Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F2/00—Processes of polymerisation
  • C08F2/01—Processes of polymerisation characterised by special features of the polymerisation apparatus used

Definitions

• an autoclave pressure profile is used to move molten nylon polymer out of the autoclave and extrude it through a dieplate. Following extrusion, the molten nylon polymer is quenched in cooling water and cut into flakes or pellets.
• the pressure profile for extrusion can be maintained using compressed nitrogen gas within the autoclave. Typical autoclave pressures can be from 3 and 9 barA.
• an operator may be only marginally successful in closing the autoclave extrusion valve in time to optimally avoid or minimize a nitrogen blow. This is due to the swiftness of the event compared to the reaction time of the operator.
• the disclosures herein relate to methods involving production of polymer and problematic issues associated therewith.
• the disclosures include methods of detecting a nitrogen blow event during a polymer fabrication process, such as a nylon or nylon 6,6 polymer fabrication process.
• such methods may generally include: 1 ) receiving with a microphone, sound information resulting from nitrogen gas passing through a dieplate that extrudes molten polymer; 2) converting the sound information into an electronic signal; and 3) evaluating the electronic signal with a logic controller at a frequency of at least once every 0.1 seconds.
• Embodiments of nitrogen blow detection systems are likewise disclosed.
• One exemplary embodiment of such a system may include: 1 ) a microphone configured to detect sound information resulting from nitrogen gas passing through a dieplate that extrudes molten polymer; 2) a converter module electronically coupled to the microphone and configured to receive sound information from the microphone and convert the information into an electronic signal; and 3) a logic controller electronically coupled to the converter module and configured to evaluate a signal from the converter module at a frequency of at least once every 0.1 seconds.
• Also disclosed herein are embodiments of a system for arresting a nitrogen blow occurring during a polymer production process.
• methods of ending a nylon polymer casting event are set forth.
• such a method may include: 1 ) anticipating an end of the casting event based on parameters of the event; 2) detecting a nitrogen blow event as recited herein; and 3) closing an autoclave extrusion valve coupled to the dieplate in response to detection of the nitrogen blow event.
• nitrogen blow and "nitrogen blow event” refer to an occurrence where nitrogen gas blows or vents out of a dieplate through which molten polymer, such as nylon 6,6 polymer, is extruded. Often, but not always, a nitrogen blow may indicate or signal the end of a casting event in which the polymer is being produced. Also, it is noted that the term “nitrogen blow” also includes blow events that may occur as a result of nitrogen and/or even other gases that may be present. Thus, the nitrogen blow in some cases may caused by a void in the molten polymer, which is typically nitrogen, but can also include or be steam or degradation gas. Thus, it is not important that the gas be nitrogen for the systems and methods of the present case to be effective, and the term “nitrogen blow” generically includes nitrogen and/or other gaseous blow events that can occur.
• the term “about” can include traditional rounding according to significant figures of the numerical value.
• the phrase “about 'x' to 'y” includes “about 'x' to about 'y'”.
• the logic controller 90 may control or
• the logic controller may control or communicate with the autoclave extrusion valve directly.
• the process control unit 80 may in some embodiments
• an assembly as shown in FIG. 2 may be used.
• alarm limits can be set according to these initial readings. Alternatively, alarm limits can be set based on prior knowledge of the casting process in general or in view of a given piece of casting equipment. In one aspect, a general alarm limit may be sound levels of about 90 db or above.
• the intensity of the sound is measured and constantly reported to the process controller and the logic controller using an electronic signal (e.g., an analog signal).
• the signal corresponds with a range of 34 dB to 94 dB.
• the configuration of the microphone signal in the process controller is such that the extrusion valve will be closed or interlocked if the measured sound-level exceeds the HH-value.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=50729851

Family Applications (1)

Country Status (4)

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Family Cites Families (4)

• 2014
  • 2014-04-10 CN CN201410143399.9A patent/CN104129062B/zh active Active
  • 2014-04-10 TW TW103113137A patent/TW201500402A/zh unknown
  • 2014-04-15 WO PCT/US2014/034152 patent/WO2014179047A1/en active Application Filing
  • 2014-04-15 EP EP14724279.6A patent/EP2992022A1/en not_active Withdrawn

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