Patent Description:
Many industries utilize peristaltic pump tubing for the delivery and removal of fluids. Since peristaltic pump tubing may be used in a variety of industries, such as the medical industry and pharmaceutical industry, thermoplastic elastomers are typically used that are non-toxic, flexible, thermally stable, have low chemical reactivity, and can be produced in a variety of sizes. With a peristaltic pump, metal rollers are in contact with the tubing. Unfortunately, an electrical charge is generated when the rollers of the peristaltic pump come in contact with the tubing. This can be problematic when medical equipment is used that is sensitive to electrical noise. For instance, when a patient is connected to an electrocardiogram and a peristaltic pump, the electrical noise from the peristaltic pump is detected by the electrocardiogram. Accordingly, medical data that are obtained must account for this electrical noise by the physician reading the results. In fact, physicians are trained to account for the electrical noise when reading the results of an electrocardiogram if a patient is connected to a peristaltic pump. It would be advantageous, however, to decrease this electrical noise so a more accurate reading can be achieved.

Accordingly, an improved tube that would at least decrease the electrical charge generated by the rollers on the tubing is desired.

<CIT> discloses a hose for use in a fluid transfer system, the hose having an electrically dissipative inner or intermediate layer.

<CIT> and <CIT> disclose peristaltic pumps with corresponding peristaltic pump tubes.

The dissipative peristaltic pump tube according to the invention includes a dissipative layer including a thermoplastic elastomer and an anti-static liquid additive, wherein the surface resistivity of the dissipative peristaltic pump tube is at least about <NUM><NUM> ohm/square, wherein the dissipative layer provides an outside surface of the dissipative peristaltic pump tube.

In another embodiment, a peristaltic pump includes a dissipative peristaltic pump tube according to claim <NUM>.

<FIG> include illustrations of exemplary dissipative peristaltic pump tubes.

The following description in combination with the figures is provided to assist in understanding the teachings disclosed herein. The following discussion focuses on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings.

As used herein, the terms "comprises", "comprising", "includes", "including", "has", "having", or any other variation thereof, are open-ended terms and should be interpreted to mean "including, but not limited to. " These terms encompass the more restrictive terms "consisting essentially of" and "consisting of. " In an embodiment, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus.

This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise.

The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and may be found in reference books and other sources within the structural arts and corresponding manufacturing arts. Unless indicated otherwise, all measurements are at about <NUM>. For instance, values for viscosity are at <NUM>, unless indicated otherwise.

The invention is defined by a dissipative peristaltic pump tube according to claim <NUM>.

The dissipative peristaltic pump tube includes a dissipative layer including a thermoplastic elastomer and an anti-static additive. "Dissipative" in reference to the dissipative peristaltic pump tube and the dissipative layer as used herein refers to at least statically dissipative. The dissipative peristaltic pump tube and the dissipative layer is electrically dissipative. The dissipative peristaltic pump tube has desirable surface resistivity, particular when in contact with rollers of a peristaltic pump, such that the dissipative peristaltic pump tube has a decreased electrical charge compared to a peristaltic pump tube without an anti-static additive. According to the invention, the dissipative peristaltic pump tube has a surface resistivity that is at least about <NUM><NUM> ohm/square. "Surface resistivity" as used herein is defined as a resistance of leakage of current along an outside surface of the tube.

According to the invention, the dissipative peristaltic pump tube includes a dissipative layer of the thermoplastic elastomer and the anti-static additive. Any thermoplastic elastomer is envisioned. In a particular embodiment, the thermoplastic elastomer includes a polystyrene, a polyester, a silicone copolymer, silicone thermoplastic vulcanizate, a copolyester, a polyamide, a fluoropolymer, a polyethylene, a polypropylene, a polyether-ester copolymer, a thermoplastic urethane, a polyether amide block (PEBA) copolymer, a polyamide copolymer, a styrene block copolymer, a polycarbonate, a polyolefin elastomer, a thermoplastic vulcanizate, an ionomer, a polyoxymethylene (POM), an acrylonitrile butadiene styrene (ABS), an acetal, an acrylic, a polyvinyl chloride (PVC), a blend, or combination thereof. In a more particular embodiment, the thermoplastic polymer is a polyvinyl chloride, polyurethane, PEBA, styrene block copolymer, a blend, or combination thereof. The thermoplastic elastomer provides a matrix for the anti-static additive to be homogeneously dispersed therein.

A liquid anti-static additive provides at least static dissipative properties, or even electrically dissipative properties, to the dissipative layer. In an embodiment, any additional anti-static additive is envisioned. Any reasonable amount of the anti-static additive is envisioned to provide at least static dissipative properties, or even electrically dissipative properties, to the dissipative peristaltic pump tube. For instance, the additional anti-static additive includes an inherently dissipative additive, a conductive additive, or combination thereof. Any inherently dissipative additive is envisioned. In an embodiment, the inherently dissipative additive includes, but is not limited to, polyether block amide (PEBA), a urethane block copolymer, or combination thereof. In an example, the inherently dissipative additive is present at an amount of about <NUM>% to about <NUM>% of the total weight of the dissipative layer. In an embodiment, the anti-static additive is a liquid additive including, but not limited to, stearic acid, ethoxylated amine, a diethanolamide, a glycerol monostearate, glycerol ester, alkyl sulphonate, ethoxylated fatty acid ester, ethoxylated , sorbitan ester, zinc stearate, or combination thereof. In an embodiment, the liquid additive is present at an amount of about <NUM>% to about <NUM>% of the total weight of the dissipative layer. In an embodiment, the anti-static additive may be any reasonable conductive additive. Exemplary conductive additives include, but are not limited to, an onium salt, carbon black, silver ion, silver metal, a quaternary ammonium salt, gold, gold alloy, copper, copper alloy, or combination thereof. In a particular embodiment, the onium salt includes a nitrogen-based onium salt. In an embodiment, the conductive additive is present at an amount of about <NUM>% to about <NUM>% of the total weight of the dissipative layer. It will be appreciated that the amounts of the anti-static additive can be within a range between any of the minimum and maximum values noted above. In an embodiment, a combination of the anti-static agent is envisioned that provides synergy such that relatively low amounts of the additives may be used to provide a desirable surface resistivity.

The thermoplastic elastomer may be formed with any reasonable component such as any precursor with the addition of any reasonable additive. An additional additive includes, for instance, a catalyst, a filler, a plasticizer, a lubricant, an antioxidant, a colorant, an optically transparent conductive additive, an adhesion promoter, heat stabilizer, acid scavenger, UV stabilizer, processing aid, or combination thereof. In a particular embodiment, the precursor, the additional additive such as the catalyst, the filler, plasticizer, lubricant, antioxidant, colorant, an optically transparent conductive additive, an adhesion promoter, heat stabilizer, acid scavenger, UV stabilizer, processing aid, or combination thereof are dependent upon the thermoplastic elastomer chosen and final properties desired for the dissipative peristaltic pump tube.

Any reasonable catalyst that can initiate crosslinking of the thermoplastic elastomer is envisioned. Exemplary catalysts include a catalyst that may be heat cured, IR radiation cured, e-beam cured, or combination thereof, such as a peroxide, a benzophenone, or combination thereof. The catalyst may or may not be used in combination with a crosslinker promoter, such as triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), or combination thereof. In an embodiment, the additive includes any reasonable optically transparent conductive additive. An exemplary optically transparent conductive additive includes, but is not limited to, an indium tin oxide particle, a silver nanowire, a carbon nanotube, or combination thereof. In an embodiment, the additive includes any reasonable adhesion promoter. Any reasonable adhesion promoter that promotes adhesion of adjacent layers is envisioned and is dependent upon the adjacent layers. Exemplary lubricants include silicone oil, waxes, slip aids, antiblock agents, the like, or any combination thereof. Exemplary lubricants further include silicone grafted polyolefin, polyethylene or polypropylene waxes, Oleic acid amide, erucamide, stearate, fatty acid esters, the like, or any combination thereof. Exemplary antioxidants include phenolic, hindered amine antioxidants. Exemplary fillers include calcium carbonate, talc, radio-opaque fillers such as barium sulfate, bismuth oxychloride, any combinations thereof, and the like. Exemplary plasticizers include any known plasticizers such as a citrate, a phthalate, a trimellitate, <NUM>,<NUM>-cyclohexane dicarboxylic acid diisonoyl ester (DINCH), an adipate, a polymeric plasticizer, a castor oil, a caster oil derivative, mineral oils, soybean oil, such as epoxidized soybean oil, the like, or any combination thereof.

Typically, the additional additive may be present at an amount of not greater than about <NUM>% by weight of the total weight of the thermoplastic elastomer, such as not greater than about <NUM>% by weight of the total weight of the thermoplastic elastomer, or even not greater than about <NUM>% by weight of the total weight of the thermoplastic elastomer. In an alternative embodiment, the thermoplastic elastomer may be substantially free of an additional additive such as a catalyst, lubricant, a filler, a plasticizer, an antioxidant, a colorant, an optically transparent conductive additive, an adhesion promoter, heat stabilizer, acid scavenger, UV stabilizer, processing aid, or combination thereof.

In an embodiment, the material content of the dissipative layer is essentially <NUM>% thermoplastic elastomer and anti-static agent. In some embodiments, the dissipative layer consists essentially of the respective thermoplastic elastomer and anti-static additive described above. As used herein, the phrase "consists essentially of" used in connection with the layer precludes the presence of materials that affect the basic and novel characteristics of the thermoplastic elastomer, although, commonly used processing agents and additional additives may be used in the layer.

<FIG> is a view of a dissipative peristaltic pump tube <NUM> according to an embodiment. In a particular embodiment, the dissipative peristaltic pump tube <NUM> can include a body <NUM> having an outside diameter <NUM> and an inner diameter <NUM>. The inner diameter <NUM> can form a hollow bore <NUM> of the body <NUM>. The hollow bore <NUM> defines a central lumen of the tube. In addition, the body <NUM> is illustrated as a dissipative layer, the dissipative layer including the thermoplastic elastomer and the anti-static additive. The dissipative layer can include a layer thickness <NUM> that is measured by the difference between the outside diameter <NUM> and the inner diameter <NUM>.

In a particular embodiment, the outside diameter <NUM> of the body <NUM> is about <NUM> inches to about <NUM> inches, such as about <NUM> inches to about <NUM> inches. It will be appreciated that the outside diameter <NUM> can be within a range between any of the minimum and maximum values noted above. In an embodiment, the inner diameter <NUM> of the body <NUM> is about <NUM> inches to about <NUM> inches, such as about <NUM> inches to about <NUM> inches. It will be appreciated that the inner diameter <NUM> can be within a range between any of the minimum and maximum values noted above.

Further, the body <NUM> can have a length <NUM>, which is a distance between a distal end <NUM> and a proximal end <NUM> of the dissipative peristaltic pump tube <NUM>. In a further embodiment, the length <NUM> of the body <NUM> can be at least about <NUM> meters, such as at least about <NUM> meters, such as at least about <NUM> meters. The length <NUM> is generally limited by pragmatic concerns, such as storing and transporting long lengths, or by customer demand.

Although the cross-section of the hollow bore <NUM> perpendicular to an axial direction of the body <NUM> in the illustrative embodiment shown in <FIG> has a circular shape, the cross-section of the hollow bore <NUM> perpendicular to the axial direction of the body <NUM> can have any cross-section shape envisioned.

In an alternative embodiment and as seen in <FIG>, a dissipative peristaltic pump tube <NUM> is an elongated annular structure with a hollow central bore. The dissipative peristaltic pump <NUM> includes an inner layer <NUM> and a dissipative layer <NUM>. The dissipative layer <NUM> is illustrated as a coating overlying the inner layer <NUM>. The inner layer <NUM> may be directly in contact with and may directly bond to the dissipative layer <NUM> along an outer surface <NUM> of the inner layer <NUM>. As illustrated, the dissipative layer <NUM> provides an outside surface <NUM> of the dissipative peristaltic pump tube <NUM>. For example, the inner layer <NUM> may directly bond to the dissipative layer <NUM> without intervening adhesive layers, such as a primer. In an exemplary embodiment, the dissipative peristaltic pump tube <NUM> includes two layers, i.e. such as the inner layer <NUM> and the dissipative layer <NUM>. As illustrated, the inner layer <NUM> includes an inner surface <NUM> that defines a central lumen of the tube. In an embodiment, the dissipative layer <NUM> includes the thermoplastic elastomer and the anti-static agent. In an embodiment, the inner layer <NUM> may be the same or different material than the dissipative layer <NUM>. For instance, the inner layer <NUM> may include the same or different thermoplastic elastomer as the dissipative layer <NUM> and may or may not include an anti-static additive. In an example, the inner layer <NUM> is an exemplary thermoplastic elastomer as described above with or without an anti-static additive. In an embodiment, the inner layer <NUM> includes an anti-static additive to provide at least static dissipative properties, or even electrically dissipative properties, to the peristaltic pump tube. In an alternative embodiment, the inner layer <NUM> does not include an anti-static additive. Any dimensions of the dissipative peristaltic pump tube <NUM> are envisioned. For instance, any thickness of the layers <NUM>, <NUM> is envisioned and is typically dependent upon the final properties desired for the dissipative peristaltic pump tube <NUM>. In an embodiment, the ratio of the thickness of the inner layer <NUM> to the dissipative layer <NUM> may be <NUM>:<NUM> to <NUM>:<NUM>, such as <NUM>:<NUM> to <NUM>:<NUM>. It will be appreciated that the ratio of the thickness can be within a range between any of the minimum and maximum values noted above.

Although illustrated as a single layer tube and a two layer tube, any number of layers is envisioned. For instance, the dissipative peristaltic pump tube includes one layer, two layers, three layers, or even a greater number of layers. Typically, the dissipative layer has a thickness of at least about <NUM> inches to about <NUM> inches. It will be appreciated that the thickness of the dissipative layer can be within a range between any of the minimum and maximum values noted above. Irrespective of the number of layers present, the outside diameter and inner diameter of the dissipative peristaltic pump tube can have any values as defined for the single layer tube <NUM> defined in <FIG>. The number of layers is dependent upon the final properties desired for the dissipative peristaltic pump tube.

In an embodiment, the dissipative peristaltic pump tube may further include other layers. Other layers include, for example, a polymeric layer, a reinforcing layer, an adhesive layer, a barrier layer, a chemically resistant layer, a metal layer, any combination thereof, and the like. Any reasonable method of providing any additional layer is envisioned and is dependent upon the material chosen. For instance, the additional layer may be an additional polymeric layer of a thermoplastic elastomer that may or may not be extruded. In an embodiment, any number of polymeric layers is envisioned. Any number of dissipative layers is also envisioned.

In an embodiment, the dissipative layer of the dissipative peristaltic pump tube may be formed by any reasonable means, such as extrusion or injection molding. In a particular embodiment, the layer of the dissipative peristaltic pump tube is formed via extrusion. Any reasonable extrusion system is envisioned. The extrusion system typically includes a pumping system and can include a number of devices that can be utilized to form at least one layer of the dissipative peristaltic pump tube. For example, the pumping system can include a pumping device such as a gear pump, a static mixer, an extruder, a tube die, a radiation cure device, a post-processing device, or any combination thereof. In an embodiment, the thermoplastic elastomer and anti-static additive may be melt processed by dry blending or compounding. The dry blend may be in powder, granular, or pellet form. In a particular embodiment, to form the dissipative layer of the dissipative peristaltic pump tube, pellets of the corresponding monomer or polymer may be compounded with the anti-static additive through a co-rotating intermeshing twin-screw extruder, cooled by a water bath, and cut into compound pellets. The dissipative layer may be made by a continuous compounding process or batch related process. The resulting pellets of the blend are fed into an extruder with a tube die. The tube is extruded through the tube die, the tube having an inner surface that defines a central lumen of the tube.

In an embodiment, the thermoplastic elastomer of the dissipative layer is cured. Any cure conditions are envisioned, such as radiation cure, thermal cure, or combination thereof. In a particular embodiment, the radiation source is sufficient to substantially cure the thermoplastic material. "Substantially cure" as used herein refers to > <NUM>% of final crosslinking density, as determined for instance by rheometer data (<NUM>% cure means the material reaches <NUM>% of the maximum torque as measured by ASTM D5289). Any reasonable radiation source is envisioned such as actinic radiation. In an embodiment, the radiation source is ultraviolet light (UV). In a particular embodiment, curing the thermoplastic material includes irradiating with ultraviolet energy with a wavelength of about <NUM> nanometers (nm) to about <NUM>. Further, any number of applications of radiation energy may be applied with the same or different wavelengths. Any thermal cure conditions are envisioned and depend on the thermoplastic elastomer chosen. When the dissipative peristaltic pump tube includes multiple layers, each of the individual layers of the dissipative peristaltic pump tube may be formed by any reasonable means and is dependent upon the material and the configured location of each of the individual layers. In an example, the inner layer of a thermoplastic elastomer is provided with the dissipative layer formed thereon, as seen in <FIG>. Typically, the thermoplastic elastomer is provided by any reasonable means such as extrusion or injection molding as described for the dissipative layer. The thermoplastic elastomer is formed into a layer, such as an inner layer of the dissipative peristaltic pump tube.

After the inner layer is formed, the inner layer may be surface treated on an outer surface that is adjacent to the dissipative layer. In a particular embodiment, the inner layer is surface treated prior to forming the dissipative layer over the inner layer. The surface treatment is to increase the adhesion of the inner layer to the dissipative layer when the inner layer is in direct contact with the dissipative layer. In an embodiment, the surface treatment enables adhesion between the two layers to provide cohesive bonding, i.e. cohesive failure occurs wherein the structural integrity of the inner layer and/or the dissipative layer fails before the bond between the two materials fails. The surface treatment may include radiation treatment, chemical etch, physical-mechanical etch, plasma etch, corona treatment, chemical vapor deposition, or any combinations thereof. In an embodiment, the outer surface of the inner layer is free of any surface treatment. In an embodiment, the adhesion between the inner layer and the dissipative layer may be improved through the use of an adhesive layer, such as a primer. In an alternative embodiment, the surface between the inner layer and the dissipative layer are free of a primer.

In an embodiment, the dissipative layer is formed by an extrusion system as described, which may be the same or different than the extrusion system used for the first layer. For instance, when the inner layer has the inner surface that defines a central lumen of the tube, the dissipative layer is extruded over the inner layer. In an embodiment, a crosshead die is used to allow extrusion of at least one layer over an adjacent layer.

Although the dissipative layer is described in this embodiment as being delivered after the inner layer is provided, any order of delivery of the inner layer and delivery of the dissipative layer is envisioned. In an embodiment, the inner layer and the dissipative layer may be co-extruded.

Once formed, the dissipative peristaltic pump tube advantageously can withstand a sterilization process. In an embodiment, the dissipative peristaltic pump tube is sterilized by any method envisioned. Exemplary sterilization methods include steam, gamma, ethylene oxide, E-beam techniques, combinations thereof, and the like. In a particular embodiment, the dissipative peristaltic pump tube is sterilized by steam sterilization. In an exemplary embodiment, the dissipative peristaltic pump tube is heat-resistant to steam sterilization at temperatures up to about <NUM> for a time of up to about <NUM> minutes. In an embodiment, the dissipative peristaltic pump tube is heat resistant to steam sterilization at temperatures of up to about <NUM> for a time of up to about <NUM> minutes. In an embodiment, the dissipative peristaltic pump tube may be sterilized via gamma sterilization of up to about 50kGy.

The present embodiments can produce a dissipative peristaltic pump tube having desirable properties. In particular, the dissipative peristaltic pump tube has less electrical charge compared to a tube without an anti-static agent. In an embodiment, the dissipative peristaltic pump tube has desirable surface resistivity of at least about <NUM><NUM> ohm/square, such as at about <NUM><NUM> ohm/square to about <NUM><NUM> ohm/square. With the desirable surface resistivity, the electrical charge and electrical noise created is substantially decreased when a peristaltic pump tube is contacted by peristaltic pump rollers. In addition, the medical data obtained when the peristaltic pump tube is used in combination with an electrocardiogram is more accurate compared to when a tube without an anti-static agent is used. Further, the addition of the anti-static agent provides a desirable volume resistivity of the dissipative peristaltic pump tube compared to a tube without an anti-static agent. "Volume resistivity" is defined as a resistance to leakage of a current through the thickness of the body, i.e. through an inner surface to an outer surface, of the tube. In an embodiment, the dissipative peristaltic pump tube has desirable volume resistivity of at least about <NUM><NUM> ohm/square, such as at about <NUM><NUM> ohm/square to about <NUM><NUM> ohm/square.

In a particular embodiment, the resulting dissipative peristaltic pump tube has desirable flexibility, substantial clarity or translucency, flow reduction, and the like. Flexibility of the final dissipative peristaltic pump tube is typically with a shore A of about <NUM> to about <NUM>, such as about <NUM> to about <NUM> as measured by ASTM D2250. Clarity of the dissipative peristaltic pump tube is checked visually and classified into four levels in terms of transparency: clear, translucent, hazy, and opaque. In an embodiment, the dissipative peristaltic pump tube is not opaque and may be clear or translucent. In a particular embodiment, the dissipative peristaltic pump tube is clear. In an embodiment, the dissipative peristaltic pump tube has a light transmission greater than about <NUM>%, such as greater than about <NUM>%, or even greater than about <NUM>% in the visible light wavelength range. In an exemplary embodiment, the dissipative peristaltic pump tube may have an average flow reduction of less than about <NUM>% of the initial starting value in water.

In exemplary embodiments, the dissipative peristaltic pump tube can be used in a variety of applications. Applications for the dissipative peristaltic pump tube are numerous. In particular, the non-toxic nature of the dissipative peristaltic pump tube makes the dissipative peristaltic pump tube useful for any application where toxicity is undesired. For instance, the dissipative peristaltic pump tube has potential for FDA, ADCF, USP Class VI, NSF, European Pharmacopoeia compliant, United States Pharmacopoeia (USP) compliant, USP physiochemical compliant, ISO <NUM> Standard for evaluating biocompatibility of a medical device, and other regulatory approvals. In a particular embodiment, the dissipative peristaltic pump tube is non-cytotoxic, non-hemolytic, non-pyrogenic, animal-derived component-free, non-mutagenic, non-bacteriostatic, non-fungistatic, or any combination thereof.

In an embodiment, the dissipative peristaltic pump tube may be used in applications such as industrial, medical applications, health care, biopharmaceutical, drinking water, food & beverage applications, dairy applications, laboratory applications, FDA applications, and the like. In an exemplary embodiment, the dissipative peristaltic pump tube may be used in applications such as a fluid transfer tube in food and beverage processing equipment, a fluid transfer tube in medical and health care, biopharmaceutical manufacturing equipment, and peristaltic pump tube for medical, laboratory, and biopharmaceutical applications. In a particular embodiment, the dissipative peristaltic pump tube may be used in a peristaltic pump in combination with an electrocardiogram.

In a particular embodiment, a fluid source, such as a container, reactor, reservoir, tank, or bag, is coupled to a dissipative peristaltic pump tube. The dissipative peristaltic pump tube may engage a pump, fitting, valve, dispenser, or another container, reactor, reservoir, tank, or bag. In an example, the dissipative peristaltic pump tube may be coupled to a water container and may have a dispenser fitting on the distal end. In another example, the dissipative peristaltic pump tube may be coupled to a fluid bag and coupled to a valve at the distal end. In a further example, the dissipative peristaltic pump tube may be coupled to a container, be engaged in a pump, and be coupled to a second container at a distal end.

Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention.

The concepts described herein will be further described in the following examples, which do not limit the scope of the disclosure described in the claims. The following examples are provided to better disclose and teach processes and compositions of the present invention. They are for illustrative purposes only, and it must be acknowledged that minor variations and changes can be made without materially affecting the scope of the invention as recited in the claims that follow.

Several materials are tested for Surface Resistivity. Samples of polyvinyl chloride (PVC) are tested with differing amounts of an anti-static additive added as a Masterbatch based on the total weight % of the dissipative layer. The anti-static additive includes a conductive additive of onium salt at up to <NUM>% weight of the Masterbatch. The dissipative layer is a coating (i.e. jacket) overlying an inner PVC layer (without any anti-static additive). All testing for surface resistivity and surface resistance is at <NUM> using ASTM D257. Electrode configuration includes placing two stainless steel rings <NUM> apart on a section of tubing with <NUM> volts applied. Results and testing conditions can be seen in Table <NUM>. "%RH" is percent relative humidity.

As seen in Table <NUM>, the addition of the anti-static additive to the thermoplastic elastomer improves the static dissipative properties of the material compared to the control.

The materials are also tested for Volume Resistivity. All testing for volume resistivity is using ASTM D257. Electrode configuration includes placing a <NUM> stainless steel sleeve (electrode <NUM>) and two stainless steel guard rings (electrode <NUM>) on outside diameter (OD) of the tube. A conductive rod is inserted (electrode <NUM>) through the inside diameter (ID) of tube with <NUM> volts applied. Results and testing conditions can be seen in Table <NUM>. "%RH" is percent relative humidity.

Volume resistivity is desirable for the resulting tube with a dissipative coating.

Claim 1:
A dissipative peristaltic pump tube (<NUM>, <NUM>) comprises a dissipative layer (<NUM>) comprising a thermoplastic elastomer and an anti-static additive, wherein the anti-static additive comprises a liquid additive,
wherein the surface resistivity of the dissipative peristaltic pump tube (<NUM>, <NUM>) is at least about <NUM><NUM> ohm/square,
wherein the dissipative layer (<NUM>) provides an outside surface (<NUM>) of the dissipative peristaltic pump tube (<NUM>, <NUM>).