Spunbonding Technology with Types, Application (Bags) and Market Future

Spunbonding Technology with Types, Application (Bags) and Market Future

Mohan B. Madiwal
Department Of Textile Manufacturing
D.K.T.E Society’s Textile and Engineering Institute, Ichalkaranji
Email: mohan.textilemates@gmail.com

 

ABSTRACT
The spunbond process is widely used to produce nonwoven fabrics. The process of making spunbond fabrics combines the production of fabrics with the production of filaments. Components of a spunbond process typically include a polymer feed, an extruder, a metering pump, a die assembly, a filament spinning, a drawing and deposition system, a web formation, a bonding zone, and a winding. High process efficiencies and excellent properties of these fabrics have made them acceptable in different areas of application like in disposable and medical applications, automotive industry, filtration, civil engineering, packaging and carpet backing applications, geotextiles, durable papers, bedding, pillows, and furnishings. A comprehensive review of the spunbonding technique, fabric characteristics, process parameters and their applications is presented in this paper. In the future, the consumption of spun bond fabrics is expected to continue to grow in both durable and disposable products. Spun bond products will also continue to rapidly increase its market share and penetrate new markets. The purpose of this paper is to have a comprehensive of spun bond technology, processes, markets, and the applications.

Keywords: spunbonding, nonwoven, polypropylene, polyester, geo composite, bags,  polymer feeding, melting, transportation and filtration,  Extrusion,  Quenching  Drawing , Laydown ,  Bonding .

INTRODUCTION
“A nonwoven is a sheet of fibres, continuous filaments, or chopped yarns of any nature or origin, that have been formed into a web by any means, and bonded together by any means, with the exception of weaving or knitting. (1) According to INDA, “Nonwoven fabrics are broadly defined as sheet or web structures bonded together by entangling fiber or filaments (and by perforating films) mechanically, thermally or chemically. They are flat, porous sheets that are made directly from separate fibers or from molten plastic or plastic film. They are not made by weaving or knitting and do not require converting the fibers to yarn.” Woven and knitted fabrics require a preliminary set of spinning yarns from fibres before fabric assembly. (5) In some nonwoven manufacture the fibres are assembled directly into fabrics (missing out the yarn stage), and in other nonwoven manufacture the fabric is made directly from the polymer (i.e. the material goes from polymers to form a stable fabric in a single processing step) (8)

Spun bond nonwoven fabrics are composedofcontinuousfilaments produced by an integrated fiber spinning, web formation and bonding process. As it eliminates intermediate steps, it is the shortest textile route from polymer to fabrics in one stage and provides opportunities for increasing production and reduction of cost.(9) In the recent past spun bond nonwovens have developed rapidly due to their excellent properties and high process efficiency. Presently it occupies the largest share among the various techniques of nonwoven fabric manufacture and finds application in different fields. (7)

HISTORY OF NONWOVEN
The term nonwoven is an interesting word. To most, the word nonwoven means “not a woven” or “not a knit”, but nonwoven fabrics are much more. The Prologue of Introduction to Nonwovens Technology provides a historical listing of possible beginnings of nonwovens. These hypothetical beginnings range from historical legends to early technology developments. The actual roots of nonwovens may not be clear but in 1942 the term “nonwoven fabrics” was coined and were produced in the United States. These early “nonwoven fabrics” were created by adhesively bonding fiber webs. The first written definition of nonwoven fabrics came from the American Society for Testing and materials in 1962 which defined them as “textile fabrics made of carded web or fiber web held together by adhesives”. Currently INDA defines a nonwoven as “sheet or web structures bonded together by entangling fiber or filaments (and by perforating films) mechanically, thermally or chemically. They are flat, porous sheets that are made directly from separate fibers or from molten plastic or plastic film. They are not made by weaving or knitting and do not require converting the fibers to yarn” (INDA). Technical definitions express the fundamental basis for the nonwoven processes, but due to the wide variety of production techniques, a general description of nonwoven fabrics is not enough. As with woven or knitted fabrics each process possesses unique characteristics. The resulting fabrics do not have much in common aside from being categorized as nonwoven. Nonwoven components such as; fiber selection, web formation, bonding, and finishing techniques can be altered to manipulate fabric properties or reverse engineer fabrics based on functional requirements. Due to its assortment of achievable characteristics nonwoven fabrics penetrate a wide range of markets including medical, apparel, automotive, filtration, construction, geotextiles, and protective. (13)

HISTORY OF SPUNBOND TECHNOLOGY
Spunbonding process was attempted to be commercialized through 1940’s and 1950’s. The spunbond process was patented by Slather and Thomas of Corning Company for the production of glass wool (US Patent 2206058). In 1945, Calendar patented similar spunbond processes for the production of mineral wool (US Patent 2382290). (6) Spun bonded nonwovens made of synthetic polymers were commercialized by the technology of Freudenberg (Germany) and Du Pont (USA) in the 1950’s and 1960’s (Hill, 1990). After that, various spun bond processing technologies such as Lutravil® (1965, Freudenberg Company), Dacron® (1971, Lurgi Kohle & Mineral öltechnik GmbH), Reicofil® (1984, Reifenhäuser), REX® (Amoco Fibers and Textiles), and S-TEX® (Sodoca) have been introduced. But all of them are similar in technology. They integrate filament extrusion (spinning), drawing, deposition (lay-down), and bonding and winding into roll goods (McCulloch, Pourdeyhimi, & Zamfir, 2003). In 1990’s equipment suppliers including Kobelco, Nordson, Hills, and others offered complete spunbond lines. In 2000’s Reifenhauser, the main turkey supplier of PP spunbond, offered bicospunbond and melt blown using Hills technology. Spunbonded production was originally limited to Western Europe, the United States, and Japan, but has since spread to virtually all areas of the world. Production lines, mainly nonproprietary, have been installed throughout Asia, South America, and the Middle East, areas and countries that previously did not participate in the technology (INDA, 2004).

FIBER USED FOR NONWOVEN FABRIC
Fibers are the basic element of Nonwovens. Manufacturers of Nonwovens products can make use of almost any kind of fibers. These include traditional textile fibers, as well as recently developed hi-tech fibers. The selection of raw fibers, to considerable degree, determines the properties of the final nonwoven products. The selection of fibers also depends on customer requirement, cost, process ability, changes of properties because of web formation and consolidation. The fibers can be in the form of filament, staple fiber or even yarn. The following table shows the significant fibers used in the Nonwovens industry all over the world.(7)

RAW MATERIALS
Many polymers including polypropylene, polyester, polyethylene, polyamide, polyurethane, etc. are used in the spunbond process. Among various polymers, isotactic polypropylene (PP) is the most widely used polymer for spun bond nonwovens production, because polypropylene is relatively inexpensive and provides the highest yield (fiber per kilogram) (Wilhelm, Hilmar, & Walter, 2002). Also, it has the lowest specific gravity and the highest versatility for the nonwovens (Editorial Staff, 1992a).

Polyester (PET) has fabric property (tensile strength, modulus, and heat stability) superior to those of polypropylene fabrics is used in almost every nonwoven process technology. However, polyester is more expensive and difficult to process than polypropylene (Editorial Staff, 1992a; Break, 2004).

Polyethylene (PE) has good chemical resistance and hydrophobicity, and excellent electrical insulation properties and it is one of the important polymers for nonwovens (Editorial Staff, 1992a).

Polyamide including nylon 6 and nylo6,6 has the properties which are highly energy intensive than PET or PP and is used to spunbonded nonwovens for packaging materials (Editorial Staff, 1992a; Smorada, 2004).

Polyurethane (PUR) has an elastic property and it is also used in spunbonded nonwovens for the applications such as disposable wear, diaper, mask, medical tape, and elastic stuffing materials. However, it has a disadvantage of high price (Editorial Staff, 1992a).

NONWOVEN MANUFATURING PROCESS
Nonwovens are typically manufactured by putting small fibers together in the form of a sheet or web (similar to paper on a paper machine), and then binding them either mechanically (as in the case of felt, by interlocking them with serrated needles such that the inter-fiber friction results in a stronger fabric), with an adhesive, or thermally (by applying binder (in the form of powder, paste, or polymer melt) and melting the binder onto the web by increasing temperature).

Staple nonwovens– Staple nonwovens are made in 4 steps. Fibers are first spun, cut to a few centimeters length, and put into bales. The staple fibers are then blended, “opened” in a multistep process, dispersed on a conveyor belt, and spread in a uniform web by a wet laid, air laid, or carding/cross lapping process. Wet laid operations typically use 0.25 to 0.75 in (0.64 to 1.91 cm) long fibers, but sometimes longer if the fiber is stiff or thick. Airlaid processing generally uses 0.5 to 4.0 in (1.3 to 10.2 cm) fibers. Carding operations typically use ~1.5″ (3.8 cm) long fibers. Rayon used to be a common fiber in nonwovens, now greatly replaced by polyethylene terephthalate (PET) and polypropylene. Fiberglass is wetlaid into mats for use in roofing and shingles. Synthetic fiber blends are wetlaid along with cellulose for single-use fabrics. Staple nonwovens are bonded either thermally or by using resin. Bonding can be throughout the web by resin saturation or overall thermal bonding or in a distinct pattern via resin printing or thermal spot bonding. Conforming with staple fibers usually refers to a combination with melt blowing, often used in high-end textile insulations.

Melt-blownMelt-blown nonwovens are produced by extruding melted polymer fibers through a spin net or die consisting of up to 40 holes per inch to form long thin fibers which are stretched and cooled by passing hot air over the fibers as they fall from the die. The resultant web is collected into rolls and subsequently converted to finished products. The extremely fine fibers (typically polypropylene) differ from other extrusions, particularly spun bond, in that they have low intrinsic strength but much smaller size offering key properties. Often melt blown is added to spun bond to form SM or SMS webs, which are strong and offer the intrinsic benefits of fine fibers such as fine filtration, low pressure drop as used in face masks or filters and physical benefits such as acoustic insulation as used in dishwashers. One of the largest users of SM and SMS materials is the disposable diaper and feminine care industry.

Spunlaid nonwovens– Spunlaid, also called spunbond, nonwovens are made in one continuous process. Fibers are spun and then directly dispersed into a web by deflectors or can be directed with air streams. This technique leads to faster belt speeds, and cheaper costs. Several variants of this concept are available, such as the REICOFIL machinery. PP spunbonds run faster and at lower temperatures than PET spunbonds, mostly due to the difference in melting points. Spunbond has been combined with melt-blown nonwovens, conforming them into a layered product called SMS (spun-melt-spun). Melt-blown nonwovens have extremely fine fiber diameters but are not strong fabrics. SMS fabrics, made completely from PP are water-repellent and fine enough to serve as disposable fabrics. Melt-blown is often used as filter media, being able to capture very fine particles. Spunlaid is bonded by either resin or thermally. Regarding the bonding of Spun laid, Reiter has launched a new generation of nonwovens called Spunjet. In fact, Spunjet is the bonding of the Spunlaid filaments thanks to the hydro entanglement.(12)

Flashspun– Flashspun fabrics are created by spraying a dissolved resin into a chamber, where the solvent evaporates.

Air-laid paper– Air-laid paper is a textile-like material categorized as a nonwoven fabric made from wood pulp .Unlike the normal papermaking process, air-laid paper does not use water as the carrying medium for the fiber. Fibers are carried and formed to the structure of paper by air.

Other- Nonwovens can also start with films and fibrillate, serrate or vacuum-form them with patterned holes. Fiberglass nonwovens are of two basic types. Wet laid mat or “glass tissue” use wet-chopped, heavy denier fibers in the 6 to 20 micrometer diameter range. Flame attenuated mats or “batts” use discontinuous fine denier fibers in the 0.1 to 6 range. The latter is similar, though run at much higher temperatures, to melt-blown thermoplastic nonwovens. Wet laid mat is almost always wet resin bonded with a curtain coater, while batts are usually spray bonded with wet or dry resin. An unusual process produces polyethylene fibrils in a Freon-like fluid, forming them into a paper-like product.

Bonding– Both staple and spunlaid nonwovens would have no mechanical resistance in and of themselves, without the bonding step. Several methods can be used:

Thermal bonding use of a heat sealer using a large oven for curing calendaring through heated rollers (called spunbond when combined with spunlaid webs), calendars can be smooth faced for an overall bond or patterned for a softer, more tear resistant bond.(9)

Hydro-entanglement: Mechanical intertwining of fibers by water jets (called spun lace)

Ultrasonic pattern bonding: Used in high-loft or fabric insulation/quilts/bedding

Needlepunching/needle felting: Mechanical intertwining of fibers by needles

Chemicalbonding (wetlaid process): Use of binders (such as latex emulsion or solution polymers) to chemically join the fibers. A more expensive route uses binder fibers or powders that soften and melt to hold other non-melting fibers together. One type of cotton staple nonwoven is treated with sodium hydroxide to shrink bond the mat, the caustic causes the cellulose-based fibers to curl and shrink around one another as the bonding technique. one unusual polyamide(Cerex) is self-bonded with gas-phase acid.(12)

PROCESS SEQUENCE

schematic diagram of spunbond machine
Figure 1

Figure 1 displays a schematic diagram of spunbond machine. The spunbond technology, in its simplest form, consists of four processes namely, spinning, drawing, web formation, and web bonding. The spinning process largely corresponds to the manufacture of synthetic fibres materials by melt-spinning process. In the drawing process, the filaments are drawn in a tensionally locked way. The web formation process forms a nonwoven web. Web bonding is generally possible by means of the web bonding processes discussed earlier. The bonding process includes mainly thermal calendar bonding. Mechanical bonding and chemical bonding of spunlaid webs are also reported.

The sequence of processes is as follows: polymer preparation —> polymer feeding, melting, transportation and filtration —> Extrusion —> Quenching —> Drawing —> Laydown —> Bonding ® Winding.

The first step to spunbond technology involves preparation of polymer. It involves sufficient drying of the polymer pellets or granules and adequate addition of stabilizers/additives. The drying of the polymer is carried out particularly for polyester and polyamides as they are relatively high hygroscopic than polypropylene. The stabilizers are often added to impart melt stability to the polymers. Then, the polymer pellets or granules are fed to an extruder hopper by gravity-feeding. The pellets are then supplied to an extruder screw, which rotates within the heated. As the pellets are conveyed forward along the hot walls of the barrel between the flights of the screw, the polymer moves along the barrel, it melts due to the heat and friction of the viscous flow and the mechanical action between the screw and barrel. The screw is divided into feed, transition, and metering zones. The feed zone preheats the polymer pellets in a deep screw channel and conveys them into the transition zone. The transition zone has a decreasing depth channel in order to compress and homogenize the melting plastic. The melted polymer is discharged to the metering zone, which serves to generate maximum pressure for pumping the molten polymer. The pressure of the molten polymer is highest at this point and is controlled by the breaker plate with a screen pack placed near the screw discharge. The screen pack and breaker plate also filter out dirt and unbelted polymer lumps. The pressurized molten polymer is then conveyed to the metering pump.

A positive displacement volume metering device is used for uniform melt delivery to the die assembly. It ensures the consistent flow of clean polymer mix under process variations in viscosity, pressure, and temperature. The metering pump also provides polymer metering and the required process pressure. The metering pump typically has two intermeshing, counter-rotating, toothed gears. The positive displacement is accomplished by filling each gear tooth with polymer on the suction side of the pump and carrying the polymer around to the pump discharge. The molten polymer from the gear pump goes to the feed distribution system to provide uniform flow to the die nosepiece in the die assembly.

The die assembly is one of the most important elements of the spunbond technology. The die assembly has two distinct components: the polymer feed distribution section and the spinneret.

The feed distribution in a spunbonding die is more critical than in a film or sheeting die for two reasons. First, the spunbonding die usually has no mechanical adjustments to compensate for variations in polymer flow across the die width. Second, the process is often operated at a temperature range where thermal breakdown of polymers proceeds rapidly. The feed distribution is usually designed in such a way that the polymer distribution is less dependent on the shear sensitivity of the polymer. This feature allows the processing of widely different polymeric materials using just one distribution system. The feed distribution balances both the flow and the residence time across the width of the die. There are basically two types of feed distribution that are employed in the spunbonding die, the T-type (tapered and untapered) and the coat-hanger type. An in-depth mathematical and design description of each type of feed distribution is given by mastubara. The T-type feed distribution is widely used because it gives both even polymer flow and even residence time across the full width of the die.

From the feed distribution channel the polymer melt goes directly to the spinneret. The spinneret is one of the components of the die assembly. The web uniformity partially hinges on the design and fabrication of the spinneret, therefore the spinneret in the spunbonding process requires very close tolerances, which has continued to make their fabrication very costly. A spinneret is made from a single block of metal having several thousand drilled orifices or holes. The orifices or holes are bored by mechanical drilling or electric discharge machining (EDM) in a certain pattern. The spinnerets are usually circular or rectangular in shape. In commercial spunbonding processes, the objective is usually to produce a wide web (of up to about 5 m), and therefore many spinnerets are placed side by side to generate sufficient fibers across the width.21 The grouping of spinnerets is often called a block or bank. In commercial production lines, two or more blocks are used in tandem in order to increase the coverage of the filaments.

The proper integration of filament spinning, drawing, and deposition is critical in the spunbonding process. The main collective function is to solidify, draw, and entangle the extruded filaments from the spinneret and deposit them onto an air-permeable conveyor belt or collector.

Filament drawing follows spinning. In conventional extrusion spinning, drawing is achieved using one or more set of draw rollers. While roller drawing can certainly be used in spunbonding, a specially designed aerodynamic device such as a venture tube is commonly adopted.

Filament deposition follows the drawing step. Filament deposition is also frequently achieved with the aid of a specially designed aerodynamic device referred to as a fanning or entangler unit. The fanning unit is intended to cross or translate adjacent filaments to increase cross-directional web.Filament deposition follows the drawing step. Filament deposition is also frequently achieved with the aid of a specially designed aerodynamic device referred to as a fanning or entangler unit. The fanning unit is intended to cross or translate adjacent filaments to increase cross-directional web.(10)

PRODUCTION SYSTEMS
The concept of spunbond technology was developed sometime in late 1950s simultaneously in Europe and USA. Since then numerous innovations are disclosed on spunbond production system. This technology is derived from filament spinning technology. Many patents were granted on filament spinning technology. The basic principles involved in it, as proposed by Hartman, are explained with the help of Figure 2.

filament spinning technology
Figure 2

Figure 2a illustrates a system of filament formation. Here air as hot as melting temperature emerges from closely to the nozzle holes, takes the filaments and draws them. The emerging air, at the same time, intermingles with the ambient air. It uses longitudinal spinnerets, with air slots on both sides for the expulsion of the drawing gas ‘1’ (primary air). The room air (secondary air) ‘2’ is carried along and after lay down of the filaments; the air is removed by suction ‘3’. This process is well suited for tacky polymers, such as linear polyurethane. The continuous filaments after web collection bond themselves (self-bond) at their crossover points due to their inherent tackiness. Crystallization, which then sets in, subsequently eliminates the stickiness of the filaments after bonding.

Figure 2b describes another system. Here the emerging air and the filaments are taken to a drawing channel. Blowing in additional pressed air the drawing effect can be realized. It uses higher draw ratio, which results in increased molecular orientation of filaments. Filaments are drawn with several air or gas streams using drawing conduits. The air is removed by suction ‘4’ after the web is formed.

Figure 2c depicts one more system. Here the cooling and drawing air are separated. It operates with regular cooling duct ‘1’ and drawing jet ‘3’. The drawing and cooling arrangements can be operated to give very high spinning speeds with the result that highly oriented filaments are produced. The room air ‘2’, of controlled temperature and moisture content, can be entrained to control the development of filament properties. The air is removed by suction ‘4’ after web formation.

Figure 2d illustrates another system that has a mechanical drawing step ‘2’ between the spinneret and lay down zones. This route is similar to conventional spinning and is especially useful for polymers, which in regular air drawing do not give optimum filament ‘4’. Webs with high strength and low elongation are generally made using this particular system.(13)

FABRIC CHARACTERISTICS AND PROPERTIES
The structure of woven and knitted fabrics permits the fibres to move readily within the fabric when in-plane shear forces are applied, resulting in better conformability, whereas calendar bonding of a spun web causes fibres to fuse and impart integrity to the sheet. The resulting structure has a stiffer handle or drape due to immobilization of the fibres in the area of fusion. The effect can be moderated by limiting the bonds to very small areas (points) or by entangling the fibres mechanically (needle punching or hydro entanglement). Saturation bonding of spun webs with chemical binders like acrylic emulsions can bond the structure throughout to give stiff sheets.

Spun bond webs offer product characteristics ranging from very lightweight and flexible structures to heavy and stiff structures, with property combinations falling between paper and woven fabrics.

The main characteristics and properties are:

  • Random fibrous structure
  • Generally white with high opacity
  • High strength-to-weight ratios compared to other nonwoven, woven, and knitted structures
  • High tear strength
  • Planar isotropic properties due to random lay down of fibers. However optical analysis of the fibrous orientation distribution shows that the conveyor face of the fabric, which is in contact with the conveyor belt is more anisotropic than the upper facz.19
  • Good fray and crease resistance
  • High liquid retention capacity due to high void content
  • High in-plane shear resistance
  • Low drape ability
  • Most are layered or shingled in structure; the number of layers increase as basis weight increases
  • Basis weight ranges from 5 to 800g/m2 but is typically 10–200g/ m2.
  • Web thickness ranges from 0.1 to 4.0mm but is typically 0.2– 1.5mm.
  • Fiber diameter ranges from 1 to 50µm, but the preferred range is 15–35µm. Randomfiber structure, breathability, resistance to fluid penetration, lint free structure, sterilizabilityand impermeability to bacteria make the fabrics suitable for use in medical field like disposable operating room gowns, shoe covers and sterilizable packaging.(13)

APPLICATIONS NONWOVEN FABRIC
Non-woven materials are used in numerous applications, including:

MEDICAL

  1. isolation gowns
  2. surgical gowns
  3. surgical drapes and covers
  4. surgical masks
  5. surgical scrub suits
  6. caps
  7. medical packaging: porosity allows gas sterilization
  8. gloves
  9. shoe covers
  10. bath wipes
  11. wound dressings
  12. drug delivery
  13. plasters

Filters

  1. gasoline, oil and air – including HEPA filtration
  2. water, coffee, tea bags
  3. pharmaceutical industry
  4. mineral processing
  5. liquid cartridge and bag filters
  6. vacuum bags
  7. Allergen membranes or laminates with nonwoven layers.

GEOTEXTILES

Nonwoven geotextile bags
Figure 3

Nonwoven geotextile bags are much more robust than woven bags of the same thickness.(Figure3)

Geocomposite drain consisting of needle-punched nonwoven filter
Figure 4

Geocomposite drain consisting of needle-punched nonwoven filter and carrier geotextiles of polypropylene staple fibers eachwas having a mass per area of 200 g/m².(Figure 4)

NONWOVEN GEOTEXTILE CONTAINERS (SAND BAGS) ARE USED FOR

  • soil stabilizers and roadway underlayment
  • foundation stabilizers
  • erosion control
  • canals construction
  • drainage systems
  • geomembrane protection
  • frost protection
  • pond and canal water barriers
  • sand infiltration barrier for drainage tile
  • landfill liners

They are more robust in handling as compared to their woven counterparts, and therefore were often preferred in large-scale erosion protection projects such as those at Amrumbank West; Narrow Neck, Queensland; Kliffende house on Syltisland, and the Eider Barrage. In the last case, only 10 bags out of 48,000 were damaged despite a high installation rate of 700 bags per day.

OTHER

  • diaperstock, feminine hygiene, and other absorbent materials
  • carpet backing, primary and secondary
  • composites
  • marine sail laminates
  • tablecover laminates
  • chopped strand mat
  • backing/stabilizer for machine embroidery
  • packaging where porosity is needed

SHOPPING BAGS

  • insulation (fiberglass batting)
  • acoustic insulation for appliances, automotive components, and wall-paneling
  • pillows, cushions, mattress cores, and upholstery padding
  • batting in quilts or comforters
  • consumer and medical face masks
  • mailing envelopes
  • tarps, tenting and transportation (lumber, steel) wrapping
  • disposable clothing (foot coverings, coveralls) andweather resistant house wrap
  • cleanroom wipes
  • potting material for plants.

WHAT IS NONWOVEN BAG?
Nonwoven bag is a green product: durable, good looking, breathable, reusable, and washable. You can print ads to any company, any industry as advertising, gifts used for a long term. Consumers get beautiful nonwoven bags when they are in shopping, and the shops have also been invisible advertising. This is good for both of them,thus it makes nonwoven bag in the market more and more popular.(4)

The nonwoven bag use nonwoven fabric as raw material, it is a new generation of environmentally friendly material, with moisture, breathable, flexible, light, non-combustion, easy to break down, non-toxic, non-irritating, colorful , low prices, recyclable and so on.

It is natural biodegradable after the bag place in the outdoor for 90 days, and place in door the life is 5 years. It is non-toxic, tasteless, and without any legacy material when you burn it, which does not pollute the environment.

RAW MATERIAL FOR NO WOVEN BAG
Nearly all of the nonwoven fabrics can use for non-woven bags, the most popular raw material is PP nonwoven fabric. (spunbond nonwoven fabric).

The weight of nonwoven material made for bags is usually 70-100g. The higher weight of fabric, the more weight capacity of bags.See all of our nonwoven fabric raw material.

BASIC PROCESS OF MAKING NONWOVEN BAG
Feeding (non-woven fabric roll) → folding → ultrasonic bonding → cutting → make the bag (punching) → waste recycling → counting → stacking

This process is for fully automotive nonwoven bag making machine. The fully automated machine can operate by 1-2 workers only. Multi-functional automatic non-woven bag making machine using touch screen operation, it can adjust within a certain range of production speed and product sizes.  At the same time, in order to further achieve energy saving and environmental protection, the machine has remained   material recovery function: the production process will collect the bag waste automatically, contribute to the 2nd use, it will reduce the labour and increase the efficiency.

THE MAKING TYPES OF NONWOVEN BAG

  1. Flat punching bag (D-cut bags)
  2. Punching bag with bottom organ
  3. Non-woven punching bag with bottom and side organ
  4. Handbag
  5. Handle bag bottom organ
  6. Handle bag bottom and side organ
  7. Vest bag
  8. Vest bag with bottom and side organ
  9. Vest bag with side organ
  10. Muzzle bags
  11. Laminated bag
  12. Special shape of the environmental protection bags.
non-woven bags
Figure 5
different nonwoven bags
Figure 6

SPUNBOND MARKET
The worldwide nonwovens market in 2007 reached 5,751 million tones equivalent to $20.9 billion dollars. The volume was about 144 billion square meters. Spunbond volume in 2007 was about 45.6% of the total output or 2.621 million tons. Spunbond includes spunbonded polypropylene (SBPP), spunbonded polyester (SBPET), spunbonded polyethylene (SBPE), spunbonded nylon and melt blown technologies. As a group, spunbond is growing about 9% per year worldwide and is forecast to reach 4.04 million tons by the end of 2012. It share of nonwoven production will be about 48% of the world’s total nonwovens (INDA, 2007)

The area of largest growth for spunbonded fabrics continues to be disposable diaper cover stock accounting for 70% of the U.S. coverstock market. Forecasts for the future growth of spunbonded fabrics continue to be favourable as consumption in both durable and disposable areas continues to grow (INDA, 2006). Growth is forecast to generally exceed the growth of all other nonwovens, which itself is expected to grow at 3~6% per annum. In addition to diaper coverstock and hygiene, growth is anticipated in geotextiles, roofing, carpet backing, medical wrap, and durable paper applications (INDA, 2004).

According to INDA (2006), the spunbond products are expected to rapidly increase in market share and penetrate new markets including some portions of the apparel market in the future.

Nonwoven products made by using the spunbond process are variously used in disposable and medical applications,automotive industry, filtration, civil engineering, packaging applications, carpet backing applications, geotextiles, durable papers, bedding, pillows, furnishings, and others (Editorial Staff, 1992a).

The spunbond process has been used for diapers and incontinence products. It has been used in medical applications such as disposable operating room gowns, shoe covers and sterilization packaging, because it has the particular properties including breath ability, resistance to fluid penetration, sterilizability, and impermeability to bacteria (Wilhelm, Hilmar, & Walter, 2002).

In automotive industry, the spunbond webs are used for tufted automobile floor carpets, for trim parts, trunk liners, interior door panel, and seat covers (Smorada , 1992).

In filtration industry, the spunbond webs are used in various applications including pool and spa, air particulate, coolant, milk and sediment for household water (Smorada, 2004). The SMS/ SMMS structures which are the combination of spunbond and meltblown are widely used as air filters in the industry (Smorada, 2004).

In civil engineering, they are used in erosion control, revetment protection, railroad bed stabilization, canal and reservoir lining protection, highway and airfield black top cracking prevention, and roofing, because it has the particular properties including chemical and physical stability, high strength, and their highly controllable structure properties (Wilhelm, Hilmer, & Walter, 2002).

CONCLUSION
Nonwoven fabrics made by spun bond process are being used in various applications like most of time that nonwoven is used for preparation of bags. The consumption of spun bond fabrics in durable and disposable products is continuously growing and the development of new products with hydro entanglement of spun bonds is expected to further increase the market. Many companies have engaged in spun bond nonwoven technology around the world. In the future spun bond products will continue to rapidly increase market share and penetrate new markets including some portions of the apparel market.(13)

REFERENCES

  1. Batra, S., Pourdeyhimi, B., Shiffler, D., TT 305 Fiber Web and Nonwoven Production, Desk Copy, North Carolina State University, USA, 2004.
  2. Neckar, B. and Das, D., Theory of structure and mechanics of fibrous assemblies, Woodhead Publishing India Ltd., New Delhi, 2011.
  3. Simmonds, G. E., Bamberger, J. D., Bryner, M. A., Designing nonwovens to meet pore size specifications, Journal of Engineered Fibres and Fabrics 2 (1), 1-15, 2007.
  4. Kallmes, O. and Corte, H., TAPPI 43 (9), 737-752, 1960.
  5. JeanBS. Theoretical orientationdensity function of spun bonded nonwoven fabric. Text Res J. 2001;71(6):509‒513.
  6. Watzl A. Spunbonding and spun lacing. Technical Textiles. 2001;44:E167‒E172.
  7. Ericson CW, Baxter JF. Spun bonded nonwoven fabric studies-I: Characterization of filament arrangement in the web. Text Res J. 1973;43(7):371‒378.
  8. Goswami BC. Spunbonding and melt blown processes. Manufactured Fiber Technology, London: Chapman & Hall. 1997. p. 561‒594.
  9. Malkan SR. An overview of spunbonding and melt blowing technologies. Taapi J. 1995;78:185‒190.
  10. Lim H. A review of spun bond process. J Tex & Apparel, Technol & Manage. 2010;6(3):1‒13.
  11. More information on the definition of a nonwoven can be found on the EDANA and INDA websites.
  12. Wadsworth L, Sun Q, Zhang D, et al. SM and SMS Laminates Produced with 100% PP Melt blown and Bicomponent Fiber PP/PE Melt blown Webs. Nonwoven Industry. 1999;30:68‒74.
  13. Wilhelm, A Hilmer ,F., & Walter, K. (2002, November). Nonwoven Fabrics ; Raw Materials, Manufacture, Applications, Characteristics, Testing processes. Weinheim: Weinheim; Wiley- VCH.

You may also like:

  1. Melt Blown Non-Woven Technology – An Overview
  2. Characteristics of Nonwoven Fabric | Uses and Specialty of Nonwoven Products
  3. Spunbonding Method for Nonwoven Fabric Production
  4. Development of Natural Fibers Based Nonwovens for Automotive Interior Applications
  5. Applications of Nonwoven Hygiene Materials
  6. Different Important Functions of Geotextile

Share this Article!

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.