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.
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It is also appreciated that according to the present invention, the polypropylene pipes consist of a polypropylene composition comprising a heterophasic propylene copolymer consisting of.
In the following a preferred process is described in more detail: When the distribution curves from these fractions are superimposed to obtain the molecular weight distribution curve of the final polymer, these dva may show two or more maxima or at least be distinctly broadened when compared with curves dfs the individual fractions.
Recommended values for the heated tool butt welding of pipes, fittings and sheets out of PP, at an outside temperature of approximately 20″C and moderate air flow Interim values have to be Interpolated. Construction materials and building All the remaining parameters and process settings as specified in DVS Thus, as the ester may be used e.
According to EN According to the invention, the total MFR of the polypropylene composition is from 0. As described above, after the polymerisation of the heterophasic propylene copolymer the rvs with additives and optional alpha-nucleating agent follows.
MFR The melt flow rates were measured with a load of 2. According to EPa trans-esterification reaction is carried out at an elevated temperature 2270-11 the lower alcohol and the phthalic acid ester, whereby the ester groups from the lower alcohol and the phthalic ester xvs places. Such Ziegler-Natta catalyst systems are known in the art and comprise a catalyst component, a cocatalyst component and an external donor.
Accordingly the heterophasic propylene copolymer of the instant invention can be typically produced in a cascade of up to 4 reactors, where the first reactor is a liquid bulk reactor preferably of loop design, the second reactor is either a liquid bulk reactor preferably of loop design or a gas phase reactor and all subsequent reactors are gas phase reactors preferably of fluidized bed design. As a consequence, each fraction prepared 220-711 a specific reactor can have its own molecular weight distribution.
PROCESS FOR BUTT WELDING OF POLYPROPYLENE – BOREALIS AG
Asakura, Polymer 29 Process according to any one of the dsv claims, characterised in that the propylene homopolymer A has an isotacticity measured as concentration of [mmmm] pentads of. The catalyst preferably contains a transition metal compound as a procatalyst component.
The bead size shows the regularity of the weldings. 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. The joining pressure is 0. As catalyst a commercially available Ziegler-Natta dvz which was prepolymerised with poly-vinylcyclohexane was used together with dicyclopentyl dimethoxy silane DCPDMS as external donor and triethylaluminium as cocatalyst.
Process according to claim 8, wherein the pipes to be dbs have a wall thickness of 10 mm and the heating-up time is from 70 – s.
The XCS content of dvd heterophasic copolymer is related to the amount of ethylene-propylene rubber, bit it is not necessarily exactly the same. Mining and minerals Sometimes, the “heating-up time” is also just called “heating time”.
Chinacridon pigments or earth-alkali metal salts of dicarboxylic acids, e. According to the invention, such catalysts are typically introduced into the first reactor only. A process of forming a weld between abutting ends of two polypropylene pipes to be joined, which comprises.
A lower limit of 0. Thus the heterophasic propylene copolymer is not cross-linked. Of the phosphorous svs nucleating agents sodium-2,2 ‘ -methylene-bis 4,6-di-t- butylphenyl phosphate or hydroxy-bis[2,4,8,tetrakis 1 ,1-dimethylethyl hydroxyH- dibenzo-[d,g]-dioxa-phoshocinoxidato] aluminium or blends thereof with Li-myristate or Li- stearate are especially preferred.
In a particular preferred embodiment the polypropylene homopolymer is produced in at least one slurry reactor or a slurry and a gas phase reactor and subsequently the rvs rubber is produced in at least one gas phase reactor. Such precontacting can also include a catalyst prepolymerization prior to feeding into the polymerization reactor proper. The welding joint quality would be influenced negatively.
Click for automatic bibliography generation. Fillers further include glass powder, glass beads, fly ash powder, asbestos powder. MFR A of homopolymer matrix 0. vvs
Magnesium dichloride can be cvs as such or it can be combined with silica, e. A second group of phosphorous based nucleating agents which may be used fort he present invention includes for example hydroxy-bis[2,4,8,tetrakis 1 ,1-dimethylethyl hydroxy- 12H-dibenzo-[d,g]-dioxa-phoshocinoxidato] aluminium CAS and blends thereof with Li-myristate or Li-stearate. A SumoBrain Solutions Company. For heating, the joining areas must contact the heated tool with low pressure.
Paint and colour industries