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Development of new agrotextiles from renewable resources and with a tailored biodegradability

Final Report Summary - BIOAGROTEX (Development of new agrotextiles from renewable resources and with a tailored biodegradability.)

Executive summary:

Increasing oil-prices, a growing threat of oil-shortages, greenhouse gases and their effect on climate change, are elements that contribute to the concern for the future of our oil based economy. The search for biobased polymers and a more extensive use of the natural resources will be needed to cope with these problems and to initiate growth in the biobased economy. Agrotextiles can offer a very attractive end market in this regard. At the moment the market is dominated by polyolefin' based agrotextiles. Other products are based on natural fibres but are degraded too fast to be very attractive. BIOAGROTEX aims at developing novel fully biobased agrotextiles with a drastically reduced impact on environment.

Different production routes are followed to develop this type of end product.

In a first route standard natural fibre based groundcovers are upgraded via application of bioresins including functional additives. For the natural fibres either recycled or upgraded side fractions of linseed or hemp production can be used. Properties of these fibre fractions are improved by optimising the fibre preparation process, including enzymatic retting or pretreatment. Upgrading the durability is performed via Furan based bioresins specially developed for this application in order to control reactivity of the resin and the flexibility of the woven or non-woven fibre mats. An alternative route using partly oil based chemicals is developed as well with included functionality to delay degradation. It is shown in lab trials using soil burial and Q-UV tests along with field trials that the developed products have a considerable extended lifetime in normal usage (greater than double).

In a second route melt processable biopolymer formulations either starch based or PLA based are evaluated for their potential in textile extrusion processes including: staple fibre, monofilament yarns, multifilament yarns and tapes. Processes are optimised to obtain the appropriate properties.

The objective to use starch based thermoplastic in these applications couldn't be reached. Improved formulations were developed that allows producing monofilaments, multifilaments and tapes, but mechanical properties are still insufficient for developing industrial products.

With PLA based formulations the complete range of textiles can be produced with acceptable properties for further processing, including production of non-wovens, knitted and woven fabrics. Also a range of functionalization routes either to improve processability and properties, to control or improve the durability of the products and to introduce specific functionalities like: colour, flame retardancy and anti-microbial properties. Also durability of these materials is tested in laboratory conditions and in real life leading to an expected life time of at least three to five years.

Project Context and Objectives:

2 Summary description of project context and objectives

2.1 Context

Increasing oil-prices, a growing threat of oil-shortages, Kyoto agreements on greenhouse gases, environmental effects and climate changes, are all elements that contribute to the concern for the future of our oil based economy. Europe is gradually preparing the shift towards a biobased economy, a multistep process that will take decennia to come to its completion. Initiatives are required to start-up this process of change and to explore at an early stage the possibilities offered by products already under development.

Textiles and especially agrotextiles offer a very attractive end market. Volumes in this market area are high and fast growing. At present, products are mainly based on Polyolefin’s (greater than 200Ktonnes/annum in Europe) and to a lesser extent other petrochemical polymers such as PA and PET are used. In most cases these agrotextiles are at the end-of-life difficult to recover from the fields and will be polluted by a vast amount of organic material and sand, making efficient recycling and even combustion with energy recovery extremely costly and not attractive.

A number of agrotextiles are based on natural fibres, but in general these products are degrading that fast in the natural environment that there lifetime is usually limited to one or maximum two years and textiles with a relatively high weight per m² are required in order to compensate a bit for the fast degradation.

2.2 Objectives

The BIOAGROTEX projects aims at the development of fully biobased agrotextiles with a controlled (or extended) durability as alternatives for the existing PP based agrotextiles or the natural fibre based agrotextiles with a very short lifetime.

Two routes are followed:

1. The development of biopolymers formulations (WP1) that can be melt-processed using a range of textile extrusion techniques including tape or monofilament, staple fibre, multifilament extrusion on laboratory and pilot scale (WP2) and on industrial scale including a range of further industrial processing trials such as knitting, weaving, needlefelt production (WP6).

Two biopolymer families are evaluated:
a. use of biopolyesters as meltprocessable polymers, with focus on PLA
b. use of starch based formulations

2. Development of natural fibres, either recycled or from low value agricultural fractions and optimising properties via (enzymatic) pretreatment to optimise yield and properties (WP4). Development of bioresin (furan based) to finish the NF based products, extending the durability without jeopardizing the mechanical properties (WP3), processing the experimental fibres into non-woven structures and finishing them on pilot scale (WP5) and upscaling further to fully integrated industrial processes (WP6).

Both routes are supported by biodegradation tests on labscale and via field tests and detailed chemical analysis of the degradation routes (WP7) along with the evaluation of the ecological impact (LCA) and the possible ecotoxicity trials.

The developed production routes will be used to produce at industrial scale demonstrators to be installed in centralised field tests allowing the evaluation of the relevant performances of the developed products. (WP8). Further supportive WPs are foreseen including Training and dissemination (WP9), IPR and Knowledge Management and Exploitation policy (WP10), Project management (WP11).

Based on this approach the following specific objectives were defined at the start of the project:

A: For the thermoplastic biopolymer formulations:
- The definition of optimised starch based formulations, that can be processed on standard textile extrusion equipment to fibres, mono- or multifilaments with acceptable mechanical and processing properties,
- The definition of optimised biopolyester (PLA) based formulations, that can be processed on standard textile extrusion equipment to fibres, mono- or multifilaments with acceptable mechanical and processing properties,
- Selected range of additives to optimise processability of the biopolymer formulations and to integrate specific properties
- To define routes to vary the (bio)degradability and lifetime of end products
- Optimised industrial extrusion processes, with output similar to production processes with standard polymers.

B: For the natural fibres
- Defining alternative sources of natural fibres based on agricultural wastes or low value side products
- Development of ecological relevant (enzymatic) preparation routes to extract fibres with optimal yield and properties, including raised hydrophilicity
- Defined processing routes for pure or blended natural fibre materials into qualitative nonwovens

C: For the biobased resins with preservation activity.
- Realisation of fully biobased water dilutable resins,
- Realisations of resins with increased reactivity allowing complete curing at acceptable temperature (max 180°C) and within 2 to 3 minutes time.
- Optimised resin formulation that doesn’t alter the mechanical properties such as stiffness or drapability
- Bioresin with high preservation action that at minimum doubles the expected lifetime of the natural fibres based ground-covers.
- Routes for industrial application of the bioresins in combination with specific functionalities
- Realisation of natural fibre based groundcovers with a reduction in weight/m² of up to 50%.
- Realisation of natural fibre based groundcovers with an extended (min doubled) lifetime

D: Realisation of demonstrators and pre-commercial products
- Developed industrial production routes for thermoplastic and natural fibres and formulations via standard textile processing techniques including weaving, knitting, non-woven production, needlefelt production - Realisation of at minimum 4 demonstrator products covering the different development routes and product types defined.

Possible demonstrator models are:
-Knitted biopolymer cloth for covering crops: creating micro-climate and crop protection against insects applied either out-door or in green houses, requested life time: 1 up to 3 seasons; limited degradation under standard conditions of use, compostable
-Biopolymer based non-woven groundcovers: support for natural grass mats: to be applied in the earth strengthening the turf and/or stabilising slopes, should retain its properties during 1 up to 5 years; slow degradation under 'soil burial test'- fast degradation under composting,
-Biopolymer based woven groundcovers (prevention of weed growth and use of herbicides, support the water housekeeping of the ground) stability during minimum 3 to 5 years, fast degradation under composting conditions
-Natural fibre based groundcovers for out-door use, weed prevention improved water housekeeping, with an extended lifetime (up to three years) due to the application of bioresins with preservation action
-Other possible domains for implementation:
natural fibres or biopolymer based agrotextiles for applications in green-houses, sun-screens, limitation of heat-loss, light reflection, … durability minimum five years under high temperature and high humidity conditions

Alternative out-door application (nets for bird protection, hail protection or sunscreens) minimum durability five years under high UV conditions.

E. Scientific proof of enhanced properties and ecological aspects of the development.
Detailed analysis of all generated materials, both on performance and ecological impacts are foreseen in order to proof the potential and the ecological relevance of the development.

The following core evaluations are defined.
- Lab scale durability testing, via different routes simulating different routes of degradation
Soil- burial test (AATCC 30-2004) resistance to biodegradation (resisting minimum 56 days, doubling the durability of standard NF based groundcovers)
Q-UV tests: resistance against UV light (min 1500 Hours)
Combined Q-UV and Soil burial tests
Hydrolysis tests under extreme conditions
Analysis of mechanical properties and molecular weight as function of durability tests
Lab scale composting tests; industrial conditions
- Real life testing via locally installed agrotextiles and via demonstrator field tests for a minimum period of 1 year.
- Ecotoxicity tests on the developed materials and after composting; to ascertain the possibility of implementation without creating toxicological side effects.
- Detailed LCA analysis taken into account, production, use and end-of-life solutions for the newly developed end-products.

Based on the realisation of these objectives and on the created knowledge base regarding interaction of product parameters, processing conditions, functional additives and durability properties it should be feasible to bring at least some of the demonstrator products to the market within short term after finalisation of the project. The generated know-how should allow via further industrial developments the creation of a large range of different agrotextiles. The results obtained could be valorised further in other application fields such as textiles, composites, injection moulded articles and can therefore contribute to some extent to the overall development of the biobased economy.

2.3 Defined workplan.

For the realisation of these objectives a multidisciplinary approach is required covering the complete production chain - starting with the development of the biopolymers up to the final textile products. At the same time the project has to pass through all stages within the innovation process; starting with fundamental research aspects, through implementation and up-scaling development of adapted testing procedures and even providing complete proof of concept via full-scale and real life demonstrators.

The structure of the workplan and the interactions between work packages are highlighted in the project scheme:

Project Results:
3 A description of the main Science and Technology (S&T) results/foregrounds

Along the four year project a multitude of results are obtained in the different research domains. Results are not reported per WP since some of the WP closely interacts with one another and are evaluating the same products or processes along the production chain: formulation, processing lab scale, processing industrial scale, definition of end products. Due to constant feed-back and fed-forward along this chain it's better to report the results per individual development topic.

Results are therefore grouped together under the following Topics:
- Results related to starch based formulations and processability to textile yarns.
- Results related to the formulations, processability and properties of biopolyesters.
- Observations on fast degrading PLA materials and problem solving.
- Alternative natural fibre sources and processing into non-wovens
- Development of biobased resins and application to natural fibre structures
- Demonstrator development and demonstrator field tests
- Durability and ecological aspects of the developed products.

3.1 Results related to starch based formulations and processability to textile yarns.

For the starch based biopolymer formulations a range of applications are already known. At present it is these type of biopolymer formulations that have the largest share in the biopolymer market Based. The applications are at present however predominantly in (food) packaging applications, film extrusion and to some extent injection moulding applications. In these applications the fast biodegradability of the products offers a major advantage. Since starch itself has very poor thermoplastic properties, it cannot be processed as such and always needs plasticizing and blending with other biodegradable polymers. Popular polymers for blending are amongst others the oil based PolyCaprolacton, and Ethylenevinylacetate or biopolymers such as PLA. Development of textiles made of starch based formulations is in its infancy and no commercial products were known at the start of the project.

The objective within Bioagrotex is that starch based formulations are developed that can be processed into the different textile products: tapes or monofilament and if possible multifilament. A minimum level of mechanical properties (tenacity level of 0.2 N/tex) should be reached in order that the products can be processed further.

As a starting point standard Solanyl formulations, basically used for film extrusion, were selected for first small scale textile extrusion trials. It was observed that these were totally inadequate for the textile processing route. Inappropriate stability and melt strength was observed. Either no filament structures could be obtained or only filaments could be produced without applying a cold drawing step and therefore resulting in a very brittle product.

It was concluded that the formulations needed adaptations and the following elements were taken into consideration:
- Intensification of the compounding process: - leading to a finer distribution of the polymer components in one another, this is observed but deblending limits the efficiency.
- Adapting water content during extrusion; - water can have a positive plastisizing effect but also catalyses degradation and hydrolysis. In combination with (bio)polyesters the water content should be kept low.
- Lowering the extrusion temperature - as low as possible (± 160°C) - in order to avoid degradation of starch and the hydrolysis of other biopolymer components.
- Evaluation of different blend compositions and ratio’s. – Raised compatibility between materials influences in a positive way the fineness of blend morphology and reduces deblending effects. A higher % of thermoplastic polymers improves processability, but final 'starch' content will become low.
- Selection of high molecular weight grade of the added thermoplastic polymer (PLA) – a considerable improvement in melt strength and therefore processability and stability was observed.

3.2 Results related to the formulation, processability and properties of biopolyesters.

PLA is one of the biopolymers available in the market for a longer time, at considerable volume (greater than 100kton) and acceptable price. The implementation is especially known in packaging applications and to a lesser extent for textiles or injection moulding. Although the first products are proposed a long route of developments still is needed to bring the biopolymer formulations and the processability to a similar level as the petrochemical based ones.

Within the Bioagrotex project the developments on the biopolyesters formulations are specific aiming at increasing the mechanical properties (tenacity and elongation at break, and reduction of brittleness), increase in processability (operating window at different process lines, production speed), improvement in processing stability (influence of temperature and humidity) and integrating functionalities in the biopolymer formulation. In addition the formulations are function of the different extrusion routes required for the different types of textile intermediates: tapes, monofils, staple fibre, FDY or POY.

For the different processes different pilot and industrial extrusion systems are used to explore the processability. The different lines have different configurations that have important consequences on the polymer requirements and processing conditions. One can differentiate between the following extrusion systems:

A. Monofilament or tape extrusion line.
This type of extrusion equipment is used for production of thicker textile monofilaments or tape material. Due to the diameter of the produced filaments more cooling is required and this is provided by quenching the melt coming from the extruder directly in a water bath. As an alternative the melt can also be deposited on a metal quench roll (internally cooled). After cooling the yarn is monofilament is heated again and drawn to a high degree (factor 5 to 12) in order that the polymer chains are stretched to the maximum and the material receives its highest tensile properties possible. This process is in general performed at a limited speed (100 a 200 m/min). The products produced via this route are amongst others used in knitted agrotextiles using monofilaments or tape production for production of woven tape fabrics.

B. POY extrusion – separate draw (texturation) step.
Fine filament yarns or staple extrusion is in general performed via air-quenching instead of water bath quenching. The production speeds are considerably higher (3000 up to greater than 5000 m/min) and spinerettes are much finer, making the process more critical. Especially the rheology of processed materials becomes more critical) (less viscous formulations required) as well as the fineness of any additives used should be below a few µm in order not to block filters or to disturb the built-up of mechanical properties.

Moreover the POY production process is a two stage process. In the first stage extrusion of the filaments take place at a high speed without a secondary drawing. Due to the high meltdrawing ratio the filaments produced gets already an important degree of orientation and therefore stability and tenacity. Nevertheless the yarn is still only a Partly Oriented Yarn and will need a secondary drawing step to obtain it's full mechanical properties and stability. This two-step production process is especially explored for the production of very fine multifilaments, which can be used in knitted crop protection products.

C. FDY extrusion – integrated drawing step.
A second production method to produce fine filament yarns is the extrusion with integrated drawing resulting in a full drawn yarn in one production step. Depending on the process, 1, 2 or even 3 stage drawings are possible. Not only multifilament yarns are produced in this way but as well staple fibre production. In that final case also texturation and cutting the yarn to the appropriate length are integrated in the same process.

E. Formulation routes or PLA based materials.
Formulation routes explored are related to:
- Initial polymer grades; varying in molecular weight, d lactic acid content (homogeneity and crystallinity) – A high MW contributes to a raised melt strength and processability and is needed to reach a higher tenacity level in the textile products. A few % d-lactic monomer content contributes to the flexibility of the products and reduces the brittleness but at higher percentages the melt temperature and the overall polymer properties are reduced too much.
- Addition of 'Poly D Lactide content': A special crystal structure is generated when a fraction of Poly D LA is blended in the PolyL LA with a higher melting point (greater than 200 °C). The highest effects are expected at 50/50 blend ratio, but also at lower % of added Poly D LA effects can be obtained. The addition contributes to a higher thermal stability of the extruded monofilaments or tapes but little effect on tenacity is observed. Due to the limited availability and higher price of the Poly D LA polymer, this route of formulation is of interest for future industrial developments.
- Incorporation of low% of other biopolymers (PHA), - can contribute to an improved processability and has an impact on draw ratio and resulting mechanical properties especially in air quenched production. Effects are variable in function of the processing routes and should be evaluated for specific end applications.
- Addition of impact modifiers and crystallisation agents – In most cases products seems to have only minor effect on the extrusion process or on the strength of the textiles produced, but crystallisation and recrystallisation behaviour is clearly influenced, contributing to textile intermediates with a raised stability. Use of these types off additives can be considered in these processes where fast crystallisation is required.
- Control of humidity content: During melt processing partial hydrolysis of PLA will occur as function of humidity content, residence time and process temperature. Predrying of polymers to below 250 ppm is in general sufficient to avoid detrimental effects during the processing. Proccesing of formulations with higher water content, will lead to uncontrolled shifts in polymer properties.
- Use of chain extenders: Chain extenders can have a positive effect on molecular weight of the biopolymer. They can contribute to reduction of the hydrolysis effect created by processing Biopolyesters with a too high humidity content (or the required level of predrying) and can improve properties and processability by counteracting the polymer hydrolysis.

An interesting side-effect is observed namely increase of dyeability; although less important for agrotextiles this can have important benefits in other application area's such as clothing.

- Use of biodegradation promoters – It is possible to add low amounts of a biodegradation promotor during the extrusion. Concentration must be low and processing conditions must be kept well under control to limit the impact on hydrolysis and lower tenacity during extrusion. The products show clearly a much faster degradation during further durability testing, especially Q-UV artificial weathering tests, than reference products. This can be of importance for applications where a reduced lifetime is required even without entering industrial composting conditions.
- Use of hydrolytical stabilisers – PLA is vulnerable to hydrolysis at high temperature e.g. 80°C and high humidity degree. Within one or two days at these extreme conditions the polymer loses its mechanical properties and the molecular weight drops drastically. It could be proven that using selected hydrolysis stabilisers under correct processing conditions will largely stop the hydrolysis process. The additive stabilises as well the melt during the melt processing stage although it is still to be advised to dry the material well before processing.

3.3 Observations on fast degrading PLA materials and problem solving.
In the course of the project two difficulties were observed for instabilities of the extruded PLA textile materials:
- Shift in mechanical properties due to reorientation and crystallisation process
- Decay in mechanical properties under warehouse conditions.

3.3.1 Shift in Mechanical properties due to reorientation and crystallisation process.

PLA is a polymer that in general crystallizes only slowly. This can create some problems during processing.

If insufficient crystallisation takes place during the extrusion process, the material will further post-crystallise after the production process, whether or not accelerated by heat treatment. In the example shown above crystallisation in a POY extrusion was so low that after winding, the post crystallisation process caused such an increase in temperature and in tension that the bobbin was destroyed completely. In most cases the effects are not that spectacular but shifts in mechanical properties of 10 to 20% can be observed in a number of cases if insufficient crystallisation on the extrusion line is obtained.

The experiences led to the following rules of thumb to optimise crystallisation of PLA yarns.

Achievement of high crystallinity and therefore high stability of mechanical properties after processing will be obtained by:
- application of low cooling rate during melt drawing,
- increased melt-drawing ratio
- additional support of crystallisation by
– stress (winding speed, draw ratio)
– nucleating additives
- application of secondary drawing (drawing on hot godets or oven)
- multistep drawing
- heat treatment of yarns: high setting temperatures.

3.3.2 Stabilisation of PLA against hydrolysis.
Although PLA is stable under standard conditions, it is easily hydrolysed at high humidity and high temperature. Within about 3 days the polymer loses its properties at 80°C and 80% rel. humidity. Although such extreme conditions are not occurring during real life of agrotextiles, it is still of interest to be able to stop this process.
Specialty hydrolytical stabilisers additives were evaluated and found that not only stop the hydrolysis at the extreme storage conditions but also inhibits the hydrolysis during melt processing.

3.3.3 Decay in mechanical properties under warehouse conditions.

During the project it was observed in a few cases that PLA materials that normally should have a high stability and should not lose their mechanical properties under 'warehouse conditions' over years started to degrade very fast. The drop in properties can occur in a few weeks to a few months' time and is totally unacceptable for commercial applications. Other materials produced under similar conditions stayed intact for several years. The phenomenon was analysed in great details.

It was observed that the direct cause of the problem is related to the growth of fungi on the material as could be observed by microscopical analyisis and microbiological tests.

3.4 Alternative natural fibre sources and processing into non-wovens.

3.4.1 Alternative natural fibre sources and upgrading of properties.
Also natural fibres are used in the development of agrotextiles. Hereby the project is focusing on NF sources either obtained via recycling, as a waste or side fraction of agricultural crops or products with a high agricultural output.

Main NF sources evaluated are recycled jute, linseed flax, hemp, hop wastes and nettle.

It was shown that hops or nettle offer no economical interesting source due to the very low fibre yield generated from these materials. Linseed and hemp offer good potential to generate fibres with high yield and good properties.

Hemp and linseed fibre fractions offer good potential to be used for technical fibre applications including agrotextiles.

Also hydrophilicity of fibre material is increased, facilitating further impregnating processing to improve homogeneity in finishing processes.

The field retting system developed can be considered for industrial exploitation for natural fibre production whether or not for agrotextile applications. The evaluated natural fibre sources have a better quality than the recycled jute, but price of these alternative sources is still higher due to the required processing. Price level is still acceptable for the application envisaged, as far as transport costs are not increasing price too much.

3.4.2 Alternative natural fibres and processing properties for non-woven production.

The processibility of the different natural fibre sources into needle felts - pure or in blends of different ratio's – were evaluated on pilot and industrial lines.

3.4.3 Evaluation of hydrophilicity via moisture management tester.

To evaluate the interaction with water, a new test method of 3D moisture spreading through the agrotextile structure was developed by use of the MMT-SDL device. The MMT was developed to measure dynamic liquid transport properties of plain textile substrates.

Moisture Management is a method to characterize the 3D liquid transport properties of fabrics. Spread of solution applied on the top side of textile substrate during its penetration through the textile structure is electronically detected.

The limits regarding weight and fabric thickness, and test conditions (prolonged time and testing liquor dose) were studied to facilitate measurements of actual agromat constructions of different weight. This improvement of methodology facilitated the evaluation of the samples processed using bioresins, enzyme treatment, and measuring the water transmission and suction behaviour as shown in the samples below.

It can be concluded that short fibre qualities:
- linseed fibre with the growing potential of nutrient production waste
- hemp as an alternative short bast fibre
can be identified as potential, effective sources. Positive efficiency of the new enzymatic process – preferably its field spray alternative (called 'bio-retting') was confirmed by repeated seasonal post-harvest trials. Special INOTEX enzymatic product (TEXAZYM SER 7 conc.) developed and tested in real field conditions. Common and enzymatic modified fibres were tested in pilot scale production of needle punch carded nonwovens. No significant differences and limitations by process-ability of various blend combinations observed.

3.5 Development of biobased resins and application to natural fibre structures

3.5.1 Development of bioresin formulations

For the development of the bioresins it was shown in an early stage that the furan bioresins are offering an increased biostability to the natural fibres they are applied to.

The treated textiles showed however disadvantages including a limited reactivity, long and harsh processing and high stiffness. Therefore the following optimisation routes were explored:
- Increase of reactivity - to reduce curing temperature and time to be compatible with the application process on natural fibres, reactivity increased via adapting functional groups and catalytic system.
- Development of water dilutable furan formulation with high water content, to allow a more homogeneous application with reduced resin content.
- Reduction of brittleness and hardness after curing via:
Development of alternative reactive monomers with longer aliphatic side chains; feasibility was tested but offers only potential at long term, due to the complex chemistry,
Blending with long chain fatty acid esters – increase in flexibility, remaining fully biobased.
- Optimisation of stability and anti-foaming via addition of the appropriate agents.

A novel hybrid BioRez® formulation was developed taken these elements into account and resulting in a fully biobased, water dilutable and stable thermoset reactive emulsion, with appropriate reactivity, to limit curing times.

3.5.2 Application of Bioresins to natural fibres based textiles
The stable hybrid furan-fatty acid based resin is infinitely water dillutable and this makes it possible to utilise the resin in any given solid content on natural fibres and to use different resin application systems. The best suited application technology for this resin was found to be full bath impregnation with an aqueous dilution of the resin. The textile is then squeezed to remove excess resin and water and is dried and cured in an oven. This application technique allows even distribution of resin throughout the cross section of the substrate as well as in width and in length. Prior to industrial tests this technology was extensively tested on 'lab'-scale coating line of Centexbel.

As an alternative also a spraying application could be developed at Ensait allowing that the application of resin stays limited to the surface of the material. This application system will create only a partial protection at the surface of the material.

3.5.3 Alternative formulation based on non-renewable chemicals

An alternative resin formulation (not biobased) was developed as back-up solution. The formulation is based on synthetic resin in combination with a synthetic anti-microbial additive AEGIS® that is well known and applied in other textile applications. Also in this case it was essential to find a proper balance in the ratio between resin and anti-microbial concentration. Other prerequisites are water dilutability, stability of the formulation, and non-toxicity of ingredients and degradation products.

Via the developed formulation 8% of the anti-microbial product (AEGIS®) and 4% of DPCLK acting as binder is applied to the fabric, along with an appropriate wetting agent. Also for this formulation the full bath impregnation offered the best properties. The polymerization, of the binder is realized via curing at 150°C up to 175°C during two to five minutes. Formulations were also applied at full industrial scale.

3.5.4 Additional functionalization of resin systems
In addition also functionalization of the formulation was explored via:
- Colouration with pigments
- Addition of Hydrophobic agents.
- Flame retardency.

Pigments (red, green, yellow/brown, black) were selected that can be integrated in the Furan formulation without destabilising the emulsion. Although it is feasible to define a red, green brown colour, the colouration effect is not that good due to the intrinsic colour effect of the Furan resin. In the future colouration still can be used to reduce the bleaching effect of sunlight of the treated fabrics and to stabilise the brown colour of the formulated products.

Devan PPT tested the compatibility of hydrophic agents with the Furan resin formulation. Some compatible products could be defined. Although cured Furan resin has as such already a hydrophic effect, the effect can be considerably enlarged. For most agrotextile applications, hydrophobicity is not a major property required.

It is of interest to combine a minimum level of FR properties to materials such as ground-covers. Applying furan resin in a sufficient amount improves flame retardency of the natural fibre based fabrics. For the Aegis treated fabrics or to further upgrade the flame retardency of the furan treated fabrics, Devan PPT developed an FR treatment: ECOFLAM P-128 (400 g/l), to be applied via full-bath impregnation. High level of flame retardency could be obtained.

3.6 Demonstrator development and demonstrator field tests

3.6.1 Demonstrator production.

Based on previous results, industrial production runs were performed both for the natural fibre based and for the biopolymer based, agrotextiles. Demonstrator end-products were defined and realised on industrial production equipment.

The following demonstrator products were defined:
3.6.1.1 Natural fibre based ground covers – La Zeloise.
La Zeloise produced are non-woven and woven jute ground covers against weed growth and soil stabilization. The purpose of this products family is to consolidate the terrain, suitable to resist external conditions and to avoid the growth of vegetation. Furthermore, the ground covering reduces the transpiration of ground, and reduces the necessity of water. A set of materials treated with the biobased Furan Hybrid resin (TransfuranChemicals) or with the synthetic Aegis formulation (Devan PPT) were tested along with reference materials.

3.6.1.2 PLA based ground cover – DS Textiles.

The demo material provided by DS Textiles is a lightweight, non-woven mat made in PLA. The felt is expected to be used as an erosion protection for slopes, and to avoid the growth of vegetation. The contemporary achievement of such two functionalities makes it necessary to have a relevant strength. To avoid a too fast degradation the non-woven was calandered to limit the microbiological contamination.

3.6.1.3 PLA based insect proof nets – TEXINOV.

TEXINOV produced industrially knitted insect screens from PLA monofilament and multifilament materials. The aim of the demonstrator is to provide a physical barrier to insects that can provide problems (illness, destroying fruits, …) to plants, trees or cultures. The net is very lightweight and permeable to air; the mechanical resistance needs to be sufficient to avoid damage during installation, and must be very resistant to UV radiations.

3.6.1.4 PLA based groundcover fabric – Bonar.

BONAR developed for the demonstrators phase a woven ground cover made in PLA as an alternative for standard PP based groundcovers. In landscaping it is used as covering of land besides highway or railways. Groundcovers are also used for weed control to reduce maintenance and the use of herbicides in public green areas or in orchards, … . Different product colours are set so as to mimic the environment (green, black, brown colours).

3.6.2 Demonstrator field tests.

Demonstrators were installed at two different installation sites representing different climatic parameters; the first is in the North of Italy in Sestri Levante and the second in the Southern of Italy, in Lecce at the Botanical Garden of University of Lecce. At both sites the durability of the materials was evaluated by following up the installed materials and regular sampling of products.

In addition at the Lecce site, the mulching effects has been evaluated for the Jute based demonstrators in combination with the evaluation of plant growth (chicory growth), irrigation included.

In addition some materials were installed as-well at the premises of the industrial partners.

The following pictures give an indication of some of the installed materials.

3.6.3 Durability tests on demonstrator products.

A range of different durability tests were performed on the experimental and demonstrator materials to follow up the degradation of the products and to get an indication of the real lifetime. Tests procedures are related to:
- Soil-burial tests –simulating materials in contact with microbiological active ground samples,
- Q-UV tests, tests with UV-light source simulating sun-light,
- Combined Q-UV test with soil-burial test,
- Aging tests under warehouse conditions or under extreme temperature and humidity conditions,
- Ecotoxicity tests for used products and their degradation products after composting

The degradation is followed by visual interpretation, analysis of mechanical properties (strength and elongation), and for the PLA materials by analysis the change in molecular weight of the polymeric samples.

3.6.3.1 Soil burial test

The natural fibre based materials as well as the PLA based agrotextiles were evaluated for their durability using the 'soil burial tests' according to AATCC 30-2004. This is a biodegradability test for textiles buried in a microbiological active soil at high relative humidity content and at a temperature of 29°C. The activity of the soil is tested via adding a reference cotton fabric that should be degraded completely after one to two weeks treatment. The experimental materials are tested for different periods in some cases up to 84 days in this accelerated soil burial test.

It can be clearly observed that materials appropriately treated with Furan based resins are protected to a large extent and will have an extended lifetime that is expected to be at least the double of the reference products. Also for products treated with the alternative Aegis formulation, a similar improvement is observed.

For the demonstrators in real field conditions it can be observed after a year that fungal attack on reference products has started considerably. The Furan treated articles are still intact except for some discolouration effect, due to the bleaching effect by the sunlight.

3.6.3.2 Follow-up of molecular weight after Q-UV and outdoor exposure of PLA

PLA based agrotextiles were tested both in soil-box degradation tests and in standard Q-UV tests. Exposure to ultra violet light according to ASTM G53-84 (4h at 60°C and 0.77W/m² followed by 4h at 50°C condensation) represents an accelerated exposure environment. This test is using UV-A light simulating outdoor sunlight, but temperature conditions are raised in order to raise the impact and reduce testing time.

As can be observed PLA materials will be slowly degraded under the test conditions defined. However the material does resists much longer than standard polymers like PP or PET if they are not functionalised with UV stabilisers. PLA as such has clearly a higher UV stability than these reference polymers. PLA easily resists up to 2000 hours of Q-UV treatment before properties drops to halve of the original values.

In contrast it is observed that hardly any reduction in MW is observed for samples in out-door weathering tests. This can be an indication that the proposed testing methodology (used in standards for testing PP, PET, PA) might be too aggressive for the PLA material and that the Q-UV results offer an underestimation of the real durability properties of PLA fabrics.

The soil burial test seems to have no impact at all on mechanical properties or on the molecular weight of the PLA material. Extended testing cycles even up to 12 months showed only a minor reduction in properties. Even the combination of Q-UV tests (1000 h) followed by further soil burial test didn’t reveal an increased speed of degradation in the artificial soil.

3.6.3.3 Fast degradation test under extreme conditions

A novel test method was defined for evaluation of the hydrolytical degradation of PLA at extreme conditions. Tests were performed in an oven at 80°C and with a relative humidity greater than 80%. Under these conditions the PLA will be completely hydrolysed and brittled. The test is mainly used to evaluate the effect of added stabilisers. Some specific additives could be defined that not only stops hydrolysis in these conditions but as-well the hydrolysis during the melt processing as could be clearly observed for a number of tests as reported earlier.

3.6.3.4 Phytotoxicity tests via seed germination and plant growth tests on soil samples with partially degraded BIOAGROTEX demonstrator materials

Phytotoxicity tests (according to OECD 208) were performed on jute based ground-covers treated with Furan or an Aegis formulation. The samples were composted and seed germination and plant growth was evaluated using different species: Garden cress (Lepidium sativum), Summer barley (Hordeum vulgare), Soybean (Glycine max)

No statistically significant effects could be observed for the different composts based on the experimental products used. It could be concluded that no phytotoxicity are present in the developed agrotextiles.

In addition to the laboratory ecotoxicity tests also the demonstrator sites were observed for any negative effects on plant growths either from weeds growing next to the installed demonstrators and of the chicory plants, planted in the middle of the ground-covers. Also in these field tests any negative effect on plant growth could be observed.

3.6.4 Conclusions from demonstrator field tests.

The installed demonstrator materials were followed-up during minimum 9 months but most materials for 15 months or more. Even then it's still insufficient to draw final conclusions on durability, since for most products a lifetime of minimum 3 years is expected.

The observations indicate already that none of the developed materials showed an unacceptable degradation level. Some of the materials clearly outperformed the reference products as was clearly the case with Jute fabrics or felts treated with Furan based or an alternative antimicrobial resin. A continued following up of the tests is performed even beyond the project timeframe. The efficiency of the reduction in weed growth is more related to the transparence of materials. Except from the lightweight woven Jute fabrics (greater than 350g/m²) all materials were sufficiently blocking the growth of weeds.

The additional tests with the chicory growth were not fully straightforward since the tests seem to be influenced too much by local differences in the test fields and large intrinsic variations between plants. Anyhow it could be concluded that no negative ecotoxic effects were observed based on the different resin formulations used to extend the lifetime of the natural fibre based groundcovers. This is observed in the field tests and in the lab scale fytotoxicity tests according OECD208.

Also for the PLA based agrotextiles it is observed that the durability of the materials both used on top of a crop or buried in the ground is sufficiently high. UV stability is high and easily outperform standard synthetic polymers such as PP or PET unless they are functionalised with large amounts of stabilisers. PLA materials, if not degraded in advance via long term UV illumination, will resist degradation in contact with the ground for a considerably long time and therefore lifetimes between 3 and 5 years are feasible in all cases.

3.7 Durability and ecological aspects of the developed products.

The BIOAGROTEX project is an ecological driven project. Therefore it is essential that the ecological advantages generated can be clearly defined and individual products can be analysed for their ecological footprint. In this regard a detailed LCA analysis for the different production processes were performed for the different demonstrator products developed that also form the basis for the commercial products defined.

Life Cycle Assessment (LCA) is a structured, comprehensive and internationally standardised method. It quantifies all relevant emissions and resources consumed and the related impact on environment, human health and resources that are associated with any goods or services. The term 'life cycle' refers to the notion that a fair, holistic assessment requires the assessment of raw material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product existence. The sum of all those steps – or phases – is the life cycle of the product.

LCA can be used in a number of direct applications, e.g. for product development (eco-design) and improvement, strategic planning, public policy making, marketing, etc.

In this project we undertake the following steps:
- Interview with the “Commissioner of the study” being the Owner of the technology in order to establish the goal, the scope and the boundaries of the study, to gain sufficient understanding of involved processes and products and to obtain high quality data for the LCI phase;
- Data collection based on which the LCA model is created;
- Input of the data in the software GaBi 5;
- Evaluation of both inventory and impact and interpretation of results;
- Model revision and refining with improvement of data quality.
This LCA study has been performed in accordance with internationally recognized guidelines (see e.g. ILCD Handbook: General guide for Life Cycle Assessment - Detailed guidance”) and standards (ISO 14044:2006 and ISO 14040:2006) main requirements.

Structural elements regarding the quantification of the environmental impact of the elementary ingredients both for the NF and biopolymer based materials have been defined and the specifications of the demonstrator production settings are taken into account to finalise the LCA analysis. The analysis offers a detailed overview of all aspects related to ecology including: demand on resources, energy, water and on aspects related to emission in air, water and the ground. The analysis takes into account production, real usage and end-of-life stage.

For the demonstrators generated a detailed LCA was performed and the key issues are summarised in a one page publishable report. These reports are the executive summary of the LCA analysis performed of each single product. These short publications are intended to be an exploitation of the results of the LCA analysis in order to show to the customer the benefit to produce and to use (and as a consequence, to implement in own facilities) a biobased product.

In addition, a BIOAGROTEX Eco-datasheet is created in order to give to the LCA analysis output a commercial / industrial address. To have a transparent methodology to assess the carbon footprint (as the LCA) and report it to the customer could represent a plus in the marketing management of the product. In this infancy stage the Eco-datasheet is in a preliminary status that could be improved and adapted according to the textile producers needs.

The aim of the Eco-datasheet is to use the Primary Footprint as a parameter of eco-friendliness of the products and processes defined. Its calculation does not need the involvement of suppliers’ or other third parties’, being exclusively based on technical data. Moreover, the Primary Footprint can be also used as a marketing means of communication, being directly linked to consumption and thus interesting in the eyes of the customer both from an economic and environmental point of view.

Potential Impact:

4 The potential impact

4.1 Exploitation approach

BIOAGROTEX is an industry driven initiative where all partners have contributed in ideas and concepts. It builds on feasibility assessment by industry and key RTD organizations in the consortium of the ideas presented. It is a major objective to bring these ideas forward and to develop technology which can be used and exploited.

The basic IPR rules are laid down in the Consortium Agreement (CA), signed at the start of the project. The CA also indicates the background knowledge of individual partners. Access to this background knowledge will be given to the other partners on a 'need to know' basis for the execution of the project. This access offered implies no transfer of ownership or right to use the information for items outside the project without written consent of the partner owing the background knowledge.

Foreground knowledge whether or not developed in joint actions is to be handled with great care. To avoid discussion concerning ownership of foreground knowledge developed during the project, the partners are instructed on good practices (logbook, lab recordings) and are described in the Quality Manual. Foreground knowledge, offering potential for commercialisation, is to be protected in an adequate and effective manner, in conformity with the relevant legal provisions and in regard to the legitimate interests of all participants. In order to maximize commercialisation potential within the consortium access rights on background and foreground knowledge will be offered on favourable conditions.

The Consortium Agreement also carefully governs issues related to the disclosure of confidential information in accordance to applicable laws and EC regulations. It further recognizes the fact that the EC Model Contract requires the use of results (commercial exploitation or further research). The Consortium Agreement specifies the responsibilities of the Partners to meet this requirement. Since it is in the benefit of all partners that the developed know-how, products and processes will be applied on a large industrial scale, access to the foreground knowledge will be offered to third parties outside the consortium on a commercial basis.

An IPR tracking system has been developed within the project during last months which collect all relevant exploitable results information and publicly available information. This tool will allow defining the freedom-to-operate and will be of assistance in defining the most appropriate way to protect the developed foreground knowledge. Non confidential information, such as analytical techniques that can be implemented into standards, or foreground knowledge once protected in an adequate way, will be released for dissemination. As the importance of dissemination is growing, strong emphasis is placed on the dissemination and promotion of results achieved in BIOAGROTEX. A multifaceted dissemination strategy is put in place going beyond standard academic publications and conferences by including measures for dissemination of results to industry to ensure take-up of the developments by industry and the market.

At an early stage of the project potential exploitable results were identified. The consortium has not limited themselves to define exploitable end products, but as well exploitable processes and products to be generated as intermediates. The following table reports the exploitable results defined during the course of the project with the company responsible and the other project partners involved.

For each exploitable result a summary table has been prepared as well as a preliminary business plan has been provided. Finally a patents scenario analysis has been performed focusing on the most relevant patents, for which a detailed description has been provided. Suggestions regarding patenting possibilities and/or strategies have been provided.

The summary table contains general information of the exploitable result as the innovation content of the result, potential customer and expected benefit, current achievement status and if necessary expected date; commercial and financial information as the time to market, evaluation of the cost to be sustained after the project, price range of the result or price of licenses, potential market size, competition against other products in terms of price or performance and the competitors; collaboration and exploitation information as partners involved, industrial partners interested in the result (partners, sponsors, etc…) and IPR strategy.

The business plan consist in 27 questions organized in eight different sections: general organisation description (current and future business activity, legal form of ownership, goals and objectives for the specific Exploitable Result), info on the management team (core assumptions of the business model and managerial objectives, business manager for the specific Exploitable Result, need for external management resources), technology information (technology as business opportunity with added value to offer new solutions to customers, development work needed to bring the technology to the market and associated costs, reaction from the competitors, bottlenecks to be overcome, standardization (reference materials - reference methodologies or regulation etc…), intellectual property rights strategies (IPRs clear within the project consortium, technology protection, comprehension of the of the state of the art current situation, including patents), products and services (stage of development of product(s)/service(s), product(s) dependence on other technologies or IPRs of 3rd parties, unique selling proposition of the product(s)/service(s) offered, competitive advantages), market analysis (market size and market growth, market segment(s) and drivers of growth, competing products and companies), preliminary marketing plan (sales targets for the Exploitable Result, strategy for pricing issues, sales methods and distribution channels) and tentative financial plan (break-even and cash flow calculations, capital needed over a period of time and level required of external funding).

As outcome of the work performed, here after, resumes of the current status, the valorisation potential and the strategies for the exploitation of the project results is presented, according to the progress of RTD work performed up to the end of the project.

4.2 Specifically generated and commercialised agrotextiles based on the project result.

Based on the results mentioned above a range of demonstrator products were defined and tested in the field. In addition durability testing was performed at lab scale conditions via soil burial tests, composting tests and fast degradation in oven or under UV-illumination. It was clearly shown that the lifetime of the natural fibre based ground-covers is at least doubled after application of the bioresin and also the PLA based agrotextiles will easily resist three to five years under outdoor conditions. No eco-toxicity effects of the materials or the products generated during degradation could be observed. Also a detailed LCA of the different demonstrator products was performed showing the ecological relevance of the products.

Based on these results a range of commercial products were developed and are commercialised:
4.2.1 Woven PLA Ground covers - DURACOVER® -Bonar Technical fabrics)
Woven groundcover fabrics, based on extruded PLA tapes, were developed by Bonar Technical Fabrics and are commercialised under the commercial name DURACOVER®. Products have a high UV resistance and the durability is guaranteed for at least 3 years. They are light weight and can be easily installed. Products are available in different colours. Several pre commercial and commercial installations have already be realised (cfr http://www.bonartf.com/en/x/159/duracover)

4.2.2 PLA fibre needelefelt groundcovers – 'HORTAFLEX' and 'WEED CONTROL®' - DS Textiles

Another set of groundcovers were defined by the Belgian company DS Textiles and are commercialised under the tradename 'HORTAFLEX®' and 'WEED CONTROL®'. These are based on PLA staple fibres processed into needlefelts, whether or not with an additional calander treatment. Products are also available that are containing the necessary seeds and can be used as seed mat. (see http://www.dstextileplatform.com online)

4.2.3 Knitted PLA insect screens – FILBIO®PLA and ULTRAVENT®PLA –TEXINOV

A third type of products are brought on the market by the French company TEXINOV. They are producing is specialty range of crop protection products (against insect, wind, hail, intense sunlight) via well defined knitted fabrics based on mono- or multifilaments yarns. A special range of PLA based products are now commercialised under the trade names FILBIO®PLA and ULTRAVENT®PLA. Due to the high UV resistance of the newly developed articles the products can outperform the present products based on PO or even on PA. (see http://www.texinov.fr online)

4.2.4 Natural Fibre based ground covers treated with bioresins - LONGLAST – La Zeloise.

A final set of groundcovers were developed based on Jute fabrics and non-wovens treated with bioresins from the Belgian company: Trans Furan Chemicals. The products are produced and commercialised by the Belgian Company La Zeloise. The major advantages of the materials developed are the extended durability of the natural fibre based fabrics (double or triple lifetime) this combined with the fully biobased character, the final compostability and the absence of any eco-toxicity effect. (see cfr http://www.lazeloise.be online).

4.2.5 Commercialisation of intermediates.

It's obvious that in order to allow the commercialisation of the above defined agrotextiles end-products, there is also commercialisation actions required for all intermediates and specialty formulations defined. Partly the materials are based on existing commercial products but also new special formulations are brought on the market. A specific example of such a product is the Hybrid BIOREZ®, but also biopolymer formulations or textile intermediates can be valorised.

4.3 Dissemination of the project results

Within the consortium it was decided to disseminate as much as possible the project approach, objectives and results as far as they don't interfere with IPR and exploitation possibilities. Dissemination is seen as a key element to visualise the novel eco-friendly products developed and to create a market demand.

During the whole course of project, 44 dissemination actions have been performed by the consortium partners.

They comprises conferences and congress (among which Aachen-Dresden International Textile Conference, European Textile Platform conference - Euratex, TEXCHEM -21st TCC CZ conference), fairs (among which Techtextil, Saint Selve fair, On the Road to a Bio-Based Economy: International event on Renewable Plastics, Textiles and Composites, Salon Vert), meeting with potential industrial partners or end user groups. These activities were supported by the posters and the flyers designed within the project.

At the end of the project a successful International Symposium: 'European Research and Innovation for a Biobased Economy' has been organized to disseminate project results, to launch the new products ain the market and to position the development towards other research initiatives towards the generation of a biobased economy.

5 Conclusion.

The Seventh Framework Programme (FP7) BIOAGROTEX project was to a large extent successful and most of the objectives defined at the start of the project were successfully realised. In a few cases alternative production routes needed to be applied to be applied in order to allow the realisation of the envisaged group of end products. This was the case for the starch based formulations, that were clearly improved but only textile products with insufficient mechanical properties could be generated. The focus was there for shifted towards the implementation of biopolyesters.

A range of optimised biopolymer resins or thermoplastic formulations were defined that could be processed on existing machinery and offer good processability and properties. Based on these results a set of different types of agrotextiles could be defined and can be directly implemented in the field. The first commercial results are already obtained and already a few hundred thousand m² of specialty agrotextiles based on the present development are sold to the market.

List of Websites:

http://www.bioagrotex.eu

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