US2594061A - Plating barrel - Google Patents

Description

April 22, 1952 F. E. NEWMAN PLATING BARREL Filed Oct. 25, 1949 a e Q .a

0 O 0 Q o o n c 0 I I I 0 a O a 0 0 I n 0 0 o 0 5 g a 0 0 0 I) 5 0 0 0 O U INVENTOR. ff/F/f/J f. A ZW/ /J/V ArromvgY Patented Apr. 22, 1952 PLATING BARREL Ferris E. Newman, New Haven, Ind., assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application October 25, 1949, Serial No. 123,441

9 Claims. 25989) This invention relates to plating barrels and more particularly to a non-metallic plating barrel which is far superior to non-metallic plating barrels heretofore employed.

In plating small metal parts, in order to save considerable handling, it has become customary in the art to place the parts in a perforated nonmetallic barrel for transfer through the cleaning and plating baths. Prolonged exposure to strong acid pickling solutions and to alkali cleaners at temperatures ranging as high as 200 F. places considerable strain on the barrel. Parts of the barrel all of which must be non-metallic include a large diameter gear (usually of the order of 16 in diameter), bearings and structural panels. A number of non-metallic In the accompanying drawings:

Fig. l is a side elevation, partly broken away in section, of a typical'plating, barrel made in accordance with my invention.

Fig. 2 is a partial end view of the plating barrel shown in Fig. 1, taken on the line 22 of Fig. 1.

Fig. 3 is an enlarged section through a laminated panel which may be employed in a modification.

In Figs. 1 and 2 of the drawings, the barrel of my invention is shown as embodying a pair of circular end members or cylinder heads I, be

tween which are arranged six foraminous panels materials have been used for the fabrication of rapidly disintegrates in acid. The prior art barrels have also been subject to other disadvantages including the high cost of manufacture due to the difiiculty of working with the materials heretofore used in construction of plating barrels. For these reasons, plating barrels heretofore available have not stood up satisfactorily in service. For a long time workers in the art have been aware of the shortcomings of the available non-metallic plating barrels but have been' unable to remedy these shortcomings. V

I have now discovered that a plating barrel far superior to those heretofore available may .be formed from a heat-cured composition'comprising a cashew nut shell oil-modified phenol-aldehyde resin which is convertible under the action of heatand an intermixed hardening agent to insoluble, infusible form, a hardening agent for the resin, typically and almost invariably hexamethylenetetramine, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth. The plating barrels of my invention are superior to prior plating barrels in the following respects: hot acid resistance, hot alkali resistance, impact strength, abrasion resistance, structural strength at 200 F., and ease of fabrication. As a result the plating barrels of my invention exhibit an extremely long service life even under the most severe service conditions and greatly reduce the cost of plating operations.

2 which have reduced end portions 3 entering corresponding recesses in the inner faces of end members I and reduced side portions 4 which enter corresponding recesses in longitudinal rail members 5 which are of square cross-section.

Rail members 5 and end members I are fixedly secured together in permanent relationship by means of studs 6 which pass through end members 1 into the ends of rail members 5. The end portions 1 of rail members 5 are reduced in size and circular in cross-section and enter corresponding circular recesses in end members I, clearance being provided between the ends of rail members 5 and the bottoms of the receiving recesses in end members I so that it is possible by means of studs 6 to draw the shoulders ofrail members 5 into tight engagement with end members l. The arrangement shown permits the ends I, rails 5 and panels 2 to be assembled into permanent tight relationship. It will be understood that in accordance with customary practice in the art. one of the panels 2 is made quickly detachable for charging and discharging the barrel. The detachable panel 2 is not illustrated because its construction is well known to the art.

Panels 2 are provided with perforations 8 which allow the cleaning and plating solutions free access into and egress from the interior of the barrel.

The following provision is made for mounting the barrel for rotation. Coaxially with the barrel at each end thereof there is provided an annular hub 9 which is tightly secured to the adjacent end member I by means of studs l0. Within each of hubs 9 there is disposed a floating, freely rotatable, sleeve bearing II which freely rotatably engages hub 9 and the stationary supporting sheave l2. Sheave I2 is fixedly securedto the conventional rubber-covered metal supporting arm 13 by means of studs 14. It will be understood that the construction of each end-of the barrel is identical and that each end of the barrel is supported in an identical manner. I As is conventional, supporting arms I3 form part of a yoke (not shown) which enables the barrel assembly to be moved easily from one tank to an other. Details of the yoke are not shown because it is conventional in the plating barrel art.

The barrel of my invention is driven in the following manner: surrounding the hub 9 and mounted coaxially with the barrel at one end thereof there is provided a driving gear 15 which is fixedly secured to the adjacent end I of the barrel by studs I 6, spacers I! serving to space the gear a suitable distance from the end I. It will be understood that the gear I is driven by a stainless steel driving gear (not shown) which is conventionally provided in the assembly in which the plating barrel is placed during operation.

In the modified form of panel 2a shown in Fig. 3, a laminated structure is employed, the major proportion of the thickness of the panel constitilting a core 20' to which facings 2l are larninated. Preferably such a laminated panel is made by assembling the uncured laminae and curing them together under heat and pressure whereby there is coalescense at the interface. Use of a laminated structure as shown in Fig. 3 enables the major portion thereof, i. e., the core 20, to be formed from the above composition with the components in proportions imparting high strength, great stiiiness, and freedom from creep at temperatures up to 200 F., and the facings 2| to be made of the material with relative proportions of the three major ingredients such as to impart high abrasion resistance.

important novel feature of the barrel of any invention is that it is constructed throughout of theabove-mentioned heat-cured composition of a cashew nut shell oil-modified phenol-aldehyde resin, a hardening agent therefor, a rubber'y copolymer of butadiene and acrylonitrile, and diatomaceous earth. I have found it possi-- ble to make every part of the barrel including not only the end members I, the panels 2 and the rails 5 but also the studs 6, the hubs 9, the studs 10, the bearings H, the sheaves l2, the studs [4, the gear l5, the studs I6 and the spacers I! from such a heat-cured composition. The result is that a barrel having remarkably long service life is obtained. In addition, the barrel is easily manufactured because of the easy mashining properties of the composition.

It will be understood that with the construction shown in the drawings, the cleaning or plating liquid can pass freely through the center ofthe hollow bearing collar or sheave I2 and has free access to the bearing assembly but does no harm because it can touch no exposed metal.

The floating bearing construction of my invention is highly advantageous because it is adapted to very long life. There is plastic-toplastic movement in the bearing mechanism and this is much superior to a bearing in which metal is substituted for any part of the bearing structure shown. The known non-metallic plating barrels available to the art heretofore have in re cent years been provided with a floating bearing made of nylon but such bearings are extremely the rubbery copolymer of butadiene and acryloto employ varying proportions of the three ingredients in constructing the various parts of the plating barrel assembly.

Thus Iprefer to form the end members i and the panels 2 or the cores of the panels 2a from the above composition in relative proportions of from to of the rubbery copolymer and correspondingly from 70 to 60% of the resin, and from 30 to 40% of diatomaceous earth. Use of these proportions gives a composition having good abrasion resistance, high modulus, and excellent dimensional and structural stability.

I prefer to form the rails 5, hubs 9, bearings l I and sheaves l2 from the above composition in relative proportions of from 30 to of the rubbery copolymer and correspondingly from 70 to of the resin, and from 30 to 45% of di atomaceousearth. These proportions impart freedom from creep at elevated temperatures, good structural strength at such temperatures,- and also (this being important in the case of the bearings ii) good resistance to wearing upon prolonged plastio-to-plastic movement.

Where a laminated type of panel 2a is employed, I prefer to form the facings 2! from the above composition in relative proportions of from 45 to% of the rubbery copolymer and correspondingly from 55 to 40% of the resin, and from 40 to 55% of diatomaceous earth. Facings formed of such a composition are unusually resistant to abrasion.

I prefer to form the driving gear Hi from a composition embodying from 45 to 60% of the rubbery copolymer and correspondingly from 55 to 40% of the resin, and from 40 to 55% of diatomaeeous earth. A gear so made displays unusual resistance to the abrasion of the matin stainless steel driving gear and excellent resist ance to accidental impact in moving the barrel from tank to tank. I

v I prefer to form the studs 0', I0, l4 and I6 from the above composition in relative proportions of from 35 to 40% of the rubbery copolymer and correspondingly from to 60% of the resin, and from 35 to 40% of diatomaceous earth. Studs formed from these proportions are resistant to creep at elevated temperatures and strong enough to enable the parts secured thereby to be tightly drawn together into permanent assembly and without shearing under the action of the wrench or driving tool.

Spacers ll are preferably formed iromthe same composition as studs 6, [0, M and It.

I have found that manufactured the various parts of the plating barrel and associated parts in the assembly from the various compositions just described considerably enhances the life of the platingbarre1and its utility becaus each-of the compositions described imparts particular properties required of each of the various parts.

The composition of matter from which the parts of the plating barrel of my invention are.

formed, can be made by first preparing a homogeneous mixture of a cashew nut shell oil-modilied phenol aldehyde resin, a hardening agent for said resin, particularly a methylene-yielding substance, especially hexa'metl'iylenetetramine, which cresols, the xylenols, etc. dric phenol, a polyhydric phenol, such as resor- ..cinol, may be used.

is capable of advancing theresin to the insoluble, infusible stage under the action of heat, a rubbery copolymer of butadiene and acrylonitrile, viz., synthetic rubber of the type known as Buna N and as GR-A, and diatomaceous earth. Upon shaping such a mixture to the desired form and heat-curing it, the shaping and curing typically being effected either by preforming the powdered mixture by pressure alone, followed by molding of the preform under heat and pressure, or by molding of the mixture directly under heat and pressure, the mixture is converted to a material having an unusual combination of physical properties.

Any cashew nut shell oi1-modified phenol-aldehyde resin capable of being advanced to insoluble, infusible form under the action of heat and a hardening agent, such as hexamethylenetetramine, may be employed in the practice of my invention. Such resins are extremely well-known, being available commercially. An example of such a resin is that known in the trade as Durez No. 12686. Another example is Durez No. 12687 which is a mixture of 92 parts of the resin sold as Durez No. 12686 and 8 parts of hexamethylenetetramine. Still other examples of such resins containing hexamethylenetetramine as the hardening agent are the resins known in the trade as Varcum 9820 and Varcum 9831. Such resins may be made in the manner disclosed in detail hereinafter.

As is well-known, cashew nut shell oil, which is obtained from the outer shell of the cashew nut, is composed largely of anacardic acid which upon heating is decomposed and converted to a longchain unsaturated phenol, known as eardanol, which has a 7-tetradecenyl side-chain,

in the position meta to the hydroxyl group on the benzene ring. While cashew nut shell oil itself may be used as obtained from the shell, I prefer to use the oil which has been heated to convert it to the phenol just described by decarboxylation in the well-known manner.

The lower molecular weight phenol used in conjunction with the cashew nut shell oil in making the resin is either a monohydric or a polyhydric, preferably the former, monocyclic phenol which contains no substituents on the benzene ring other than hydrogen, hydroxyl groups and lower alkyl side-chains. Examples of such lower molecular weight phenols are pheno1 itself, and

its homologues, such as ordinary cresylic acid which is a mixture containing the three isomeric Instead of a monohy- While the proportion of cashew nut shell oil used in making the phenolic resin may vary widely, I prefer to use it in an amount ranging from 3 to 12 mole per cent based on the sum of the moles of the cashew nut shell oil and the lower "nut shell oil used in making the resin may be outside the range given; thus it may range from 2 mole per cent up to 50 mole per cent based on the sum of the moles of the cashew nut shell oil and the phenol.

size.

Ordinary phenol is the preferred phenol for making the resin. As ordinary phenol is replaced by cresol, there is a tendency for the resin obtained to become softer with a consequent lowering of the hardness of the cured product.

The resin is typically made by heating a mix-? ture of the lower molecular weight phenol, the cashew nut shell oil (either as such or in the tie-,- carboxylated form) and an aldehyde, typically formaldehyde, in the presence of a suitable resinforming catalyst, usually an acid, such as an in organic acid, e. g., sulfuric or hydrochloric acid, or an acid-reacting material, as zinc chloride, to an oil-soluble stage. During the final stage of the reaction, the resin is advanced to the desired state at which it is still convertible to insoluble, infusible form under the action of heat and a hardening agent, and volatile materials are removed therefrom, these objects preferably being accomplished simultaneously by passing superheated steam through the charge until the residual mixture has reached the desired temperature, say 150 C. to 225 C. The residual mixture is then dumped from the kettle and allowed to cool. The cooled resin is then blended with the Buna N and the diatomaceous earth in the manner described hereinafter. v

The resins used in accordance with the present invention are characterized by being completely miscible in all proportions with butadiene acrylonitrile rubbery copolymers of relatively high aorylonitrlle content, 1. e., containing from 35 to 45%, or even more, of combined acrylonitrile. I

As the rubbery copolymer of butadiene and acrylonitrile used in the practice of the present invention, I much prefer to employ those rubbery copolymers containing a relatively high proportion of combined acrylonitrile, say from 35 to 45%, because these rubbery copolymers are completely compatible with the resin whereas rubbery copolymers or lower acrylonitrile content often tend to exhibit somewhat diminished compatibility resulting in somewhat poorer physical properties. A butadiene-acrylonitrile rubbery copolymer which gives unusually satisfactory results in the present invention is that known commercially as Hycar OR-15 which contains about 42% combined acrylonitrile. Another material which gives very excellent results is that known as Perbunan 35 which contains about 35% comblned acrylonitrile.

Less preferably, I may use rubbery copolymers of butadiene and acrylonitrile containing less than 35% combined acrylonitrile, say from 15% up to 35%. Examples of such copolymers arethose known commercially as Perbunan 26 and Per bunan 18 which contain approximately 26 and 18% acrylonitrile, respectively. As the combined acrylonitrile content is lowered, the compatibility with the phenolic resin tends to progressively decrease and the physical properties of the product tend to be progressively poorer.

The third major component of the composition usedin the practice of the present invention is diatomaceous earth. Any of the forms of granular or powdered diatomaceous earth commonly available commercially may beused in the practice of my invention. Usually the diatomaceous earth has a relatively small particle Generally it is so fine that substantially all of it will pass a 100 mesh sieve. Usually the particle size of this material will cover a range of from as large as 100 microns down to particles too small to be seen. I have obtained very satisfactory results using the diatomaceous earth known in the tradeas Dicalite 14W, also'kno'wn asgrade L, put outby the Dicalite Company.

- In addition to the three. principal components mentioned. above, the composition used. in the plating barrels of my invention. also contains a hardening agent, preferably hexamethylenetetramine or its known equivalent, in amount su'flicient to advance the resin to hard, infusible, insoluble condition during curing at elevated temperatures. Typically, the amount of hardening agent required to accomplish this is relatively smallin proportionto the other components. Usually the proportion of this hardening agent will range from to by weight based on. the resinv alone.

.. The composition may also contain small amounts of other suitable materials such as mold lubricants, pigments and coloring agents to give the-desired color, anti-oxidants for the rubber, etc. If desired, vulcanizing agents, such as sulfur, and other vulcanizing ingredients, such as the usual vulcanization accelerators and activators, may also be present although they are not necessary and in some cases it is believed that slightly better results are obtained without the use of such rubber vulcanizing agents and ingredients r The. foregoing ingredients are cornmlngled tog'ether to form a uniform homogeneous mixture in any suitable manner, typically by means of a Banbury mill or a roll mill of the type used for compounding rubber. The resulting mixture is sheeted out, as on a rubber calender, and is allowed to cool. It is then comminuted, as by chopping orgrinding, to a powdered or granulated material of suitable sizev for use in making preforms or for use directly as a. molding powder. It is usually preferable to refrigerate. the sheeted stock to. facilitate the chopping or grinding. Typically, the stock is cooled to 35F., or below, for this purpose. A conventional rotary knife machine may be used for grinding or chopping the mixture.

The resulting granular or powdered. material may then be preformed with. pressure but without heat to give preforms from which finished articles can'be. molded by subjecting'the preforms to heat and pressure to give the desired shape and cause the material to flow together and thus coalesce to a. continuous, integral form and at the same time tional molding methods such as compression molding or transfer molding or by simple placement into a mold cavity between heated platens and. subjection to an elevated temperature, say'of the order of 300 to 350 F., and to pressure, say of the order of 100 to 4000 lbs. per square inch, toform a cured sheet, slab or other article. A marked advantage of the mixture is that extremely high'molding pressures such as are commonly required with the conventional phenolic molding materiar'via, pressures of the order of 8 2000 lbs. per square inch and over, are not required. Pressures of. the order of 200 to 150.0 lbs. per square inch are ample for molding; the material of the present invention. Another advan tage is that the material cures very rapidly so that the productivity of the molding equipment is high. I

Regardless of the method of forming or shaping the mixture, th molding temperatures, pressure and time should be such that the mixture flows properly together to give a solid, uniform,

integral molded article and that the phenolic.

resin is converted to the insoluble, infusible state. The curing time required may vary widely, say from ten minutes to four hours, depending upon many factors, such as whether or not preforming was used, the thickness of the molding, etc. There seems to be no limit on curing time be yond which the properties of the material deterl crate. There is however, a minimum time, namely, the time required for complete curing; at the end of this time the physical properties of the mixture have reached their maximum.

The material of the present invention can be molded to very close tolerances. This makes it possible, for example, to mold the material directly into such articles as gears [5 with the teeth formed in the mold and with no need for: subse-- quent machining. This i in marked contrast to Composition A Pounds llycar OR-15 l6 Durez 12687 30 Dlcalite 14W 14 Zinc stearat 0.25 Anti-oxidanL. O. 3 ax 0. 25 Iron oxide pigment 3. 0

This composition when mixed and processed as described above is very satisfactory for the con struction of end members i, panels 2, rails 5, hubs 9, bearings II, and sheaves l2.

Composition B Pounds Hycar 0R-l5. l. 10.80 Durez 12687 16.56 Dlcalite 14W. 10. 00 waxwhnuw 0.2'7 Antibxldcnh. 0. 18 Iron oxide plgn1ent 3.12

This material is very satisfactory as a material from which to make end members I, panels 2, rails 5, hubs 9, bearings ll, sheaves l2, studs 6,

l0, l4 and i6 and spacers l1.

Composition 0. l Pounds Hycar ORl5. 24 Durcz 12687.. is Dicalite 14W LS Zinc stearate. 0.3 Anti-oxidant. 0. 2i

This composition is usually suitable for the manufacture of driving gear l5 and iacings 21 of panels 2a. Where facings 2! of this composition are provided, the core may be formed of Composition A above for good stiffness.

This material is extremely well suited for the fabrication of gear 15.

Composition E Pounds Hycar OR-l5 Durez 12687." Dicalite 14W. Zinc stearate" Anti-oxidant". Iron Oxide Pigment" Th'is'composition is very suitable for the manufacture of rails 5, hubs 9, bearings I I, and sheaves l2.

From the foregoing description it will be seen that the present invention provides a plating barrel which effectively overcomes the disadvantages of prior art non-metallic plating barrels. The barrels of my invention are simple and easy to construct and are rugged and long-lived in service. They withstand the action of cleaning and plating solutions remarkably well even at elevated temperature as high as 200 F., and also resist abrasion and impact. The excellent machining characteristics of the material from which they are formed and its relatively low cost are unusually advantageous. The plating barrels of my invention are highly inert chemically and electrically so that no problem of contamination thereby is presented. Numerous other advantages of the plating barrels of my invention will be apparent to those given in the art.

The composition of matter described herein is disclosed and claimed in my copending application Serial No. 98,153 filed June 9, 1949. Silent gears made of this composition are described and claimed in my copending application Serial No. 98,152 filed on the same day.

Having thus described my invention what I claim and desire to protect by Letters Patent is:

1. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, and a plurality of longitudinal rail members between said panels, said parts being composed of a heat-cured composition comprising a'cashew nut shell oil-modified phenolaldehyde resin convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth, the relative proportions being as follows: in said end members and in at least a major proportion 'of the thickness of said panels from to 40% of said copolymer and correspondingly from 70 to 60% of said resin, and from 30 to 40% of diatomaceous earth; in said rail members from 30 to of said copolymer and correspondingly from 70 to 55% of said resin, and from 30 to 45% of diatomaceous earth; said percentages being by weight based on the sum of said 901 51 and said resin.

2. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, a plurality of longitudinal rail members between said panels, and a floating freely rotatable sleeve bearing located at each end of the barrel coaxially therewith centrally of said end members, said parts being composed of a heat-cured composition comprising a cashew nut shell oil-modified phenol-aldehyde resin convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth, the relative proportions being as follows: in said end members and in at least a major portion of the thickness of said panels from 30 to 40% of said copolymer and correspondingly from l0 to 60% of said resin, and from 30 to 40% of diatomaceous earth: in said rail members and in said bearings from 30 to 45% of said copolymer and correspondingly from 70 to 55% of said resin, and from 30 to 45% of diatomaceous earth, said percentages being "by weight based on the sum of said copolymer and said resin.

3. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of, foraminous panels held longitudinally between said end members and formingthe sides of the barrel, a plurality of longitudinal rail members which with said end members support said panels, a floating freely rotatable sleeve bearing located at each end of the barrel co.- axially therewith centrally of said end members, and a hub located at each end of the barrel coaxially therewith centrally of said end members, said hubs being fixedly connected to said end members, said bearings freely rotatably floating inside said hubs in frictional engagement there}- with, said parts being composed of a heat-cured composition comprising a cashew 'nut shelljoilfmodified phenol-aldehyde resin. convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, at rubbery copolymer of butadiene and acrylonitrile, anddiatomaceous earth, the relative proportions being as follows: in said end members and in at least a major proportion of the thickness of said panels from 30 to 40% of said copolymer and correspondingly from 70 to 60% of said resin, and from 30 to 40% of diatomaceous earth; in said rail members, said bearings and said hubs from 30 to 45% of said copolymer and correspondingly from 70 to 60% of said resin, and from 30 to 45% of diatomaceous earth; said percentages being by weight based on the sum of said copolymer and said resin. a,

4. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, a plurality of longitudinal rail members between said panels, and a driving gear fixedly connected to one of said end members coaxially with the barrel, said parts being composed of a heat-cured composition comprising a cashew nut shell oil-modified phenol-aldehyde resin convertible -to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth, the relative proportions being as follows: in said end members and in at least a major proportion of the thickness of said panels from 30 to 40% of said copolymer and correspondingly from 70 to 60% of said resin andfrom 30 to 40% of diatomaceous earth; in said rail members from 30 to 45% of said copolymer and correspondingly from 70 to 55% of said resin, and from 30 to 45% of diatomaceous earth; in said gear from 45 to 60% of said copolymer and correspondingly from 55 to 40% of said resin, and from 40 to 55% of diatomaceous earth; said percentages being by weight based on the sum of said copolymer and said resin.

5. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, a plurality of longitudinal rail members which with said end members support said panels, a floating freely rotatable sleeve bearing located at each end of the barrel coaxially therewith centrally of said end members, a hub located at each end of the barrelcoaxially therewith centrally of said end members, said hubs being fixedly connected to said end members, said bearings freely rotatably floating inside said hubs in frictional engagement therewith, and a driving gear fixedly connected to one of said end members, said driving gear being mounted coaxially with said barrel and surrounding one of said hubs, said parts being composed of a heat cured composition comprising a cashew nut shell oil-modified phenol-aldehyde resin convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery polymer of butadiene and acrylonitrile, atomaceous earth, the relative proportions being as" follows: in said end members and in at least a major proportion of the thickness of said panels from 30- to 40% of said copolymer and correspon'dingly from '70 to 60% of said resin, and from 30 to 40% of diatomaceous earth; in said rail members, said bearings and said hubs from 30 to 45% of said copolymer and correspondingly from '70 to 55% of said resin, and from 30 to 45% of diatomaceous earth; in said gear from 45 to 50% of said copolymer and correspondingly from 55 to 40% of said resin and from 40 to 55% of diatomaceous earth; said percentages beingby weight based on the sum of said copolymer and said resin.

6. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, a plurality of longitudinal rail members between said panels, said rail members having recesses into which said panels extend, andstuds securing said rail members to said end members, said parts being composed of a heatcured composition comprising a cashew nut shell oil-modified phenol-aldehyde resin convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery copolymer of butadiene and acrylonitrile, and di atomaceous earth, the relative proportions being as follows: in said end members and in at least a major proportion of the thickness of said panels from 30 to 40% of said copolymer and correspondingly from 70 to 60% of said resin and from 30 to 40% of diatomaceous earth; in

said rail members from 30 to 45% of said polymer and correspondingly from 70 to 55% of said resin and from 30 to of diatomaceous earth; in said studs from 35 to {40% of said copolymer and correspondingly from 65 to 60% of said resin, and from 35 to 40% of diatomaceous earth; said percentages being by Weight based on the sum of said copolymer and said resin.

7. A plating barrel comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, .a plurality of longitudinal rail members between said panels, said panels being held in recesses in said end members and said rail members, a floating freely rotatable sleeve bearing located at each end of the barrel coaxially therewith centrally of said end members, a hub located at each end of the barrel coaxially therewith centrally of said end members, said hubs being fixedly connected to said end members, said bearings freely rotatably floatinginside said hubs in frictional engagement therewith, adriving gear mounted coaxiallywith said barrel and surrounding one of said hubs, studs fixedly securing said end members to the ends of said rail members, and studs fixedly securing said driving gear to one of said end members, said parts being composed of a heat-cured composition comprising a cashew nut shell oil-modified phenol-aldehyde resin convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth, the relative proportions being as follows: in said end members and in at least a major proportion of the thickness of said panels from 30 to 40% of said copolymer and correspondingly from 70 to 60% of said resin,.and from 30 to 40% of diatomaceous earth; in said rail menfloers, said bearings, and said hubs from 30 to 45% of said copolymer and correspondingly from '70 to or" said resin, and from 30 to 45% of diatomaceous earth; in said gear from 45 to of said copolymer and correspondingly from 55 to 40% of said resin and from 40 to 55% of diatomaceous earth; in said studs from 35 to 40% of said copolymer and correspondingly from to 60% of said resin and from 35 to 40% of diatomaceous earth; said percentages being by weight based on the sum of said copolymer and said resin.

8. A plating barrel "assembly comprising a pair of end members forming the ends of the barrel, a plurality of foraminous panels held longitudinally between said end members and forming the sides of the barrel, a plurality of longitudinal rail members between said panels, a hub located at each end of the barrel coaxially therewith centrally of said end members, a driving gear mounted coaxially with said barrel and sur rounding one of said hubs, a floating freely rotatable sleeve bearing located at each end of the barrel coaxially therewith and inside said hubs, a stationary sheave located at each end of the barrel coaxially therewith and inside said bearings, said bearings freely rotatably floating between said hubs and said stationary sheaves and in frictional engagement with said hubs and said sheaves, studs fixedly securing said end members to the ends of said rail members, studs fixedly securing said hubs to said end members, and studs fixedly securing said driving gear to the adjacent one of said end members, said parts being composed of a heat-cured composition comprising a cashew nut shell oil-modified phenol-aldehyde resin convertible to insoluble, infusible form under the action of heat and a hardening agent, a methylene-yielding hardening agent for said resin, a rubbery copolymer of butadiene and acrylonitrile, and diatomaceous earth, the relative proportions being as follows: in said end members and'in at least a major proportion of the thickness of said panels from 30 to 40% of said copolymer and correspondingly from 70 to 60 96 of said resin, and from 30 to 40 of diatonlaceous earth, in said rail members, said hubs, said bearings and said sheaves from 30 to 45% of said copolymer and correspondingly from 70 to 55% of said resin, and from 30 to 45% of diatomaceous earth ;'in said gear from 45 to 60% of said copolymer and correspondingly from 55 to 40% of said resin and from l to 55% of diatomaceous earth; in said studs from 35 to 40% of said copolymer and correspondingly from to 60% of said resin, and from 35 to 40% of cliatomaceous earth; said percentages being by weight based on the sum of said copolymer and said resin.

REFERENCES CITED The following references are of record in the file of this patentL UNITED STATES PATENTS Number Name Date 478,630 Newhall et al. 1 Jul 12, 1892 690,240 Cutler Dec. 31, 1902 800,692 Thorpe Oct. 3, 1905 1,934,461. Hartley Nov. 7, 1933 2,480,022 Hogaboom Aug, 23, 1949 OTHER REFERENCES Shepard et a1., Modern Plastics, pages 154-156. 210, 212, Oct. 1946.

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