JPS59500095A - Method of Forming Yieldable Thermal Bonds in Autoclavable Medical Product Instruments and the Like - 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] Forming yieldable thermal bonds in autoclavable medical products instruments and the like How to do it.

Technical field of the invention The present invention generally relates to the assembly of molded parts using polyvinyl chloride resin compositions. With regard to flashing, more specifically, there is a possibility of breakage between such molded parts, or Concerning the formation of connections that can yield.

The present invention also provides an autoclavable medical product device that includes breakable parts. Regarding the assembly of.

Description of prior art ``SUPPORT ASSEMBLY FOR CANNUES AND SIMILARS'', filed December 2, 1981. Edward Garver, U.S. Patent Application No. 326.736 entitled ``Briere'' , and ``Thermal bonding to cannulae and similar'' filed on December 2, 1981. U.S. Patent Application No. 32 entitled "Autoclavable Thermoplastic Materials" No. 6,738 should be noted.

In addition, the application filed on December 2, 1981, ``Mischief-proof canyule support assembly'' Edward Garver F+ and Kenneth Zabi Of note is U.S. Patent Application No. 326,737 to Elski.

Polyvinyl chloride-based resin compositions are the largest volume thermoplastic plastics in the world. Consists of shoes. This is because such resin compositions are chemically inert and sufficiently are stable for a long time and their properties are thereby maintained even when exposed to natural forces for long periods of time. Because they are maintained, they are flexible and can range from soft to hard and transparent to We can produce products ranging from opaque to opaque in all colors, and They are able to provide these benefits listed above at an economical cost. It is the truth.

Plasticized polyvinyl chloride resins have wide applications in medical product equipment; These resin compositions are approved for blood contact and are tested during commercial autoclaving. Because it does not undergo thermal deformation in the range of sterilization temperatures encountered (approximately 230 to 250 degrees below) It is true.

Forming connections between components of a medical product device that can rupture or yield is often desired. For example, in a cannula support assembly, Enclose the cannula and protect the sterile integrity of the cannula before use, but at the moment of use. Fits securely to the hub for convenient removal when desired to expose the cannula. It may be desirable to have a covered cover member.

In this situation, thermal bonding techniques may be used to securely mate the cover to the hub. It is desirable that By utilizing thermal bonding technology, adhesives or other foreign substances Use can be avoided. Additionally, thermal bonding technology itself requires large-scale, automated manufacturing. construction planning.

Unfortunately, plasticized polyvinyl chloride compositions typically used in medical product devices are There is a tendency to form thermal bonds that become progressively stronger as the thermal B history of the bond increases. So As a result, plasticized polyvinyl chloride resin compositions are desirable for medical products and devices. Forming thermal bonds that can easily rupture or yield requires careful attention to the thermal history of the bond. Requires deep control execution. Without such control, the bond will easily become stronger. It is possible to physically break the material without permanent deformation of the joined materials. It is.

Careful control of such thermal history is significantly complex, and if the equipment is relatively Must undergo intense and long autoclaving and pasteurization heat exposure If not, it may be impossible.

Therefore, one of the main objects of the present invention is to provide f′ It also improves the thermal bondability of the component, which, once established, substantially increases its strength as a result of subsequent heat exposure. There is no permanent deformation of the joined parts despite long heat and dew. can form yieldable thermal bonds that selectively rupture in response to the application of human force. The purpose is to provide a method to change it.

Summary of the invention To achieve this and other objectives, the present inventors The thermal bonding properties of the composition can be significantly improved by adding a measured amount of silicone oil. I discovered that I can change it. This silicone modified composition is resistant to heat exposure. can be thermally bonded to compatible materials such as polyester. death However, once established, the thermal bond so formed may have an extended or Even if it is strengthened, its strength does not gradually increase. Rather, the history of passion changes the resin composition itself. Bonding does not result in permanent deformation of the plastic material unless chemical degradation is reached can always be selectively ruptured in response to the application of human power.

The present inventors also found that the thermal bonding properties of the polyvinyl chloride resin composition advantageously modified by further addition of calcium carbonate to the silicone/silicone mixture. I discovered that I can have sex. Further addition of calcium carbonate to the mixture is relatively A more stable material that consistently breaks with forces falling within a narrowly defined range of forces. Leads to thermal bonding.

Due to the specific modification of the polyvinyl chloride resin composition according to the present invention, autoclave Yieldable heat bonding well suited for processable medical product equipment and mass production techniques The relationship will be established. −1 Once established, the bond gradually increases in strength as a result of additional heat exposure. The desired It can be broken even when it is broken. For the purposes of the present invention, modified compositions The limited thermal bonding properties of bonding are self-contained and innate, and bonding ■Specific thermal bonding history cautions Does not rely on deep control.

Other features and benefits of embodiments of the invention will be apparent from the following detailed description, drawings and This will become clear when considering the claims.

Drawing description FIG. 1 shows a heat-bonded heat-bonded heat-sealing crab embodying various features of the present invention. blood collection, including a phlebotomy needle carried by a Yule support assembly; 1 is a plan view, partially broken away and partially sectional, of a storage and sampling unit; FIG.

2 is a perspective view of the tamper-proof cannula assembly shown in FIG. 1; FIG.

FIG. 3 shows a tamper-proof cannula assembly generally along line 3-3 of FIG. FIG.

4 and 5 show the cover member of the cannula support assembly shown in FIG. FIG. 3 is a perspective view illustrating the sequence of breaking of the safety connection between the hub and the hub.

Before describing embodiments of the invention in full detail, the invention will be described below in its application. The description is limited to details of the construction and arrangement of the components illustrated in the accompanying drawings. You should understand that there is no such thing. The invention is capable of other embodiments and embodiments. It can be realized or implemented in various ways. Additionally, the words used here are for descriptive purposes only. It should be understood that saving money should not be considered as a limitation.

Description of preferred specific examples A medical product device in the form of a cannula support assembly 10 is shown in the drawings. rear Support assembly IJ 10 incorporates various features of the present invention, as described in detail in Even the friend I want to materialize has a special@. However, the main issue described here The description may be used in numerous environments other than the specific medical product equipment situation illustrated and described. It should be recognized that it can be adapted for use.

With this in mind, a typical blood collection, storage and sampling unit 1 2 is shown in FIG. Although various configurations are possible, the specific In the example, the unit 12 is typically made of medical grade polyvinyl chloride plastic. It includes a blood collection container 14 which is a flexible bag made of stick material. or Blood donor tube typically made of medical grade PVC plastic material 16 is integrally attached to and supported by the container 14. Shape of intravenous needle 18 The cannula body has a donor tube in flow communication with the outer end 17 of the donor tube 16. It is attached to the outer end 17 of the tube 16. The needle 18 collects blood after venipuncture from the patient or the donor. from the donor tube 16 into the container 14.

In this particular work environment, the cannula support assembly IJ O is utilized to support the phlebotomy needle 18.

This time is used in FIGS. 2-5 and telekinesis to support the phlebotomy needle 18. A specific example of assembly IJ 10 will be referred to. In these 8 bodies, Assembly IJ 10 G, i is compact and easy to handle, and can be operated at the operator's fingertips. 4 and 5 (see particularly FIGS. 4 and 5). The hub means 38 , the phlebotomy needle 18 is moved beyond one end 43 of its actuating or beveled end 36 to the entire hub means 38. It is supported by extending it in the axial direction.

The hub means 38 includes a strut portion 39 (as best seen 7" in FIGS. 3 and 5). ), the strut portion 39 projects outwardly from one end 43 of the hub means 38, and Concentrically surrounds an adjacent portion of the working end of needle 18.

Although the hub means 38 can be configured in a variety of ways, in the illustrated embodiment, the hub means 38 December 1981 entitled "Cannula Support Assembly and Method of Making the Same" Disclosed in U.S. Patent Application No. 326,729 by Emil 5oika, filed on the 2nd. It is structured according to the established policy.

More specifically, hub assembly 388 includes first member 22 and second member 24. include. The first and second members 22 and 24 each have a substantially uniform cross-sectional shape. It has an elongated tube-like shape. Quoted above, fsoik, 'I's special sweat comes out. As pointed out in the application, this structure is compatible with conventional ram or screw extrusion. The first and second members 22 and ? 4. do.

However, the hub means 38 years old] and its associated strut portion 39 are either integrally molded or It is supported in a bore 42 formed with the understanding that it can be manufactured as a compression molded unit or as a compression molded unit. an unsupported body portion 26 and opposite ends, each disposed outwardly of the first member 22; 28 and 30, respectively.

The second member 24 also has a bore 32 within which a stem 34 of a phlebotomy needle I8 (see FIG. 3) is provided. See j) is fixed. The hole 34 is inserted into the second member bore 32 by various means, e.g. For example, by adhesive or epoxy bonding (Emil 5oika, cited just above). (as disclosed in the patent application of ), or the previously cited Edward Garver's "Cannula and Similar Support Assemblies and Methods of Making the Same" ” and “autoclavable heat bondable to cannulae and similar Hardened by thermal bonding as disclosed in the US patent application entitled Plastic Materials J. can be worn.

Because of this construction, the working end 36 of the needle 18 is located at the second end adjacent the end 43 of the hub means 38. is supported in an exposed position projecting outwardly beyond the end of the member. Illustrated examples of birds In this case, this end 28 is the strut portion of the hub means 38 previously described. It corresponds to 39.

The other outwardly disposed end 3o of the second member 24 is the end of the donor tube 16. 17.

The first member 22 is preferably arranged on one outer surface in the axial direction of the bore 42 of the first member. Includes an outwardly projecting ridge or shoulder 40' (H) extending along the needle 18. Proper alignment of the beveled end 36 of the beveled end 36 to the hub means 38 during assembly The reference point of the object and the point of reference. The sharpest part of the needle 18 will not break the skin during venipuncture. A proper direction of inclination is desirable because it ensures that.

Facilitating initial alignment of beveled end 36 of needle I8 during assembly operations In addition, the ridges 40 provide a barrier to the operator's hand to aid in positioning the beveled end 36 during venipuncture. (See Figure 5).

Assembly 10 further protects the sterile integrity of pre-venepuncture phlebotomy needle 18 and protects its sterile integrity. cover means 46 for sealing the needle 18 against fluid loss before and after use. nothing.

As best seen in FIGS. 3 and 5, cover means 46 covers hub means 38. Fits concentrically around the strut portion 39 (the terminal end 28 of the second member) It has an open end 5o. The cover means 468 further includes an end 50 extending from the needle 1. It includes an open interior 48 which serves to contain the working portion 36 of 8.

The cover means 46, like the hub means 38, may be configured in a variety of ways.

However, in the illustrated embodiment, cover means 46 is identical to hub means 38. , constructed in accordance with the guidelines disclosed in the 7-vsoika patent application cited above. It will be done.

More specifically, the cover means 46 has an open interior 48 therebetween. having a substantially uniform cross-sectional shape with extending oppositely spaced ends 5o and 51 It takes the form of an elongated tube (see Figures 2 and 5). 1st and 2nd part As with the construction of materials 22 and 24, this elongated, tubular, generally uniform shape , the construction of the cover means 46 using known ram or screw extrusion techniques. possible. However, like the hub means 38, the cover means 46 may It should be recognized that can be manufactured as compression molded parts.

The cover means 46 extends in the axial direction to facilitate knob and operation by the operator. In the illustrated embodiment, the ridges 52 are uniformly spaced apart in the radial direction. Formed externally (see back of Figure 4 and Figure 5).

As seen in FIG. 3, the inner diameter of the interior 48 of the cover means 46 is preferably Exceeds the outer diameter of the exposed portion 36 of the dissection needle 18. This cover means 46 is the hub means. 38, the open interior is exposed to the outside of the needle 18 along its entire length. and is disposed radially outwardly of and in a discontinuous relationship therewith.

A fluid-tight seal is then achieved with the needle 18 within the open interior confines of the cover means 46; In the illustrated embodiment, the cover means 46 is made of an elastically compressible material such as compression molded rubber. vi54, preferably made of material. Member 54 is located at the top of open interior 48. The cover is placed on the outermost side of the means 46 so as to occupy only the outer 11N portion. It may be inserted into a press-fit relationship through the open end 51 (see Figure 3).

As seen in FIG. 3, member 54 includes hub and cover means 38 and 46. When connecting t'L, seal the outermost tip 37 of the beveled end 36 of the needle 18 and wrap it. Room fowl that has an enclosing shape are included in Bokeno) 56. Pocket 56 is that sealing the needle tip 37 from communication with the remainder of the open interior 48 of the cover means 46; and provides positive fluid isolation for the needle 18 within the open interior 48.

Only the outermost tip 37 of needle 8 is in sealing contact with pocket 56 of member 54. When the cover means 46 is removed to expose the needle 18, the gap between the needle 1B and the cover means 46 is has minimal friction or drag. Such removal is therefore needle 1 8 has no tendency to draw fluid out of the 8. For the same reason, Kaba means 46 No. Reattachment to the means 38 is also accomplished with minimal effort.

In the preferred and illustrated embodiment, the force serving to break the connection means 41 is , the cover means 46 is rotated around the strut portion 39 by screwing the means 46 It will be done.

According to the present invention, the magnitude of the rotational force required to break the connecting means 41 is It is greater than the nominal amount of force, such as that imparted by a mere interference fit.

This minimizes the chances of any accidental breakage of the connection means 4 during handling.

However, still in accordance with the present invention, the required force is reduced to cover means 46 or hub means 46. The amount of permanent rotational deformation of the strut portion 39 of 38 is not large enough. Therefore, in Figure 5 "showing": After the connecting means 41 is broken, the support portion 39 and the cover means 46 are connected. around the n1 pillar part 390, keeping it physically intact and keeping the groove part unchanged. The open end portion of the cover means 46 allows for subsequent reattachment of the cover 50.

Preferably, the cover means 46 is less than the rotational force exerted on the connecting means 41 at that point. It can be elastically deformed around its axis in response to strong rotational force. I will write about it in detail later. As described above, before the connecting means 41 is breached, its integrity is further compromised. Provides full top visible and fusible security.

However, according to the invention, after the first breaking of the connecting means 41 t', Any subsequent reattachment and removal of cover means 46 to hub means 38 is relatively painless. easily achieved. This prescribed reading means has been breached and the sterile integrity of the needle 18 has been breached. There is no doubt about that.

Connection means allowing a selectively breakable connection between the end portion 50 and the strut portion 39 can be diverse. In a preferred embodiment, the means 41 remain in the strut portion 39. A limited or precipitating surface formed along the concentric interface of the open end portion 50 instead. It takes the form of a thermal bond 45 that can be collapsed. This limited thermal bonding 45 is used for the strut portion 50. careful balancing of the material used in the cover means 46 to the material used; This occurs as desired in combination with careful selection of the optimal joint area between them.

More particularly, all materials for the hub and cover means of assembly 10 All governing selections are that assembly 10 is made of a material suitable for contact with human blood. It is the desirability of being made.

It is also highly preferred that the entire assembly 10 be autoclavable.

With respect to the hub means 38, a polyvinyl chloride plastic material is connected to the first member 22. It is well suited for use.

A strut portion 39 (which constitutes the end 28 of the second member 24 in the illustrated embodiment) ), additional selection preferences arise for materials. For example, the entire second member 24 The body material is made of medical grade PVC tubing for ease of installation. can be solvent bonded to it, and blood and parenteral fluids can leak through it. Can be heat welded to needle 18 in a manner that minimizes the chance of air gaps or voids in the joint Mouth is preferable.

As discussed in the Edward Garver patent application cited above, the second (and whose ends 28 therefore constitute three strut sections) are preferably Manufactured and sold as HY T RE L4056 by E, I, and Teyupon. Approximately 60% by weight of thermoplastic polyetherester and Eastman, K・0DARPETG Copo by Chemical, Progukun, Inc. Poly(ethylene terephthalate) manufactured and sold as Riester 6763) ”’ (i=consisting of a polyester material consisting of approximately 40% by weight of the based copolymer) be molded. This polyester material can be autoclaved and Needles] Demonstrates excellent bonding properties to 8.

The selection of a polyester material that allows for tight bonding properties to the needle 18 may, on the one hand, The selection of the material of the cover means 4G to achieve the desired thermal bonding 45 is repeated. Become sloppy.

For example, blood contact approved and autoclaveable polypropylene The material is that too! However, it cannot be approved for use as a cover means 46.

This is because the polypropylene material is chemically similar to the polyester material of the strut section 39. This is because there is no

As a result, the surface structure of polypropylene materials can be improved by e.g. flame treatment or corona discharge. Therefore, no thermal or other bonding between the two materials is possible unless they are changed. , especially with the desired limited junction 45.

In addition, it is suitable for blood contact, is autoclavable, is known as a widely used The use of plasticized polyvinyl chloride string resin composition O is also not approved. Like that Although some compositions may be heat welded to the polyester material of strut portion 39, these In general, the bonding strength of plasticized polyvinyl chloride resin composites is determined by the heat of the vinyl. As the history or MIB increases, it gradually rises at t, and the polyester support portion 39 It reaches a size that easily exceeds the torque resistance (approximately 20 inches ounces).

Referring to example ■ in the table below, autoclaving (approximately 230°F to 250°F) After exposure to temperatures between To break the thermal bond between the tail post section 39 and the support section 39, always It may be necessary to apply more than 22 inch ounces of excess pull-off torque. Strut part A rotational deformation of 39 minutes occurs.

Next, referring to the following example of dragon Mite calcium carbonate (Thompson-Weinman product) is added to polyester. Polychlorinated to reduce the pull-away torque below the torque resistance strength of the three tell columns. It has been found that the thermal bonding properties of vinyl resin compositions cannot be changed appropriately. The trigger that occurs Release torque varies widely between 19 and 26 inch ounces after autoclaving It was observed that

However, as you can see in the table below, silicone on vinyl The addition of a small amount (approximately 3% by weight) of (Dow Corning 200, 12,500Cs) This causes a significant change in the thermal bonding properties of the polyvinyl chloride resin composition and increases the thermal bonding strength. It was discovered that this caused a significant decrease in the degree of After autoclaving, its maximum value (1 inch ounce) is less than the torque resistance of the polyester support section 39. It has been discovered that providing a delimited range of pull-off torque is Coating carbonate on vinyl-silicone mixtures, as shown in Example 1 in the table below. Addition of Si is unlikely to reduce the observed maximum pull-off torque below. It was later discovered. Addition of calcium carbonate also applies to vinyl-silicone mixtures alone. relatively narrower than the one brought into the pull-off torque range. .

Therefore, a more uniform product can be obtained.

For example, using all of the compositions in Example V in the table below, 60 cups can be made in one batch. <71 chicks destruction [After the rock, travel six pieces-. One means 46;;ll, within a limited range of 9 to 14 inch ounces; It had a pulling torque. Experience f = 8 Large pull-off torque (1 unit) is 1 6 inch oz.

In my experience, the minimum torque (2 units) is 8 inches oz.

This leads to an even narrower and more limited pull-off torque range (the effect of calcium carbonate is This is surprising in light of Example H discussed above.

(Margin below) Polyvinyl chloride resin composition 75 approx. 19, 26 silicone 2.91 I'chio'' Example　■ Polyvinyl chloride resin composition 7209 Silicone 291 Example　■ Polyvinyl chloride resin composition 77.00 Silicone 3.1 The weight percent of the polyvinyl chloride resin composition in the table above is based on the weight percentage of the polyvinyl chloride resin, plastic agents (such as di-2-ethylhexyl phthalate) and suitable heat stabilizers. (such as epoxidized soybean oil and metal soaps). The resin composition is rotated Blended in a mixer, silicone is added along with stabilizers. blend After proper mixing, transfer the blend from the mixer to the pump blender/cooler. , add calcium carbonate directly to the blend. The resulting blend is then shown in the drawing. The cover can be extruded to form the cover means 46.

The separation torque is applied when the cover means 46 is rotated relative to the polyester strut section 39. is measured around the strut section 39.

For example, pull-off torques within the ranges associated with ■, ■, and V require careful application of force. and therefore cannot occur inadvertently or accidentally. But long Careful application of the force required to generate the full pull-off torque within this limited range The use is within the physical capabilities of the average user without undue effort or fatigue.

The narrow range of pull-off torques associated with examples ■ and ■ is such that they are This is preferred because it allows for a more uniform final product.

In order to obtain a uniform pull-off torque with a relatively narrow limit tI related to Example ■ and V, For this purpose, a thermal bond 45 is formed along the length of the open end portion 50 and the strut portion 39. The surface area of the interface between the Measured to be square inches.

Additionally, the relatively narrow limited pull-off torque associated with Examples ■ and V can be uniformly A heat exposure cycle of approximately 30 minutes at approximately 250°C is preferred to obtain was decided.

After this thermal exposure cycle, the hub means 38 and the accessible cover means 46 are removed from the second Handle, sterilize and pasteurize as the final assembly 10 as shown in the figure. be able to. Desirable limits of thermal bonding between cover means 46 and strut portion 39 The strength (when measured as the pull-off torque shown in the table) is determined by autoclave sterilization. and does not increase significantly during additional heat exposure caused by pasteurization.

For example, 18 covers 46 were molded using the composition of Example Liester strut section 39 was exposed to approximately 250 degrees Fahrenheit for 75 hours continuously. child After long-term heat exposure, all but three of the thus molded cover means 46 become 9 The pull-off torque was within a narrow range of 14 inches ounces.

Even more significant, none of the 46 covers exceeded 14 inches of ounces. There was nothing with release torque.

The specific range of pull-off torque associated with examples ■ and ■ can be found in the table in absolute values. Varies depending on the joint 450 surface area and the specific heat sterilization cycle used. However, they are still below the level at which rotational deformation of the strut part occurs. was observed to remain consistently. For this reason, the joining 45 itself is automated in mass production. Enabling manufacturing technology.

Due to the limited thermal bonding45 described so far, the assembly IJIO is actually ζ It is a sliding protection. As shown in FIGS. 4 and 5, the cover means 46 is opened. To remove, the assembly 46 is attached to the hub means 38 by applying the necessary separation torque. It is necessary to twist carefully until the end is reached. The joint 45 also includes a cover means. It can also be broken by pulling sideways, but the effort involved in this technique It should be recognized that there is much more to it than that.

Further, the materials in examples In, IV and ■ in the table above are each semi-rigid and the required It is elastically deformable in response to a torque less than the pull-off torque. This thing , usually a cover around the strut portion 39, which serves to resist torsion of the means 46. The presence of the joint 45 generates enough torque to break the cover means 46 or the joint 45. causing it to twist or deform elastically in place of itself (first (See Figure 4). This elastic twisting of the cover means 46 does not permanently deform the cover means 46. stomach. For this purpose, the user may later reconnect the cover means 46 around the support section 39. A hippopotamus means 46 can be shot around itself without affecting its ability to By observing whether G can be sexually twisted or transformed, It is possible to quickly test for the presence of junction 45.

Furthermore, the polyester material of the strut portion 39 and the vinyl/silicone material of the cover means 46 Breaking of the joint 45 between the carbon/calcium carbonate material (e.g. ■ and V), opening It was observed that this was accompanied by a popping sound.

For the purpose of the present invention, if the cover means 46 is provided without elastic deformation, it is possible to If the hub means 38 can be removed without making a banging sound, this is the thermal bonding 45. serves as a clear indication that it has been broken before in all possibilities. mosquito The bar member 46 has therefore probably been previously removed and refitted. needle 18 Sterile integrity is questionable.

It was observed that the materials in Examples ■ and ■ loosened in the presence of heat. this desirable Due to its nature, the end 50 of the cover means 46 is normally a tight interference fit on the strut portion 39. It can be of specified dimensions.

This fit temporarily secures the cover means over the strut portion 39 during manufacturing operations. this The mating also provides intimate contact along the joining area and facilitates the formation of a hermetic thermal joint. . However, during thermal exposure and formation of thermal bond 45, end 50 of cover 46 slack and match the outer dimensions of the strut portion 39.

Therefore, after the thermal bond 45 is broken t', the end 50 of the cover means 46 is substantially unsupported. It can freely rotate around the column section 39.

The free rotational fit of the mouth allows removal of the cover means 46 during venepuncture and, if desired, This greatly facilitates reinstallation of the cover means 46 onto the strut portion 39. It is also connected It serves as another external indication that Coupling 45 is broken.

From the above, it can be seen that the limited thermal bonding 45 described so far is limited to one member (cover and means 4). (corresponding to column 6) around the associated column member (corresponding to column 39 of column means 38). Widely applied for use in a variety of situations where a removable bond is desired. You should realize that you can get it.

Thermal bond 45 forms a tamper-proof connection between cover means 46 and hub means 38. Ru. This connection is hermetic in nature and therefore ensures that the needle 18 or 20 is sterile before use. serves to preserve integrity, is intentionally limited in strength, and is protected against subsequent heat exposure. The strut part is not affected by 39 to provide a pull-off torque below the point at which deformation of the cover 46 occurs; Preserves the structural integrity of the strut section 39 for later reinstallation and allows the user to Check whether the sterile integrity of the cannula is breached promptly and easily before venipuncture. allow the decision to be made.

The invention is set forth in the various claims.

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Claims (1)

[Claims] 1 Despite long-term heat exposure, polyvinyl chloride resin compositions or heat that can be selectively broken in response to the application of a force that does not result in permanent deformation of the material Polyvinyl chloride resin compositions can be bonded with compatible materials. A method of modifying thermal bonding properties, the resulting mixture comprising approximately 3% by weight silicone. The method characterized in that silicone is added to the resin composition so as to contain . 2. Mix the resin so that the final mixture contains about 20 to 25% by weight of calcium carbonate. Claims further comprising the step of adding calcium carbonate to the composition/silicone mixture. The method described in box 1. 3. Parts molded from polyvinyl chloride resin composition and polyester composition There is no permanent change in either part despite long-term heat exposure. A method for forming thermal bonds that can be selectively broken in response to the application of non-forming forces. the resin such that the resulting mixture contains about 3% by weight silicone. Step of adding to the composition during molding, and the resulting raw resin composition/silicone mixture contacting the member made from the polyester composition with the member made from the polyester composition; and then place the two parts at their contact points with sufficient heat to bond them together. A method as described above, comprising the step of exposing to heat. 4. Powder the resin so that the final mixture contains about 20 to 25% by weight of calcium carbonate. The method further includes the step of adding calcium carbonate to the composition/silicone mixture during molding. The method described in item 3 of the scope of the request. 5. Approximately 60% by weight of thermoplastic polyester and poly(ethylene terephthalate) further comprising the step of creating a polyester composition of about 40% by weight of the based copolymer. Method 0 of claim 3 or 4 6. The thermal exposure step comprises exposure at about 250° F. for about 30 minutes. Method of Section 5. 7. The step of bringing the members into contact forms a contact area of approximately 0.05 square inches. The method of claim 5, comprising: 8. The step of adding silicone involves adding 50% by weight or more of the resin composition and silicone. 4. The method of claim 3 comprising forming a mixture comprising about 3% by weight. 9 about 72 to 77% by weight of the resin composition, about 3% by weight of silicone, and The resin composition is adjusted such that the remainder of the mixture is calcium carbonate. Claims further comprising adding calcium carbonate to the product/silicone mixture Method of Section 8. 10. In an autoclavable medical product device, the first member and the second member Between the two parts, there should be no permanent deformation of either part despite long-term heat exposure. 1. A method of forming a thermal bond that can be selectively broken in response to the application of a strong force, the method comprising: , containing 50% by weight or more of a polyvinyl chloride resin composition and about 3% by weight of silicone. molding a first member having a first chemical composition; and fully molding a second member having a second chemical composition containing an ester material; bringing the first and second members into contact; and placing the two members at their point of contact. the process of exposing them to sufficient heat to thermally bond them together The method characterized in that it comprises: 11. The molding step of the first member includes the resin composition/silicone mixture 12. In the molding process of the first member, the resin composition is approximately 72 to 77% by weight, and the silicone is approximately 3% by weight. % by weight of the first material, with the remainder of the first material comprising calcium carbonate. 12. The method of claim 11, comprising: 13 The molding process of the second member consists of about 60% by weight of thermoplastic polyester and polyester. Copolymer based on ethylene terephthalate containing about 40% by weight. 12. The method of claim 10 or claim 11, comprising making the material of claim 2. 14. The thermal exposure step comprises exposure for about 30 minutes at about 250 ℃ below. The method of Section 13. 15. The step of bringing the two members into contact forms a contact area of approximately 0.05 square inches. 15. The method of claim 14, comprising: