Packaging container production equipment and packaging container production method

An apparatus for making a packaging container from a sheet-like web comprising:

• a web feeding roller for transporting the sheet-like web along a feed path in a direction lengthwise of the sheet-like web, said web feeding roller having at least two modes of operation including a high-speed mode and a low-speed mode, said web feeding roller transporting said sheet-like web at first rate in its high-speed mode and transporting said sheet-like web at a second rate, lower than said first rate, in its low-speed mode;
• a web tensioning device including a pivotally mounted rocking arm and a dancer roller rotatably secured at a distal end of said rocking arm, said dancer roller applying a pressing force against the sheet-like web while said web tensioning device pivots between upper limit and lower limit positions;
• detection means for detecting the presence of said web tensioning device at said upper limit and said lower limit positions;
• web feed rate control means for switching operation of said web feeding roller between said high speed and low speed modes responsive to detection of said web tensioning device at said upper limit and lower limit positions;
• tube forming means for forming the sheet-like web into a tubular web;
• sealing means for sealing portions of the tubular web by pressing together opposing sides of the tubular web, said sealed portions of said tubular web extending in a direction orthogonal to the lengthwise direction of the tubular web;
• mark detecting means for detecting registration and timing of predetermined detection marks on the web with points of detection established in advance;
• a drive cylinder connected to said rocking arm for setting the pressing force applied by said tensioning device;
• and
• web tension control means for controlling said drive cylinder to change the value for pressing force set by said drive cylinder responsive to variation in the timing of the detected registration.