Abstract: The process for production of a heat-stable and light-fast product consisting of multifilaments, monofilaments or flock for textile and industrial applications includes mixing from 0.2 to 0.5% by weight, based on the amount of product, of a UV absorber having a melting point of from 135 to 145° C. and a colorant having a melting point greater than 180° C. with a polyester powder at room temperature to form a starting mixture; feeding from 1 to 100% of the starting mixture and from 0 to 99% by weight PET granules into a cooled feed zone of a twin-screw extruder; operating the twin-screw extruder to melt, knead and homogenize the feed to form polymer strands, which are then cooled and cut to form a compound; and subsequently melt-spinning the compound to form the product. When the product is made by this method the UV absorber is incorporated in the product, thus avoiding the additive-related manufacturing problems.
Abstract: In a process for production of an aluminum foil (10) coated with sealable and sterlisable plastic (14) based on polypropylene (PP) or polyethylene (PE), the plastic (14) is coextruded with an adhesion-promotion agent (16) and combined with an aluminium foil (24) between two rollers (20, 22). The aluminium foil (10) coextrusion-coated in this way, to increase the adhesion strength between the aluminium foil (24) and the plastic layer (14), then passes continuously through an oven (26) with temperature (TO) set such that the temperature of the plastic layer (14) and the adhesion-promotion agent (16) lies above the crystallite melt point (TK) of the plastic. The coated aluminium foil heat-treated in this way, after emerging from the oven (26), is cooled shock-like such that the crystalline proportion at least in the surface area of the cooled plastic layer (14) and the crystallites in this area are as small as possible.
Type:
Application
Filed:
December 1, 2000
Publication date:
July 5, 2001
Inventors:
Hans-Rudolf Nageli, Franz Kolb, Werner Hammon, Werner Hartmann
Abstract: A polyolefin porous material is produced by synthesizing silica particles, polysiloxane particles or crosslinked vinyl polymer particles having an average particle diameter of 0.01 to 0.1 &mgr;m in a molten polyolefin to obtain a polyolefin composition. The polyolefin composition is subsequently subjected to molding and stretching to obtain a polyolefin porous material. The obtained polyolefin porous material contains fine particles dispersed therein, substantially without forming agglomerates, and has an average pore diameter of 0.005 to 0.1 &mgr;m. The small pore diameter allows the material to be used as a liquid/liquid separation membrane, a base material for precision filtration, or a separator for batteries.
Abstract: The invention is lyocell fiber characterized by a pebbled surface as seen at high magnification and having a variable cross section and diameter along and between fibers. The fiber is produced by centrifugal spinning, melt blowing or its espunbonding variation. The fibers can be made in the microdenier range with average weights as low as one denier or less. The fibers have inherently low gloss and can be formed into tight yarns for making fabrics of very soft hand. Alternatively, the fibers can be formed into self bonded nonwoven fabrics.
Type:
Grant
Filed:
March 16, 1998
Date of Patent:
May 22, 2001
Assignee:
Weyerhaeuser Company
Inventors:
Mengkui Luo, Vincent A. Roscelli, Amar N. Neogi, Richard A. Jewell
Abstract: The invention relates to a process for the manufacture of cellulosic flat films and of cellulosic membranes in the form of flat membranes whereby a solution of cellulose in an aqueous tertiary amine oxide is extruded by means of an extrusion nozzle, which has an extrusion gap, whereby the solution is shaped in the form of a film and the solution is led into a precipitation bath via an air gap and is characterized in that an extrusion nozzle is used which has an extrusion gap with a minimum length of 40 cm.
Type:
Grant
Filed:
June 14, 1999
Date of Patent:
January 23, 2001
Assignee:
Lenzing Aktiengesellschaft
Inventors:
Christian Schlossnikl, Siegfried Ambrosch, Heinrich Firgo, Peter Gspaltl
Abstract: Hydrophobic polyolefin fibers are provided with an internal hydrophobic polysiloxane of the formula
in which X, Y, R1, and R2, which may be the same or different, or substituted or unsubstituted independently of each other, are aliphatic groups having not more than about sixteen carbon atoms, R1 and R2 also being selected from among aryl groups, and z being a positive number sufficiently high that the polysiloxane is hydrophobic (z is generally a least 10). The invention also provides a novel polymer melt for spinning these hydrophobic fibers. The fibers can be cut into staple lengths and carded and bonded to form hydrophobic woven and nonwoven products suitable for use in hygiene devices such as diapers. Such devices are improved by these fibers, which, as spun, present a greater hydrophobicity than melt-spun polyolefin fibers lacking the internal siloxane lubricant, the improved hydrophobicity is evidenced by an advancing contact angle for the as-spun fibers of at least about 95°.