Project to Research Use of Bio-based or Recycled Feedstocks for PU Processing

TAGS:  Sustainability and Bioplastics     Thermoplastic Composites   

At Kaiserslautern University of Applied Sciences, Department of Applied Logistics and Polymer Sciences, a team led by Prof. Dr. Gregor Grun and Prof. Dr. Sergiy Grishchuk is researching the use of bio-based or recycling-based raw materials in semi-industrial polyurethane processing as part of the international EU project BIOMAT. Hennecke's LABFOAM pilot plant will be used for the numerous practical tests.

Foams and Composites with High Proportion of Renewable Feedstocks

Sustainable raw materials and the reduction of CO₂ emissions from the production of flexible foams and other PUR products are becoming increasingly important. Many companies from industry and trade are wondering how they can reduce the proportion of crude oil and environmentally harmful propellants in their production.

For this reason, BIOMAT was launched in 2021. In this EU-funded project, scientists from eight nations are researching the development of sustainable foams and composites with a high proportion of renewable raw materials. BIOMAT aims to reduce the greenhouse gases produced during the production of foams and composites by 30 to 50 percent and to replace more than half of the material used with renewable raw materials.

This research project requires numerous tests with various new raw materials in a wide variety of formulations in order to investigate the respective foaming behavior, durability and other properties of the products. In order to obtain reproducible results and, in particular, to avoid the traditional "cup tests", a Hennecke LABFOAM was put into operation at the Pirmasens campus of Kaiserslautern University of Applied Sciences in 2022. The machine system is the ideal partner for test series and product innovations in the field of polyurethane processing.

Precise Simulation of a Large-scale Industrial Plant

Developing and testing new formulations on a conventional block foam plant is a resource-intensive undertaking. For this reason, Hennecke has developed the LABFOAM, which – to put it simply – replicates the reactive part (wet end) of a continuous production system on a small scale and thus enables test series with low output quantities. Nevertheless, it achieves results that are almost identical in quality to those of a continuous production plant.

The high-precision high-pressure metering pumps and the tried-and-tested Hennecke mixing technology are used for this purpose. In addition, each individual dosing line is designed for the processing of an application-specific range of raw materials, so that an equally wide range of possible test series can be realized. With minimal use of raw materials, the results of highly scalable industrial production can be precisely simulated and tested.

LBFOAM: Designed for Viscosities of up to 35,000 mPas

At the Pirmasens campus, the material properties and possible applications of biopolyols are now being investigated – also on behalf of industrial companies. "Biopolyols are preferably obtained from organic waste," explains prof. Dr. Gregor Grun. These can be fatty acids, triglycerides, sugars or other suitable organic residues. However, many of these materials are currently still difficult to obtain commercially.

Another challenge in the use of biopolyols is that they consist of secondary hydroxyl groups and therefore react comparatively slowly. At the same time, attention must be paid to the low flowability of many biopolyols, for which LABFOAM is excellently suited, as it is designed for viscosities of up to 35,000 mPas. In addition to the extraction of biopolyols, the polymer department in Pirmasens is also researching the synthesis of biopolyesters in order to produce materials that are as compostable as possible or to improve the recycling of polyurethane foams.

There are several good reasons why the university chose Hennecke's LABFOAM laboratory system. Of particular importance to the research team was the ability to automate, the independent dosing lines and the individually adjustable parameters for the up to 25 different raw material components.

"A special advantage of the LABFOAM is the patented NOVAFLEX technology for the production of CO₂-driven foams, which make it possible to dispense with blowing agents that are harmful to the environment and health and is unique in laboratory systems," emphasizes prof. Dr. Sergiy Grishchuk. At the same time, the system also impresses with its small space requirement. The wide range of possible applications can be found in less than ten square meters. The system control via the FOAMWARE is identical to the operation of continuous production systems.

"With just a few clicks, we can create new formulations with a wide variety of components and additives, send them to the machine and start testing," reports Philipp Haag, PhD student in the team and one of the LABFOAM operators. Compared to mixing by hand, this means a significant advantage in terms of accuracy, time saving, raw material consumption and quality of the foam.

Already 65% Bio-based Content Possible

The results of the first year of use are promising. For example, it is already possible to produce flexible foam with a bio-based content of around 65 percent without having to accept any loss of quality.

"Another crucial aspect of LABFOAM is that it is not limited to the production of flexible foams," adds prof. Sergiy Grishchuk. Reason enough for the researchers to also investigate the use of organic materials in semi-soft PU foams or rigid foams, such as those used for insulation in components with a sandwich structure.

"I can also imagine that other types of prepolymers, such as epoxy prepolymers, will be processed and studied in the plant," reports prof. Sergiy Grishchuk.

The BIOMAT project managers are pleased to be able to train the students in the field of polymer chemistry as part of this research and development project and to give them the opportunity to familiarize themselves with industry-related processes at the plant. This benefits not only the students, but also numerous employers in the polyurethane processing industry, who attach great importance to practical experience. The transparent exchange of knowledge and information with Kaiserslautern University of Applied Sciences also offers important added value for Hennecke, especially with regard to new market requirements with regard to sustainable raw material solutions.

Source: Hennecke