Heat-sealable shrink film based on polypropylene
    2.
    发明授权
    Heat-sealable shrink film based on polypropylene 失效
    基于聚丙烯的热密封膜

    公开(公告)号:US5234733A

    公开(公告)日:1993-08-10

    申请号:US346788

    申请日:1989-05-03

    摘要: A shrink film which is comprised of a plurality of polyolefinic layers is disclosed. The base layer comprises polypropylene and a hydrogenated hydrocarbon resin admixture, and the top layers on each side of the base layer comprise polyolefinic sealable raw materials. The film possesses a shrinkability of more than 15% in the transverse direction and of less than 6% in the longitudinal direction, both measured at 90.degree. C. Also disclosed is a process for manufacturing the film comprising coextrusion followed by stretching of the film in the longitudinal and transverse directions, whereby stretching in the longitudinal direction is performed such that the double refraction value .DELTA.n of the longitudinally oriented film is not greater than 15.times.10.sup.-3.

    摘要翻译: 公开了一种由多个聚烯烃层组成的收缩膜。 基层包括聚丙烯和氢化烃树脂混合物,基层每侧的顶层包含聚烯烃密封的原料。 该膜在90℃下在横向上具有大于15%的收缩率和在纵向上的收缩率小于6%。还公开了一种制造该膜的方法,包括共挤出,随后将膜拉伸 纵向和横向,由此进行纵向拉伸,使得纵向取向膜的双折射率ΔTAn不大于15×10 -3。