Extremely lightweight nonwoven fabrics can be produced as sheet structures using meltblown technology. In this technology the interaction of laminar sheets of hot air and a polymer streams extruded from orifices provides long fine fibers that are collected on a surface in a form of belt or drum. Because the meltblowing process employs air of a high velocity to hit the molten polymer as it exits the orifices, it elongates the polymer strands from a 500 micrometer (mm) diameter to diameters as small as 0.1 mm. Meltblown fiberwebs are characterized by their extreme entanglement of such long and fine fibers, which produces coherency and strength. Due to such fine fibers, meltblown structures are lightweight with good covering power and display a high insulating value and excellent filter characteristic. Meltblown webs are characterized by their softness, bulk, absorbency, low porosity and poor abrasion resistance. The fiber and fiberweb structure characteristics qualify the meltblown fabrics for protective clothing.
One of the most important issues in the production of protective garments is the fabrication of the article using minimal seaming or joining. The seams and joins represent potential hazard to the users, who rely on protective clothing that covers the entire body surface area. This paper describes the development of a technology that is capable of producing shaped/molded (three-dimensional or 3D) meltblown structures with no seams by integrating meltblown and robotic technologies.
Experiments were conducted using the integrated technology to uniformly spray meltblown polypropylene fibers on a mannequin mold using two control algorithms: (i) A rule-based 3D controls and (ii) A constant velocity controls. The results obtained showed that the rule-based controls produced more uniform meltblown fabrics as compared to the constant velocity control strategy.
By: Raoul Farer, Eddie Grant, Tushar K. Ghosh, Abdelfattah M. Seyam, and Subhash K. Batra College of Te
Submit Date: 12/31/1999 20:00