Melt-blown webs having a widened process window and better barrier properties(3rd drop, cm H2O resp. mbar). The melt-blown webs are made from so-called controlled rheology propylene (CR-PP), which has been visbroken without the use of peroxide but with a specific type of visbreaking additive.

Melt-blown webs having a widened process window and better barrier properties(3rd drop, cm H2O resp. mbar). The melt-blown webs are made from so-called controlled rheology propylene (CR-PP), which has been visbroken without the use of peroxide but with a specific type of visbreaking additive.

A method of creating a soft and lofty continuous fiber nonwoven web is provided. The method includes providing two molten polymer components having different melting temperatures to a spinneret defining a plurality of orifices, and flowing a fluid intermediate the spinneret and a moving porous member. The moving porous member is positioned below the spinneret. The method includes using the fluid to draw or push the two molten polymer components, in a direction that is toward the moving porous member, through at least some of the plurality of orifices to form a plurality of individual bi-component continuous fiber strands. The method includes depositing the continuous fiber strands on the moving porous member at a first location to create an intermediate continuous fiber nonwoven web, and removing and/or diverting some of the fluid proximate to the first location to maintain loft and softness in the deposited intermediate continuous fiber nonwoven web.

A method of creating a soft and lofty continuous fiber nonwoven web is provided. The method includes providing two molten polymer components having different melting temperatures to a spinneret defining a plurality of orifices, and flowing a fluid intermediate the spinneret and a moving porous member. The moving porous member is positioned below the spinneret. The method includes using the fluid to draw or push the two molten polymer components, in a direction that is toward the moving porous member, through at least some of the plurality of orifices to form a plurality of individual bi-component continuous fiber strands. The method includes depositing the continuous fiber strands on the moving porous member at a first location to create an intermediate continuous fiber nonwoven web, and removing and/or diverting some of the fluid proximate to the first location to maintain loft and softness in the deposited intermediate continuous fiber nonwoven web.

A nonwoven extending in a machine direction and a perpendicular cross-machine direction and having fibers bonded by a pattern of thermal bonds. The thermal bonds comprise larger bonds having an individual area of at least 1.0 mm.sup.2, in particular at least 1.5 mm.sup.2; and smaller bonds having an individual area of less than 1.0 mm.sup.2, in particular from about 0.10 mm.sup.2 to about 1.0 mm.sup.2. There are at least as many smaller bonds as larger bonds, the ratio of the number of smaller bonds may be in particular about two.

A nonwoven extending in a machine direction and a perpendicular cross-machine direction and having fibers bonded by a pattern of thermal bonds. The thermal bonds comprise larger bonds having an individual area of at least 1.0 mm.sup.2, in particular at least 1.5 mm.sup.2; and smaller bonds having an individual area of less than 1.0 mm.sup.2, in particular from about 0.10 mm.sup.2 to about 1.0 mm.sup.2. There are at least as many smaller bonds as larger bonds, the ratio of the number of smaller bonds may be in particular about two.

A bonded and entangled non-woven structure made of at least 50% staple fibers by weight of the bonded and entangled non-woven structure, and at least a partial bonding of the fibers of the non-woven structure. The at least partial bonding including thermally activated bonds between a first polyolefin material produced with a catalyst including at least one metallocene catalyst and having a melting point in the range 130-170 C. and a second material having a melting point which is at least 10 C. higher than the melting point of the first material, the weight of the first material in the non-woven structure being at least 3% of the weight of the nonwoven structure.

The present invention relates to a nonwoven fabric comprising a plurality of polypropylene-containing fibers that form a nonwoven web, which fibers in addition contain a slip agent, the web has a side which is provided with an alternating pattern which consists of individualized bonded areas which bonded areas are in the form of rods which are arranged in the cross direction of the web, the alternating pattern of individualized bonded areas defines a non-bonded area, the web has a basis weight on the range of from 5-25 g/m.sup.2, the surface of the bonded areas is in the range of 5-20% of the total surface of the side, and the surface of the non-bonded area is in the range of 80-95% of the total surface of the side. The present invention further relates to a process for forming the nonwoven fabric.

The present invention relates to a nonwoven fabric comprising a plurality of polypropylene-containing fibers that form a nonwoven web, which fibers in addition contain a slip agent, the web has a side which is provided with an alternating pattern which consists of individualized bonded areas which bonded areas are in the form of rods which are arranged in the cross direction of the web, the alternating pattern of individualized bonded areas defines a non-bonded area, the web has a basis weight on the range of from 5-25 g/m.sup.2, the surface of the bonded areas is in the range of 5-20% of the total surface of the side, and the surface of the non-bonded area is in the range of 80-95% of the total surface of the side. The present invention further relates to a process for forming the nonwoven fabric.

A semipermeable membrane support containing polyolefin-based fibers, which can withstand repeated washing and backwashing, makes it easy for a semipermeable membrane component to permeate thereinto and difficult for the component to strike therethrough, and is excellent in adhesion to the semipermeable membrane and adhesion between a non-coating surface thereof and a resin frame. The semipermeable membrane support which is used by forming the semipermeable membrane thereon is a wet-laid nonwoven fabric containing core-sheath type conjugate fibers composed of polypropylene as a core component and polyethylene as a sheath component and has a burst strength of 300 to 1,000 kPa, or the Bekk smoothness and 75 mirror surface glossiness of the coating surface on which the semipermeable membrane is to be formed of the semipermeable membrane support being more than the Bekk smoothness and 75 mirror surface glossiness of a non-coating surface on the opposite side.