Earth's Best... Only Better

By Ellen Wuagneux, Associate Editor | April 2, 2008

nonwovens offer Mother Nature a boost in agricultural & landscape end uses

What do a hobby gardener and an industrial farmer have in common? More than you might think. Nonwovens are playing a growing role in agriculture and landscape applications—as well as in the backyards of many consumers—because they offer an array of benefits such as efficiency, breathability, strength, water permeability, thermal/UV stability and recyclability. Both consumer and professional growers are interested in earlier harvests, higher yields, better quality, improved plant growth and protection from weather, insects and other negative environmental influences.

    In terms of technology, spunbond, spunlace and needlepunched nonwovens dominate in these applications, but film (plastic) sheets and woven structures are still posing stiff competition for nonwoven fabrics. As in all segments of the nonwovens industry, the ultimate purchase comes down to the two “Ps” of performance and price.

    Johns Manville (JM), which exclusively sells polyester spunbond products into these markets,
is one company feeling the squeeze as polypropylene prices have not increased as sharply as polyester prices have. “Customers want as good or better a product but we still have to meet a certain price point,” commented Bruce McDowell, technical sales engineer. “Polyester products are slightly more expensive than polypropylene, so the challenge is to really bring value and efficiency. We need to offer strength and durability while keeping costs down.”

New Fangled Farming

On the commercial end, growth is slow but steady at about 2-3% with new agricultural techniques helping to open up opportunities for nonwovens. This is a natural fit for nonwovens, according to Dirk De Saedeleir, research and development director of Belgian producer DS Technical. “What’s the most important goal in agriculture and horticulture? Yield and time to market,” he opined. “Nonwovens can increase the yield per acre of crops and shorten the time for crops, vegetables and fruit to be brought to the market. It is also important to increase the chances of a successful harvest. Nonwovens can provide protection against bad weather conditions, bugs and mosquitoes, the sun, germs, fungi and erosion in a sustainable manner.”

    In one new commercial farming method, tunnel culturing, nonwovens are making inroads because of their heat-retaining properties. Japanese producer Kuraray is leading the way in this area and has unveiled its Kuraflex lightweight nonwoven fabric for use as a heat-retaining material for tunnel culture commercial farming. Sales of the new product began last month.

    Extreme drops in temperature at night during the cold season can slow crop growth or even result in frost damage. To counter these problems, Kuraray has developed a heat-retaining sheet material made of highly bulky fibers, drawing on the company’s nonwoven fabric manufacturing technology. Although the new nonwoven fabric is thin and light, it boasts high heat-retaining characteristics. In particular, when the new product is used in tunnel culturing employing the new “external heat-retention” installation method, which aims to prevent slowdowns in crop growth, heat-retention is improved as the material effectively blocks heat loss from the tunnel interior.

    According to Kuraray, heat retention dramatically improves productivity, with significant results having been attained, especially in lettuce farming. One example of the new Kuraflex fabric’s success is its trial use at a lettuce farm (Okayama Fujita Lettuce Association) located near the company’s Okayama plant. Kuraray reported that the following results were delivered: larger, higher quality lettuces; shorter culture period due to growth promotion; shorter harvest period due to uniform growth (enabling mass-harvesting).

    Kuraray plans to promote the sale of its new product for application in lettuce farming, while expanding the scope of applications to the cultivation of other vegetables.

    Freudenberg is another company keeping an eye on professional growers’ up and coming approaches, one of which is high-tech biological gardening. “The trend of increasing quality and productivity in professional vegetable production as well as the trend to biological gardening requires new approaches and methods,” observed Christof Schroeder, corporate communications manager. “The farmers ask for high support to secure and improve their yields.”

    The company’s Lutrasil polypropylene nonwovens target just these types of demands. “Thanks to its advanced mechanical and physical characteristics, Lutrasil spunweb coverings make a good choice for professional growers,” said Mr. Schroeder. “They have been purpose-developed for the applications in horticulture in close cooperation with specialized institutes.”

    The first of Lutrasil’s advantages is temperature management, which is achieved through a well-balanced air exchange that creates an excellent micro-climate for plant development and growth. Lutrasil also offers maximized durability that stems from optimum raw materials and a 50% increase in UV protection; excellent water and light permeability and optimum protection against pests.

Spins On Spunbond

Another company offering spunbond nonwovens for agricultural end uses is Turkish producer General Nonwovens. The company produces nonwoven and composite roll goods for the agriculture, horticulture and landscaping industries. Under the brand name AgriGen, General Nonwovens offers poly­propylene and polyester spunbond nonwoven roll goods for use in crop covers, turf protection products, nursery protection and weed control fabrics, consumer gardening and landscaping products, root bags, containers and capillar matting.

    According to Alican Yilankirkan, business development director, “The key advantages of our products are breathability, insect/bird protection, water permeability, protection against humidity and increased productivity.” Mr. Yilankirkan went on to say that nonwovens are now well known in local Turkish markets and are preferred over films. “The farmers have realized that the promised increase in fruitfulness by nonwovens makers is really true by their own experiences,” he said.

    Also a spunbond specialist, JM sells its lightweight 100-120 gpsm Duraspun nonwovens into the landscape market and is underway with efforts to become a larger player in this market. The fabric allows moisture to pass but reduces weed growth, and—like all of JM’s agricultural offerings—is 100% polyester spunbond.

    “We are looking to increase our volumes in this area,” reported Mr. McDowell, “and are working on plant and process improvements at our Spartanburg, SC facility that will allow us to make Duraspun lighter and thinner. The 120 gpsm limit is not normally light enough for landscape applications, and we are producing some products now at about 90-95 gpsm or 2.7 opsy. This will make us more competitive.”

    JM’s polyester spunbond competes against traditional fabrics made of polypropylene. Although polyester tends to be priced higher than polypropylene, Mr. McDowell pointed to advantages such as UV stability and higher strength offered by the material. “It’s a higher density product and is tougher and stronger than most polypropylene alternatives.”

    In the area of crop protection, the company has sold some fabric to cover crops to prevent damage from frost. “One recent project in Texas has been successful,” commented Mr. McDowell.

    Meanwhile, in the erosion control field, JM supplies a distributor that sells into the golf course market where its 013140 fabric has been accepted as the product of choice for use under sand traps.

    One new product from JM is a Silt Fence replacement, which was co-developed by JM and Silt-Saver and is being distributed by Silt-Saver. The new product offers high efficiency filtration for protecting rivers, creeks and streams while reducing soil erosion on development projects. Currently, Silt -Saver is underway with state-by-state efforts to replace existing woven polypropylene products. “The concern in these projects centers around protecting water sources, especially in the southern U.S. where rainfall is limited,” explained Mr. McDowell. “We’re looking to achieve broader acceptance rather than having to sell state-by-state. It has been a tough sell for nonwovens but we have the performance advantage for these applications,” he said.  

A Greener Tomorrow

Looking ahead, Freudenberg’s Mr. Schroeder expects the market demand for nonwovens in agriculture to increase. “Further growth will be derived from new geographical markets where the benefits of this technology are not yet popular as they are just in the initial stage of development,” he said. “They will improve the functionality and get more professional in growing vegetables.” However, he warned that gains will be limited by intense price competition.

    For General Nonwovens’ Mr. Yilankirkan, the future of agricultural nonwovens will be impacted by changes in weather conditions, the most important example being global warming. He also predicted that the increasing importance of water resources will lead both governments and farmers to pay more attention to increased productivity and saving water. “Nonwovens producers should exert an effort to make the government and farmers conscious about the advantages of using nonwoven products in the agricultural sector.” He added that green issues are currently not a priority for end users in local markets in Turkey but, in light of new environmental regulations coming up, he expects their effects to become more visible.

    While eco-efforts may still be in their infancy in some regions, many producers are placing their bets on environmental trends and are going green now. One such company is DS Technical, which has introduced Hortaflex, an eco-fleece made of Ingeo fiber. The new product is the result of a long cooperation between DS and NatureWorks LLC to develop a range of articles shown for the first time at Techtextil 2007. Hortaflex is an alternative to the oil-based materials normally used in weed control that can be returned to the soil when composted under certain moisture and temperature conditions found in industrial composting facilities.

    Typical target applications for Hortaflex include groundcovers, landscaping fabrics and erosion and weed control. The Ingeo fiber used in making Hortaflex fleece is the first man-made fiber based on a 100% annually renewable resource, not oil. Conventional mulch and barrier fleeces use the world’s finite oil reserves as their source material.

    “Using these nonwovens avoids the use of herbicides or pesticides and they minimize labor cost (i.e. growers do not need to spray against weeds every year),” said Mr. De Saedeleir. Hortaflex comes in three different forms—needlepunched, seeded with grass and calandered. The calendered version is an alternative to the plastic used in horticultural environments (such as those used to grow strawberries).

    The Hortaflex product is offered in weights ranging from a lightweight 120 gpsm nonwoven fabric to a rugged 1.5 kpsm fabric for landscaping, erosion protection and stabilization as well as weed control barriers and pre-seeded grow mats. DS Technical Nonwoven can also customize this fabric with modifications such as weight, tenacity and elongation requirements and processes such as needlepunching, calendering or laminating. Speciality functional additives can also be applied.

    Ingeo is a nature-based fiber derived from agricultural resources and is made from NatureWorks polymer, which demonstrates a significant reduction in greenhouse gas emissions. Hortaflex is an alternative to the oil-based materials normally used in weed control. The use of Ingeo allows Hortaflex to be returned to the soil when composted under the right moisture and temperature conditions found in industrial composting facilities. “This, in the long term, closes the product’s production cycle and provides an added environmental benefit, especially when gardeners or horticulturists are faced with the task of removing the barrier fabric after a few years when changing over a garden or landscape,” Mr. De Saedeleir said.

    While developing the production process for the Hortaflex range, initial tests show that with the addition of grass seeds, better germination and growth results were observed when compared to conventional cellulose carpet-based structures. “This, combined with the added benefit of lighter weight structures, means Horta­flex can offer a positive alternative for the existing mulch-mats for the growing trend of green roof applications, enhancing the eco-options for architecture as well as contemporary landscaping,” he stated. “We are also setting up a range of protective nonwovens made on the basis of regenerated flakes of polyester bottles.”             

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