ProfessorDirector, The University of Tennessee, Knoxville, TN
Administrative Assistant, Salamies' Inc., South Charleston, WV
Pages: 22 Published: Jan 1992
In this study more effective methods of applying a fluorochemical finish to relatively inexpensive melt blown/spunbond (MB/SB) nonwoven laminates developed in the Textiles and Nonwovens Development Center (TANDEC) at The University of Tennessee, Knoxville (UTK) were investigated with respect to improved performance and lower cost. The two possible end-uses for the MB/SB laminates are operating room drapes and gowns and apparel for agricultural workers, such as, pesticide applicators. In addition to comparing finishing techniques, the thermal bonding sequence of a MB/SB laminate before and after finishing also was studied to determine the effects on repellency, barrier properties, laminate bonding strength, air permeability and hand.
Polypropylene melt blown webs produced on the 20-inch (0.51 m) Exxon melt blown pilot line at UTK were laminated with an experimental point bonded spunbond polypropylene fabric. Polypropylene melt blown and spunbond laminate samples were thermally bonded with a smooth roll calender both before and after fluorochemical (FC) finishing by the more conventional padding technique and by two low wet pickup methods, foam finishing and kiss roll applications. Repellency (oil, alcohol and water repellency), barrier properties (water impact resistance and air permeability), and bonding strengths were examined.
Surprisingly, the MB/SB laminates, which were thermally bonded prior to finishing, picked up substantially less finish due to decreased porosity, but had much improved oil and alcohol repellency. The foam finished laminates had the highest oil and alcohol repellency values followed by those prepared by kiss roll and finally the padding techniques. Although all of the finished MB/SB laminates had excellent water spray ratings and water impact penetration resistance (due to the barrier properties of the melt blown component), the key to oil and alcohol repellency appears to be the concentration of FC finish deposited on the outer surface of the laminate.
As would be expected, the thermally bonded laminates had lower air permeability, as compared to the unbonded laminates. The melt blown and the spunbond components separately had appreciably higher air permeability. However, the air permeability values of the MB/SB laminates, which were thermally bonded before FC finishing were generally greater than a slightly lower weight commercial spunbond/melt blown/spunbond (SMS) fabric, which had been thermally point bonded. Laminate bonding strengths were much lower than the commercial point bonded SMS fabric, but were believed to be suitable for some protective clothing applications.
protective apparel, breathable barrier fabric, nonwoven, operating room fabric, pesticide protective fabric, melt blown, spunbond, melt blown/spunbond laminate, repellent finish, foam finishing, roller coating, kiss roll coating, thermal bonding
Paper ID: STP19179S