Views: 0 Author: Site Editor Publish Time: 2024-11-08 Origin: Site
In order to select the shrinkage rate of large cast polyurethane elastomer products more accurately, the influences of process conditions, environmental factors and product structure on the shrinkage rate were systematically investigated, and the change curves of shrinkage rate with time were measured. The reasons were analyzed. The results show that the product structure has the greatest influence on the shrinkage rate, the process conditions also have a greater influence on the change of shrinkage rate, while the fluctuation of environmental conditions is the reason for the late fluctuation of shrinkage rate. The selection of shrinkage rate is one of the key factors to determine the success of mold design. Especially for large (part size in 1 o00 m / n or more) polyurethane elastomer products, because of its shrinkage rate is large (generally in the 1.5% or so), if the shrinkage rate is not selected properly, light is to increase the amount of mold repair, extend the manufacturing time of the mold, increase the cost of the mold; heavy is due to the size of the mold is too large and scrapped. Therefore, it is important to analyze the reasons for the shrinkage of polyurethane elastomers and study the qualitative relationship between shrinkage and process conditions for the design of cast polyurethane elastomer molds. In this paper, through a large number of process experiments, a more comprehensive study of process conditions, structural factors and environmental conditions on the impact of shrinkage.
The changing law of shrinkage of polyurethane elastomer is:
1) increase with the increase of mold temperature;.
2)with the prolongation of the aging time is jagged change; and
3) with the increase of the ambient temperature and reduce.
4)Fluctuation with the increase of ambient humidity; and
5)Different mold structures have different degrees of hindrance to shrinkage, with the longitudinal direction being the smallest and the transverse direction being the largest; and
6)Shrinkage increases with the increase of flow path length before a certain length, and decreases with the increase of flow length after exceeding a certain length.
It can be seen that the process conditions have a certain impact on the shrinkage rate, and the most significant effect of temperature; the structure of the product itself has a greater impact on the shrinkage rate, polyurethane elasticity of the system is mainly caused by the different flow paths; environmental factors are the later impact factors, their changes are the main factors of the fluctuations in shrinkage rate.
In many fields such as industrial protection and building waterproofing, polyurea materials have been widely used for their excellent performance advantages. In order to give full play to the characteristics of polyurea materials, a high-performance spraying equipment is crucial, and the CNMC-A25 po
On March 31, 2025, Hightop Group's housewarming celebration was held in the new headquarters office building at 66 Xinyuan Road, Jining. All Hightop employees, partners and other industry leaders gathered together to witness important milestones in the development of the enterprise and open a new ch
In the era of the booming development of cross-border e-commerce, a piece of good news has added a beautiful color to the commercial map of Shandong Province. Recently, the Shandong Provincial Department of Commerce officially announced the "Shandong Provincial Department of Commerce on the identifi
construction field Thermal insulation: can be used for building roofs, walls, floors and other parts of the thermal insulation treatment, such as in the new residential and commercial buildings of the external wall spraying inorganic fiber wool, can effectively prevent the heat transfer, reduce ener
Recently, Jining Economic Development Zone grandly held the second high-quality development and high-level opening conference. The conference aims to fully implement the spirit of the central and provincial and municipal private enterprises Symposium, summarize the effectiveness of high-quality deve
Polyurethane foam is widely used for its excellent thermal insulation, heat preservation and sealing performance in the fields of building thermal insulation, industrial thermal insulation and many other areas that require sealing and filling. As the key equipment in the construction of polyurethane
Recently, Liu Xiaolin, Secretary of the Party Working Committee and Director of the Management Committee of Jining Economic and Technological Development Zone in Shandong Province, Cai Dahu, Director of the Economic and Technological Development Zone Innovation and Entrepreneurship Center, and relev
Spring Festival does not close, for this year's Spring Festival holiday, CNMC Machinery's Ali International Station store got a good start. We started the year with a salesman, we harvested more than 1.4 million in sales, of which the largest single order reached one million.CNMC Machinery is a subs
Hey,friends!Can you believe it? 2025 is just around the corner! I wanted to reach out and send you my happiest wishes for the upcoming year.Our time working together this past year has been so much fun, and we've overcome challenges and celebrated victories side by side. I'm really looking forward t
The moon is very bright at the fifteenth day of the month, and the love is even stronger at the Mid-Autumn Festival; the Mid-Autumn Moon is the most round in a year, and the osmanthus rabbit is accompanied by Chang'e; the warmest thing on earth is the reunion, and we are looking forward to the night