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Novel PUR foaming manufacturing process with reduced toxic isocyanate content

Final Report Summary - FREEFOAM (Novel PUR foaming manufacturing process with reduced toxic isocyanate content)

Executive Summary:
Flexible Polyurethane Foam is one of the most versatile materials ever created, present in cars, in all upholstered furniture and bedding material, under carpets, and even as packaging and insulating material. The European polyurethane foam sector has 50.000 companies that employes over 1.6 million people. The science and manufacturing techniques used in today’s production o polyurethane (PUR) expanded foam use isocyanate to fully react the polyurethane mixture during the foaming process. However, an inherent aspect of this process is the release of isocyanate molecules to the atmosphere (‘free isocyanate'). This has given rise to real concerns over the possible detrimental effect to the health of people who are exposed to this free isocyanate environment during the production process. Isocyanate is included in the 2003 European schedule of occupational diseases, and it has been established that ten to twenty percent of asthma cases recorded in EU are due to isocyanates.

The aim of the FreeFOAM project is to reduce the risks to health by lowering the concentration and emission of free isocyanate into the atmosphere. This will involve a new method of isocyanate encapsulation, a new PUR foam formulation and a new foaming method for manufacturers.

During the project a unique, homogeneous reactive mixture for PUR foaming purposes where reactants are physically separated by using functionalized microcapsules of isocyanate conveniently dispersed on polyol mixture component was produced. The reactive system has allowed to increase the mixture reactivity due to the performed compatibility and hence, homogeneity between isocyanate and polyol components while decreasing the exposure of workers to harmful emissions by lowering the residual monomer content on the foam, avoiding the emissions and migration of such components from foams. In addition, the used solution will allow decreasing the generated waste due to bad cell homogeneity and product density as consequence of bad mixing process.
FreeFOAM brings together a consortium of nine organizations to deliver the project led by CETEM (Science & Technology - Spain) and includes Inspiralia (Research - Spain), Polymer Expert (Innovative & Research - France), Tagra (Technology & Innovative - Israel), Plama-pur (Flexible PUR Producer - Slovenia), Cosmetic Valley (Development & Innovative - France), Lesarki grozd (Wood Industry Association - Slovenia), ZCHFP (Chemical & Pharmaceutical - Slovakia) and BFM (Furniture Industry Association - United Kingdom).

Finally achieved results were:

New Method for Isocyanate Encapsulation.
New PUR foam formulation based on polyols and microencapsulated isocyanate.
New foaming method for PUR foaming manufacture.

Project Context and Objectives:
The overall objective of the FreeFOAM project is to offer to the European PUR foam sector a new method of microencapsulation of isocyanate opening up a new way of polyurethane processing. FreeFOAM proposes a unique, homogeneous reactive mixture for PUR foaming purposes where reactants are physically separated by using encapsulated isocyanate conveniently dispersed on polyol mixture component.

The Reactive System allows:

-Mixing isocyanate and polyol together without reaction.

-Controlled breakage of the capsules and controlled release of isocyanate.

-Decrease the generated waste due to bad cell homogeneity and product density as consequence of bad mixing process.

This new polyurethane processing method can also reduce health risk of workers during foam manufacturing by lowering the concentration of free isocyanate and reducing the emission of the same to the atmosphere.

In order to achieve this goal, the Consortium partners have pre-validated the overall system up to a semi-industrial scale.

The development of non-ionic and ionic surfactants has resulted in optimal surfactants for the production of micro-capsules. The surfactant synthesis has been scaled up to 5o liters with accurate reproducibility. The characterization proved high production yields (NMR and FTIR) and confirmed the expected chemical structure. Apart from that, all the surfactants were characterized in terms of cloud point, CMC, surface tension, etc. Also the interaction of different surfactants with different elements of the system has been studied.

Different encapsulation methods have been evaluated and some requirements/targets have been stablished to monitor the development of the encapsulation process. Experiments modifying different parameters (temperature, reaction time, stirring speed, etc) have been performed and it has been demonstrated that the isocyanate can be encapsulated. In order to optimize the encapsulation procedure different conditions as reaction time, temperature, concentration, stirring speed or pH have been studied. Finally the application of innovative ionic surfactants and the design of a new micro-encapsulation process has allowed to produce high isocyanate content micro-capsules for its integration into foaming process. The process has demonstrated to be cost effective scalable and compatible with the development of advanced functionalities.

Different formulations for the production of different foams have been defined. These formulation have been selected as reference for the development of the FreeFOAM process have been produced at both laboratory and semi-industrial scale.

After the achievement of optimal structure foams at lab scale and the design of specific strategies in order to adjust the semi-industrial process resulting foams. The results of the semi-industrial were stable foams compatible with industrial uses and the accurate definition of the modifications to implement on industrial processes in order to adopt FreeFoam technology.

RTD´s generated outcomes have been transferred to the FreeFoam Consortium during technology transfer and training activities. FreeFOAM Consortium forms a balanced supply chain able to exploit generated foreground. The AIG´s have defined the route to market and the strategies for route to market funding. To ease later exploitation activities, the Consortium have carried out an intensive Dissemination and Exploitation activity including, networking, IPR management and fluid communication with the different stakeholders in foam industry.

Project Results:
FreeFoam resulting foreground knowledge that the project will generate is the following:

New Method for Isocyanate Encapsulation:
New microencapsulation process (including surfactant development) and functional microcapsule containing the isocyanate reactant covered by organic/inorganic hybrid shell with appropriate functionalization that will enhance the mixture reactivity and homogeneity between isocyanate and polyol.
Potential areas of application for these results are those related to the preservation of fragrances, controlled delivery of drugs, preservation of volatile compounds and controlled release of inner material with specific properties under specific conditions of temperature, pH, under sonication, etc. Pharmacy, cosmetic, chemical, agro-chemical, food and other industry, constitutes the major sector where the new method could be applied.

New PUR foam formulation based on polyols and microencapsulated isocyanate:
New foam formulation consists on an advance homogeneous PUR formula composed by a mixture of proper polyols, microcapsules containing isocyanate and needed additives such as amines, water and catalyst.
The main market of this new PUR foam formula will be the PUR foam manufacture industry by both slab- stock and moulding processes for flexible foam processes. Also, the use of this technology would be applied for rigid PUR and PIR foaming industry. Upholstery, automotive, construction and bedding, constitutes the most important sectors of application of these technology.

New foaming method for PUR foaming manufacture:
The new foaming method consists on an innovative foaming process by using new PUR reactive system based on previous reactive mixture with enhanced properties: mechanical properties, density, homogeneity of the foam.
The new foaming method will be applied for flexible PUR foaming industry in standard facilities, automotive sector that require of special design and complex frames or under special situations.

Potential Impact:
The FREEFOAM project will benefit the involved partners by:

1. Creating a new and advanced polyurethane foam system with enhanced properties and reduced toxicity.

2. Creating a new PUR foam system that decrease the exposition to isocyanate monomer to which those workers are exposed during foam manufacture, allowing these manufacturers to achieve needed requirements for market labelling.

3. Creating a new PUR foam with enhanced properties, a safe, ecological and environmentally friendly product that allows reduction of imports and increased European exports.
Strategic competitive developments will be achieved in:

1.Increased economic business through exploitation of FREEFOAM polyurethane foaming system. The associated companies would increase their production capacity while decreasing production costs and lost labour, and reducing waste generation. All these benefits would be achievable through the adaption of the proposed technology.

2.Associated SMEs would have a new technological knowledge that would be translated into better products and services. In that way, associated SMEs would demonstrate a higher understanding of end-users interests and needs while manufacturing more homogeneous polyurethane foams

3.FreeFOAM will allow achievement of a determined knowledge and technology which will be translated into a new product and process with a high value, being sustainable, safe and environmentally-friendly.

Due to the performance and cost benefits of the FreeFOAM technology in comparison with current technology that uses to make a mixture of isocyanate and polyol, the FreeFOAM consortium has estimated that it is possible to achieve a proportion of the current flexible polyurethane foam market. The consortium has planned to achieve the 1% by volume of European market after 5 years post-project through a competitive sales strategy. After month 12, it is planned to access to the American and Japanese markets. A total of 0,5% of those markets are planned to be taken.

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