Abstract: The invention relates to a sandwich panel comprising A. a core layer of polypropylene particle foam, B. cover layers of fiber-reinforced polypropylene and also optionally C. decorative layers, wherein the core layer includes from 1 to 30% by weight of recyclate particles of components A, B and optionally C.

Abstract: The invention relates to expanded polypropylene beads having a density of from 5 to 200 g/l and a bead diameter of from 1 to 10 mm which comprise from 0.002 to 20% by weight of graphite particles.

Abstract: The invention relates to sound-absorbent foam moldings which have a sound-absorption level according to DIN 52215 of from 30 to 95% in the frequency range from 0.5 to 4 kHz. The foam is an incompletely fused molded polyolefin or polystyrene foam with from 10 to 40% interstitial volume.

Abstract: The invention relates to expandable styrene polymers for elastic polystyrene foams, comprisinga) from 75 to 98% by weight of polystyrene and/or a styrene copolymer containing at least 50% by weight of copolymerized styrene,b) from 2 to 25% by weight of at least one styrene-soluble elastomer,c) from 1 to 15% by weight, based on the sum of a) and b), of a low-boiling blowing agent, and, if desired,d) conventional additives in effective amounts,where the unfoamed beads have a structure in which the elastomer phase is dispersed in the polystyrene phase in the form of cell particles, and to foams and foam moldings produced therefrom.

Abstract: Moldings made from polyolefin particle foams having a mean density of from 0.015 to 0.100 g/cm.sup.3 and having at least two different regions whose densities differ by from 0.005 to 0.030 g/cm.sup.3 have a transition zone between the different density regions having a thickness of not more than 25 mm. A method of forming the moldings, using removable mold dividing walls, is described.

Abstract: A shock-absorbing propylene polymer composite molding containsa. a layer with a thickness of from 0.5 to 10 mm which contains a propylene polymer having a melting point of from 130.degree. to 165.degree. C.,b. an intermediate layer with a thickness of from 0.05 to 0.5 mm comprising a hot-melt adhesive based on an olefin copolymer having a melting point of from 90.degree. to 140.degree. C.,c. a foam layer with a thickness of from 3 to 200 mm and a density of from 0.015 to 0.1 g/cm.sup.3 based on a propylene copolymer having a melting point of from 125.degree. to 155.degree. C.,d. an intermediate layer with a thickness of from 0.05 to 0.5 mm comprising a hot-melt adhesive based on an olefin copolymer having a melting point of from 90.degree. to 140.degree. C.,e. a layer with a thickness of from 0.5 to 10 mm which contains a propylene polymer having a melting point of from 130.degree. to 165.degree. C.

Abstract: Moldings made from polyolefin particle foams having a mean density of from 0.015 to 0.100 g/cm.sup.3 and having at least two different regions whose densities differ by from 0.005 to 0.030 g/cm.sup.3 have a transition zone between the different density regions having a thickness of not more than 25 mm.

Abstract: Novel foams having a density of from 0.01 to 0.1 g/cm.sup.3, based on a copolymer comprising ethylene, propylene and a C.sub.4 - to C.sub.8 -.alpha.-olefin, and having a torsion modulus of from 100 to 800 N/mm.sup.2 have high tensile, compressive and flexural strengths and at the same time high elongation at break.

Abstract: Foam particles of propylene polymers which have shrunk from 40 to 95% of their original volume and have a bulk density of from 10 to 30 g/1 can be expanded if they are treated with air or nitrogen under superatmospheric pressure, subsequently decompressed. If desired post-foamed by heating and, after aging, re-treated with air or nitrogen under superatmospheric pressure, subsequently decompressed and aged under atmospheric pressure until the pressure in the cells has dissipated.

Abstract: Foams having high compressive strength are obtained by extrusion of a mixture of a styrene polymer and from 3 to 9% by weight of a blowing agent consisting of from 80 to 100% by weight of CO.sub.2 and from 0 to 20% by weight of one or more halohydrocarbons or hydrocarbons which are gaseous at room temperature, the mixture being extruded into a zone under from 0.1 to 2 bar gage pressure and the foam being allowed to stabilize under this pressure.

Abstract: Polyolefin foams which have a density of from 30 to 300 g/l, do not exhibit after-shrinkage and possess taut cells are prepared by letting down a polyolefin/blowing agent gel, the latter first being let down to 0.1-10 bar gage pressure and the foam being kept at this pressure until it has cooled to at least 20.degree. C. below the expansion temperature.

Abstract: Shaped articles are produced by heating and compressing particles of foamed olefin polymer containing crosslinked portions in molds, the pressure being reduced during compression in the mold.

Abstract: Foam moldings of olefin polymers are prepared by heating, and pressing together, foamed particles of an olefin polymer, containing crosslinked constituents, in molds, a temperature gradient of from 0.5.degree. to 25.degree. C per cm of loose mass of particles being established in the mold, which has a gas-permeable wall on the lower-temperature side.