TMT successfully relies on SIGMASOFT® Virtual Molding

Company: Zhuzhou Times New Material Technology Co., Ltd. (CRRC Group)
SIGMASOFT® user: since 2014
Main application: Evaluation and optimization of Vulcanization processes
License: Elastomer, Thermoplast (floating)
Website EN:

Vulcanization is the most important step in the manufacturing and processing of rubber products. Vulcanization time directly affects the performance of the final product. Compared with a conventional simulation, SIGMASOFT® Virtual Molding can better predict the vulcanization time of rubber and reduce the number of production trials and the cost of product development.

A famous rubber product manufacturer in China, Zhuzhou Times New Material Technology Co., Ltd. (TMT), is mainly engaged in the research, development and engineering application of polymer materials, such as vibration reduction and noise reduction, lightweight, etc. Their products involve rubber, plastic, composite materials and more and are mainly used in the fields of rail transit, automobile, new energy and building vibration reduction and isolation.

TMT designed a rubber auxiliary spring, which has a circular shape composed of four layers of metal spacers and three layers of rubber. Its maximum outer diameter is 320 mm, and the height is 214 mm. The main purpose of this example is to evaluate the best vulcanization time of the product. Thus, the product development cycle should be effectively shortened, and the cost of product development reduced.

Based on years of experience of their project engineers, they first used the conventional simulation to predict the vulcanization time of the product. Because of the complex product shape and because the post vulcanization effect cannot be considered in the calculation, using the conventional simulation will lead to a long product development cycle and high development costs. Therefore, TMT decided to change the method to SIGMASOFT® Virtual Molding, which considers many factors during the simulation. It accurately analyzes the reasonable vulcanization time of 55 min, 60 min and 70 min in a short time, and accurately predicts the corresponding degree of vulcanization in the product. For the auxiliary spring the final vulcanization degrees for the different vulcanization times are shown in the following pictures.

Figure 1 – Distribution of the degree of vulcanization for 70 min vulcanization time – the overall degree is high with values between 99.4 % and 100 %
Figure 2 – Distribution of the degree of vulcanization for 60 min vulcanization time – the inner areas show the lowest degree of 98.1 %
Figure 3 – Distribution of the degree of vulcanization for 55min vulcanization time – the least cured areas show a value of 96.3 %, which is too low to guarantee a stable mechanical performance
When the vulcanization degree of the rubber reaches over 98 %, its physical and mechanical performance reach a steady state. Therefore, 60 min could be identified as the optimal vulcanization time for the rubber auxiliary spring. Afterwards, the accuracy of the software analysis was also verified by a swelling test and a vertical stiffness test.

Compared with the conventional simulation, SIGMASOFT® Virtual Molding shows a higher accuracy of calculation results. This method can not only greatly improve the efficiency of vulcanization process design, but also reduce the number of production trials and product development costs.

Main engineer Mr. Liu said, “Our company TMT was the first one in China to use SIGMASOFT® to simulate rubber vulcanization process starting in 2014. At present, we have successfully applied SIGMASOFT® to the design guidance of vulcanization process parameters for rubber products, which has become an essential part of our process design. Compared with the conventional simulation, it effectively shortens the process design time and saves costs during development."