Exxonmobil Chemical Patents Inc.

Univation Technologies, LLC

Thomas Redden Veariel

Costas George Gogos

Chong Peng

Yuet Meng Chu

Bruce Jon Savatsky

Linjie Zhu

David Geoffrey Marrow

David A Yahn

David Todd

Bainian Qian

Sandy Clay Hinds

Gogos G Costas

Kelli Lynne Tilston

George Varcelia Yenetchi

Diwalker Singh

Thierry Polchlopek

Kelli L Tilston

Costas G Gogos

David B Todd

Embodiments of an invention disclosed herein relate to devices, processes, and systems for processing one or more polymers.

Devices, systems, and processes for processing polymers

Embodiments of an invention disclosed herein relate to devices, processes, and systems for processing polymers.

Melt fracture is reduced, without the necessity of polymer processing-aid additives specifically designed to alleviate exit region surface melt fracture phenomenon, by heating at least a portion of the die through which the polymer is extruded. The die exit region is maintained at a temperature above the bulk melt temperature of the polymer extruded through the die exit hole.

Melt fracture reduction

Method and systems for online analysis of a polymeric material within a mixing device are provided. In certain embodiments, the methods and systems subject the polymeric material to Raman spectroscopy analysis. The Raman spectroscopy provides analysis of polymer properties that may include melt index, density, viscosity, molecular weight, molecular weight distribution, weight ratios of different polymers comprising the polymeric material, additive concentrations, crosslinking agent concentrations, scissoring agent concentrations, and combinations thereof. The spectroscopy results can be used to provide process control to adjust operating parameters of the mixing device and/or an associated polymerization process. The mixing device may be an extruder. The methods and systems may also include a processor for evaluating the results of the Raman analysis and automatically adjusting the mixing device and/or polymerization processes.

On-line properties analysis of a molten polymer by raman spectroscopy for control of a mixing device

The present invention is a process for transitioning from a first polymerization reaction to a second polymerization reaction incompatible with the first polymerization reaction in a gas-phase reactor. The novel process comprises conducting multiple polymerization reactions, capturing and storing a substantially contaminant-free polymerization product from each multiple polymerization reaction for use as a selected substantially contaminant-free seedbed in a second polymerization, wherein the polymerization product from each multiple polymerization reaction is rendered substantially contaminant-free by stripping or venting reactants and contaminants and is maintained as substantially contaminant-free by storage under an inert atmosphere.

Process for transitioning between incompatible catalysts using a substantially contaminant free seedbed

The present invention is a process for transitioning from a first polymerization catalyst system to a second polymerization catalyst system incompatible with the first polymerization catalyst system in a gas-phase reactor. The novel process comprises conducting a first polymerization reaction using a first polymerization catalyst system; stopping the first polymerization reaction; removing the contents of the first polymerization reaction from the reactor while maintaining a substantially closed system; then, in the substantially closed system, introducing a substantially contaminant free seedbed into the reactor; introducing a second feed system and a second catalyst system into the reactor; and conducting a second polymerization reaction.

Method for transitioning from a catalyst to an incompatible catalyst in a gas-phase reactor

Growing community of inventors

Houston, TX, United States of America

Thomas Redden Veariel