Research On Hot Stamping Process Of 3D Erect Cotton And Thermodynamic Analysis

3D vertical cotton is a new environmental perspective nonwoven fibrous material.It has the advantages of high resilience,high compression resistance,strong breathability,light texture,and not easy to yellow.Therefore,3D vertical cotton is widely used by molding technology in women’s mold cups,aircraft,high-speed rail,automotive interiors,sound insulation materials,medical and other fields.During hot compression molding,the compression parameters determine product quality.Scholars have explored the impact of the molding process of fiber materials and the constitutive equation on the molding laws of products,and have proposed a method for optimizing the structure of mold thermal homogenization,etc.But,the law of 3D vertical cotton molding parameters affecting product molding quality is unknown.The changes of heat flow field in double bullet molding machine molding cavity have not been researched.The design and optimization of shaped molds for double bullet molding machine lack the substantial progress.To solve the problems of yellowing,breakage,this paper mainly researches the 3D vertical cotton hot stamping process parameters for product forming rules,the heat distribution of the cup molding process in twin-bullet presses,and the design and optimization of special-shaped molds.The research content is as follows:(1)Analyze the forming principle of traditional pneumatic molding equipment and double bullet molding equipment,and study the influence of 3D upright cotton hot molding process parameters on the quality of 3D upright cotton molding cup quality.Derive the theoretical heat transfer formula of 3D upright cotton under the comprehensive action of multiple heat transfer methods during the hot molding process of the double bullet molding machine.(2)Taking the difference between the mold cup depth before and after washing and the compression rate of the mold cup as the evaluation indicators,the main molding parameters affecting the molding of the mold cup were measured by the orthogonal test method,and the influence factors were judged according to the evaluation results and ranked.Obtain the best molding parameters of 3D upright cotton.(3)Contrast and analyze the three hypothetical mathematical models of special-shaped mold cups,and select the mathematical model that best fits the special-shaped mold cups.The temperature distribution of the fluid domain in the molding cavity during the molding process of the double bullet molding machine was analyzed and compared with the molding efficiency of traditional molding equipment.(4)Use UG11.0 to model the special-shaped mold,take the average temperature of 6 points on the surface of the special-shaped mold and the temperature extreme value between 6 points as the quality evaluation indicators,and analyze the degree of influence of each factor using the orthogonal experiment method For the main influencing factors of mold cup molding,select the most excellent mold model in the orthogonal test.Process the most excellent molds,build an experimental platform,use the AT4516 multi-channel temperature tester to measure the 6-point temperature change on the mold surface,analyze the data,and verify the optimized shaped mold model.In this paper,the influence of the quality of molding cups on the molding parameters of 3D upright cotton fabric materials is determined.The most important factor in hot molding is the molding temperature,and the second most important factor is the molding pressure.Design the special-shaped mold for the twin-bullet press,and use the orthogonal test method to optimize the structure of the special-shaped mold cup,and find that the largest factor that affects the special-shaped mold is the length of the major axis of the oval in the Y direction,and the second most important factor is the oval in the X direction Long axis size.Explore the temperature distribution inside the molding cavity during the molding process of the twin-bullet press,and obtain the molding time of the twin-bullet press.Compared to the thermo-mechanical analysis of the twin-bullet press and the molding time of the traditional pneumatic press,the production efficiency of the twin-bullet press is increased by 15%.With the Comparation of the temperature data of the experiment and the numerical simulation,it meets the requirement of uniform temperature distribution on the surface of the mold cup,it can ensure the quality of the mold cup,which can be produced in batches.