Melt (Dry) Spinning (Spunmelt Technologies)
Melt spinning or spunmelt technologies, including filament extrusion, melt-blown and spunbond processes, are used to form fibers or filaments. [Krause, Johnson and Ferencz, US Patent 7,722,347 (5/25/2010) ]
In the spunbond process, a molten polymer is extruded under pressure through a large number of holes in a spinneret or die. The resulting continuous filaments are quenched and then drawn by devices such as slot draw systems, attenuator guns, or Godet rolls. These continuous filaments are collected as a loose web upon a moving porous surface, such as a wire mesh conveyor belt. [Krause, Johnson and Ferencz, US Patent 7,722,347 (5/25/2010) ]
Melt blowing is a process for producing fibrous webs or articles directly from polymers or resins using high-velocity air, or another appropriate force, to form filaments and nonwoven fabrics. [Krause, Johnson and Ferencz, US Patent 7,722,347 (5/25/2010) ]
Monofilament extrusion is the extrusion of a single thread from a polymeric melt. Monofilaments are an essential part of our life from fishing line and strings for squash, tennis, racketball rackets and badminton. Monofilaments are used in yarn and synthetic rope used in fences, construction, greenhouses, orchards and fastening.
[Wikipedia, Monofilament (7/24/2010)] [Monofilament Fiber Extrusion]
Filament – a single thread or thin, flexible threadlike object
[Merriam-Webster Dictionary, 7/24/2010]
Recent US Patents
12/28/2010
7,857,608
Fiber and nanofiber spinning apparatus
Fabbricante et al of SpinDynamics, New York have developed a method for spinning fibers, or fiberizers, using a rotary fiber-making die system made up of thin plates, stacked to define slots through which the material forming the fibers will flow. The die allows for different size and types of fibers, including nanofibers having a diameter of less than 1 micron.. Plates means the dies can be manufactured cheaply, with easier clean-outs and replacements. (RDC 6/29/2011)
9/28/2010
7,802,977
Apparatus for melt spinning and windup of synthetic yarn
Schroter and Weigend of Oerlikon Textile, Germande developed a device for melt spinning and winding up synthetic yarns comprising a spinning appliance, a treating appliance and a windup machine. (RDC 12/7/2010)
Recent Journal Articles
Melt spinning of semi-crystalline compound fibers
(5573-5586) Polymer 52 #24 (2011)
Blanco-and Ramos of the Universidad de Málaga, Spain, developed a two-dimensional model of the fluid dynamics, heat transfer, molecular orientation and crystallization of the melt spinning of semi-crystalline compound fibers. The model employs a Newtonian rheology, includes the effects of both temperature and flow-induced crystallization, and accounts for the effects of the molecular orientation on both the stress tensor and the crystallization through a Doi–Edwards formulation and the Avrami–Kolmogorov kinetics, respectively. It is shown that, even at moderately low Biot numbers, the temperature across the compound fiber is not uniform owing to heat losses; for the cases studied here, the temperature non-uniformities are mainly a function of the Biot number, the thermal conductivity and the pre-exponential factor and activation energy of the viscosity law for the cladding. It is also shown that the cross-sectional averaged temperature predicted by the two-dimensional model exhibits the same qualitative trends as those of an asymptotic one-dimensional model which does not account for axial conduction and which is only valid for slender fibers at low Reynolds and Biot numbers. (RDC 11/3/2011)
Preparation of poly(ε-caprolactone)/poly(ε-caprolactone-co-lactide) (PCL/PLCL) blend filament by melt spinning
(1944–1950)Journal of Applied Polymer Science 123 #4 (2012)
Gupta, Ray and Ray of the Indian Institute of Technology, India, prepared poly(ε-caprolactone)/poly(ε-caprolactone-co-lactide) (PCL/PLCL) blend filaments with various ratios of PCL and PLCL by melt spinning. Crystallinity of blend decreased with the addition of PLCL and the fracture surface becomes rougher at higher PLCL content. (RDC 11/2/2011)
Optimization of acrylic dry spinning production line by using artificial neural network and genetic algorithm
(735–744)Journal of Applied Polymer Science 120 #2 (2011)
Vadood, Semnani and Morshed of the Isfahan University of Technology, Iran showed that an artificial neural network (ANN) using the back propagation training algorithm could predict the color index. ANN parameters including the number of hidden layers, number of neurons in each layer, adaptive learning rate, activation functions and numberr of max fail epochs. (RDC 1/11/2011)