A method of making multilayer foam sheet from recycled polyester sources, which may be used for packaging applications. The method comprises a co-extrusion system comprising at least two single screw extruders. A low I.V. polyester feedstock comprising up to 100% of the polyester flakes from recycled sources with an intrinsic viscosity (I.V.) of lower than 0.8 dL/g as measured by ASTM D4603-18 is directly being fed into the extruders. Supercritical physical blowing agent is introduced into the melted polyester feedstock in at least one of the extruders wherein the processing temperature is in the range of 15% lower than the melting temperature and 15% higher than the melting temperature. Then, coextruding the feedstock from the extruders of the co-extrusion system through a flat sheet die to make a multilayer foam sheet, wherein at least one layer is a foam layer comprising low I.V. polyester.

A die for extrusion molding includes an extrusion port configured to extrude a plastic composition, and a plastic flow channel configured to cause the supplied plastic composition to flow to the extrusion port. The plastic flow channel includes a supply flow channel, and an extrusion flow channel. The supply flow channel is configured to be supplied with the plastic composition. The extrusion flow channel has an upstream end coupled to the supply flow channel, and downstream end having the extrusion port. In the extrusion flow channel, a flow channel cross-sectional area perpendicular to the flow direction of the plastic composition in the extrusion flow channel gradually changes to the extrusion port, and an inner wall surface of a flow channel has a protruding surface protruding toward an inside of the flow channel in a cross section including an extrusion central axis and parallel to the extrusion central axis.

Embodiments of the present disclosure disclose a composite crystal flooring. The composite crystal flooring may have a multi-layer structure. The composite crystal flooring may include a substrate layer. The substrate layer may include at least a first structural layer, a second structural layer, and a third structural layer. The second structural layer may be located between the first structural layer and the third structural layer. A foaming density of the second structural layer may be less than 1.1 grams per cubic millimeter. Components of the second structural layer may include polyvinyl chloride, one or more inorganic fillers, at least one foaming agent, at least one foaming regulator, at least one lubricating agent, and at least one stabilizer. The one or more inorganic fillers may include modified fly ash, hollow glass microbeads, and composite calcium. The composite crystal flooring with a low density may have good thermal stability and rigidity.

A multilayer film having enhanced toughness and optical properties is provided. The multilayer film includes a base layer, an outer layer, and a tie layer between the base layer and the outer layer. The multilayer film can also include additional layers. Methods for making such multilayer films are also provided. Multilayer films according to the present invention are particularly useful packaging applications where rupture resistance and high clarity are desirable.

An extrusion molding die includes an extrusion outlet, a plastic flow channel, and a temperature adjusting channel. The extrusion outlet is configured to extrude a plastic composition including at least one kind of plastic. The plastic flow channel is configured to allow the supplied plastic composition to flow toward the extrusion outlet. The temperature adjusting channel is configured to allow a temperature adjusting medium to flow. The temperature adjusting channel includes three or more temperature adjusting channels arranged around the plastic flow channel. Each of the temperature adjusting channels is arranged at a position in ±10% of (360°/N) in a rotation direction about an extrusion center axis relative to an adjacent temperature adjusting channel, where a number of the temperature adjusting channels is N.

A staple cartridge assembly for use with a surgical stapling instrument includes a staple cartridge including a plurality of staples and a cartridge deck. The staple cartridge assembly also includes a compressible adjunct positionable against the cartridge deck, wherein the staples are deployable into tissue captured against the compressible adjunct, and wherein the compressible adjunct comprises a first biocompatible layer comprising a first portion, a second biocompatible layer comprising a second portion, and crossed spacer fibers extending between the first portion and the second portion.

Methods of forming polymeric foams are provided. The methods may involve co-extruding a foam layer along with one or more skin layers. In some embodiments, the skin layer(s) may be removed (e.g., in a peeling operation); while, in other embodiments, the skin layer(s) may form part of the final article. The methods are particularly well suited for producing polymeric foams from polymeric materials that are considered to be difficult to foam by those of skill in the art.

A preparation method of a high-rate foamed polylactic acid (PLA) sheet includes first-stage extrusion, second-stage extrusion, and foamed sheet extrusion. The method requires the following raw materials in parts by mass: 88 to 94 parts of PLA, 1 to 2 parts of a nucleating agent, 2 to 5 parts of a foaming agent, and 2 to 5 parts of an additive. The new method effectively solves the problems of low foaming rate, low strength, and the like in the industrial production using carbon dioxide, and a prepared PLA sheet with high foaming rate and excellent surface performance can be used in the fields of food packaging, disposable fully-degradable lunch boxes, and the like.

A method for directly preparing a foamed polylactic acid (PLA) product from a PLA melt includes PLA melt preparation, feeding, and two-stage extrusion. In the two-stage extrusion, a pressure at an outlet of a first-stage twin-screw extruder is 15 MPa to 17 MPa, a PLA melt is fed at a rate of 250 kg/h, a foaming additive is fed at a rate of 7.5 kg/h to 10 kg/h, and a foaming gas is fed at a rate of 2.8 L/h to 7.5 L/h. The method can ensure both foamability and quality of a material and reduce more than ⅓ of energy consumption; and an obtained product has an adjustable foaming rate of 3 to 25, a crystallinity of 40.3% to 48.5%, a tensile strength of 8.7 MPa to 19.6 MPa, and an apparent density of 0.05 g/cm.sup.3 to 0.4 g/cm.sup.3.

Described herein is a method for producing an intrinsically foamed polyamide and a shaped article including the intrinsically foamed polyamide.