73results about How to "Shorten plasticizing time" patented technology

The invention relates to the technical field of vinyl chloride resin, in particular to a preparation method of high-impact polyacrylate grafting vinyl chloride emulsion copolymer resin. A single emulsifier and a single initiator are adopted by the original synthesis process, and tests proof that the single emulsifier can enable polymer latex not to be stable, and therefore, a stable polymerization product can not be obtained; the single initiator enables a polymerization system not to be stable, and reaction is difficult to control; freezing demulsification, filtering, washing, drying and thelike are adopted as treatment processes of a vinyl chloride grafting copolymer emulsion to form a thick and big aggregated particle structure, and the product performance is low; moreover, much wastewater and many waste residues are generated in the process. In the invention, the stability of the latex is ensured by adopting a compound emulsifier and a compound initiator, which ensures that the latex has better average particle diameter, the polymerization system is stable and the reaction is easy to control; centrifugal spray drying is adopted to treat emulsion resin, and thereby, a good resin product with even particle size distribution and good processing performance can be obtained; and the wastewater and the waste residues are not generated, the process flow is short and the energy can be saved and the consumption can be lowered.

The invention relates to a method for operating an injection-moulding machine, having at least one plasticization device (2, 3) with at least one plasticization screw (3) which can be driven in rotation about a screw longitudinal axis (5) and so as to be movable in translation along the screw longitudinal axis (5), wherein, by way of the plasticization device (2, 3), a plastics melt (14) for injection into a mould cavity is provided in a screw antechamber (9), wherein, for the injection of the plastics melt (14) into the mould cavity, that is to say at least during an injection phase and during a follow-up pressure phase, the plasticization screw (3) is driven both in translation and in rotation by way of at least one drive device, wherein the driving of the plasticization screw (3) in rotation is performed with a rotational speed (nscr) such that a backflow (mdruck) of the melt from the screw antechamber (9) back into screw flights (71) of the plasticization screw (3) owing to a translational injection movement of the plasticization screw (3) has superposed on it an opposing delivery flow (mschlepp) effected by way of the rotation of the plasticization screw (3), wherein a flow difference (m[delta]) between backflow (mdruck) and opposing delivery flow (mschlepp) arises, and the flow difference (m[delta]) is, at least during the injection phase, influenced by influencing of therotational speed (nscr) of the plasticization screw (3), and the method is performed without using a backflow preventer.