The Dow Chemical Company

Dow Global Technolgoies LLC

Martin H Tusim

Kyung W Suh

Christopher P Christenson

Chung Poo Park

Martin C Cornell

Michael E Schaller

Vyacheslav D Grinshpun

Andrew R Brush

Jonathan D Park

Bharat Indu Chaudhary

Chung P Park

Ian MacMillan Ward

Johan A Thoen

Robert L Sammler

Kevin Louis Nichols

Brett M Birchmeier

Jin Zhao

Russell P Barry

Glen Peter Thompson

Timothy W Rhoads

Phil Caton-Rose

Philip D Coates

James T Grimes

Kevin R Hughes

An inventive solid state drawing die has shaping walls that define a shaping channel and that, in the course of solid state drawing, direct polymer composition along a drawing path. Each cross section of the drawing path (and, hence, polymer composition in the drawing path) is non-circular, substantially proportional to one another, contains a centroid that lies on a substantially straight line parallel to the drawing direction and all cross sectional dimensions are 1.5 millimeters or more.

Substantially proportional drawing die for polymer compositions

Prepare a foam structure that includes hollow coalesced foam strands and, optionally, solid coalesced foam strands using an extrusion die block equipped with apertures that promote forming the hollow strands and, optionally, the solid foam strands.

Hollow strandfoam and preparation thereof

The present invention relates to a foam, a process for preparing the foam and an article containing the foam. The foam contains a coupled propylene polymer and has a density in of from 9.6 to 801 kg/m and has either a foamability factor of more than 1.8 to less than 2.8 and an open cell content less than 20 percent, or a foamability factor of at least 2.8 and less than 15 and an open cell content of less than 50 percent. The process includes heating a coupled propylene polymer having a melt flow rate from 0.2 to 20 g/10 min and a melt strength of at least 39 cN to a molten state to produce a molten polymer material and mixing said molten polymer material with a blowing agent under conditions to produce a foamed material having a density in the range of from 9.6 to 801 kg/m .

Propylene polymer foams

A process for making a polymer foam sheet, which comprises (i) extruding through an annular extrusion die a foamable composition comprising at least one polypropylene polymer and at least one blowing agent, at a pressure, temperature, and extrusion rate sufficient to prevent foaming of the composition prior to exiting the die, under conditions sufficient to form a foam tube having a density of at least 16 kg/m,and no greater than 200 kg/m,, an open cell content of less than 70 percent, a circumference of at least 1 meter, and a foam thickness of at least 2 mm and no greater than 25 mm, wherein the blowing agent is used in an amount of from 0.2 to 4.5 moles per kg of polymer, (ii) allowing the foam to cool to a temperature below the melt temperature of the polypropylene, and (iii) cutting the tube of foam along its radius to form a foam sheet, wherein at least 70 percent by weight of the polymer in such sheet is a polypropylene having a melt strength in the range of from 25 to 60 cN when measured at 190&deg; C.

Method of forming a thermoformable polypropylene foam sheet

An energy absorbing article having a direction in which impact resistance is desired is formed of extruded thermoplastic foam exhibit anisotropic compressive strength. The extrusion direction of the thermoplastic foam is aligned substantially parallel with the direction in which impact resistance is desired to provide an energy absorbing article exhibiting a high ratio of compressive strength to weight.

Energy absorbing articles of extruded thermoplastic foams

A polymer blend foam having smooth skin and/or an open-cell content of at least 20 volume percent, a crosslinked gel content of no greater than 10 percent, a minimum cross-sectional area of at least 1000 mm.sup.2, and a density of no greater than 250 kg/m.sup.3. The blend includes (A) a substantially random interpolymer having polymerized therein (1) a vinyl or vinylidene aromatic monomer and/or a sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer, and (2) one or more of ethylene and a C.sub.3-20 aliphatic .alpha.-olefin; and (B) an olefin polymer based on one or more of ethylene, C.sub.3-20 aliphatic .alpha.-olefins, and C.sub.3-20 aliphatic .alpha.-olefins containing polar groups. The olefin polymer (B) lacks any of the vinyl or vinylidene aromatic monomers found in (A).

Olefin polymer and .alpha.-olefin/vinyl or .alpha.-olefin/vinylidene

Disclosed is an extruded, unitary, closed-cell olefin polymer foam structure in plank form. The foam structure has a cross-section of 2 or more inches in one dimension and 18 or more inches in the other dimension. The olefin polymer material has a melt index of about 3.5 grams/10 minutes or less. The foam structure contains a blowing agent of about 75 mole percent or more 1,1-difluoroethane based upon the total moles of blowing agent. Further disclosed is a process for making the foam structure at a shear rate of about 400/second or more. It was found surprising that 1,1-difluoroethane which has relatively low solubility in olefin polymers, could be used to make olefin polymer foam structures of large cross-section.

Process for making large cross-section olefinic polymer foam structure

Novel, expandable polymeric blends comprising at least one vinylaromatic monomer-acylonitrile resinous material, an effective amount of at least one blowing agent, and from about 0.2 to about 1.0 percent by weight, based on the weight of resinous material, of an expansion aid consisting essentially of triethylene glycol. The triethylene glycol expansion aid unexpectedly reduces the amount of expansion agent required to expand the composition, particularly to low density products, without adversely affecting the final properties of the foamed product.

Plasticizers for expandable styrene-acrylonitrile resin

The clumping together of expandable vinylaromatic-acrylonitrile copolymer particles during expansion of such particles is substantially completely reduced by coating the unexpanded virgin particles with from 0.2 to 1.5 weight percent, based on weight of expandable copolymer particles, of particulate magnesium oxide.

Anti-clumping agents for expandable vinylaromatic-acrylonitrile

Expandable and expanded particles are prepared from an alkenyl aromatic polymer and a volatile fluid blowing agent mixture of a first blowing agent of 1,1-difluoro-1-chloroethane; and a second blowing agent selected from normal pentane, isopentane, neopentane or mixtures of the various pentanes.

Expandable and expanded alkenyl aromatic polymer particles

The present invention relates to expandable and expanded alkenyl aromatic polymer particles having the ability to use a decreased amount of blowing agent to produce an expanded alkenyl aromatic polymer particle of an equivalent bulk density or the same amount of blowing agent to produce an expanded alkenyl aromatic polymer particle having a decreased bulk density by including a density modifier in the expandable alkenyl aromatic polymer particle in an amount of about 0.005 to 0.5 weight percent by weight of the total mixture. Also included as part of the invention are methods of making the expandable and expanded alkenyl aromatic polymer particles wherein the expandable and expanded alkenyl aromatic polymer particles have a density modifier included in an amount of about 0.005 percent to about 0.5 weight percent by weight of the total mixture.

Expandable and expanded alkenyl aromatic polymer particles and methods

A substantially rustle-free thermoplastic film and container made therefrom. The film may be a multilayer structure, a skin of which is formed of a chlorinated polyethylene resin blend. The composition of said structure is such that quietness is imparted without detracting from the extrudability and other physical characteristics necessary for practical applications. A vapor barrier may be included as a core layer. A particular application for the present invention is an ostomy bag.

Quiet film and container

An improved process for adding magnesium oxide to polymeric compositions based on vinylidene chloride copolymers. The improvement comprises forming a pre-mixture of the magnesium oxide and an ethylene-vinylalkanoate dispersing medium or agent and thereafter blending an amount of the pre-mixture with the vinylidene chloride copolymer composition.

Growing community of inventors

Midland, MI, United States of America

Martin H Tusim