Abstract: An improved extrusion melt polymerization method for continuously making polyetherimides is disclosed wherein a mixture of an organic diamine and an aromatic bis(ether anhydride) is continuously fed through an inlet opening into a screw extruder having a second opening downstream from the inlet opening. The mixture is passed through a first extruder zone maintained at a low temperature to a zone where the mixture is melted and water of reaction is continuously removed through the second opening. A melt seal may be employed between the second opening and a third opening through which water of reaction may be removed under vacuum.

Abstract: A gate valve structure is shown embodying an elongate slide member movable within an elongate housing. The slide member carries a pair of annular seals spaced apart along the length of a valve body and has a bore therein extending through the valve body at a location between the seals. By linear movement of the slide member the bore and seals are each selectively registerable with aligned openings through the housing. This valve structure has operating and maintenance characteristics, which are particularly advantageous for use in the charging and/or discharging of fixed bed coal gasifiers.

Abstract: A non-woven rug, or the like, is formed by heat sealing a covering material at spaced intervals to a plastic backing and thereafter shrinking the backing to bulk the facing fabric. The heat sealing of the facing fabric to the backing causes a partial loss of orientation in the seal area therein bringing about a bulking or crinkling of the backing. The backing is preferably of a thermoplastic material having a foaming agent incorporated therein which is foamed after the completion of the heat sealing and heat shrinking procedures. Also included in the disclosure are the features of the backing fabric independently, i.e., incorporation of a foaming agent into a plastic which is extruded and thereafter heat sealed and/or stretch oriented and shrunk prior to the activation of the foaming agent to foam the fabric.

Abstract: In coextruded or extrusion coated, laminated, polymeric films which have been stretched by the inflated bubble technique, liquid can be entrapped between the collapsed bubble walls and can migrate to an interior layer of the laminate to treat same when the layer adjacent to the entrapped liquid is liquid permeable. For example, in a polyethylene/nylon/ethylene vinyl acetate/entrapped water/ethylene vinyl acetate/nylon/polyethylene laminated film the entrapped water will diffuse through the ethylene vinyl acetate layers to keep the nylon layers plasticized and impact resisitant.

Abstract: A film of ethylene vinyl acetate having a narrow molecular weight distribution and a saran composition that is a blend of emulsion and suspension polymerized saran or a saran composition that includes emulsion polymerized saran of the type generally considered suitable for liquid coating. A laminate including the film and composition and the method for production thereof including sequentially melt extruding tubular films of ethylene vinyl acetate which is irradiated, saran and ethylene vinyl acetate and then bubble orienting the three-ply laminate. The laminate is employed for packaging and forming packages of bone-in fresh red meat.

Abstract: The invention disclosed is directed to a new improved apparatus for vacuum skin packaging an article between two flexible web layers. The apparatus includes two molds, each having an inner wall defining a generally concave open cavity and terminating to a lip about the cavity opening, means for receiving and releasing web layers in wall-conforming shape, means for releasably receiving outer portions of the web layers adjacent the lips, means for registering the molds to provide a partially enclosed third cavity, and means for reducing pressure substantially throughout the third cavity by removing gaseous composition therefrom through a passageway means provided by portions of the lips which are spaced apart when the molds are in packaging register. Also disclosed is a process for vacuum skin packaging. If desired, the process may be performed using the apparatus.

Abstract: The invention disclosed is directed to a packaging assembly including a body having an open channel for supporting a trough-shaped web having a product disposed therein; a cover cooperable with the body and the web to form a substantially air-tight chamber about the product, at least one of the body and the cover having a hole for aid in vacuumizing the chamber; means for moving the body and cover into and out of chamber-forming relation; and means operable within the chamber for sealing the web to form a sealed web package containing the product. A process for packaging is also disclosed.

Abstract: An apparatus and process for laminating a flexible sheet of covering material to a foamed thermoplastic sheet wherein the process includes the steps of expanding aged or directly extruded thermoplastic foam sheet by heat until the foam has reached its softening point; heating the covering material to above the melting point of the foam; and, applying the heated covering material to the softened foam sheet to bond the sheet to the foam thereby forming a laminated product.