Method for determining molding characteristic and injection molding machine

A method for determining a molding characteristic of an injection molding machine, comprising the steps of:

• injecting a first resin having certain resin properties with a nozzle left open under a plurality of preset molding conditions, and detecting an injection pressure produced at that time by using a pressure sensor;
• storing pressure data detected by the pressure sensor as reference pressure data, together with screw position data or time lapse data, in a storage device;
• injecting a second resin, having at least one different resin property, with the nozzle left open under at least one of the plurality of molding conditions where the reference pressure data was obtained, and obtaining detected pressure data with respect to the screw position data or the time lapse data using the pressure sensor;
• displaying the detected pressure data and the stored reference pressure data on a display;
• and
• determining a variation of the molding characteristic based on the displayed data.

A method for determining a molding characteristic of an injection molding machine, comprising the steps of:

• injecting a first resin having certain resin properties with a nozzle left open under a plurality of preset molding conditions and detecting an injection pressure produced at that time using a pressure sensor;
• storing a pressure data detected by the pressure sensor as reference pressure data, together with screw position data or time lapse data, in a storage device;
• injecting a second resin, having at least one different resin property, with the nozzle left open under an optional molding condition to obtain detected pressure data with respect to the screw position data or the time lapse data using the pressure sensor;
• finding interpolated reference pressure data with respect to said optional molding condition by interpolating from the reference pressure data stored in the storage device;
• displaying the interpolated reference pressure data and the detected pressure data on a display;
• and
• determining a variation of the molding characteristic based on the displayed data.

A method for determining a molding characteristic of a injection molding machine, comprising the steps of:

• injecting a first resin having certain resin properties with a nozzle left open under each of a plurality of preset molding conditions, and detecting an injection pressure produced at that time using a pressure sensor;
• storing pressure data detected by the pressure sensor as reference pressure data, together with screw position data or time lapse data, in a storage device;
• injecting a second resin, having at least one different resin property with the nozzle left open under at least one of the plurality of molding conditions and obtaining detected pressure data with respect to the screw position data or the time lapse data using the pressure sensor;
• displaying the detected pressure data and the stored reference pressure data on a display;
• and
• determining a variation of the molding characteristic based on the displayed data.

An injection molding machine, comprising:

• a pressure sensor for detecting an injection pressure;
• a storage device that stores pressure data detected by said pressure sensor when a first resin having certain resin properties is injected under molding conditions scheduled in advance with a nozzle in the injection molding machine left open, in connection with at least one of screw position or a time elapsed, as reference pressure data;
• and
• a comparator that outputs an alarm when detected pressure data with respect to screw position or time elapsed, obtained by injecting a second resin, having at least one different resin property with the nozzle left open, under the same molding conditions as that used in the injection of the first resin with the nozzle left open, exceeds a set monitoring width of the reference pressure data.