Melt blown

L. C. Wadsworth and A. M. Jones, "Novel Melt Blown Research Findings," paper presented at INDA/TEC, The InternationalNomrovens Technological Conference, Philadelphia, Pa., June 2—6,1986. 

A. M. Jones and L. C. Wadsworth, "Advances iu Melt Blown Resius," paper presented at TAPP11986 Nomrovens Conference, Adanta, Ga., Apr. 21-24,1986. 

These pads, made from nonwoven, melt-blown polypropylene materials, absorb fat lost during the cooking process, minimising its contact with food, and more fat is allowed to cook out (52). 

Mechanical strength becomes an important criterion, because wound cells (spiral-type construction), in which a layer of separator material is spirally wound between each two electrodes, are manufactured automatically at very high speed. Melt-blown polypropylene fleeces, with their excellent tensile properties, offer an interesting option. Frequently two layers of the same or different materials are used, to gain increased protection against shorts for button cells the use of three layers, even, is not unusual. Nevertheless the total thickness of the separation does not exceed 0.2 - 0.3 mm. For higher-temperature applications (up to about 60 °C) polypropylene fleeces are preferred since they offer a better chemical stability, though at lower electrolyte absorption [ 114"]. 

Only very recently the production of melt-blown polypropylene fleeces with considerably thinner fiber diameter became possible [100], thus making it possible — a low-cost hydrophilization provided — to achieve attractive properties with regard to small pore size and excellent tensile performance for use in highly automated assembly processes. 

Wet-laid Wet-laid Wet-laid Wet-laid Melt-blown grafted ... 

One of the important aspects of the development of P-plastomers was the expectation that these materials were amenable to plastics processing such as fiber and film formation and yet would yield soft elastic fabrication. This combination was hitherto unknown [24]. The formation of nonwoven fabrics including spun-bond and melt-blown nonwoven fabrics as well as their laminated forms has been documented. Similarly, cast film operation to form elastic monolithic films or composite structures which are not only amenable to these processes, but also to a variety of postfabrication processes have been described. 

Polymer scientists and engineers have developed a wide variety of processes by which to convert polypropylene into useable articles. These processes include fiber-spinning, production of melt blown and spun bond non-woven fabrics, film production, blow molding, and injection molding. The following sections describe these processes and the resulting properties of the product as a function of the process. 

Melt-Blown and Spun-Bond Non-Woven Fabrics... 

Fiber products account for about 15% of polypropene consumption. The products range from continuous filaments for carpeting and rope to melt-blown fibers for nonwoven goods. Specific applications include outdoor carpets, yarns for upholstery and automobile seats, and replacements for canvas in luggage and shoes, disposable goods (diapers, surgical gowns), ropes, and cords. 

A comparison of a 10-ft section of 8-inch diameter 3M melt blown polypropylene boom... 

Melt-blown nonwoven fabric TPX are used as separator materials. They are thin, but sufficient in mechanical strength and possess superior shape retention at elevated temperatures. 

However, melt-blown nonwoven fabrics with a microscopic variation of basis weight in different parts are a further drawback. The variation changes little even after the melt-blown nonwoven fabrics are pressed or embossed with metal rolls or press plates. Accordingly, the fabrics or pressed products, when used as separators, cause a microscopic nonuniform passage of electrolytes or ions in different parts of the membrane. 

Most LLDPE produced worldwide is made into thin film, either melt blown or cast from the melt. Blown film is produced by extrusion of LLDPE melt through a circular die with a large diameter, up to 100-120 cm. and a narrow gap, usually less than 1 mm. The tube of molten polymer expands from internal air pressure and forms a bubble of a larger diameter, Typically, the blow-up ratio, the ratio of the final film tube diameter to the circular-die diameter, is between 1.5 1 and 4 1. LLDPE cast film is manufactured by depositing potymer melt on a rotating heated... 

Disposable cartridge filters should be made of synthetic, non-degradable materials such as nylon or polypropylene. Their construction can be spun-bonded or melt-blown, string-wound, and pleated. These are described below. 

String-Wound, and Melt-Blown Cartridge Filters ... 

One of the most recent developments in the use of polyolefin fibers is in composites of spunbond (SB) and melt-blown systems. Some examples of structures being made are SB/MB, known as SM, SB/MB/SB, or SMS, and other combinations of SB and MB. The... 

Fig. 12.23. Spunbond/melt-blown composite, SMMS, containing two layers of melt-blown microfibers sandwiched between two layers of spunbonded material and bonded by hot calendaring. (Source Madsen, J. B Nonwovens World, p. 69, 2001, August-September.)...

Hayes [5] prepared a five component biodegradable blend that was used in melt blown containers consisting of bis(2-hydroxyethyl)-terephthalate, (IV), lactic acid, tris(2-hydroxyethyl)-trimeUitate, (V), ethylene glycol, and poly(ethylene glycol) using manganese (II) acetate tetrahydrate and antimony(III) oxide as initiators. 

In the submicron range of particle sizes, there are at least two media types to consider depth and microporous membrane. Typically, depth media is melt-blown fibrous nonwoven type (Fig. 18.13). Membranes are basically cast or expanded microporous films. Depth filters with a wrapped or pleated construction are used for slurry filtration (see Fig. 18.14a and b). Membrane... 

There have been some efforts in slurry recycling to reduce CoO of CMP consumables. In a recent study [37], the effluent samples were characterized for pH, trace-metal levels, viscosity, specific gravity, mean aggregate particle size, and LPC (>1.0 rm) before and after depth (melt-blown polymeric media) filtration. The study showed that the use of a recycled fumed silica slurry (recycled five times) decreased the CMP removal rate and the coefficient of friction (COF) by 40%. A perfect relationship was observed between the removal rate and COF. It was concluded that the increase in mean aggregate particle size, which lowers the contact area between the abrasive particles and the wafer, had some impact on the removal rate data. In general, there is a stronger emphasis on slurry additives and chemical action in current CMP processing with much lower maximum defectivity performance specifications [2]. 

Anonymous (2006) Cellulose melt blown non-woven technology ready for commercialization. Technical Textiles 3/2006, E 129... 

Fig. 21 Cartridge filters (A) Wound cartridge and (B) melt blown cartridges. (From Ref.. ) (View this art in color at WWW. dekker. com.)...

G. S. Bhat, V. Narayanan and L. C. Wadsworth, Dimensionally Stable Polyester Films, Fibers, Yarns and Melt Blown Nonwovens, U.S. Patent 5,753,736 (issued May 19, 1998). 

G. S. Bhat, Y. Zhang, L. C. Wadsworth, and M. Dever, "Processing of Post-Consumer Recycled PET into Melt Blown Nonwoven Webs, International Nonwovens Journal, 3,6 54-61 (1994). 

Recent studies have indicated direct correlations between surface area and catalytic activity of metal oxide sensors (Li et al. 1999). Therefore, it is evident that incorporating catalytic particles by coating techniques may affect surface area and catalysis. Studies by Lee and Bhat (2003) have demonstrated that by incorporating small amounts of electrospun nanoflbers in spun-bond and melt-blown nonwovens, barrier properties such as flitration efficiency and air permeability can be improved. 

PLA and PHB may be processed because of their thermoplastic properties in the usual thermoplastic processing systems by using extrusion, injection molding, melt spinning, blowing film, and melt-blown techniques. 

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