US3769934A

US3769934A - Sample preparing apparatus

Info

Publication number: US3769934A
Application number: US00326610A
Authority: US
Inventors: J Dunn
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1973-01-26
Filing date: 1973-01-26
Publication date: 1973-11-06
Anticipated expiration: 1990-11-06

Abstract

An apparatus for impregnating samples consisting of a sample cavity, a closure for the cavity, fluid ducts for introducing solutions of chemicals and for draining the excess of the solutions, a means for developing pressure within the cavity and a pressure measuring means.

Description

United States Patent 1191 Dunn, Jr. Nov. 6, 1973 SAMPLE PREPARING APPARATUS [56] References Cited [75] Inventor: James L. Dunn, Jr., Lake Jackson, UNITED STATES PATENTS 972,380 10/1910 Jenkins 123/65 S 1,341,255 5/1920 Blume et al. 123/65 S X [73] Assgnee' 313 311 2,032,028 2/1936 Rees 118/50 x i 3,150,220 9/1964 Howell v 249/83 ux 22 Filed; Jam 2 1973 3,241,193 3/1966 Pohlman.... 249/95 X 3,564,657 2/1971 Aoki 425/154 X [21] Appl. No.: 326,610

Related Appncation Data Primary Examiner--Morris Kaplan [60] Continuation-impart of Ser. No. 99,240, Dec. 17, Atmmy wmlam Yates et 1970, abandoned, which is a division of Ser. No. 868,347, Oct. 22, 1969, abandoned. [57] ABSTRACT An apparatus for impregnating samples consisting of a [52] US. Cl. 118/121, 118/421 Sample Cavity a closure for the cavity, fluid ducts for {g :3 1 introducing solutions of chemicals and for draining the le 0 care excess of the solutions, a means for developing pressure within the cavity and a pressure measuring means.

1 Claim, 1 Drawing Figure SAMPLE PREPARING APPARATUS CROSS-REFERENCE TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION The preparation of samples for testing the effects of various chemical treatments is an art which demands considerable experience before meaningful and reproducible results are consistently obtained. Inexperienced personnel have difficulty obtaining uniform distribution of chemicals throughout the sample; thus, inconsistent results are obtained. One factor contributing to this nonuniformdistribution is the nonuniform evaporation or drying of carriers from the test sample. Another factor stems from the method used to remove excess treating solution as well as the attitude of the sample during drying, e.g., hanging, lying flat, etc. It is therefore an object of the present invention to provide a device in which a test sample can be uniformly impregnated with a test chemical and the excess test chemical and carrier, if any, uniformly removed. In ad'- dition', the" apparatus of thep'resent invention is readily cleaned and maintained.

BRIEF DESCRIPTION OF TI-IE DRAWING The sole FIGURE of drawing illustrates the apparaoriented slot 19 in its periphery which mates with the outlet 17 in the housing when the piston 12 is fully inserted. The piston is provided with a radial conduit 20 from one edge to the center where it connects into the space 21 between protuberance 18 and axial bore 15, thereby providing a path for fluid from the interior of the chamber 11 to the well 15 and outlet 17. The housing 10 is also provided with a small drain 23 connecting the chamber 11 with the outlet 17 to insure the liquid in the lowest part of the chamber 11 is removed. The piston 12 has an Of ring 22 about its periphery which forms a fluid-tight seal when the piston 12 is inserted into the housing 10 of chamber 11. O-ring 22 has several small notches 22A cut into its surface to provide access for fluid into O-ring recess or seat portion of piston 12 thereby enabling fluid to enter radial conduit 20 by passing between the O-ring 22 and the O- ring recess around the piston 12. The notches 22A are in the surfce nearest the face of the piston 12.

tus of the invention in position to expressexcess impregnant. v

BRIEF DESCRIPTION OF INVENTION The apparatus of the present invention comprises a housing 10, a chamber 11 located in the housing, apiston l2 slidably engagable into the chamber, a frame member 14 having'a receiver 14a atone end to receive I the chamber 11. The chamber 11 can be of any shape and is preferablya cylindrical bore in the housing. The end or base of the bore forming the chamber 11 within the housing 10 is provided with asmaller diameter axial bore 15 which is a well-like extension of the chamber 11 to receive a fluid expressed from the chamber 11 during impregnation of a sample S in the chamber. The housing 10 is provided with an inlet conduit 16, which permits the introduction of a fluid into the chamber 1 1 adjacent the base of the chamber 11, and an outlet conduit 17 from the axial bore or well 15 for removal of the fluid during insertion of the piston. These two conduits l6 and 17 in the housing are preferably located on opposite sides of the housing with the outlet 17 being the lower. The piston 12 is designed to be matingly and slidably insertable into the chamber 11 and axial bore 15 in a fluid-tight relationship. The piston 12 has a facial protuberance 18 which mates loosely into the well or bore 15 when the vpiston 12 is fully inserted into the chamber 11. The protuberance 18 also has an axially The apparatus of the present invention is employed to impregnate samples with chemicals and has particular application to impregnation of flammable materials with flame-retardant chemicals in accordance with the following steps: A piece of fabric cut to the appropriate size and in a ring shape is weighed, positioned on the piston 12 over the facial protuberance 18 thereof, and, the piston 12 is inserted into housing 10. A treating solution, containing a flame retardant chemical to be tested and a low-boiling solvent therefor, is introduced through inlet 16 into the chamber 11. The inlet is stoppered or otherwise closed off to prevent evaporation of the solvent. After an appropriate period during which time the sample is impregnated with the solution, a pressure is applied by operation of the hand screw 13. The pressure applied is measured by the gauge indicated as a part of section 14. The application of pressure at this point in time serves to express excess liquid from the sample. During application of pressure, the chamber 11 is subjected to a short burst of air introduced through inlet 16 which serves to sweep the excess fluid from chamber 11 through the outlet drain 17 when the valve is opened. Following the air-sweep, the sample is removed from the apparatus, dried and again weighed todetermine the amount of treating chemical picked up by the sample. In a series of experiments employing the apparatus of the present invention wherein the pressure utilized is identical to that of previous runs using the same chemicals and solvent in the same proportions, it was found that the percent chemical in the dried fabric was substantially identical, i.e., within experimental error.

The sample, being circular and having a center hole, is readily adaptable for testing the burning rate of fabrics treated with flame retardant chemicals. The center hole provides a point of application for the flame which permits more reproducible test results.

I claim: g

1. An apparatus for impregnating samples comprismg:

1. a housing having a cylindrical chamber extending thereinto and an axial bore extending from the interior terminus of said chamber into the housing, said axial bore having a radial dimension less than that of said chamber and a longitudinal dimension less than said chamber;

2. a piston slidably and matingly engagable into said chamber with a fluid tight seal therebetween and having a protuberance extending from the face of said piston loosely into said axial bore when said piston is substantially fully inserted into said chamber said sample being disposed between the piston face and said terminus;

3. means provided through said housing wall to permit introduction of impregnating fluid into said chamber whereby to impregnate said sample and means provided through said housing wall to permit draining of excess fluid therefrom when said piston is in its fully inserted position;

4. means to facillitate draining including an opening in the face of said piston and located at the base of said protuberance and communicating with the space between said protuberance and bore, a channel extending radially through said piston and communicating said opening and said means to permit draining, a longitudinally oriented slot in the side wall of the protuberance remote from said opening, channel means extending through said cylinder and communicating the means to permit draining with both the slot and the space between the piston face and the said terminus;

5. a frame member having at one end a receiver for said housing and at the other end a means for applying pressure to said piston when disposed in said housing and, said receiver being provided with a pressure measuring means whereby to control the degree of expressing fluid through said drain and thus to control the degree of impregnation of said sample.

Claims

1. An apparatus for impregnating samples comprising: 1. a housing having a cylindrical chamber extending thereinto and an axial bore extending from the interior terminus of said chamber into the housing, said axial bore having a radial dimension less than that of said chamber and a longitudinal dimension less than said chamber; 2. a piston slidably and matingly engagable into said chamber with a fluid tight seal therebetween and having a protuberance extending from the face of said piston loosely into said axial bore when said piston is substantially fully inserted into said chamber said sample being disposed between the piston face and said terminus; 3. means provided through said housing wall to permit introduction of impregnating fluid into said chamber whereby to impregnate said sample and means provided through saId housing wall to permit draining of excess fluid therefrom when said piston is in its fully inserted position; 4. means to facillitate draining including an opening in the face of said piston and located at the base of said protuberance and communicating with the space between said protuberance and bore, a channel extending radially through said piston and communicating said opening and said means to permit draining, a longitudinally oriented slot in the side wall of the protuberance remote from said opening, channel means extending through said cylinder and communicating the means to permit draining with both the slot and the space between the piston face and the said terminus; 5. a frame member having at one end a receiver for said housing and at the other end a means for applying pressure to said piston when disposed in said housing and, said receiver being provided with a pressure measuring means whereby to control the degree of expressing fluid through said drain and thus to control the degree of impregnation of said sample.