JPH04505806A - Method and apparatus for testing the impermeability of coated products such as latex gloves or condoms - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] For testing the impermeability of coated products such as latex gloves or condoms. Method and device The subject of the invention is a coated product, in particular a surgical glove or a condom. A method and apparatus for testing the impermeability of latex products.

Many industrial products, such as surgical gloves or condoms, are essential to the user. must be intact. Latex gloves are actually used by medical workers, especially used by surgical personnel and therefore during patient surgery. It is necessary to ensure that there is no infection either in the patient-to-medical direction or in the patient-to-medical worker direction. It is.

Recent diseases such as AIDS are due to this lack of defects in products on the market. It only increases the demands.

Products currently on the market undergo two types of testing: destructive and non-destructive. destruction Physical testing is only possible based on statistics and therefore cannot guarantee that the product is completely defect-free. stomach. Instead, in non-destructive testing, the product is also used in a valuable way, but The method and equipment used only recognize the largest holes in the product to be detected. , detecting holes with small diameters that allow a proportionally large number of microorganisms to pass through. That is completely impossible.

A first known method consists of testing the dielectric constant of the product.

The product is gently placed over a rigid metal mold until the product completely tightens the mold. This Yu The knit is soaked in a dielectric bath such as salt water, the material and thickness of the product is sensed, and the salt water is to prevent dielectric breakdown from occurring. On the other hand, holes in the product Once present, arc formation and dielectric breakdown occur.

This test shows that holes of very small diameter are blocked by the product's natural elasticity. The fact that the sensitivity is reduced and therefore destruction is prevented despite the presence of the hole Mau. In addition, this test is performed even if no dielectric breakdown occurs, even if the product has been immersed in salt water. If so, it is completely destructive, since it cannot be brought to market. This device has Another disadvantage is the risk of error and the inability to use products with complex designs. It is impossible. For example, with gloves, the gloves are completely fitted into the metal mold. It is very difficult or even impossible. Air layer between the metal mold and the glove would increase the dielectric resistance and falsify the results.

An alternative method and test consisting of testing the dielectric resistance of a product that does not rely on a liquid bath. Scanning devices are known. In this case, place the product gently over the metal mold and apply the first potential. This type brought about approaches spherical electrodes where different potentials are applied.

The presence of holes causes dielectric breakdown between the mold and the electrode. Electrodes generally have a spherical shape. In this case, it is essentially the edges of the product that are inspected, and the Not the body itself. ---1 Such methods and devices allow for non-destructive testing of products, but this testing Like the one mentioned above, it is very partial and has poor sensitivity with a high risk of error. do.

This electrode device has been modified to use a rotating brush with dielectric bristles. follow The brushes are the same and always receive the first potential, while the brushes are at a different potential. This is the part that receives the information. The brush rotates itself and the bristles interact with the product. It is meant to be in contact.

The diameter of these hairs is very small, so if there is a hole, the hairs passing through the front of this hole causes a dielectric breakdown and thus a hole is detected.

This improved method allows inspection of the entire product, no longer in parts. However, on the other hand, one of the bristles will pass through any hole the product may have at the correct right angle. However, the required sensitivity is still lacking and If the product does not swell, these methods and devices can be used to detect small diameter holes. It is understood that it would be impossible to do so.

Testing using gas-analytical methods and equipment is also known. Such a method is This consists of inflating the product using a chemical gas with certain properties, which This chemical gas and the gas outside the product in the enclosure are analyzed. Ru. Once the analyzer detects the presence of gas in the product inside the enclosure, Leakage from the inside of the glove to the outside can be confirmed. This method inspects the entire product. However, it poses two essential disadvantages: first, the postproduction of the gas analyzer The fact that gas is caused by The second is the need to clean the analyzer and wait for it to reinitialize. completely impermeable to allow gas to enter the interior of this product. Therefore, by falsely detecting the presence of a product leak that is not actually present, the analyst may There is nothing you can do to prevent accidental leaks.

In addition, balancing such testing with systematic industrial testing will require the necessary speed. The gloves and their gas-filling equipment appear to be insufficient due to the degree of Complete impermeability between the

Therefore, existing methods and equipment do not allow 100% inspection of manufactured products. to detect all holes, including holes on the order of a few microns or holes with no breaks in the material. Not reliable enough for various users.

Posts a considerable risk, especially for the medical team.

Some users therefore decide to use two pairs of gloves instead of one, for example. Therefore, they are forced to double their protection, resulting in excessive prices and production costs. causes excessive consumption of natural products such as latex, which is limited.

Regarding condoms, the unreliability of impermeability is the unreliability of certain diseases such as AIDS. As a result, there is no doubt that proliferation cannot be guaranteed.

A method for detecting leaks, particularly leaks in rocket engine circuits, is disclosed in U.S. Pat. No. 772,789. This method uses laser consists of illuminating the product being processed at the source. The circuit is radiated by a laser source The gas absorbs this light by pressurizing it with a specific gas appropriate to the wavelength of light being emitted. collect. Therefore, any leakage will absorb light locally, sometimes with gas and sometimes without. This can be determined by overlapping and comparing images from time to time.

Such a method is differential photometry.

Such methods suffer from a number of disadvantages that prevent them from being applied to overcome the presented problem. bring about. For coated products that are actually elastic, the need as described Using a certain precise method, a first image of the unexpanded coated product is stored and the expanded It is not possible to store a second image of the coated product and compare these. Ru.

Furthermore, the equipment requires expensive equipment and uses laser light to control the product being tested. Complete fixation and optical equipment with specific gases are required; such conditions , high-speed inspection of small deformable products in industrial environments in large quantities at a very low cost. It's not compatible with that.

It is therefore an object of the present invention to ensure that all manufactured products are free from material tears to be detected. Industrial proportions of the manufacture of these products with holes of very small diameter containing no products provide methods and equipment that can be tested in the Its inspection cost is low, it can be applied to products with complex shapes, and it does not cause product contamination. It is assumed that

For this reason, coated products according to the invention, especially elastic ones such as latex surgical gloves, The method for testing the impermeability of thin coated products made of materials with Introducing gas into the object at a slightly greater pressure relative to the surrounding gas and leakage The invention is characterized in that the eruption is displayed using polarized interference means.

According to another feature of this method, the gas introduced into the object is different from the surrounding gas. has a molar mass.

The method according to the invention includes illuminating the product and leakage spout indication for leakage spout indication. converting the change in phase introduced by the passage of light into a change in the intensity of light or color It is characterized by consisting of.

According to one embodiment, the method uses polarized light interferometry.

According to the invention, the method also provides that the product is rotated by itself and It is characterized in that it is configured to detect leakage gushing.

The optical device for carrying out the method includes a support for the product, a light source and a polarized It is characterized by comprising an optical interference device.

The optical device includes, in particular, a separating plate, a first device for processing incident light, a concave mirror, and a reflected light. a second device for processing the product, a video camera, and a display screen. characterized in that the support is arranged upstream of the mirror in the incident light Optical devices with special features include polarizers, optical condensing lenses, and birefringent devices. There is.

According to another feature, the optical device is an afocal device with two achromatic doublet lenses. Consists of.

In the industrial inspection device using a white light source according to the present invention, the product support part is arranged in the longitudinal direction of the object. be able to rotate and move by itself about an axis that is parallel to the direction axis and the plane of the mirror It is characterized by

The invention will be described according to particular embodiments of the invention and with reference to the accompanying drawings, in which: FIG.

Figure 1 shows an interferometric optical bench for incandescence, and Figure 2 shows a vertical plane of industrial inspection equipment. A cross-sectional view on the surface, and FIG. 3 is a top view of this device.

In FIG. 1, an optical bench 10 is capable of generating incident light 14. It consists of a white light source 12. The incident light is processed by the first part 15 of the optical bench. Object 16 to be inspected before being processed and then reflected by mirror 18 illuminate. Next, this reflected light 20 is applied to an optical bench to form an image. processed by the second part 22, the image is read by the camera 24 and screened Sent to 26th.

White light source 12 is a conventional 6 volt heat lamp. The bench allows the emitted light to pass through The linear polarizer 28 is configured to distribute the amplitude orientation in a preferred manner. ing. The bench consists of an optical condensing lens 30, and the light beam generated from the polarizer is The incandescent lamp then passes through the lens and onto the birefringent device 32 placed after the condensing lens. form a filament image. It is arranged in such a way.

A separation plate 34 that reflects 50% of the light while allowing the remaining light to pass is located on the condenser lens. between the lens and the birefringent device. In that direction, light is reflected at 90 degrees. The sea urchin is turning. The birefringence device used in this particular embodiment is equal to 5 minutes in angle. Wollaston prism with new angular division sm).

In fact, the surface of the incident wave is deflected in two longitudinal and transverse directions by this birefringence device. The transmitted waves maintain linearly polarized amplitudes at 90 degrees to each other to .

The bench also consists of a mirror 18 to which the waves are transmitted from the birefringent device 32. On the other hand, in the case of product 1 to be inspected, gloves are placed so that they are interposed in the light beam. be done. The product 16 is mounted on a rotating support 36 through which it is ejected. It is expanded by the gas 34.

The mirror 18 is concave and the center of its curvature is located at the center of the birefringent device; The light beam 20 reflected by the mirror 18 is now focused on the birefringent device 32. let The second part of the optical bench apparatus consists of two achromatic doublet lenses 40.4 It consists of an afocal device 38 consisting of two parts. This afocal device has two elements: It forms an image of the sunlight source 12 on the lens 44 of the video camera 24, and this This is because it is possible to provide an image of the product located in the focal area of the lens.

A polarizer is placed in front of the video camera that reads the light beam generated from the optical bench. 46. Then, there is an absorption filter 48 that adapts the light to the light sensitivity of the camera, or an afocal device. It is interposed on the output side of the station 38.

The operation of this device will be explained. The sunlight emitted by light source 12 is transmitted through polarizer 28. Since the light is polarized and focused by the condenser lens 30, the image of the filament of the light source 12 is duplicated. is formed on the refracting device 32. Therefore, the light emitted from this birefringent device is leaks to product 16 whenever it is unobstructed. Assuming there is no deflection, the rays are directly reflected off the mirror and directed in the opposite direction of the birefringent device. pass to. The birefringent device is placed in a plane containing the center of curvature of the mirror.

If the product 16 has holes, the gas 34 introduced into the product 16 with excessive pressure will , leaks through the hole and squirts out of this product 16.

The light emitted from the birefringent device is thus passed through this leaking jet and converted. fruit In particular, Bradstone's law is based on the following formula: bring.

(n-1)/d-constant where "n" is the refractive index and "d" is the concentration of gas associated with air. When “d” changes, “n” also changes.The gas introduced under excessive pressure now becomes , has a different molar mass than the atmosphere.

Changes in the refractive index "n" are accentuated by interference. Leaking squirts of them clearly on the screen 26 as a change in intensity or color that stands out from the background. appear.

In the described embodiment, the gas is introduced at excessive pressure into the product 16 to be inspected. is carbon dioxide, while the surrounding medium is air at atmospheric pressure. Therefore gasification The chemical properties result in a molar mass different from that of air, and the color of leakage jets and their backs. This makes it easier to distinguish and contrast the scenery, and also helps increase the sensitivity of the device. There is. Furthermore, the support 36 on which the product 16 is arranged is itself rotatable. When installed and located in a plane approximately perpendicular to the leakage jet or incident beam, the product The leakage jet is detected regardless of the orientation of the jet with respect to the surface of the Ru.

As a variation of the interferometric optical bench for mountain use, the Wollaston prism is particularly Replaced with Savart polarizer.

The Wollaston prism itself can be regular or wide field. be.

In Figure 2, a partial cross-sectional view shows an industrial equipment for testing the impermeability of coated products. It shows the location. In one illustrated example, the coated product is a surgical latex glove. Ru.

The device 90 consists of a mounting frame 92 supporting a rotating plate 97. Drives the rotary plate to rotate. The shaft 96 is a hollow tube that is attached to the frame 92 via a bearing 98. Ru. The pinion 100 is fixed to this shaft 96 and is connected to the drive shaft 104 of the motor 106. Driven by an integral drive pinion 102.

Glove support rotatably mounted relative to plate 94 via bearing 110 108 are provided on this plate 94, and are arranged regularly, especially around its periphery. has been done. The support portion 108 holds a friction drive roller 112 at its lower portion.

The end portion 114 of the support portion 108 is a truncated cone so as to support the open end of the glove. support The portion 108 is also hollow and is open at its end 114 and its opposite end 1]6 It's closed. The support 108 also has a joint 118 and is rotated by a coupling 120. The gas fitting 122 extends to the rotating gas fitting 122. This gas joint 122 is connected to a gas joint (not shown). It includes a fixed duct 124 connected to a source.

The frame 92 also includes a drive device 126 consisting of a drive shaft 130 and an integral drive roller 128. The end of the drive shaft holds a pinion 132. This shaft 130 is mounted so as to be freely rotatable relative to the frame 92 via a ring 134. . The pinion 132 interacts with a drive chain 136 and is itself rotated by a pinion 138 of a drive motor 141 integral with the frame 92. It will be done.

The device 90 includes several drive devices 126 regularly arranged on concentric circles of the plate 94. Consists of. The installation of these drives is supported by drive rollers 128 of each device 126. All drives 126 interact with the friction rollers 112 of the holding part, and all drives 126 are driven by the same chain. 136 in simultaneous rotation. It goes like this.

In addition, the device is completed by an enclosure 140, shown schematically in the drawing, in which An optical bench 10 is arranged at.

In FIG. 3, at various locations 142, 144, 146, 148, the product being inspected is Expanding and rotating, inspecting and indicating leaks, transporting, deflating and moving and positioning the product. are shown respectively.

The operation of this device will be explained. The support plate 94 shows the gloves in each position in an orderly manner. rotates on its own. The plate is rotationally driven by a motor 106. Support part 1 08 has a regular edge on the periphery of this plate, with an operator-accessible end]14. properly placed. The operator places gloves on end unit 14 of support 108 at position 148. Position the glove by covering the open end of the glove. When support 108 reaches position 142 , rotary joint 122 supplies pressurized gas to the glove via connection 120 and joint 118. and inflate the gloves. At the same time, the inflated glove is rotated by the support section 108. When the friction roller 112 comes into contact with the drive device 126, the support portion Therefore, it is itself rotationally driven. This first rotation stabilizes the glove on its support. make it possible to As a result of the rotation of plate 94, this same support 140 , where it is rotated by another drive 126 . The gloves are automatically positioned in the beam at the center of the optical bench 10 and The output is displayed on a screen provided for this purpose. Support part After the rotation plate has completely rotated, the rotating plate connects the support 108 and its and the gloves to the transfer position 146. In this position, the connecting portion 120 is connected to the outside air. The glove can then be deflated and removed from the support 108 by the operator.

This type of equipment automates the inspection of at least the products 16 and This enables compatibility with industrial manufacturing. Actually the whole inspection is done at alternating times. The principle is that during the indication phase of gas leakage, the rotary plate 94 This is because it is necessary to wait for the support to rotate before rotating, and this inspection time is to remove the inspected product and position the new product to be inspected. Advantageously used by pelleters. For simplicity, the inspection device shown is circular. However, without any inconvenience, an operator of 1 Å or more is attached to one end, and an operator of 1 Å or more is attached to one end. Transforms into one or more inspection lines configured such that the operator is at the other end. You can also

Similarly, a gas leak spout will be displayed on the screen and if you are near this screen Visually detected by the operator but not read by the video camera. A method for analyzing the captured images will be provided and the analysis will be performed in comparison with the analysis of the control sample images. It is also possible to In this case, the inspection and judgment will be performed automatically by a machine. You may let them. The operator's role is therefore to inspect the work satisfactorily and to assemble the product. Attachment to and removal from a location are performed.

Such a method using the main device or its variants can be used without contaminating or damaging the product. Enables 100% inspection of industrially manufactured products. A hole of about a few microns, The majority of holes of small diameter are detected by the fact that the gloves have been inflated. causing an increase in diameter. For example, in dielectric testing, the parasitic effects of air layers are avoided. Therefore, the risk of incorrect interpretation is eliminated.

Furthermore, the impermeability of the product-support joints avoids consuming large amounts of gas. However, it should not affect the results for two reasons. No. Reason 1 is that if there is a leak, the operator or analyzer will know that the leak is within the useful area. The second reason is that the product-support joint This means that the location is conveniently located outside the ray.

Submission of translation of written amendment (Article 184-8 of the Patent Law) August 9, 1991

Claims (26)

[Claims] 1. Surgical gloves made of elastic material, thin, especially latex, or In a method for testing the impermeability of coated products such as condoms, Introducing the gas at too much pressure relative to the surrounding gas and polarizing the leaking plume 1. A method characterized by displaying using interference means obtained by 2. The gas introduced into the product must have a different molar mass than the surrounding gas A method according to claim 1, characterized in that: 3. The surrounding gas is air and the introduced gas is carbon dioxide. The method according to claim 1 or 2. 4. Indication of leakage spouts is introduced by illuminating the product and passing the leakage spout. converting a change in the phase of the light into a change in the intensity of light. The method according to any one of claims 1 to 3. 5. Indication of leakage spouts is introduced by illuminating the product and passing the leakage spout. converting a change in phase of the image into a change in color. The method according to any one of items 1 to 4. 6. Any of the preceding claims characterized in that a polarized light interference method is used. The method described in 7. Previous claim characterized in that the final image is displayed by video means The method according to any one of the following. 8. The final footage is analyzed and compared to reference footage to enable automated inspection. A method according to any one of the preceding claims, characterized in that the method comprises: 9. The product is rotated by itself to detect leakage spurts across its surface. A method according to any one of the preceding claims, characterized in that: . 10. It consists of a support for the product, a light source and a polarized light interference device. Carrying out the method according to any one of claims 1 to 9 characterized in Optical equipment for. 11. a separation plate, a first device for processing incident light, a concave mirror, and a processing for reflected light. The support part of the product consists of a second device, a video camera, and a display screen. according to claim 10, characterized in that it is arranged upstream of the mirror in the incident light. Device. 12. Claim 10 or 11, wherein the light source is a white light source. The device described in. 13. The light source is an incandescent lamp placed at 90 degrees in the optical path of light between the mirror and the camera. According to any one of claims 10 to 12, characterized in that Device. 14. The first device further includes a linear polarizer interposed between the light source and the separator; It consists of an optical condensing lens and a birefringence device placed between a separating plate and a concave mirror. Receives an image of an incandescent lamp filament generated from a light lens and reflected by a plate. Any one of claims 10 to 13, characterized in that The device according to item 1. 15. The birefringence device is a Wollaston prism. 15. The device according to claim 14. 16. The center of curvature of the concave mirror coincides with the center of the birefringent device. The apparatus according to any one of items 10 to 15. 17. The second device has two achromatic double lenses and uses a video camera to capture the image of the light source. This video camera forms an image of the object in its focal area. A claim comprising: an afocal device configured to: and a linear polarizer. The device according to any one of the ranges 10 to 16. 18. Consists of an absorption filter placed upstream from the video camera to control the light level. Claim 1, characterized in that the camera is adapted to the light sensitivity of the camera. The device according to any one of items 0 to 17. 19. The support for products placed upstream from the mirror in the incident light is It can move by rotating itself about an axis parallel to the axis of direction and the plane of the mirror. The device according to any one of claims 10 to 18, characterized in that: 20. The support is a hollow tube connected to the pressure gas by a rotating joint. Apparatus according to any one of claims 10 to 19, characterized in that: 21. a line having several supports and rotation means for these supports; a position for positioning and movement of the product on these supports, and a position connected to each of the supports. positions for distributing the pressure gas, positions for optical inspection, transport positions and more. Implementing the method according to any one of claims 1 to 9, characterized in that Automatic equipment for inspecting successive coated products for inspection. 22. The support is freely rotatable on a circular plate which is itself rotationally driven. 22. Device according to claim 21, characterized in that it is attached to. 23. Each support is adapted to interact with means for rotating the support. Claim 21 or 2, characterized in that The device according to item 2. 24. The means for rotating the support are rotationally driven by the same drive chain. 24. A device according to claim 23, characterized in that it is a roller. 25. The gas supply is interrupted when the positioning of the product and the position for movement are at right angles. Claims 21 to 24, characterized in that: Device. 26. Claim 2, characterized in that the position for optical inspection consists of an enclosure. 26. The device according to any one of items 1 to 25.