By a News Reporter-Staff News Editor at Politics & Government Week -- A patent application by the inventors FUJIMOTO, Kentaro (Kobe-shi, JP); ISHIMARU, Takeshi (Kobe-shi, JP), filed on February 17, 2017, was made available online on September 28, 2017, according to news reporting originating from Washington, D.C., by VerticalNews correspondents.
This patent application is assigned to Sumitomo Rubber Industries, Ltd.
The following quote was obtained by the news editors from the background information supplied by the inventors: "Tube pumps and pinch valves are known, for example, to include a flexible tube such as flexible tube made of a rubber or a soft plastic.
"In such a tube pump and a pinch valve, a flow channel is defined by an inner surface of the tube, and only the inner surface of the tube contacts a fluid. Therefore, the flow channel can be always kept clean, for example, by changing the tube after use. This arrangement is effective for prevention of fluid cross-contamination and the like.
"Further, the tube pump and the pinch valve can be advantageously used, for example, for transporting a slurry containing solid particles without clogging and a malfunction thereof.
"Therefore, the tube pump and the pinch valve are widely used in a variety of fields such as of chemicals, semiconductors, foods and biotechnology.
"When the tube pump is used, the tube is squeezed in one longitudinal direction. More specifically, a region of the tube is diametrically pressed to collapse a part of the internal flow channel of the tube and, in this state, the pressed region is moved in one longitudinal direction along the tube, whereby the fluid in the flow channel is fed out in that direction.
"Therefore, it is important, in terms of the fluid transportability in the tube pump, that the tube of the tube pump can be promptly restored to its original state by its intrinsic resilience and restorability to thereby have a sufficient volume to contain a sufficient amount of fluid after the pressed region is moved to release the tube from the pressing.
"On the other hand, the pinch valve is selectively brought into a closed state in which a part of the tube is diametrically pressed to collapse a part of the internal flow channel of the tube to close the flow channel, and an open state in which the tube is released from the pressing and restored to its original state by its intrinsic resilience and restorability to open the flow channel, whereby the closing/opening of the flow channel is controlled to inhibit or permit fluid flow.
"Therefore, it is important, in terms of the responsiveness of the pinch valve, that the tube can be promptly restored to its original state by its intrinsic resilience and restorability to thereby open the flow channel after the tube is released from the pressing.
"It is contemplated to use a tube of a fluororubber, which is soft, chemically stable and highly resistant to chemicals, as the tube to be incorporated in the tube pump and the pinch valve.
"However, the fluororubber is highly adhesive after being crosslinked. Therefore, a longer period of time is required for the restoration of the tube from the collapsed state to the original state by the intrinsic resilience and restorability of the tube after the tube is released from the pressing.
"Therefore, for example, the tube pump is liable to have a reduced fluid transportability, thereby failing to promptly feed out a minute amount of fluid. The pinch valve is liable to have a reduced open/close responsiveness.
"To cope with this, it is proposed to form a coating film made, for example, of a fluororesin on the inner surface of the fluororubber tube defining the flow channel, for example, for suppression of the adhesiveness (Patent Document 1 and Patent Document 2)."
In addition to the background information obtained for this patent application, VerticalNews journalists also obtained the inventors' summary information for this patent application: "Problem to be Solved by the Invention
"The aforementioned arrangement is liable to complicate the structure of the tube and the production process of the tube.
"Further, the formed coating film is liable to be worn or peeled off in a shorter period of time due to friction of fluid flowing through the flow channel and solid particles contained in the fluid, resulting in contamination of the fluid.
"It is an object of the present invention to provide a fluororubber tube which is made less tacky by suppressing the intrinsic adhesiveness of a crosslinked fluororubber without the formation of the coating film which may otherwise complicate the tube structure and the tube production process or may result in contamination of the fluid. Thus, the fluororubber tube is improved in fluid transportability, for example, when being used for a tube pump, and is improved in open/close responsiveness when being used for a pinch valve.
"Solution to Problem
"According to the present invention, there is provided a fluororubber tube formed from a rubber composition containing a fluororubber, not less than 3.8 parts by mass and not greater than 4.1 parts by mass of a polyol crosslinking agent, and not less than 3 parts by mass and not greater than 7 parts by mass of a carbon black based on 100 parts by mass of the fluororubber.
"Effects of the Invention
"According to the present invention, the fluororubber tube is made less tacky by suppressing the intrinsic adhesiveness of the crosslinked fluororubber without the formation of the coating film which may otherwise complicate the tube structure and the tube production process, or may result in contamination of the fluid. Thus, the fluororubber tube is improved in fluid transportability, for example, when being used for a tube pump, and is improved in open/close responsiveness when being used for a pinch valve."
URL and more information on this patent application, see: FUJIMOTO, Kentaro; ISHIMARU, Takeshi. Fluororubber Tube. Filed February 17, 2017 and posted September 28, 2017. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220170268494%22.PGNR.&OS=DN/20170268494&RS=DN/20170268494
Keywords for this news article include: Chemicals, Sumitomo Rubber Industries Ltd.
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