[Also see my article on Melt Blown Fabric]
Spun bond fabric is a type of non-woven fabric. Fine filaments of polypropylene are extruded from a die and are gathered onto a collector (usually has very tiny holes for air currents to go through) thus forming a “web”. The arrangements of such filaments can be customized by changing the direction of the collector. The goal is to gather these filaments uniformly on the collector. The next stage is passing the collected filaments through hot rollers (or bed of hot needles) to heat-bond the fibers.
Polypropylene is a common spun bond product from polyester flakes. Spun bond polypropylene has desirable characteristics such as (but not limited to): moldability to different shapes/applications; durability; permeability; stability; tensile strength; UV stable.
Common uses for such material include (but not limited to): shoe covers (booties), bags, craft projects; aprons, masks, and medical gowns.
North Carolina State’s Nonwovens Institue (NWI) is using a special process of spun bond fabric to make masks to help combat COVID-19. NWI’s process does not require the meltblown filtration layer. Instead the mask material is made by putting two different polymers together. This saves production time and resources. ExxonMobile and NatureWorks are two companies offering staple materials to NWI for making PPE.
References
- North Carolina State’s Nonwovens Institute (NWI), https://news.ncsu.edu/2020/04/a-necessary-filter/
