Measuring and testing – With fluid pressure – Porosity or permeability
Patent
1997-03-26
1998-10-20
Williams, Hezron E.
Measuring and testing
With fluid pressure
Porosity or permeability
73 40, 324557, G01N 1508, G01N 2700, G01M 304
Patent
active
058248820
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The invention concerns a device for checking the porosity of dielectric foils, particularly rubber products, such as condoms and protective gloves with a cover holder that is made of durable, electrically conductive material and over which the rubber product is placed, and of one or more outer electrodes that are on the side of the skin of the rubber product opposite the cover holder, whereby the cover holder and the outer electrodes are connected to a source of voltage and to an electrical gauge via electrical currents.
Other than for reasons of contraception, condoms are being increasingly regarded as protective devices against sexually transmitted diseases, particularly the virus that causes AIDS. Therefore, given the necessity of their impermeability for the essentially smaller viruses as compared to bacteria, the demand for condoms has inevitably risen. It is, however, a fact that latex, which is used to manufacture condoms, has shown in a number of cases such an evidence of pores that viruses are able to penetrate. The reason for this is that latex is constructed from interwoven macromolecules, thereby causing the manifestation of selective pores as well as a jagged surface with variable durability in the walls. The formation of porosity will never occur when other materials such as polyurethan are used. Nevertheless, the user is at a disadvantage here since polyurethan is plastic and therefore prevents the user from achieving the genuine feeling that he desires.
Given the fact that through the process of manufacturing condoms the impermeability of viruses cannot be guaranteed, testing each individual condom after manufacture is of great importance. Studies have shown that approximately 60% of condoms are virus-preventive. The remaining 40% percent, however, contains porous areas through which viruses can penetrate. Therefore, condoms do not offer 100% protection from infection. Doctors are well aware of this problem and consequently always use two pairs of gloves while operating in case they come into contact with blood. In this way, any areas on the gloves that may have pores can be physically separated from one another so as to essentially reduce the possibility of infection.
2. Description of the Prior Art
Existing procedures for testing the porosity of condoms consist in placing the condom on a metal cover holder and by means of an outer electrode measuring the condom's electrical resistance. Consequently, the condom is placed with a known device in a conductive fluid, whereby the outer electrode acts as the wall of the fluid bath. The disadvantages of this procedure are first that the condom must be dried immediately afterward and second that the entire surface must be integrally measured, which does not allow the individual pores to be localized.
In another procedure the outer electrode is a metal screen which is placed under high voltage, whereby the occurrence of disruptive discharges is measured. This procedure, however, is not foolproof given that the latex is selectively destroyed by the sparks emitted by the disruptive charges. Furthermore, the formation of ozone acts as a disadvantage.
Consequently, the purpose of the invention is to develop a device for testing the porosity of condoms in such a way that individual pores can be determined and localized within a diameter of 25 to 75 nanometers.
SUMMARY OF THE INVENTION
The invention will carry out its task based on the following data: the outer electrodes are in the form of points; the outer electrodes and the cover holder are relatively moveable toward one another so that the skin of the rubber product is gradually scanned by the outer electrodes; the current produced from the source of voltage between the cover holder and the outer electrodes is an alternating current or pulsating direct current; the gauge measures the flow of current in each electrode and by this measurement corresponds to the electrode in a reference measurement for the state in which there is an abs
REFERENCES:
patent: 4875358 (1989-10-01), Marsh et al.
patent: 5196799 (1993-03-01), Beard et al.
patent: 5389097 (1995-02-01), Bennett et al.
patent: 5455507 (1995-10-01), Horenstein
patent: 5499898 (1996-03-01), Vonier et al.
patent: 5524478 (1996-06-01), Joy et al.
patent: 5595704 (1997-01-01), Hayashi et al.
Gormley Gregory J.
Griebel Robert Andre Emil
Politzer Jay L.
Schindler Edwin D.
Williams Hezron E.
LandOfFree
Device for checking the porosity of thin rubber products does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for checking the porosity of thin rubber products, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for checking the porosity of thin rubber products will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-246158