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

The invention provides polyvinyl alcohol, which is characterized by having the average degree of polymerization in a range of 50-500, the alcoholysis degree in a range of 30-65 mol%, and the viscosity no more than 1500 mPa*s. Polyvinyl alcohol is prepared into an aqueous solution, which is taken as an auxiliary dispersant for suspension polymerization of vinyl polymers. The cloud point of an aqueous solution, the concentration of which is 5 wt%, (that is, a polyvinyl alcohol aqueous solution of 5 wt%), is no less than 1 DEG C and less than 15 DEG C. The viscosity measured at 25 DEG C of an aqueous solution, the concentration of which is 40 wt%, is no more than 1500 mpa*s. Gel and layering don't appear in an aqueous solution, the concentration of which is in a range of 30wt%-50wt%, in at least one year, so that the aqueous solution is extremely excellent in stability.

The invention relates to an auxiliary dispersant, which is an aqueous solution of polyvinyl alcohol possessing a following structural formula: (img file='dest_path_image001.TIF' wi='399' he='125' / ), wherein m, n, x, y and p are integers, n is less than 135 and greater than 30, m is less than 165 and greater than 20, m / m+n is 40mol%-55mol%, x is greater than or equal to 1 or less than 20, y is less than 20 and greater than 1, p is greater than or equal to 0 or less than 5; R is hydrogen atom or methyl, R1, R2, R3 are hydrogen or alkyl. The auxiliary dispersant is used in a suspension polymerisation reaction of vinyl, and has strong dispersing capability and good dispersing stability to the monomer droplets, the influence of polymerization condition of vinyl compounds can not generated; the prepared vinyl polymer has the advantages of uniform porosity distribution and high porosity amount, and has good removal performance to the residual monomer from the reaction, a plasticizer with excellent absorption capability is added during a subsequent processing process, The processing property is excellent, the plasticizing time can be shortened, and fish eye number is reduced.

The invention discloses a PVC injection molding material and a PVC injection molding method capable of forming a high-light mirror surface effect on the surface of a product. The PVC injection moldingmaterial comprises the components in percentage by weight: 30-50% of PVC resin, 15-25% of dioctyl terephthalate, 18.5-38% of calcium carbonate, 2-8% of stabilizer and 1.5-2% of methyl methacrylate and acrylonitrile copolymers. The injection molding method comprises the steps: firstly, uniformly stirring the components; heating the components to be in a molten state; closing a mold; carrying out filling, carrying out injection molding by an injection molding machine, wherein the injection molding pressure at the first stage is 15-30Bar, the flow at the first stage is 15-35mm / s, the injection molding time at the first stage is 2-5s, the injection molding pressure at the second stage is 15-30Bar, the flow at the second stage is 20-40mm / s, the injection molding time at the second stage is 1-3s, the injection molding pressure at the third stage is 10-25Bar, the flow at the third stage is 10-25mm / s, and the injection molding time at the third stage is 2-4s; maintaining the pressure; carrying out cooling; and carrying out demolding. By using the injection molding method disclosed by the invention, a high-light mirror surface effect can be formed on the surface of the product, the requirement of a terminal client to the appearance of the product can be met, and meanwhile, the competitiveness of the product on the market can be improved.

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.

The invention provides an anti-aging injection molding formula which comprises the following raw materials of PVC resin, polycaprolactone, lignin, silicone oil, barium stearate, cadmium stearate, zincstearate, borax, methyl cellulose and calcium carbonate. Compared with the prior art, the anti-aging injection molding formula disclosed by the invention has the following beneficial effects that service life of a manufactured plastic product is greatly prolonged, PVC resin plasticizing time can be shortened, PVC resin processing fluidity is improved, an injection molded part has high strength and is not prone to be broken, and normal work of the injection molded part is ensured.

The invention discloses a functionality calcium carbonate and a preparation method thereof. The functionality calcium carbonate is prepared by compound treatment technology of 'wet method + dry method' of superfine coarse whiting, fine calcium carbonate particle, nanometer calcium carbonate and a modification agent. The functionality calcium carbonate of the invention can promote resin plasticization, reduce melt viscosity, improve melt fluidity and melt intensity, make product surface smooth and fine and have the function of processing an addition agent ACR, and meanwhile is provided with the function of strengthening coupling and excellent surface modification effects. Appropriate increasing of padding of the system does not affect each performance index of the product. The functionality calcium carbonate and the preparation method thereof has the advantages of improving dispersivity and compatibility of each component of prescription system, improving plasticity of bonding strengthof interface layer, having excellent interface layer performance, realizing the function of annealing strengthening and strengthening.