Purpose: To determine the influence of mold material, mixing blade rotation force, forced push cylinder speed, material compression, and screw fill rate on the machine's ability to dose and shape the spring roll filling in the mold, ensure the filling drops accurately onto the rice paper, and minimize mass loss after the process.
Equipment and materials for the experiment:
Equipment: scale and caliper.
Materials: 10kg Spring Roll Filling Consisting of Chicken and Various Ingredients Mixed According to the Restaurant Owner's Recipe:
• Chicken: 6kg (minced)
• Cabbage: 2kg (finely chopped)
• Carrot: 1kg (finely chopped)
• Wood Ear Mushrooms: 500g (soaked in water and finely chopped)
• Green Onions: 500g (finely chopped) Experimental Method:
The spring roll filling, after being mixed, will be refrigerated for long-term preservation, ensuring stickiness and preventing water release. The filling is divided for use over several days, with each experiment using 5kg of filling placed into the hopper. The filling is extruded into the mold cavity by a screw conveyor, and the rice paper wrappers are fed into the conveyor belt sequentially to perform the filling process.
Figure 6.91: Loading the Filling into the Mixing Hopper
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Evaluation Method: The effectiveness of the machine's filling dosing is evaluated by measuring the output filling dimensions with a ruler, weighing the output with a scale, and assessing the ability to wrap in subsequent stages.
Procedure and Data Collection: Spring roll wrappers are placed on the conveyor belt to receive the filling. The experiment continues until the mold cavity is depleted. In each trial, the rotation speed is set sequentially at 10-20-30-40-50-60-70-80-90-100 RPM (based on the motor speed controller settings), with each wrapper fed every 12 seconds.
Results:
Speed Pass Detects Pictures
20 Fail
The filling had some adhesion, but the mold cavity was not fully filled. The output filling weight was only about 70% of the required weight.
30 Pass
The filling dropped correctly onto the wrapper, meeting the size and weight requirements, with good ingredient adhesion.
40 Fail
The filling structure was too compressed, exceeding the required weight (>110%).
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50 Fail
Although the speed did not increase compared to 40 RPM, the filling started to release water, causing it to stick to the pusher and not drop onto the wrapper, leading to clogging and improper filling.
Table 6.10: Experimental Results of Machine Operation
Conclusion: During the experiment, the team found that at 30 RPM, the filling achieved uniform size and appearance. The weight of each filling ranged from 90-110% (52g-64g) of the required weight (60g ±5g) over 10 trials. The results were consistent with the initial data selected.
At 30 RPM, with a 12-second interval between each releasing cycle, some issues arose that need fixing:
Survey Factor Cylinder’s force Cylinder’s speed
Airflow rate (throttle valve discharge level)
Cases Problems Reason Adjustment Result
The cylinder speed pushes
the mold cavity out
slowly
The mold cavity pushed out slowly compared to the rice paper's moving speed, causing deviation in the falling position.
Close the throttle valve at low air flow levels (<40%), the piston pushes out slowly
Open the throttle valve at medium level (40-60%) to ensure the moderate piston push-out speed.
The mold cavity is pushed out at the time the rice paper moves forward, ensuring the falling position of the filling and not affecting the rolling time of a cycle.
The cylinder speed pulls
the mold cavity in slowly
The mold cavity moves slowly into the mold, prolonging the mold filling time for the next filling cycle.
Close the throttle valve at low air flow levels (<40%), the piston pulls in slowly
Open the throttle valve at a
medium level (40-60%) to ensure the moderate piston pull-in speed.
The mold cavity is pulled in at a moderate speed, saving filling time during the rolling process to prepare for the next rolling cycle.
The cylinder speed pushes
the mold
The base- cylinder-01 (section 6.4.9) is
Open the throttle valve at a high air flow level
Adjust the throttle valve to a medium air
The base-cylinder- 01 has no
deformation,
117 cavity out
and pulls it in fast
deformed when performing the operation.
(60-100%), the piston's ejection speed is very fast, the cylinder pushing and pulling force is large.
flow level (40- 60%), moderate piston
movement speed.
ensuring durability for parts and molds.
The cylinder speed pushed the filling
down.
When pushed, the filling falls slowly due to the weak pushing force, causing misalignment on the rice paper, making it difficult to roll.
Open the throttle valve at low flow, the piston moves down slowly, the thrust is weak.
Open the throttle valve to
maximum (100%), the piston moves at maximum speed
=> Stronger thrust.
The filling is pushed down firmly and
immediately falls onto the rice paper.
Material to manufacture
the push- head
When
experimented many times, the filling adhesed to the push-head and not falling firmly, causing a deviation in the falling position on the rice paper.
The push head is made of POM plastic, has a smooth and hard surface, and is not avoid the adhesion.
Replace POM plastic material with PTFE (TEFLON) plastic material with good anti- sticking ability.
The filling does not stick to the push-head when the piston is pushed down, ensuring the filling falls in the correct position on the rice paper when
producing large quantities.
Table 6.11: Experimental results and adjustment of machine problems
Conclusion: After adjusting the cylinder's in and out speeds, the speed of pushing the filling down, and changing the material of the filling pusher head, when the machine operates at 30 revolutions per minute, it produces consistent products in terms of size and required weight. The filling drops into the appropriate position for subsequent rolling stages, ensuring efficient filling for each spring roll.
Figure 6 92: The position of the filling on the rice paper meets the requirements