Abstract
This report is to discuss the bowing phenomenon and the sag elimination tension for biaxial oriented PA 6 film process, which consists of double bubble tubular film process and the thermosetting tentering.
The bowing phenomenon does not occur in the heat set of the triple bubble tubular process. However, there is a serious problem of the bubble stability when the sufficient thermosetting by the tubular process is carried out, so the heat set by the tenter process is required. The bowing phenomenon arises when the annealing is carried out by the tenter method. The bowing distortion becomes large when the annealing temperature is high and film relaxation ratio is large.
It is possible to reduce the bowing distortion when thermosetting is carried out in a two-step tenter process. The shrinkage stress of the stretched film was relaxed in the heat treatment during the second step whose temperature is higher than the first one. A two-step heat treatment was able to decrease the bowing distortion compared with the one-step heat treatment.
When the bowing phenomenon occurred, shrinkage percentage in hot water changes along the cross-direction of a film. The humidity expansion coefficient in the film which increases as the increasing shrinkage percentage in hot water is related to the molecular orientation. The sag also increased with increasing the bowing distortion. The bowing distortion and the sag elimination of tension have proportional connection.
References
1 Kase, S., Kono, N., Higuchi, T.: Bull. Faculty of Textile Sci.11, p. 303 (1987).Search in Google Scholar
2 Kase, S., Nishimura, T., Sonoda, Y., Kado, M., Tamura, K.: Bull. Faculty of Textile Sci.12, p. 33 (1988).Search in Google Scholar
3 Nishimura, T., Kase, S., Hino, K.: Bull. Faculty of Textile Sci.13, p. 69 (1989).10.1002/jgt.3190130109Search in Google Scholar
4 Kase, S., Nishimura, T.: J. of Rheology34, p. 251 (1990).10.1122/1.550127Search in Google Scholar
5 Sakamoto, K.: J. of Jpn. Rheology Sci.19, p. 89 (1991).10.1678/rheology1973.19.2_89Search in Google Scholar
6 Sakamoto, K.: J. of Soc. Polym. Process. (Seikei-Kakou)3, p. 496 (1991).10.4325/seikeikakou.3.496Search in Google Scholar
7 Sakamoto, K.: Kobunshi Ronbunshuu48, p. 671 (1991).10.1295/koron.48.671Search in Google Scholar
8 Nonomura, C., Yamada, T., Matsuo, T.: J. of Jpn. Soc. Polym. Process. (Seikei-Kakou)4, p. 312 (1992).10.4325/seikeikakou.4.312Search in Google Scholar
9 Yamada, T., Nonomura, C.: J. of Appl. Polym. Sci.48, p. 1339 (1993).10.1002/app.1993.070480808Search in Google Scholar
10 Nonomura, C.Yamada, T.: J. of Jpn. Soc. Polym. Process. (Seikei-Kakou)5, p. 703 (1993).10.4325/seikeikakou.5.703Search in Google Scholar
11 Nonomura, C., Yamada, T.: J. of Appl. Polym. Sci.49, p. 1393 (1994).Search in Google Scholar
12 Nonomura, C., Yamada, T., Matsuo, T.: Int. Polym. Process.10, p. 334 (1995).10.3139/217.950334Search in Google Scholar
13 Fujita, S., Nonomura, C., Yamada, T.: J. of Jpn. Soc. Polym. Process. (Seikei-Kakou)9, p. 605 (1996).10.4325/seikeikakou.8.605Search in Google Scholar
14 Takashige, M., Kanai, T.: Int. Polym. Process.5, p. 287 (1990).10.3139/217.900287Search in Google Scholar
© 2004, Carl Hanser Verlag, Munich
