| 摘要 |
Provided is a longitudinal stretching apparatus which enables an unstretched sheet to be transported by being put in close contact with a low-speed roll in the longitudinal stretching apparatus even if the unstretched sheet formed of a thermoplastic resin is thick, and which is effective in maintaining the quality of a film after stretching. Specifically, provided is a longitudinal stretching apparatus which stretches a continuous unstretched sheet formed of a thermoplastic resin to form into a longitudinal stretched film while allowing the unstretched sheet to travel in the continuing direction of the unstretched sheet, the apparatus being characterized by including a low-speed roll group, a heat stretching part, and a high-speed roll group which are disposed from upstream to downstream in the traveling direction of the unstretched sheet, wherein the low-speed roll group has the functions of passing the unstretched sheet by bringing the unstretched sheet into contact with a plurality of rolls and preheating the unstretched sheet to about the softening temperature thereof, and a contactless preheating part for heating the unstretched sheet in contactless manner is further provided at the upstream portion of the low-speed roll group. |
