Showing papers on "Plastomer published in 2004"

Toothed belt for use with oil and relative timing control system

Abstract: Toothed belt (1) for use with oil comprising a body and a plurality of teeth (4) extending from at least a surface of the body; the teeth are covered by a coating fabric (5). The toothed belt comprises a plurality of resistant inserts (3) produced from at least a first and a second material. Preferably, the resistant inserts are constituted by glass fibres and carbon fibres. Preferably, a resistant layer (8) is made to adhere over the coating fabric (5), said layer comprising a fluorine based plastomer with the addition of an elastomeric material, wherein the plastomer is present in a greater amount than the elastomeric material. The elastomeric material forming the body of the belt is preferably a copolymer obtained from a diene monomer and a monomer containing nitrile groups, wherein the nitrile groups are between 33% and 49%, preferably 39 weight % with respect to the copolymer.

Thermoplastic olefin compositions and injection molded articles made thereof

Abstract: A thermoplastic polymer composition that exhibits substantially isotropic post injection molding shrinkage. The thermoplastic polymer composition includes a blend of highly crystalline polypropylene homopolymer, an ethylene-C4-8 α-olefin plastomer and talc having a D50 of about 2.0 µm or less. The thermoplastic polymer composition exhibits post injection molding shrinkage, low temperature impact strength and tensile strength that is similar to or better than relatively expensive engineering resins and blends. The thermoplastic polymer composition according to the invention is particularly useful for forming injection molded parts for motor vehicles.

Rotational molding of polypropylene/ultra‐low‐density ethylene‐α‐olefin copolymer blends

Abstract: This work investigates the performance of blends in rotational molding, by using an industrially relevant system consisting of polypropylene (PP) and an ultra-low-density ethylene-α-olefin copolymer (or polyolefin plastomer, POP). Specifically, the effect of POP content and PP type on the sintering and densification behavior, as well as the rotomolded part properties and morphology, was examined. The sinter-melting curves of these blends exhibited bimodality, due to the wide melting point difference between the two polymers. Increasing POP content resulted in higher sintering and densification rates, as well as improved impact properties and elongation at break, counteracted by lower stiffness. Selection of a polypropylene component with lower viscosity led to better sintering and densification characteristics, due to enhanced flow properties. Better overall performance in terms of mechanical properties was obtained when polypropylene/polyethylene impact copolymers, as opposed to a PP homopolymer, were used. Polym. Eng. Sci. 44:1662–1669, 2004. © 2004 Society of Plastics Engineers.

Seals comprising at least one flexible lip designed to be in contact with a sliding window of an automobile

Abstract: This seal comprises at least one flexible lip ( 3 ) designed to be in contact with the sliding window ( 4 ) of an automobile via a surface coated with a film ( 5 ) of a hard material with a low friction coefficient, characterized in that a layer of a cellular plastomer or cellular elastomer is inserted between the lip and the hard material with a low friction coefficient so as to separate them virtually completely.

A toothed belt

Abstract: Described herein is a toothed belt (1) comprising a body (2) made of elastomeric material, in which there is embedded a plurality of longitudinal filiform resistant inserts or cords (3), and a toothing (4) coated with a coating fabric (5); on top of the coating fabric (5) there is made to adhere a resistant layer (8), which increases resistance to wear of the toothed belt and comprises a fluorine-based plastomer with addition of elastomeric material, in which the plastomer is present in a larger amount than is the elastomeric material and in which the majority of the particles constituting the fluorine-based plastomer have a size less than 10 µm. The resistant layer (8) is applied directly on the fabric (5) via spreading. The fluorinated plastomer preferably has a base of polytetrafluoroethylene compound.

Rheological analysis of bitumens by dynamic shear rheometer: effect of the thermal history on the results

Abstract: In order to prevent binder-related pavement failures, it is very important to be able to characterize the performances of bituminous binders that play an essential role in the construction and reinforcement of pavements. However, because of its specific and complex composition, bitumen is a visco-elastic material whose intrinsic rheological properties depend upon the temperature and the loading time. One way to characterize this particular behaviour is to measure the response of the material under dynamic loading conditions, for instance in shear mode. The visco-elastic nature at high and intermediate pavement temperatures can then be described by Dynamic Oscillatory Shear Rheometer (DSR) measurements. But, the applicability of the preparation of test samples usually carried out on neat bitumens is now questioned when analyzing, in particular, modified binders: test standardisation becomes more and more necessary with a wide agreement on the required specifications. This paper points out the effect of the test sample preparation on the rheological results obtained by DSR measurements. In this study, two different sample preparations were used to explore the thermal effect: loading the binder into moulds, 24 hours prior to testing in the rheometer, or loading of the sample directly into the plates gap. In order to cover a variety of sampling procedures, a 70/100 penetration grade bitumen was chosen and two Polymer modified Bitumens were manufactured by adding 3% of saturated plastomer (Ethylene/Vinyl Acetate) or 3% of unsaturated elastomer (Styrene/Butadiene/Styrene) to this base bitumen. These three binders were then tested before and after ageing. Moreover, the effect of temperature rising up or going down during testing in the rheometer was determined on a 6% saturated plastomer modified bitumen. Because of this high degree of modification (phase inversion), the temperature effect was exalted. This effect was then studied against both sample preparations previously analysed. In conclusion, the determination of the complex modulus and the phase angle using a Dynamic Shear Rheometer appears to be sensitive to the sample preparation and especially to the thermal history of the binders. Consequently, in order to make relative comparison between samples, it seems very important to have the same sample thermal history. This one appears to be more critical in the case of plastomer modified bitumen. For the covering abstract see ITRD E121480.

Improved adhesives for fluoropolymer films and structures containing same

Abstract: Adhesives useful for adhering fluoropolymers are provided. The adhesives are a blend of linear low density polyethylene, ethylene polymer plastomer, polyolefin elastomer and modified polyolefin having acid or acid derivative functionality. Composite fluoropolymer/adhesive structures are also provided.

Polypropylene film for use in cold seal cohesive applications

Abstract: A polyolefin multilayer film containing a polyolefinic core layer and a first polyolefin skin layer of a blend, wherein the first polyolefin skin layer does not contain a thermoplastic or natural rubber and provides a cold seal receptive surface for a cold seal adhesive is disclosed. The blend includes an ethylene propylene random copolymer at 50-90 wt. % of the skin layer and metallocene catalyzed plastomer at 10-50% wt. % of the skin layer, a metallocene catalyzed isotactic polypropylene polymer or a butene propylene copolymer that contains from 5 wt % to 22 wt % of butene.

Radiation shielding material for protective clothing, such as aprons or the like

Abstract: The invention relates to a lead-free radiation shielding material, for aprons or the like, wherein a radiation absorption material based on elements having an atomic number higher than 50 is integrated into an elastomer or a plastomer. The aim of the invention is to improve one such radiation shielding material such that it can be stretched to form a film, that the production thereof is technically possible and cost-effective, and that the lead equivalent characterising the absorption capacity remains constant over the energy range of the radiation between 40 kV and approximately 120 kV. To this end, the elastomer or plastomer of the radiation shielding material to be processed into a film, for radiation absorption, contains metallic bismuth or bismuth compounds as the only additive.

A toothed belt and manufucturing process

Abstract: Described herein is a toothed belt (1) comprising a body (2) made of elastomeric material, in which there is embedded a plurality of longitudinal filiform resistant inserts or cords (3), and a toothing (4) coated with a coating fabric (5); on top of the coating fabric (5) there is made to adhere a resistant layer (8), which increases resistance to wear of the toothed belt and comprises a fluorine-based plastomer with addition of elastomeric material, in which the plastomer is present in a larger amount than is the elastomeric material and in which the majority of the particles constituting the fluorine-based plastomer have a size less than 10 µm. The resistant layer (8) is applied directly on the fabric (5) via spreading. The fluorinated plastomer preferably has a base of polytetrafluoroethylene compound.