is a wholly-owned subsidiary of PolyOne Corporation. is a wholly-owned subsidiary of PolyOne Corporation.

VALUE BENEFITS OF USING THE FLEXCART MICRO SYSTEM The FlexCart Micro metering system is market leading: • Robust and dependable system control • Reliable yield (typically 95%+) and sustainable packaging • Capability of data networking and remote internet support • Small footprint & LN standard recyclable delivery packaging FLEXCART™ MICRO LIQUID METERING SYSTEM Combined with sustainable delivery packaging ATTRIBUTE FLEXCART MICRO Footprint (LxW cm) 60 x 35 Controller options 3000 5000 Typical max. throughput (kg/hr) 250 Max. metering rate (cc/s) 10 Continuous use No Transfer pumps N/A Metering pumps PC/Peri Interchangeable cassette Yes Note: PC = Progressing Cavity Pump Peri = Peristatic Pump PLANETPAK™ CONTAINERS AND LN PACKAGING OPTIONS The FlexCart suite of metering systems is designed to work with the standardized PolyOne range of packaging typically achieving 99% reliable yield on continuous operating systems, while at the same time also achieving a sustainable packaging format in terms of full recyclability.

PolyOne Tekno Polimer Mühendislik Plastikleri Sanayi ve Ticaret Anonim Şirketi (Turkish Legal Entity Information)

At PlastIndia 2018, Avient exhibited under its former name, PolyOne.

It’s in this spirit that we joined legacy PolyOne and the Clariant Masterbatch business, two complementary businesses, and formed a new one that we’ve named Avient. We are better together through: Keeping Safety First — PolyOne and Clariant are both ACC Responsible Care® companies, and nothing is more important than the health, safety and well-being of our people. Leading in Sustainability — PolyOne and Clariant are both founding members of the Alliance to End Plastic Waste, and we are committed to meeting the needs of the present without compromising the ability of future generations to do the same.

Avient was formed as PolyOne Corporation on August 31, 2000 from the consolidation of The Geon Company (Geon) and M.A. Wulfsohn 73 AVIENT CORPORATION Exhibit 23.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in the following Registration Statements: (1) Registration Statement (Form S-8 No. 333-238246) pertaining to the PolyOne Corporation 2020 Equity and Incentive Compensation Plan; (2) Registration Statement (Form S-8 No. 333-231236) pertaining to the PolyOne Supplemental Retirement Benefit Plan (As Amended and Restated Effective January 1, 2014); (3) Registration Statement (Form S-8 No. 333-217879) pertaining to the PolyOne Corporation 2017 Equity and Incentive Compensation Plan; (4) Registration Statement (Form S-8 No. 333-205919) pertaining to the Amended and Restated PolyOne Corporation 2010 Equity and Performance Incentive Plan; (5) Registration Statement (Form S-8 No. 333-181787) pertaining to the PolyOne Corporation 2010 Equity and Performance Incentive Plan; (6) Registration Statement (Form S-8 No. 333-166775) pertaining to the PolyOne Corporation 2010 Equity and Performance Incentive Plan; (7) Registration Statement (Form S-8 No. 333-157486) pertaining to the PolyOne Retirement Savings Plan; (8) Registration Statement (Form S-8 No. 333-47796) pertaining to Post-Effective Amendment No. 3 on Form S-8 to Form S-4 pertaining to the Geon Company 1993 Incentive Stock Plan, the Geon Company 1995 Incentive Stock Plan, the Geon Company 1998 Interim Stock Award Plan, the Geon Company 1999 Incentive Stock Plan, the PolyOne Corporation Deferred Compensation Plan for Non-Employee Directors and the M.A. Hanna Company Long-Term Incentive Plan; (9) Registration Statement (Form S-8 No. 333-141029) pertaining to the PolyOne Retirement Savings Plan and the DH Compounding Company Savings and Retirement Plan and Trust; and (10) Registration Statement (Form S-3 No. 333-236116) of PolyOne Corporation of our reports dated February 22, 2022, with respect to the consolidated financial statements of Avient Corporation and the effectiveness of internal control over financial reporting of Avient Corporation, included in this Annual Report (Form 10-K) of Avient Corporation for the year ended December 31, 2021.