layer of polyamine polymer modified by being contacted with a compound containing at least two functional groups reactive to amino groups. The coated substrate is then contacted with noble metal ions.

Abstract: The surface of a substrate made of substantially crystalline polyimide is converted to form a layer of substantially amorphous polyimide. The substantially amorphous layer is formed by treating the crystalline polimide surface with a base followed by treatment with an acid to form a polyamic acid layer, which is reimidized to form a substantially amorphous layer by a low temperature heat cycle. Metals or polyimides can be deposited onto this amorphous layer, which is then cured to convert the amorphous layer to substantially crystalline polyimide. This process enhances the adhesion of the metal or polyimide layer without introducing contamination (new foreign materials or new functional groups) from surface treatments of adhesion layers.

Abstract: Conductive surfaces such as copper and/or tungsten surfaces, particularly copper circuitry areas of printed circuit board substrates or fused tungsten circuitry areas of fused tungsten-ceramic packages, are activated for receipt of electroless nickel plating thereon by providing the surfaces with particulate zinc metal, particularly by contact of the surfaces with an aqueous suspension of particulate zinc metal.

Abstract: This invention concerns a process for applying organic amino thiols to polyimide surfaces to improve the metal adhesion to such surfaces.

Abstract: A process of electrolessly metallizing a body on the surface thereof with a metal coating incorporating particulate matter therein, which process comprises contacting the surface of said body with a stable electroless metallizing bath comprising a metal salt, an electroless reducing agent, a complexing agent, an electroless plating stabilizer, a quantity of particulate matter which is essentially insoluble or sparingly soluble in the metallizing bath, and a particulate matter stabilizer (PMS), and maintaining said particulate matter in suspension in said metallizing bath during the metallizing of said body for a time sufficient to produce a metallic coating with said particulate matter dispersed therein.

Abstract: Described herein is a process for desmearing and etching back the surface of a nonconductive substrate which comprises (a) contacting the substrate with a strong acid; (b) then contacting the substrate with an aqueous basic solution; and (c) contacting the substrate with a reducing agent dissolved in a strong acid.

Abstract: A method for producing extremely smooth metal coatings on zincated aluminum substrates using a special double zincating procedure and/or a specially formulated electroless metal plating bath employing a unique plating process.

Abstract: Certain organic polymeric materials are capable of reversibly accepting or donating electrons from a reducing entity. The redox sites in the polymer accept electrons and, as a result, a change in the properties of the polymer occurs. This change is useful in modifying or etching the polymeric material. The material can be modified by incorporation of metallic seeds into the material at a controlled depth. The seeds are incorporated by interaction of cations of the metals with the redox sites in the polymer, which cause the reduction of the cations to form the neutral metallic seeds. Subsequent exposure of the polymeric material containing the seeds to an electroless bath causes further deposition of metal having the desirable characteristic of good adhesion to the polymeric material. Etching of the polymeric material can be carried out as a result of an increase in solubility of the polymer in aprotic solvents when its redox sites have accepted electrons.

Abstract: The surface modification of polyimide materials by a chemical process is disclosed to provide a variety of functional groups on the surface. The surface is treated to produce polyamic acid carboxyl groups which are subsequently reacted with epoxies, hydrazines, or alcohols. The carboxyl groups can be also be subjected to other organic reactions, such as reduction with metal hydrides and the like. The versatility and controllability of this process lends itself to promoting adhesion of the polyimide to similarly treated polyimides, other polymers and other substrates as well as combining with metals such as metal catalysts used for depositing conductors on non-conductive surfaces such as circuit boards.

Abstract: An electroless gold plating composition comprises an aqueous solution of alkali metal gold cyanide, alkali metal cyanide, alkali metal hydroxide, a reducer selected from borohydrides and alkyl amine boranes, and a stabilizer having the formula ##STR1## wherein R.sub.1 is --COOH, --OH, --CH.sub.2 OH, or --SO.sub.3 H (or an alkali metal salt thereof), R.sub.2 is --COOH, --OH, --Cl, --H, (or an alkali metal salt thereof) and is disposed in the 2, 5, or 6 ring position, and --NO.sub.2 is in the 3 or 4 ring position. This composition has a pH of 12.5-14.0, is heated at 85.degree.-95.degree. C., and operates at an oxidation/reduction potential of -550 to -700 millivolts to produce high purity gold deposits of amorphous structure and good hardness for electronic applications. The composition may be replenished as many as ten turnovers.