Melabar Accordingly it is appreciated that the polypropylene homopolymer has a rather high isotacticity, measured as pentad concentration [mmmm], i. The conventional Ziegler-Natta catalysts for isotactic polymerization of propylene generally have an operating temperature limit of around 80 0 C, above which they either become deactivated or lose their stereo-selectivity. For those embodiments where the alpha-nucleating agent is not a polymeric nucleating agent, the nucleating agent is typically present in the polypropylene composition in an amount of from 0. Process according to claim 8, wherein the pipes to be joined have a wall thickness of 10 mm and the heating-up time is from 70 — s. The content of XCS of the heterophasic propylene copolymer correlates closely with the amount of ethylene-propylene rubber.
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This fact is visible on the kind of beads. Reference is made in this context to B. Preferably the total MFR of the polypropylene composition is from 0. Materials handling equipment The residence time must be chosen such that a sufficiently high degree of homogenisation is achieved.
Preferably the polypropylene composition comprises 0. ZN from Basell, may be used for producing the heterophasic propylene polymers of the invention.
The components of the catalyst can be fed into the reactor separately or simultaneously or the components of the catalyst system can be precontacted prior to the reactor. You have no items in your shopping cart. DVS Such precontacting can also include a catalyst prepolymerization prior to feeding into the polymerization reactor proper.
Their use is disadvantageous in the present invention, because of cost reasons. Also other transition metal compounds, such as vanadium, zirconium, chromium, molybdenum and tungsten compounds can be mixed with the titanium compound. A number of welding techniques is used, including heated tool butt welding also called butt weldingelectro fusion welding, heated tool socket welding, extrusion welding, hot gas welding.
A still further group of suitable nucleating agents includes resin acids also called rosin acids and esters and metal salts of resin acids, in particular sodium, calcium and magnesium salts. Talc concentrations up to 1. Good processability must be ensured, while maintaining all other desired properties. Heating times are mentioned in table 2, column 3.
The heated tool should be withdrawn in such a way that the heated joining areas are neither damaged nor contaminated. Process according to any one of the preceding claims, characterised in that the polypropylene pipes consist of a polypropylene composition comprising a heterophasic propylene copolymer consisting of. The melting enthalpy H m of the cvs propylene copolymer correlates with the crystallinity of the heterophasic propylene copolymer.
Flexural Modulus of the composition is MPa. An important parameter which is used to ensure that the good impact properties of the polypropylene composition is the intrinsic viscosity IV of the XCS content of the heterophasic propylene copolymer. Process according to claim 8, wherein the pipes to be joined have a wall thickness of 10 mm and the heating-up time is from 70 — s. Chinacridon pigments or earth-alkali metal salts of dicarboxylic acids, e. Ziegler-Natta catalysts, which are commercially available, e.
Magnesium dichloride can be used as such or it can be combined with silica, e. The composition was compounded in a twin screw extruder at a temperature of 0 C.
The strands were quenched in cold water and pelletised. The novel welding process is in part performed according to DVS Description of heterophasic propylene copolymer A heterophasic propylene copolymer according to the invention has preferably a multiphase structure with a continuous propylene homopolymer matrix and inclusions of ethylene- propylene rubber comprising at least an amorphous elastomeric phase. Further in case the polypropylene homopolymer is of multimodal, like bimodal, in view of the molecular weight, it is appreciated that the individual fractions are present in amounts influencing the properties of the material.
Our offices will be closed from December 24, to January 2, inclusive. The titanium compound used in the preparation of the procatalyst is preferably an organic or inorganic titanium compound, which is at the oxidation state of 3 or 4. Aircraft and space vehicle engineering Related Posts
DVS 2207-11 PDF
Kisar This fact is visible on the kind of beads. Preferably the total MFR of the polypropylene composition is from 0. Search Expert Search Quick Search. Petroleum and related technologies Alert me in case of modifications on this product contact us.
Standard DVS 2207 1 for Butt Fusion Welding
Arashidal In the following a preferred process is described in more detail: This low polymerization temperature may put a practical limit on the heat removal efficiency of the loop reactor. Two pipe sections at a time were heated tool butt welded according to DVS 1: A heterophasic propylene copolymer were produced in a two step process. One of the most widely implemented pipes in sewerage applications have a nominal wall thickness of 10 mm. Also other transition metal compounds, such as vanadium, zirconium, chromium, molybdenum and tungsten compounds can be mixed with vds titanium compound. Magnesium dichloride can be used as such or it can be combined with silica, e.