Abstract: Injection-moulded refrigerator liners of a thermoplastic polymer characterized by the presence of means for mechanical bonding on the insulating foam.

Abstract: Polymers and copolymers of propylene are modified by grafting with polyalkenylenes having a trans double bond content of higher than 30%. The preparation is carried out via thermic treatment of the propylene (co)polymer with said polyalkenylene at a temperature comprised between 200.degree. and 350.degree. C. an the presence of a free radical initiator other than peroxide.

Abstract: A process is presented for fabricating composite bodies of thermoplastic material including a foamed core bonded to a compatible thermoplastic sheet. A sheet of thermoplastic material is first preheated and then thermoformed on a first half-mould. The first half-mould with the thermoformed sheet is positioned opposite a second half-mould to form a hollow chamber therebetween. A foamable thermoplastic material containing one or more liquid hydrocarbons is injected into the hollow space at a temperature sufficiently high to permit the foamable material to expand and bond to the thermoformed sheet.

Abstract: A process for producing bodies of polymeric material having an outer shell and a core of foamed material is disclosed. The process includes the steps of: providing a mold having a pair of separable half-molds arranged facing each other; extruding a tubular thermoplastic parison between the half-molds; closing the half-molds around the parison, thereby defining a hollow space between the parison and walls of the mold; injecting into the inside of the parison a thermoplastic polymeric material admixed with a physical blowing agent, the parison expanding into contact with the walls of the mold, and conforming to the shape of the mold; and removing the article form the mold.

Abstract: Crystalline propylene (co)polymers modified by grafting with a vinylpolybutadiene having 1,2-structure content of at least 10%.Said (co)polymers are reacted with a liquid vinylpolybutadiene in the presence of a non-peroxidic radical initiator at a temperature in the range 200.degree. to 350.degree. C., the liquid vinylpolybutadiene having a 1.2-structure content of at least 10% and being generally used in amounts within the range 0,5 to 20% by weight.

Abstract: Crystalline propylene (co)polymers modified by grafting with a vinylpolybutadiene having 1,2-structure content of at least l0%.The (co)polymers are reacted with a liquid vinylpolybutadiene in the presence of a non-peroxidic radical initiator at a temperature in the range 200.degree. to 350.degree. C., the liquid vinylpolybutadiene having a 1,2-structure content of at least 10% and being generally used in amounts within the range 0.5 to 20% by weight.

Abstract: An apparatus for injection molding of non-precatalyzed resins. Catalyst and resin flows are injected into a mixing chamber through a pair of catalyst injection nozzles and a pair of resin injection nozzles, each angled toward the ejectment end of the mixing chamber. The resin injection nozzles are located closer to the ejectment end of the mixing chamber than the catalyst injection nozzles. The injection nozzles are arranged substantially 90.degree. from one another with the resin injection nozzles opposed from each other and the catalyst injection nozzles opposed from each other.

Abstract: Multilayer and multifunctional packaging elements having a high-absorption activity toward aqueous liquid substances as well as barrier properties toward gases such as oxygen and carbon dioxide are prepared by thermoforming.The packaging elements includes an inner porous layer, an intermediate absorbing layer and an outer sheet having high barrier properties toward gases. The intermediate layer may contain anti-bacterial agents.

Abstract: A device for moulding articles of composite material includes a pressurizable gasket and an injection head the end of which is flush with the impression of the mould. After low-pressure filling the mould impression with jets of resin and catalyst so oriented as to secure the mutual mixing thereof, the pressurizable gasket allows the half-moulds to be further approached to each other and obtaining thereby the impregnation of the reinforcer element previously charged into the mould impression.

Abstract: Polymers and copolymers of propylene are modified by grafting with polyalkenylenes having a trans double bond content of higher than 30%. The preparation is carried out via thermic treatment of the propylene (co)polymer with said polyalkenylene at a temperature comprised between 200.degree. and 350.degree. C. an the presence of a free radical initiator other than peroxide.

Abstract: A folding case of polymeric material comprises two equal elements which can be coupled in a rapid way. Each element comprises a side wall of the case articulated, by means of film hinges, to a base panel and to two side panels suitable for defining, respectively, a half portion of the bottom wall and half portions of side folding walls of the case.

Abstract: An improved method for injection molding of non-precatalyzed resins in which the catalyst and resin flows are injected in a mixing chamber co-current with one another angled toward the ejectment end of the mixing chamber, The resin flow is injected closer to the ejectment end of the mixing chamber than is the catalyst flow.

Abstract: A module for removing polluting agents from the surface of the sea consists of absorbent polyolefinic fibres enclosed inside a permeable sheath having a short-length bundle configuration with a star-like or lenticular cross-section. After absorbing oily substances, the cross-section of the module becomes polygonal or circular.

Abstract: A process for preparing thermoinsulating and/or structural double-walled molded bodies, which comprises the following steps:(a) heating two sheets made of thermoplastic polymer to a temperature equal or slightly higher than their softening point;(b) inserting between the two sheets a pre-mold made of an expanded polymeric material;(c) thermoforming in a mold the two sheets on the pre-mold;(d) soldering together the two sheets on their rims by means of a pressure applied on them by the mold.

Abstract: an apparatus for producing bodies of polymeric material having an outer shell and a core of foamed material is disclosed. The apparatus includes an extruder and accumulation chamber for extruding a tubular element, i.e., a parison, and a second extruder and accumulation chamber for injecting a foamable polymeric material for forming the core of the body inside the parison. The injection occurs inside the walls of a mold, which causes the tubular parison to undergo swelling due to the expansion of the foamable material until the parison conforms to the shape of the mold.

Abstract: A die for co-extruding structural shapes is provided with a central cylindrical duct through which the molten polymeric material destined to constitute the central core of the structural shape flows, and a conical gap, coaxial with the central duct, into which the polymeric coating material is fed which will constitute the outer skin of the structural shape.

Abstract: A process for fabricating manufactured articles from fiberglass reinforced thermoplastic sheets, which consists of forming said plates while they are heated at their melting point and coupled with a barrier film, by either blow-moulding or thermoforming.

Abstract: A process for preparing thermoinsulating and/or structural double-walled molded bodies, which includes the following steps:(a) heating two sheets made of thermoplastic polymer to a temperature equal or slightly higher than their softening point;(b) inserting between the two sheets a pre-mold made of an expanded polymeric material;(c) thermoforming in a mold the two sheets on the pre-mold;(d) soldering together the two sheets on their rims by means of a pressure applied on them by the mold.

Abstract: A process for preparing thermoinsulating and structural formal articles in which(a) a thermoplastic polymer sheet is heated at a temperature above its softening point;(b) the heated thermoplastic polymer sheet is thermoformed on a thermoinsulating foamed preform made of substantially the same polymeric material; and in which(c) prior to the thermoforming in step (b), the thermoinsulating foamed preform is cooled to prevent excessive collapse of the surface of the thermoinsulating foamed preform resulting from contact with the heated sheet.

Abstract: Blow molding and thermoforming processes in which a mold system having low thermal inertia mold-halves provided with heating and cooling systems is utilized for producing plastic articles coated with surface-upgrading films of high melting polymers or polymers exhibiting a high scratch resistance to improve mechanical characteristics of the molded article. The films may be positioned, before the mold is closed, close to the low thermal inertia mold-halves. Rapid heating and rapid cooling of the mold-halves in contact with the surface-upgraded films permit strength adhesion of the upgrading material to the surface of the molded article.