US2236398A - Apparatus for drying finishes - Google Patents

Description

March 25, 1941.

F. E. DRUMMOND APPARATUS Fon DRYING FINISHES Original Filed April 17, 1939 2 Sheets-Sheet l "l P IIE. 1

IIIII'IlIIlIIIIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIII IN VENT OR` FLSM E. l/MMND ATTORNEY March 25, 1941. I F, E DRUMMQND 2,236,398 l APPARATUS FOR DRYING FINISHES Original Filed April 17, 1939 2 Sheets-Sheet 2 lOXYGEN OR OXYGEN OR ENRICHED HIR f ENRICHED GIR g x R17 71 r y OXYGEN OR ENRICHED HIR WITH OXIDATION .c gALvsr l FAN IB v uuuun nnnnnn l T nopnqu l KIQ v HEATING ELEMENT INVENT OR.

BY raso/w f. 0MM/40,110

TOR/VEY Patented Mar. 25, 1941 v APPARATUS FOR DRG FNISHES Folsom E. Drummond, Dayton, Qliio, assignor to New Wrinkle, Inc., Dayton, Ohio, a corporation of Delaware Original application April 17, 1939, Serial No.

268,217. Divided and this application September 20, 1939, Serial No. 295,804

3 Claims. (Cl. 34-19) My invention relates to an apparatus for dry- This application is a division of my application ing coating compositions, and more particularly Serial No. 268,217, filed April 17, 1939.

to a machine for drying or baking coating films In general, the wrinkling of coated lms is" in the production of wrinkle nishes. The inbrought about by unequal drying ofthe film provention, however, is adapted for accelerating the ducing surface volume changes which develop in- 5 t drying of various types of coating compositions troverted folds in the surface skin of the film prowhich dry to a hard flexible lm :by oxidation, duclng a wrinkle finish. In the case of drying polymerization, evaporation of solvents or a comoil coating films comprising wrinkling oils, for bination of these actions. example China wood or oiticica, it has been found It is one object of this invention to devise a that folds or Wrinkling of the lm surface may 10 drying apparatus to produce wrinkle finishes by be brought about by excess oxidation and pOlyheat .treating coating lms made using the conmerization at the surface of the film. This invenventional -non-wrinkling oil vehicles such as lintion provides an improved apparatus fOI' effectn seed, perilla, soya, .bean oil, poppy seed, fish oils ing this to produce a wrinkle coating on articles.

1i and the like, which oils ordinarily dry to a In the accompanying drawings: 10 smooth, glossy, non-wrinkling iilm. Figure 1 is a vertical sectional view of an ar- Another object is to provide an apparatus fo;` ti-cle having an irregular or wrinkle finish thereproducing articles having Wrinkle nishes from 011;

compositions comprising blends of non wrinklmg Figure 2 is a vertical sectional view through an and wrinkling oils, which wrinkling 011s indude oven showing the manner of exposing the ma- 2'0 China wood, oiticica, and poyok in blown, unterial t0 heat and ultra-Violet ray lamps fOr dlyblown or raw state. ing coated articles;

Another object, is vto provide an Improved de- Figure 3 is a similar sectional view illustrating vice for drying coated compositions of the drythe arrangement' for baking finishes which are 2e ing oil or oleoresinous type which ordinarily dry appllied t0 beth Sides 0f Panels D11-Sheets; 25 to a smooth surface se that they will dry to a Flgufe 4 1S a Slmilar View 1n Sectlon taken wrinkle mush, through a circular oven having heat and ultra- Another object is to provide an improved do violet ray lamps mounted around the interior 3 vice for accelerating the surface drying of coat- Wan to concentrate 'the heat 'and light on .ir'

ing compositions in order to produce a Wrinkle regular shapedl articles which are to "be dmed or irregular s ace mm' toligii'ells a silnilar view of an oven as in Fig Another object of this invention is .to provide a .baking oven having a controllable atmosphere ure 1 iuustratmg the utmza'tion of heat lamps lone with means for admitting oxygen to enrich for `baking coated articles to cause the coating to a' c dry to a hard, s 00th nish or neg ar rinkle ililee atmosphere in contact with the coated ar 3a surfaceas desired.

Figure 6 1s an elevation view, partly 1n section, @other 9h39 1s 'to provlde an apparatus for of an oven showing the arrangement for admitrapldlyba'kmg coated artclesting heated air which has been enriched with 40 A notler @meet is 'te provlde an apperatusfer oxygen and having an oxidation catalyst incor- 40 subleetmg articles Coated t0 heeft and ozomzed porated therewith for drying coated articles to or oxygen enriched atmosphere during drying of produce a, Wrinkle nish the Coated lHl- Referring to the drawings in detail, Figure 1 AnOtheI ObJeCt is -tD provide all enclosure fOr shows a panel or article A having a, Smooth force air drying coated articles by means of oxy- Surface coating B In Figures 2 3 and 4 an 45 gen 0f Ozone enrlehed heated en' Whleh aise oven generally designated I0 is illustrated for carries small amounts of an oxidation promoting drying coated articles, according to my inven- Catalyst fOr increasing the Oxidation activity tion, t-o accelerate the drying of the coa-ting to onthe lm surface so 4as to Produce a wrinkle a hard, smooth film or Wrinkle surface finish. nlSh- The ovens are constructed in the form of tun- 50 Another object is to provide an improved apnels or rectangular enclosures having suitable paratus for accelerating the oxidation and poly- .means f-or supporting and conveying coated armerization of coatin-g compositions applied to 'ticles into and out of the drying oven. Heat is articles in a thin film so as to lessen the timev supplied 4by banks of reflector equipped incanfor drying coating films to a dust-free finish. descent lamps Il which are arranged within the enclosure so as to concentrate the rays onto the surf-ace of the coated larticle. Preferably infrared radiating electric lamps having carbon filaments are used for this purpose.

Interposed between the heat lamps I I are ultraviolet irradiating means I2. 'Anysuitable source of ultra-violet rayproducing means can-be employed, the quartz mercury arc lamp of the Cooper-Hewitt type being readily applicable. Ultra-violet irradiation from a carbon arc. may

also be used if desired. The heat lamps and ultra-violet lamps may be arranged in alternate relationship so as to provide even distribution of heat and ultra-violet irradiation of the atmosphere adjacent the articles being dried. I n general the lamps should be placed between ten and thirty inches from the coated article. The light drying enclosures are not hermetically sealed so as to permit the ready exit of products of oxidation during drying of the coated articles.

In the modification illustrated in Figure 4 the oven I3 is of circular construction and the heat and ultra-violet lamps are maintained in spaced relationship around the Walls so as to effectively direct the rays against all sides of an irregular shaped article. The lamps may, if desired, be made adjustable so that their position can be changed relative to each other. It will also be understood that the number of heat lamps or ultra-violet lamps may be varied as required to increase or decrease the temperature of the en closure and the ultra-violet irradiation of the atmosphere.

Ultra-violet irradiation provides means for ionizing the air in contact with the coating film forming ozone which accelerates the surface drying by auto-oxidation. 'I'his oxidation of the coating is enhanced by the heat lamps resulting in rapid surface drying of the film which expands laterally due to the oxidation and increased volume to produce folds or creases over the entire film surface. By this method of accelerating the surface drying rate of films, coating compositions, particularly of the drying oil type, which under the ordinary drying and baking temperatures do not produce va wrinkle finish, are made to dry to a satisfactory wrinkle finish. Heretofore in the compounding of wrinkle finishes, the use of substantial amounts of tung oil, oiticica oil or synthetic wrinkle resins of the drying oil acid modified type has been required for the, production of wrinkle finish coating compositions. By the improved method of accelerating the surface drying rate of coating compositions according to this invention, the use of large amounts of these expensive drying oils is unnecessary and in general may be substituted by linseed oil, soya bean oil and the like non-wrinkling oils.

In Figure 5 the baking oven I4 comprises an endless conveyor I5 which is arranged for conveniently moving the coated articles into and out of the light drying enclosure. In this in stance ultra-violet lamps are omitted and the heat lamps II alone used. Oxygen or ozone enriched air is introduced into the drying oven as at I6. Where drying oil compositions used in coating the articles comprise raw China wood oil or similar drying oils which havenot been heat treated to a sufficiently high temperature to eliminate crystallization or gas checking, the* nitrogen dioxide content of the atmosphere may be maintained above 4 to 5 parts per million parts of air which brings about crystallization or gas checking of the nlm. Ordinarily, however,

gas checking will not be produced even with articles coated with raw drying oils due to the com- The usual drying oil coating compositions com.V

prise metallic oxidation catalysts such as cobalt, manganese, lead in the form of linoleate or acetate, alone or mixtures of these. These driers enhance the wrinkling and materially speed up the drying of the film especially when dried by the use of heat rlamps as in'this invention. To accentuate surface oxidation atomized organic solutions of metallic driers such as cobalt or manganese in the form of oleates, stearates, naphthenates, etc. may be introduced into the drying ovens to form a part of the atmosphere in contact with the coating film. Metal driers colloidally'dispersed in an oil soluble solvent such as butyl alcohol `or petroleum spirits may be utilized.

This modication is illustrated in Figure 6 wherein the required temperature in the oven I1 for baking the coated articles is maintained by the introduction of preheated air, as shown, into which hasl been introduced oxygen or ozone enriched air together with an oxidation catalyst. It will be understood that heat lamps may be employed together with the circulating heated air for maintaining the temperature in the baking oven I1 if desired. A fan generally designated I8 may be employed for forcing the circulation of air through the-heating lelement I9 and circulating it through the oven, as shown in Figure 6.

The oxidation catalyst which Vmay be introduced into the oven may comprise atomized organic peroxide such as acetyl or phthalyl or benzoyl peroxide dissolved in benzol or toluol. This solution may be suitably sprayed into the oven chamber'or carried into the oven by the oxygen or stream of air being conducted into the oven. In this manner sufficient amount of oxidation catalyst can be placed in contact with the surface` of the coating film on the articles to accelerate the surface oxidation and drying of the coating to produce a satisfactory wrinkle finish. This will be enhanced further by the use of coating compositions comprising metallic driers. enameis may be dried to a wrinkle nish.

The usual temperatures employed in producing wrinkle finishes on metal surfaces are ofV the order of 150 up to approximately 450 degrees F. For producing wrinkle rfinishes on wood, paper and similar materials somewhat lower temperatures, such as to 150 degrees F. may be used. The elevated temperatures produce a more rapid oxidation of the film surface and promote the production of wrinkle finishes and in general accentuate the wrinkle. Lower temperatures of baking usually require higher per'- centages of drying oils having poly-conjugated double bond structure in order to sufficiently accelerate the oxidation rate of the nlm surface during the treatment to produce a wrinkle o1' irregular surface nish.

As an alternative manner of contacting the surface of the coating film with the oxidation catalyst, a thin film of the solution carrying the catalyst may be lightly sprayed over the coating just prior to introducing the coated articles into the baking oven. Further in place of the oxidation catalyst mentioned, oxidized turpentine which is high in active peroxide of oxygen Clear varnishes as well as pigmented Y and ultra-violet radiating lamps in said enclo' sure, said infra-red and ultra-violet lamps being arranged in alternate relationship and spaced from the walls of said enclosure so that the ultra-violet and infra-red rays intersect and overlap before contacting the surface ofv the coated article being dried.

2. A drying apparatus comprising an encloaasaaee sure, means for retaining coated articlesto be dried therein, means for heating the air in said enclosure comprising infra-red heat lamps, said lamps being spaced from'the walls of said enclosure and arranged lso that the rays from said lamps intersect and overlap prior to contacting the surface of the articles being dried, means kfor introducing oxygen in said enclosure to increase the content of oxygen above that normally present in ordinary air. A

3. A drying apparatus comprising an 'enclosure, means for supporting coated articles to be dried therein, means for heating air and circulating Iit through said enclosure, means for introducing oxygen and oxidation catalyst in the air being circulated through said enclosure, said oxygen being added in sumcient amount to sub,- stantiall'y increase the oxygen content of said air above that normally' present-in ordinary air.

FoiSoM E.A DRUMMOND. 20

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