Die lip opening/closing device

Patent metadata

Field	Value
Publication number	US-12434418-B2
Application number	US-202218560762-A
Country	US
Kind code	B2
Filing date	Mar 30, 2022
Priority date	May 21, 2021
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

Provided is a die lip opening/closing device capable of preventing wear and damage on an actuator of a pusher. According to the present invention, there is provided a die lip opening/closing device, the device including an opening/closing structure configured to open and close a die lip of a T-die in response to a linear motion of a pusher, and an actuator configured to actuate the pusher to move linearly, wherein the pusher includes a plurality of sub-pushers disposed along a longitudinal direction of the die lip, and the actuator is provided for each of the sub-pushers.

First claim

The invention claimed is:

1. A resin feeder comprising an extruder, an accumulator, and a T-die, wherein
the T-die comprises a die lip and a die lip opening/closing device comprising:
an opening/closing structure configured to open and close a die lip of a T-die in response to a linear motion of a pusher; and
an actuator configured to actuate the pusher to move linearly,
wherein the pusher comprises a plurality of sub-pushers disposed along a longitudinal direction of the die lip, and
the actuator is provided for each of the sub-pushers, wherein
the accumulator is configured to be filled with resin melted and kneaded in the extruder,
the T-die is configured to be filled with the resin filling the accumulator,
and configured that during the filling of the T-die with molten resin, the die lip is closed,
and configured that when the T-die is sufficiently filled with the molten resin required for molding, the die lip opening/closing device is configured to open the die lip, and a molten resin sheet is extruded through a slit of the die lip, wherein
each of the sub-pushers is provided with a pusher-bar,
a pusher head is provided at an end portion of the pusher bar,
the opening/closing structure comprises a receiving piece and a die lip piece,
the die lip piece comprises a bending portion formed into a thin wall with a block cut out, a receiving piece connection to which the receiving piece is attached, and a fixing portion fixed to a body of the T-die,
the receiving piece connection and the fixing portion are connected by the bending portion, and
the pusher head is configured to press the receiving piece connection through the receiving piece.

2. The resin feeder of claim 1 , wherein the actuator is constituted by a linear-acting cylinder.

3. The resin feeder of claim 1 , wherein
the receiving piece is provided with an accommodating recess for accommodating the pusher head,
the pusher head is sandwiched between an upper wall and a lower wall in the accommodating recess,
the accommodating recess extends toward a side of an entrance of the accommodating recess, and the upper wall and the lower wall do not contact the pusher head in a vicinity of the entrance of the accommodating recess.

4. The resin feeder of claim 1 , wherein each of the sub-pushers is provided with a plurality of the pusher bars.

5. The resin feeder of claim 2 , wherein
the receiving piece is provided with an accommodating recess for accommodating the pusher head,
the pusher head is sandwiched between an upper wall and a lower wall in the accommodating recess,
the accommodating recess extends toward a side of an entrance of the accommodating recess, and the upper wall and the lower wall do not contact the pusher head in a vicinity of the entrance of the accommodating recess.

6. The resin feeder of claim 2 , wherein each of the sub-pushers is provided with a plurality of the pusher bars.

Assignees

• Kyoraku Co Ltd

Inventors

• Yamasaki Yoshihiro
• Ito Shuji
• Tanji Tadatoshi

Classifications

• B29C48/302

  being adjustable, i.e. having adjustable exit sections · CPC title

• B29C48/313 Primary

  by positioning the die lips · CPC title

• B29C48/475

  using pistons, accumulators or press rams · CPC title

• B29C48/388

  using a screw extruder and a ram or piston · CPC title

• B29C48/365

  using pumps, e.g. piston pumps · CPC title