Method of extruding and pelletizing expandable polymeric composition with recycling of transparent water supplied across the face of the extrusion die
First Claim
1. A method for providing pellets of extrusion compounded expandable polymeric compositions comprising:
- (a) introducing a blowing agent and said polymeric compound into an extruder in a ratio of flowing agent to polymeric compounds sufficient to provide expansion of a composition of the polymeric compound and blowing agent upon elevation of temperature to the activation temperature of the blowing agent,(b) extruding a composition of said polymeric compound and blowing agent discharging underwater through a pelleter at a temperature below the flowing agent activation temperature,(c) supplying a stream of water across the die face of said pelleter for cooling and transporting pellets, said water being supplied at a predetermined first temperature in a range to maintain pellets below blowing agent activation temperature but sufficiently elevated to cause formation of uniform pellets,(d) supplying additional transport water downstream of said pelleter in an amount and of a temperature further to cool the pellets and total flow of transport water to a second predetermined temperature in a range substantially to prevent activation of blowing agent by heat retained in said pellets, and(e) separating the cooled pellets from said transport water.
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Accused Products
Abstract
A method for providing pellets of extrusion compounded expandable polymeric compositions by (a) introducing a blowing agent and polymeric compound into an extruder, (b) extruding a composition containing the blowing agent and polymeric compound with discharge of the extrusion underwater through a pelleter at a temperature below blowing agent activation temperature, (c) supplying a stream of water across the die face of the pelleter at a predetermined first temperature sufficient to produce pellets, (d) supplying additional transport water downstream of the pelleter to further cool the pellets to a second predetermined temperature, and (e) separating the cooled pellets from the transport water. In an additional embodiment collecting the separated pellets, conditioning the transport water to the first predetermined temperature, and recycling the transport water to the die face.
In a process for extruding and transporting pellets in which an extruder discharges underwater through a pelleting device a method for controlling the temperature of the pellets in which transport water is supplied to the die plate of the pelleter at the first predetermined temperature sufficient to produce pellets and additional transport water supplied downstream of the pelleter further to cool the pellets to a predetermined second temperature.
In a method for transporting pelleted material a control system that comprises sensing and operating conditions, generating a signal according to the operating condition, and diverting flow of the pelleted material in response to that signal.
70 Citations
11 Claims
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1. A method for providing pellets of extrusion compounded expandable polymeric compositions comprising:
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(a) introducing a blowing agent and said polymeric compound into an extruder in a ratio of flowing agent to polymeric compounds sufficient to provide expansion of a composition of the polymeric compound and blowing agent upon elevation of temperature to the activation temperature of the blowing agent, (b) extruding a composition of said polymeric compound and blowing agent discharging underwater through a pelleter at a temperature below the flowing agent activation temperature, (c) supplying a stream of water across the die face of said pelleter for cooling and transporting pellets, said water being supplied at a predetermined first temperature in a range to maintain pellets below blowing agent activation temperature but sufficiently elevated to cause formation of uniform pellets, (d) supplying additional transport water downstream of said pelleter in an amount and of a temperature further to cool the pellets and total flow of transport water to a second predetermined temperature in a range substantially to prevent activation of blowing agent by heat retained in said pellets, and (e) separating the cooled pellets from said transport water. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. In a process for extruding and transporting pellets in which an extruder is discharged underwater through a pelleting device a method for controlling the temperature of the pellets comprising
(a) supplying transport water to the die plate of said pelleter at a predetermined first temperature in a range sufficiently elevated to form uniform pellets but below a specifically designated temperature, and (b) supplying additional transport water downstream of said pelleter at a flow and temperature further to cool said pellets to a predetermined second temperature in a specifically designated range.
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11. In a method for transporting pelleted material a control system comprising:
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(a) sensing the operation of a device transporting an additive to the inlet of the extruder process, (b) generating a signal according to said sensed operation, and (c) diverting flow of said pelleted material in response to said signal.
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Specification