the German guideline DVS Part 11(1) are followed. (see Table 1 below). Process steps in butt welding according to DVS guidelines. Table 2. of the Technical Committee of the. German Welding Society – DVS. Page 2. DVS- Technical Codes and Bulletins .. DVS ()* Welding of. DVS-Technical codes and bulletins can be obtained from: DVS Media .. DVS ()* Welding of thermoplastics – Heated tool welding of pipes.
The heterophasic propylene copolymer has the following characteristics: The branching index g’ correlates with the amount of branches of a polymer.
This fact is visible on the kind of beads. Reference is made in this context to B.
PROCESS FOR BUTT WELDING OF POLYPROPYLENE – BOREALIS AG
Raised mechanical loads during or directly after the remove are allowed only after elongated cooling. 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.
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Such precontacting can also include a catalyst prepolymerization prior to feeding into the polymerization reactor proper. A parameter of the degree of branching is the branching index g’.
According to dvw embodiment, a catalyst to be used in the invention is disclosed in EP which discloses a method for preparing a procatalyst composition from magnesium dichloride, a titanium compound, a lower alcohol and an ester of phthalic acid containing at least five carbon atoms.
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 220711 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.
In such a procedure, the catalyst system used may be varied between stages but is preferably the same for all stages. 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 expression “multimodal” or “bimodal” used herein refers to the modality of the polymer, i. 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