Patent Application
20080179427
This invention relates to a hand-held shower assembly. More particularly, this invention relates to a hand-held shower assembly employing components with an embedded antimicrobial additive.
As is known, hand-held shower assemblies are typically fabricated with a hose that can be connected at one end to a valve in a shower stall and a spray head that can be connected to the opposite end of the hose for dispensing streams of water onto a user. Typically, the hose has been encased within a sheath of water repellant material. Generally, the hose is connected to a valve at an elevated height in the shower stall while the spray head is mounted on a vertically disposed wall bar via a slidable connection so that the height of the spray head can be adjusted for use. As a result, the hose forms a depending loop within which water may collect. Over time, the standing water in the loop creates a site for bacterial growth.
Accordingly, it is an object of this invention to prevent the growth of bacteria in the hose of a hand-held shower assembly.
It is another object of the invention to prevent the growth of bacteria in a spray head of a hand-held shower assembly.
Briefly, the invention provides a hand-held shower assembly with components that are manufactured with an antimicrobial additive embedded therein. In particular, the shower assembly is provided with a hose that is made of a flexible polymeric material having an antimicrobial additive embedded therein as well as a spray head that is made of a polymeric material having an antimicrobial additive embedded therein.
In an alternative embodiment, the hose and/or the spray head may have the water conveying passages of each provided with an antimicrobial additive.
The antimicrobial additive in the polymeric material is preferably an inorganic silver ion exchange system. In addition, the additive may include an inorganic copper and/or zinc.
The amount of additive in the polymeric material constitutes 1% to 5% by weight of the total weight of the component, i.e. hose or spray head. In this respect, an amount of less than 1% of an additive is insufficient to have an antimicrobial effect.
In order to make a hose in accordance with the invention, the antimicrobial additive is compounded into various polymers by up to 40% by weight with the exact correct additive being specified for each polymer. Compounding takes place in an extruder in which the base polymer is melted and the additive introduced into the polymer melt stream, for example through a side feed in the extruder. The extrudate extruded from the extruder is pelletized and collected into a mass of pellets in which the additive constitutes an amount of from 10% to 40% by weight of the mass. This resulting master batch is then mixed with virgin polymer of the same type as in the mixture to achieve a mixture in which the antimicrobial additive is an amount of 1% to 5% by weight of the mixture. For example, the mixture may be obtained by blending of the master batch and the virgin polymer in a drum roller for 1 hour, capped with nitrogen, if possible to keep the mixture dry.
Thereafter, using a closed feeding system or sealed hopper to avoid contamination, the mixture is extruded through a suitably shaped die to form a hose having a longitudinal passageway for a flow of water.
In order to form a spray head, the mixture is injection molded in a die to form the spray head with at least one passage for a flow of water.
Depending on the polymer used, the amount of additive may be different. Suitable polymeric materials include polyvinyl chloride (PVC) polyacetal, polyamide (Nylon), polycarbonate, low-density polyethylene, acrylonite butadiene styrene (ABS), a thermoplastic vulcanizate (Santoprene) and Rotomold polyethylene (PE).
These and other objects and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings wherein:
Referring to
In particular, the hose 11 has an inlet end for connection to a water conveying means, such as a tap 13, located at an elevated position in a wall 14 of a shower stall. The outlet end of the hose 11 is connected to the spray head 12 to deliver water thereto in known manner. The hose 11 has an inner annular surface 17 that defines a passage for a flow of water to the spray head 12.
Referring to
As Illustrated in
When the shower assembly 10 is not in use, the spray head 12 is held by the connector 15 on the wall bar 16. In this position, the hose 11 forms a loop as indicated. Typically, water collects at the bottom of the loop of the hose 11 and, over time, may provide a site for the collection and growth of bacteria.
In accordance with the invention, the hose 11 is made of a flexible polymeric material that has an antimicrobial additive embedded therein. The hose 11 may also be surrounded by a sheath or plastic covering in a conventional manner.
The antimicrobial additive is an trimodal efficacy of an inorganic silver ion exchange system.
The antimicrobial additive constitutes to 1% to 5% by weight of the total weight of the hose 11. In addition, the additive may conclude at least of 1% of an inorganic copper and/or zinc.
In order to form a hose, an antimicrobial additive master batch is first prepared. In this respect, the antimicrobial additive is extremely hydroscopic and will absorb a significant amount of moisture if left exposed to the air. Hence, the additive is maintained in a dry state and is processed in a dry state.
The additive is thermally stable up to 800° C. and maybe dried with heat.
The resin selected to make the master batch should be the same resin used in the final product.
During processing, the base resin is melted, for example, using a twin-screw extruder utilizing a mid- to low-screw speed and melting temperatures. The antimicrobial is introduced into the polymer melt stream, for example, through a side feed located approximately half way down the extruder barrel. Upon extrusion, the extrudate that consists of the base resin and the additive is pelletized in a suitable manner and immediately collected and sealed in a shipping container or returned to a desiccant dryer. The resulting master batch contains from 10% to 40% by weight of the antimicrobial additive.
In one embodiment, the master batch is blended with the virgin resin at a ratio to form a mixture wherein the additive constitutes an amount from 1% to 5% by weight of the mixture. Blending may be carried out in a drum roller for 1 hour with the mixture being maintained in a dry condition.
After blending, the resulting mixture is extruded in a suitable extruder to form a hose 11 having an internal annular surface defining a passage for a flow of water. Alternatively, the mixture may be injected into a injection molding apparatus in order to mold a spray head 12 having at least one passage for a flow of water.
The antimicrobial additive that is embedded within the hose 11 acts to stop the growth of any bacteria that may otherwise collect or form within the water passage of the hose 11.
Since the antimicrobial additive is embedded in the hose 11, the additive will not dissipate over time or become eroded over time.
Referring to
Alternatively, the antimicrobial additive may be applied as a powder coating on the passage 17 of the hose 11 and/or the passage 18 of the spray head 12. For example there are low temperature and UV light cure products that can treat plastic with a conductive material. Also, a metal shower head may be treated with the antimicrobial additive.
The thickness of a coating of the antimicrobial additive is a range of 0.001 inches to 0.030 inches.
The invention thus provides a simple technique for stopping bacterial growth within the water conveying elements of a hand-held showerhead assembly. Further, the invention allows the internal surfaces of a hand-held shower assembly that cannot be cleaned by traditional methods to be protected by the antimicrobial additive.
