In-mold labeling (IML) process - introduction to electrostatic adsorption method

Publisher:思为客

Release Date:2024.12.06

With the improvement of automation of injection molding equipment, in-mold labeling (IML) technology is becoming popular at home and abroad. In-mold labeling products are generally favored by the industry for their advantages such as high definition, good three-dimensional effect, scratch-resistant surface, increased aesthetics of packaging containers, improved economic benefits, environmental protection, and enhanced anti-counterfeiting. The following mainly introduces the key points of electrostatic adsorption in injection mold in-mold labeling.

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For injection molding in-mold labeling, an automated robot attaches the label to the inner wall of the mold. After the mold is closed, the mold is filled with injection molding. The resin melts the hot-melt adhesive resin on the back of the in-mold label at high temperature, so that the label and container are integrated.

If the synthetic label is electrostatically charged, it can be attached to the inside of the mold to bond the label to the film casting. For low-static applications, it can be charged manually. For automatic systems, there are two ways to charge the tag.

Pick up the label directly and place it on the mold

1) The vacuum suction cup on the robot arm picks up the label;

2) The label is moved into the mold cavity, and after touching the contact surface, the suction cup blows back;

3) At the same time, the electrostatic generator generates static electricity to charge the charging plate, IML foam pad and label for a short time through the electrostatic generator head;

4) The robotic arm is removed and the label is adsorbed in the mold cavity.

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Some robot arm suction cup grippers are tapered or cylindrical rather than flat, which makes it easier to place labels into mold slots, such as cup-shaped molds.

1) Use an air nozzle to blow the label to the edge of the gripper, and adsorb it to the gripper through vacuum suction;

2) The label is moved into the mold, and after touching the contact surface, the suction cup blows back;

3) Charge the charging board, IML foam pad and tags for a short time at the same time;

4) The robotic arm is removed and the label is adsorbed in the mold.

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Blow the label into the mold

The label is charged using an electrostatic generator, and the charged label is affixed to the mold by wind force.

1) The robotic arm uses vacuum suction to grab the label;

2) The suction cup blows the label while the static electricity generating head charges the label;

3) The mold should be grounded, and there should be no contact between the robot arm and the mold.

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Some cup-shaped or similar molds are labeled, and the label should be affixed to the push-in male mold, not inside the mold cavity like the first type.

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In-mold labeling (IML) process - introduction to electrostatic adsorption method

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