POLYPROPYLENE - MORE AND MORE PRESENT IN THE TECHNICAL FIELD

Transcription

1 BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI Publicat de Universitatea Tehnică Gheorghe Asachi din Iaşi Tomul LVI (LX), Fasc. 2, 2010 SecŃia TEXTILE. PIELĂRIE POLYPROPYLENE - MORE AND MORE PRESENT IN THE TECHNICAL FIELD BY GEORGETA POTOP and CĂTĂLIN VÎLCU Abstract. Within the wide range of fibre products of polypropylene, an important position belongs to the products executed through non-conventional procedures - spunbonds and meltblown, materials obtained through spinning interweaving process (spunbonds), and materials obtained by melt spinning with air blowing (meltblowing method). As applications of these intermediate products, one can mention: carpet holders, packings, insertions, technical linings, filters, protection cloths, agro-textiles, high mass geo-textiles, etc. Key words: polypropylene, spunbonds, meltblown, geo-composites. 1. Introduction About 20% of the polyolefin fibres are destined to the technical products, which is justified by the optimum cost/performance and tenacity/cost ratios. The technologies used to produce highly tenacious fibres, the high extrusion rates, as well as the non-conventional procedures to manufacture the unwoven products are the premises of new technical utilizations [1]. The evolution of the intermediate products consumption within the period is presented in Table 1. The consumption of polypropylene fibres for industrial applications keeps increasing [2]. According to the estimations of the Japanese Chemical Fibres Association (JCFA), the consumption in 1995 was of 686,000 tones, which represented 45% of the annual total, and it was predicted to get to 802,000 tones in 2005, Table 2.

2 10 Georgeta Potop and Cătălin Vîlcu Table 1 Consumption of Intermediate PP Products in Europe PP Products ,000 t [%] 1,000 t [%] Short fibres , Spunbonds/meltblown , Multi-filament yarns , Stripes , Yarns split from films , Belts 110 6, Single -filament yarns 50 3, Total Source: EATP- European Association of textile polyolefines Table 2 Evolution of Technical Products, Thousands Tons/Years Year Products Bedding-cotton 242 (35%) 240 (32%) 245 (30%) Cars 168 (24%) 174 (23%) 175 (22%) Geo-textiles 62 (9%) 85 (11%) 105 (13%) Medical and sanitary items 50 (7%) 72 (10%) 96 (12%) Environment items 19 (3%) 23 (3%) 29 (4%) Agriculture-fishing 26 (4%) 28 (4%) 28 (4%) Others 120 (17%) 121 (16%) 125 (16%) TOTAL Estimations based on the data supplied by JCFA 2. Agro-Textile and Geo-Textiles The agro-textile and geo-textile materials have wide development prospects since they provide the environment protection, being used for platforms for waste deposits, control and improvement of the soil erosion, water resource management, roads, bridges and railroads constructions. The geo-textiles are woven or unwoven materials that need to possess mechanical and chemical resistance, resistance to mould, putrefaction, therefore resistance to the soil and weathering effects. In a proportion of 60-70% the geotextiles are made of polypropylene, since they respond to the main requirements: permeability, steady structure, deformation resistance. Most of the polypropylene geo-textiles are interwoven, but they can be also made of short fibres.

3 Bul. Inst. Polit. Iaşi, t. LVI (LX), f. 2, Intermediate Spunbonds/Meltblown Products These are products manufactured through non-conventional procedures. The procedure of spinning interweaving (spunlaid method), is a oneoperation procedure, carried out in the polymer spinning phase, a procedure appeared in the1980 s. The products were named spinning interwoven (spunbond). The principle of the method consists in the following: the high fineness spun filaments are uniformly distributed on a surface and reunited in a textile veil by calendering, interweaving or thermal consolidation (self-adhesion, with a thermo-adhesive fibre or with special agents) [3]. The veil is made through different filaments deposition ways: electrostatic system, dynamic gas flow, elliptical oscillators. The obtained products have controlled properties in terms of mass, width, thickness, softness, resistance. The spinning interwoven products are more uniform than the usual unwoven products; they have an improved heat insulating capacity and a higher absorption capacity. They can be grained, dyed, printed, subjected to anti-static and anti-microbial treatment, etc. The applications of these materials are: carpet supports, packing, insertions, high-mass geo-textiles, etc. The procedure of melt spinning with air-blowing (sputtering method- meltblown) becomes industrial in 1970 and it is meant to process the very low viscosity polymers, therefore the polyolefin too. The principle of the methods consists in the following: just after the filaments come out from a special nozzle, they get in contact with two hot air jets, which break them, resulting in very fine fibres, with title under 1 dtex. The main advantage of this method is the possibility to obtain very fine filaments, products with excellent insulating and filtering properties, a reason for this process to open new fields of utilizations, such as: medical items, technical linings, protection clothes, furniture cloth, etc. The interest for these products has increased during the last years, a reason for many companies to produce polyolefin fibres. In the following the main manufacturing companies are mentioned, specifying also the trade name of the product: Neuberger SpA Italy (Base), Corovin GmbH - Germany (Corovin), Don & Low Nonwovens Great Britain (Dal Tex), Crown Zellerbach USA (Fibertex), HJR Fiberweb AB Sweden (Holmestra), Kimberly Clark USA ((Kim Cloth), Wayn Tex Inc. USA (Polybond), Polyfelt GmbH Austria (Polyfelt), Sodoca Ltd. France (Sodoca, Sodospun). TenCate Polyfelt PGM Products TenCate Polyfelt PGM is high-quality geo-composite products, from the manufacturing to the assembling technology. Each Polyfelt product is especially and precisely conceived to respond to certain requirements, within a wide variety of applications. The Polyfelt products can be used for filtering, draining, reinforcing and protection.

4 12 Georgeta Potop and Cătălin Vîlcu Generally, the geo-composite materials make the foundation on which the roads, railroads, tunnels, hydro technical constructions, land stabilization, drains as well as civil and industrial engineering are built. The utilization of geo-composites to reinforce the asphalt lining and to delay the crack s appearance is of constant concern for the Polyfelt Company, which developed complex solutions based on geo-composites, solutions improved and perfected in the course of time. The deterioration of the carriageway surfacing (asphalt or cement concrete) is generated by several factors, among which: traffic intensity, climate, stresses existing between the road layers, material quality, work execution quality, whose effects can be delayed by means of the geo-synthetic materials that can accomplish the following tasks: Reinforcement of asphalt lining; Anti-crack element; Sealing; Stress relieving; Increase the support adhesion. Polyfelt PGM 14 anti-crack membrane [4]. This is a 100% polypropylene geo-textile material made of UV stabilized fibres, mechanically consolidated (spunbond). The product accomplishes three important functions: it seals, diminishes the inter-layer stresses, provides a uniform bond between the layers. Fields of application: maintenance of low and medium traffic roads, tar treatments, local repairs, sealing the asphalt lining. Table 3 presents the main technical data of the PGM 14 product. Table 3 Technical Data of the PGM 14 Product Product Properties UM PGM 14 Tar absorption kg/m Maximum tensile strength kn/m 9 Separation strength (long.+ cross.) /2 % 55 Plucking elongation % > 50 Separation strength N 520 Thickness at a load of 2 kn/m 2 mm 1.1 Mass g/m Variation coefficient % < 10 Softening point ºC 165 Recycling 100% recoverable through conventional methods Delivery forms: Width Length m m 1.0; 1.9; 3.0;

5 Bul. Inst. Polit. Iaşi, t. LVI (LX), f. 2, Among the advantages of this material, one can mention: extension of the service life of the asphalt roads (Fig. 1), sealing, with insignificant loss of up to <500 kpa (Fig. 2). Fig. 1 Service life of the asphalt roads. Fig. 2 Sealing. Polyfelt PGM G geo-composite for asphalt reinforcement [4]. This is a geo-composite with increased resistance, consisting of 100% polypropylene filaments, UV stabilized, mechanically consolidated and reinforced with glass fibres. It combines the excellent reinforcing properties of the glass fibre filaments with the optimum capacity of the unwoven geo-textile to retain the tar, thus ensuring the efficient maintenance and extension of service life of the road structure. Fields of application: road bed widening, anti-crack element at joints, anti-undulation membrane, highways, airports, heavy vehicle parking, mountain roads with big temperature differences. The main technical data of the product are presented in Table 4.

6 14 Georgeta Potop and Cătălin Vîlcu Table 4 Technical Data of the PGM G Product Product Properties UM PGM G 50/50 PGM G 100/100 Tar absorption (unloaded) kg/m Tensile strength (long./cross.) kn/m 50/50 100/100 Eye dimension mm 40x40 40x40 Breaking elongation % 3 3 Resistance at 2% elongation kn/m 34/34 68/68 Thickness at 2 kn/m 2 loading mm Mass g/m E module for glass fibre MPa Softening point (glass) ºC Recycling 100% recoverable through conventional methods Figs. 3 and 4 present the PGM G layer laying and its effects respectively, as well as examples of PGM G geo-composite utilization. Fig. 3 Geo-composite position as asphalt reinforcing element. Fig. 4 Effects of the PGM G geo-composite: a without geo-composites, increased stresses appear at the crack level; b with geo-composite the stresses at the crack level are considerably diminished.

7 Bul. Inst. Polit. Iaşi, t. LVI (LX), f. 2, Fig. 5 presents the possible applications of the PGM G product. Fig. 5 Application examples: a repairing the road surface after excavations; b partial reinforcement of a longitudinal crack through milling; c complete reinforcement of old asphalt roads; d complete reinforcement of the asphalt. Among the advantages of the PGM G geo-composite one can mention: Taking over high stresses at small elongations (<3%); Sealing the asphalt cracks; Durability; Excellent stress relieving capacity; Uniform adherence; Recycling possibility. 4. Conclusions The polypropylene consumption for industrial applications keeps increasing. In a proportion of about 60-70% the geo-textiles are manufactured of polypropylene, since they respond to the main requirements: permeability, steady structure, deformation resistance. Most of the polypropylene geocomposites are interwoven. The interest for these products considerably increased during the last years, a reason for many companies to manufacture polyolefin fibers. Among these one can mention the successful company Polyfelt GmbH Austria with the Polyfelt product. The TenCate Polyfelt PGM geo-composites represent a cheap and innovative method to repair the surface road cracks. At the same time, these products significantly diminish the crack generation due to glasss fiber reinforcement and the tar retention capacity offered by the polypropylene textile component. Received: October 5, 2009 Gheorghe Asachi Technical University of Iaşi, Department of Technology and Design of Textile Products s: gpotop@tex.tuiasi.ro cvilcu@tex.tuiasi.ro

8 16 Georgeta Potop and Cătălin Vîlcu R E F E R E N C E S 1. Vîlcu C., Cercetări teoretice şi experimentale privind obńinerea firelor tip lână din polipropilenă modificată, destinate producńiei de covoare. Ph. D. Diss., Gheorghe Asachi Technical University of Iaşi (2007). 2. Grigoriu A., Blaşcu V., Grigoriu G.E., Fibre poliolefinice prezent şi viitor. Edit. Tehnopress, Iaşi (2000). 3. Hideo Sakakura, Industria fibrelor de polipropilenă în Japonia. Conf. EATP Praga, New Fibres, Mai (2000). 4. * * * NotiŃe tehnice, firma Polyfelt GmbH Austria. POLIPROPILENA TOT MAI PREZENTĂ ÎN DOMENIUL TEHNIC (Rezumat) În gama largă de produse fibroase în care se prezintă polipropilena un loc important revine unor produse realizate prin procedee neconvenńionale spunbonds şi meltblown, materiale obńinute prin procedeul de interńesere prin filare şi respectiv materiale obńinute prin procedeul de filare din topitură prin suflare cu aer (metoda pulverizării). Ca aplicańii a acestor produse intermediare pot fi menńionate: suport pentru covoare, ambalaje, inserńii, căptuşeli tehnice, filtre, îmbrăcăminte de protecńie, agrotextile, geotextile cu masă mare etc.