The process of making paper bowl is essentially a precise process of turning flat paper into 3D paper bowls through automation. Its core logic can be divided into four modules: ``material pretreatment-automatic forming-structural reinforcement-quality inspection ''. Its working mechanisms are analysed from the point of view of technical principles as follows:
I. Material Pretreatment: Precisely meet molding requirements
Raw material selection and pre-treatment
Use single-sided or double-sided laminated paper (PE/PLA coating) to ensure water resistance and heat sealability.
Paper needs to be pre-printed with a pattern and then cut into fan-shaped or circular blanks with a cutter. Dimension error should be controlled to ±0.5mm.
Design of Paper Feed System
vacuum adsorption or mechanical clamping technology is used to accurately transport billets to forming stations, preventing paper from shifting and producing waste products.
Some models are equipped with automatic deviation correction devices that adjust paper positions in real time through photoelectric sensors.
II. Automated Forming: Multi-station collaborative operation
Cups Curl and Heat Seal
The heating module (such as a ceramic heating tubes) partially heats the edges of the paper to 180-220°C, softens the paper and then rolls it into a conical platform shape via a mould.
pressure rollers is synchronously pressurized to fuse the heat sealing area and form the cup wall structure. Seal strength must be ≥5N/15mm (meet national standards).
Bottom Punch and Seal
Rinse the bottom circle of the cup from the roller paper to match the diameter of the inside of the cup wall, with an error of not more than 0.2mm.
Combine the bottom of the cup with the wall of the cup by hot pressing or ultrasonic welding. For some models, a raised texture is pressed at the sealing point to improve the stability of the structure.
Rolling edges and lubrication
The curl mechanism folds the rim of the cup inwards by 1-2mm to create a smooth rounded angle that prevents scratching the user.
The spray system sprays food-grade silicone oil on the rolled edge to reduce friction coefficient and facilitate subsequent demolding.
III. Structural Reinforcement: improving durability and safety
Multi-layer composite process (optional)
For paper bowls that need to be loaded,such as hot soup bowls, a layer of aluminum foil or reinforced paper can be placed on the inside of the bowl to improve heat insulation and compressive strength.
The lamination process is performed by thermoclave or mechanical interlocking to ensure the interlayer bonding force ≥ 3N/cm2.
Edge reinforcement technology
The sealing point between the edge of the cup and the bottom of the cup is formed by double pass heat pressure process to strengthen the structure and prevent leakage or deformation.
Some models have laser detection system that monitor the width and integrity of sealing lines in real time.
IV. Quality Inspection and finished product output
Online detection system
The roundness of cup mouth and verticality of cup body are detected by visual sensor to remove malformed products.
leakage tester put negative pressure on the finished product to test the sealing performance of the cup bottom seal. The leakage rate should ≤ 0.5%.
Automatic counting and packaging
Finished product enters the collection box via conveyor belt. Counting the number recorded by sensors. When the box is full, it triggers an alarm or automatically changes the box.
Some models can be attached to a packaging machines to automatic bagging or box paper bowls.
V. Technological Extension: adaptation to Diverse Demands
Quick mold replacement
With a modular design, the same dishwasher can be configured with different moulds to produce 6-32oz (approximately 180-950ml) paper bowls.
Die replacement time generally does not exceed 15 minutes, do not require professional tools.
Use eco-friendly materials
By adjusting heating temperature and pressure parameters, it can be compatible with degradable materials such as PLA coated paper and bamboo fiber paper to meet the requirements of the "plastic restriction order.
Some models are equipped with a waste recycling system that shatters the remaining material after being flushed and then repulses it, reducing the loss of raw materials.
