Design And Research Of Cold Runner Die For Large Asymmetrical Rubber Products

Rubber injection molding technology is mainly applied to multi-mode multi-cavity small rubber products and large-scale symmetrical rubber products.The symmetry of the structure of the cold flow channel of large-scale rubber products with symmetrical structure is relatively simple,and it is easy to achieve the consistency of injection pressure and injection speed of each gate.However,in the design of asymmetrical large-scale rubber product cold runners,the consistency of injection pressure and injection speed at each gate is not easily achieved during design.Therefore,such rubber products are likely to cause quality problems such as uneven quality,air bubbles,patterns,and weld marks during injection molding.Therefore,such rubber products are likely to cause quality problems such as uneven quality,air bubbles,patterns,and weld marks during injection molding.For large-scale rubber products with structural asymmetry,molding methods are generally adopted,but such methods have problems such as low molding efficiency,unstable quality,and high operating strength.In view of the above situation,this paper takes the outer windshield of high-speed railway car as the research object,and designs and researches the cold flow channel of asymmetric large-scale rubber products.The cold runner system was designed using PRO/E software,and the rubber flow process in the cold runner was simulated by POLYFLOW software.The velocity field,pressure field,viscosity field,and shear in the preliminary design scheme of the eight cold runners were respectively used.The speed field is analyzed and studied.Based on the analysis results,the structure and parameters of the cold runner were optimized.The main work of this article is:(1)By reviewing a large number of related literature and literature,the status quo of the cold runner technology at home and abroad and the development of heat transfer technology for plate vulcanizers are summarized and the cold runner system is designed.(2)Application of PRO/E Software to 3D Modeling Exterior Gears of High Speed Rail Cars,combined with reference materials and empirical formulas,the preliminary design of the cold runner gating system for the outer windshield of high-speed railway car was completed.(3)The finite element analysis software POLYFLOW was used to simulate the flow of rubber in the flow channel.Eight preliminary design schemes were studied with injection speed,gate diameter,and runner size as variables.By comparing the velocity field,pressure field,viscosity field and shear rate field generated during the flow of the rubber compound,the optimal design scheme was determined.(4)Using the law of conservation of energy and the law of Fourier heat transfer,the temperature control system of the cold runner was designed and studied.According to the requirements of the vulcanization process conditions,the conditions of the cold runner heating conditions were determined,and the parameters such as the heating and cooling medium in the cold runner,the arrangement of the holes,and the diameter of the hole were designed to ensure that the cold runner temperature control requirements were met.