Advanced quality control tools for manufacturing bimodal and multimodal polyethylene resins

Patent metadata

Field	Value
Publication number	US-12552880-B2
Application number	US-202318208359-A
Country	US
Kind code	B2
Filing date	Jun 12, 2023
Priority date	Feb 28, 2018
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

A method of determining multimodal polyethylene quality comprising the steps of (a) providing a multimodal polyethylene resin sample; (b) determining, in any sequence, the following: that the multimodal polyethylene resin sample has a melt index within 30% of a target melt index; that the multimodal polyethylene resin sample has a density within 2.5% of a target density; that the multimodal polyethylene resin sample has a dynamic viscosity deviation (% MVD) from a target dynamic viscosity of less than about 100%; that the multimodal polyethylene resin sample has a weight average molecular weight (M w ) deviation (% M w D) from a target M w of less than about 20%; and that the multimodal polyethylene resin sample has a gel permeation chromatography (GPC) curve profile deviation (% GPCD) from a target GPC curve profile of less than about 15%; and (c) responsive to step (b), designating the multimodal polyethylene resin sample as a high quality resin.

First claim

What is claimed is:

1 . A system for monitoring multimodal polyethylene quality comprising:
a testing system configured to characterize a plurality of multimodal polyethylene resins for density, melt index, and one or more resin properties comprising at least one of dynamic viscosity, gel permeation chromatography (GPC) curve profile, weight average molecular weight (M w ), or combinations thereof; wherein each of the plurality of multimodal polyethylene resins is characterized by a melt index that is within 30% of a target melt index; and wherein each of the plurality of multimodal polyethylene resins is characterized by a density that is within 2.5% of a target density; a computer system configured to receive the one or more resin properties from the testing system, wherein the computer system comprises at least one processor; wherein the at least one processor compares the one or more resin properties with corresponding target properties; wherein the at least one processor, when at least one of the one or more resin properties is different when compared to the corresponding target property, designates the resin as low quality resin; wherein the at least one processor, when the one or more resin properties are the same when compared to the corresponding target properties, designates the resin as high quality resin; and a sorting system configured to receive quality resin designations from the computer system, wherein the sorting system physically segregates the low quality resin from the high quality resin for further storage or processing.

2 . The system of claim 1 , wherein the at least one processor compares the dynamic viscosity of each of the plurality of multimodal polyethylene resins with a target dynamic viscosity (η c *); wherein comparing the dynamic viscosity comprises calculating a dynamic viscosity deviation (% MVD) from the target dynamic viscosity; and wherein % MVD is calculated using the following equation:

%
⁢

MVD

=

100
×

∑
i

[

(

η
s
*

)

ω
i

-

(

η
c
*

)

ω
i

(

η
c
*

)

ω
i

]

2

i

,

wherein

(

η
s
*

)

ω
i

is the dynamic viscosity of the multimodal polyethylene resin at a shear rate ω i , wherein

(

η
c
*

)

ω
i

is the target dynamic viscosity at the shear rate ω i , wherein i represents the number of data points collected for the dynamic viscosity (η s *) across the range of shear rate (ω i ), and wherein i is equal to or greater than 3.

3 . The system of claim 2 , and wherein the dynamic viscosity of the multimodal polyethylene resin is the same as the target dynamic viscosity (η c *) when % MVD is less than about 100%.

4 . The system of claim 1 , wherein the at least one processor compares the GPC curve profile of each of the plurality of multimodal polyethylene resins with a target GPC curve profile; wherein comparing the GPC curve profile comprises calculating a GPC curve profile deviation (% GPCD) from the target GPC curve profile; and wherein % GPCD is calculated using the following equation:

%
⁢

GPCD

=

100
×

∑
j

Abs
⁡
(

(

dw

d
⁡
(

Log
⁢
M

)

)

P
,
j

-

(

dw

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Yu Youlu
• Deslauriers Paul J
• Inn Yongwoo

Classifications

• B07B2220/02

  Plastics · CPC title

• G05B21/00

  Systems involving sampling of the variable controlled (G05B13/00 - G05B19/00 take precedence) · CPC title

• G05B13/00

  Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion (G05B19/00 takes precedence) · CPC title

• C08F210/02

  Ethene · CPC title

• B01J2219/00209

  transforming a sensed parameter · CPC title