Description

PLAneo®
Polylactide Technology
UIF Polycondensation Technologies
State-of-the-art process for a sustainable polymers

Biopolymers
Polycondensation Technologies by Uhde Inventa-Fischer (UIF)
UIF Polycondensation Technologies offer our proprietary, cutting-edge polycondensation technologies for producing various grades of polyesters, polyamides and sustainable biopolymers, such as polylactic acids, with customizable viscosity levels ranging from high to medium to low.

These technologies are based on Uhde Inventa-Fischer’s know-how, the engineering experience gained in the construction of more than 450 polymer plants worldwide since 1924 and through intensive research and development work in close cooperation with prominent scientific and industrial partners. UIF Polycondensation Technologies has successful established a large variety of self-developed, patented technologies and processes in the global market. Our customers can take advantage of these technologies to gain an edge over their competitors.

UIF Polycondensation Technologies, as part of thyssenkrupp Industrial Solutions’ electrolysis and polymers business unit, are located in Berlin, Germany and Domat/Ems, Switzerland. Around 150 polymerization specialists and engineers cover the entire field of professional project execution, from plant engineering with the delivery of proprietary and key equipment only up to procurement and construction services for turnkey EPC projects, working in close cooperation with local organizations of thyssenkrupp Industrial Solutions.

Polylactic Acid (PLA)
A sustainable polymer
Polylactic acid (PLA)
Polylactic acid or polylactide is a biodegradable and sustainable thermoplastic aliphatic polyester derived from renewable resources. The feedstock for the UIF Polycondensation Technologies PLAneo® process is lactic acid. PLA can be used as a substitute for a vast number of materials such as PET, PP and PS, helping to conserve fossil resources, such as petroleum, while at the same time reducing CO2 emissions. It is also well-known for its biodegradability as well as very good recycling properties.
Process Development
The process is based on continuous PLA polymerization of polymer grade lactic acid, produced by fermenting glucose or sucrose,
which is then converted into lactide and subsequently purified.
PLA polymerization is similar to other melt-phase processes such as PA 6 and PET production, areas in which UIF Polycondensation Technologies has a wealth of experience and a range of proven
equipment.
The development of the PLAneo® process involved several steps:
After successful lab-scale polymerization, Uhde Inventa-Fischer
set up a continuously operated miniplant in Berlin in 2005 to optimize the design of reactors and equipment. Then, in 2011 an industrial-scale pilot plant was successfully started up in Guben,
Germany. The PLAneo® process licensed by UIF Polycondensation Technologies is based on more than 50 years of experience in the development, engineering and design of leading polymerization
processes and in the construction of more than 400 production plants throughout the world.
The 500 t/year pilot plant in Guben was built in order to demonstrate the PLAneo® process and to set up a reliable, industrial-size scale-up. This enables UIF Polycondensation Technologies to
license their PLA production technology for plants with annual capacities up to 100,000 tonnes. The PLAneo® technology can also be customized to produce a variety of polymer grades. Samples can be produced at our pilot facilities.
A complete basic engineering package for an fully integrated industrial-scale PLA production plant starting from glucose or sucrose as the feedstock has been prepared (see 3D layout on the
right). In June 2016, UIF Polycondensation Technologies signed its first contract for a PLA production plant with a capacity of 10,000 t/year.
Lab and bench-scale testing Industrial scale
Long track record of process development and scale-up from bench scale to industrial scale
Pilot plants: PLA, LA, PET, rPET, PBT, PA, PBS, PTT
2
PLAneo®
Technology
Process description
The lactic acid (LA) required for polymerization is fermented from
glucose or sucrose. In order to meet the high purity requirements,
LA is subjected to several subsequent purification steps to obtain
thermally stable polymer-grade LA.
In the first polymerization step, lactic acid is concentrated to
remove any residual water. An oligomer of limited molecular weight
is then produced in the subsequent polycondensation stage. This prepolymer is thermally depolymerized to form lactide, the cyclic dimer of lactic acid.
In order to obtain high molecular weight PLA, the monomer lactide has to be very pure prior to polymerization. A purification step for the crude lactide, stemming from the depolymerization, is therefore necessary. UIF Polycondensation Technologies has developed a unique, patented distillation technology, using dividing-wall columns to produce high-quality lactide. In addition, the quality of the lactide can be tailored for the different grades of PLA. In the subsequent ring-opening polymerization, the PLAneo® process uses a combination of a specially designed stirred-tank reactor and an efficient plug-flow reactor. Before pelletizing, the polymer melt must be stabilized and the remaining lactide removed. UIF Polycondensation Technologies’ proprietary recipe for the stabilization of PLA, in combination with its unique one-step demonomerization technology, guarantees a very low residual monomer content. As a new biodegradable and bio-based polymer, PLA faces stiff competition from standard, petrochemical-based polymers, such as PET, PS and the polyolefines – not only on a technical, property-related basis, but also, and not least, price-wise.
In this regard, the efficient use of the feedstock is very important as the feedstock cost has a huge impact on production cost. Here lies the main advantage of the PLAneo® process from UIF Polycondensation Technologies. The conversion of lactic acid to PLA is close to its theoretical maximum thanks to the unique purification and polymerization techniques for meso-lactide. Meso-lactide, which is a side-product of the PLA process, usually has to be separated and hydrolyzed back to lactid acid, thus reducing the overall efficiency and increasing the feedstock conversion cost. In the
PLAneo® process from UIF Polycondensation Technologies, meso-lactide is polymerized and blended with standard, crystalline PLA, without adversely affecting the properties of the PLA produced in the PLAneo® process. On the contrary, some properties, such as elongation at break are even improved. The PLAneo® process from UIF Polycondensation Technologies is able to produce all PLA grades available on the market: from fast crystallizing types to nearly amorphous ones.

PLAneo® Process Flow Diagram
VAC
Water
Lactic Acid
2-Step
Prepolymerization Cyclising
Depolymerization
VAC
VAC
VAC
Lactide
Purification
Meso-Lactide
Residue
Ring-Opening
Polymerization
L-Lactide
Demonomerization
PLA
Polylactic acid (PLA) 3
Available PLA Product Portfolio
PLA Product Features
Properties and Applications
Outstanding mechanical properties:
• Excellent tensile strength
High modulus of elasticity
• Glossy and very clear
Easily printable
• Low surface tension
Wicking properties
• Highly comfortable sportswear
Low water vapor barrier
• Vegetables stay fresh
Very good aroma barrier
• Fruit, cheese and sausages keep their flavor
PLA grades
PLA can be produced in many different grades. The two main parameters distinguishing the grades are molecular weight and crystallinity of PLA. The crystallinity is directly related to the D-lactide content. In general the following rule can be applied: the lower the D-lactide content the higher the crystallinity. Fast-crystallizing types are e.g. required for fiber applications or injection molding,
whereas medium or high-D-content grades are used for thermoforming or film applications. Thanks to its high flexibility of use, the PLAneo® process from UIF Polycondensation Technologies is particularly suitable for producing PLA with a wide range of viscosities and crystallinities for various downstream applications.

Applications
PLA can be processed for all types of applications: Packaging material such as extruded sheets for thermoforming, biaxial-oriented films and plastic bottles; textile materials such as filaments,
staple fibers, and nonwovens; and compounds, such as biodegradable films and injection-molded materials.

PLA Properties
Crystallinity (%) 10–40
Glass transition temperature (°C) 55–60
Melt index range (g/10 min.) 2–20
Melting temperature (°C) 130–170
Molecular weight Mw (Dalton) 100,000 to 250,000

HQ : Germany