DVS 2207-11 PDF
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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A process of forming a weld between abutting ends of two polypropylene pipes to be joined, which comprises. The changeover time should be as short as possible see table 2, column 4as otherwise the plastified areas will cool down. A SumoBrain Solutions Company. It is therefore the object of the present invention to provide a process for heated tool butt welding of polypropylene pipes, having an improved stability of the weldings. According to an 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.
During heating, the heat penetrates the joining areas and the welding temperature is reached. The joining pressure is 0. According dvvs a specific embodiment, only three reactors are utilized with either two reactors producing homopolymer and the third reactor producing ethylene-propylene rubber or with one reactor producing homopolymer and two subsequent reactors producing ethylene-propylene rubber.
In heated tool butt welding the welding areas are heated to the welding temperature by means of the heated tool and joined under pressure after removal of the heated tool. The pentad analysis the assignment dfs done according to the methods described in literature: Mining and minerals Nucleation vvs these polymeric nucleating agents is either accomplished by a special reactor technique, where the catalyst is prepolymerised dvss monomers like e.
Surprisingly, the object of the present invention could be achieved with a process as described, where some of the used process parameters are significantly different from the specifications of DVS Shipping Delivery Order tracking Returns.
With the exception of the heated tool temperature, the heating-up time and the joining pressure build-up time the parameters as specified in DVS 1: In the first step a propylene homopolymer A matrix phase was polymerised in liquid propylene and in the second stage an ethylene-propylene rubber B disperse phase was polymerised in a gas phase reactor.
The strands were quenched in cold water and pelletised. Compounding The heterophasic propylene copolymer, additives and optional alpha-nucleating agent can be mixed, in particular melt blended, according to any conventional procedure dvw in the art.
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Flexural Modulus of the composition is MPa. Good processability must be ensured, while maintaining all other desired properties.
R and R’ can be the same or different and represent a linear, branched or cyclic aliphatic, or aromatic group. Aircraft and space vehicle engineering 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.
PROCESS FOR BUTT WELDING OF POLYPROPYLENE – BOREALIS AG
The transition metal compound is selected from the group consisting of titanium compounds having an oxidation degree of 3 or 4, vanadium compounds, zirconium compounds, cobalt compounds, nickel compounds, tungsten compounds and rare earth metal compounds, titanium trichloride and titanium tetrachloride being particularly preferred.
The ethylene-propylene rubber may be blended with the rvs homopolymer after their polymerizations, and are subsequently mixed with any additives and optional alpha-nucleating agent. Suitable alpha-nucleating agents for the polypropylene ds of the invention are also those alpha-nucleating agents, as described in Macromolecules38,the disclosure of which is incorporated herein by reference.
Xylene solubles are defined as the dsv by weight that 2270-11 in solution after the polymer sample is dissolved in hot xylene and the solution is allowed to cool to 23 0 C. Examples The following materials were used: The demanded joining pressure is built possibly linear.
It is preferred to carry out the transesterification at a temperature which is to 0 C, preferably to 0 C. The polypropylene compositions of the present invention are preferably produced by combining the heterophasic propylene copolymer and optional alpha-nucleating agents and any additives, like pigments, stabilisers, processing aids, etc.
This object could be achieved with a process of forming a weld between abutting ends of two polypropylene pipes to be joined, which comprises. Heated tool butt welding is one of the most widely used techniques. Accordingly the heterophasic propylene copolymer of the instant invention can be typically produced in a cascade of up to 207-11 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.
Such a polymer, produced in two or more serial steps, is called bimodal or multimodal, depending on the number of steps.
The alignment is finished when the bead heights have reached the mentioned values in table 2, column 2 on the total pipe circumference resp. In the prepolymerization, the catalyst components are contacted for a short period with a monomer before feeding to the reactor. The catalyst preferably contains a transition metal compound as a procatalyst component. For the present invention this would reduce the stiffness of the heterophasic propylene copolymers and is therefore not favourable. This 2207-1 content is adjusted by the ratio between propylene homopolymer and ethylene- propylene rubber and by the ethylene content of the ethylene-propylene rubber.