Methods and systems for producing pressware
A system for forming a pressware product from a web of a roll of material includes a positive mold, a negative mold, a heating element, an actuator, a force sensor, and a control system. The positive mold forms a top surface of the pressware product. The negative mold forms a bottom surface of the pressware product. The heating element is coupled to the positive mold or the negative mold. The actuator shifts the positive mold or the negative mold to cut and form the pressware product in a single stroke. The force sensor detects the forming force applied by the actuator, and the control system directs the actuator to adjust the forming force.
1 . A method of forming a pressware product from a web from a roll of material, the method comprising:
pressing, via one or more forming station actuator, the web between a positive mold of the positive mold assembly and a negative mold of the negative mold assembly to form the pressware product, the positive mold assembly including a including the positive mold with a bottom surface for forming a top surface of the pressware product and a positive punch shiftable relative to the positive mold with an edge configured to cut the web to separate the pressware product from the web, and the negative mold assembly including a negative mold with a top surface for forming a bottom surface of the pressware product and a trim die plate with an edge configured to cut the web in cooperation with the edge of the positive punch, the positive mold assembly and the negative mold assembly being shiftable relative to one another, wherein the one or more forming station actuator is configured to shift the positive mold assembly relative to the negative mold assembly;
heating, via a heating element coupled to at least one of the positive mold or the negative mold, the pressware product;
generating, via a force sensor, sensor data representative of a forming force applied by the forming station actuator;
shifting, via the one or more forming station actuator, the positive punch relative to the positive mold to cut the pressware product from the web;
receiving, via a control system in communication with the force sensor and the forming station actuator, a signal representative of the sensor data; and
directing, via the control system, the forming station actuator to adjust the forming force based at least in part on the sensor data.
2 . The method of claim 1 , wherein the positive mold assembly includes one or more nitrogen gas spring configured to help press the positive punch against the web.
3 . The method of claim 1 , wherein the positive mold includes a central portion and an annular portion extending around the central portion, the central portion and the annular portion cooperatively presenting a surface that forms the top surface of the pressware product.
4 . The method of claim 3 , wherein the annular portion is a draw ring vertically shiftable relative to the central portion.
5 . The method of claim 4 , wherein the central portion comprises a flange configured to pull down the draw ring.
6 . The method of claim 3 , wherein the annular portion is integral to the central portion.
7 . The method of claim 1 , further comprising holding, via the one or more forming station actuator, the positive mold and the negative mold pressed against the pressware product so that the pressware product is heated via the heating element.
8 . The method of claim 1 , wherein at least one of the positive mold assembly or the negative mold assembly includes an insulator plate.
9 . The method of claim 1 , wherein the web from the roll of material comprises paper and the positive punch and the negative mold are made of metal.
10 . The method of claim 1 , wherein the positive mold assembly comprises a plurality of rows of positive molds, and the negative mold assembly comprises a plurality of rows of negative molds so that multiple rows of pressware products are formed in one stroke.
11 . A method of forming a pressware product from a web from a roll of material, the method comprising:
pressing, via one or more forming station actuator, the web between a positive mold of a positive mold assembly and a negative mold of a negative mold assembly to form the pressware product, the positive mold assembly including a positive mold with a bottom surface for forming a top surface of the pressware product and a positive punch shiftable relative to the positive mold with an edge configured to cut the web to separate the pressware product from the web, and the negative mold assembly including a negative mold with a top surface for forming a bottom surface of the pressware product and a trim die plate with an edge configured to cut the web in cooperation with the edge of the positive punch, the positive mold assembly and the negative mold assembly being shiftable relative to one another, wherein the one or more forming station actuator is configured to shift at least one of the positive mold assembly relative to the negative mold assembly;
shifting, via the one or more forming station actuator, the positive punch relative to the positive mold to cut the pressware product from the web;
holding, via the one or more forming station actuator, the positive mold and the negative mold pressed against the pressware product so that the pressware product is heated via a heating element coupled to at least one of the positive mold or the negative mold;
generating, via a force sensor, sensor data representative of a forming force applied by the one or more forming station actuator;
receiving, via a control system in communication with the force sensor and the forming station actuator, a signal representative of the sensor data;
adjusting, via the control system, the forming force applied by the one or more forming station actuator based at least in part on the sensor data; and
shifting, via a height adjust assembly, the positive mold assembly relative to the negative mold assembly to adjust a forming depth of the positive mold within the negative mold.
12 . The method of claim 11 , wherein the positive mold includes a central portion and an annular portion extending around the central portion and configured to shape a rim of the pressware product, the central portion and the annular portion cooperatively presenting a surface that forms a top surface of the pressware product.
13 . The method of claim 12 , wherein the annular portion is a draw ring shiftable relative to the central portion.
14 . The method of claim 12 , wherein the annular portion is integral to the central portion.