Automatic Mattress Packing Machine: Things You May Want to Know

Saudi Arabia Continuous Foam Project Case-Complete Procurement for a New PU Foam Factory

Project Background

In September 2021, we received an inquiry from Abdullah, a client from Saudi Arabia. He planned to build a new PU foam factory serving the Saudi local market and the Yemeni market, mainly for furniture and mattress flexible PU foam products. He also planned to include downstream processing.

The client had local foaming workers and some basic production conditions in place. As the project moved forward, it required coordinated planning of target products, equipment configuration, factory layout, and the connection between foaming and downstream processing.

Early Communication and Project Support

For this project, we first discussed the target market and product direction with the client, then communicated the basic requirements for furniture and mattress flexible PU foam production, including density, hardness, and the connection with downstream cutting and processing.

Based on the client’s factory conditions, we provided a factory layout plan to organize equipment placement, production flow, the connection between the foaming area and downstream processing area, and operator working space.

During the communication process, we held multiple video meetings with the client and showed him our real flexible PU foam production process. This allowed him to directly understand the operating condition of the continuous foam machine, the process connection during foaming, and how downstream cutting and processing would fit into actual production.

In terms of equipment discussion, the communication focused on the client’s specific questions, including ease of daily operation, the practical differences between different equipment designs, and which configurations were more suitable for the current project conditions.

The rebonded foam machine purchased by this client

Why the Client Finally Chose Us

The client first inquired about a continuous foam machine. As the communication progressed, the discussion moved step by step toward complete line configuration and factory setup. His final decision to continue the project with us was mainly related to the following points.

1. Timely replies kept the communication moving forward
In the early stage of a new PU foam factory project, questions continue to increase. During the process, the client kept adding details related to product direction, equipment connection, factory arrangement, and manpower coordination.

In this project, the client’s questions were continuously answered, and the communication did not stop at any stage. Once one point was clarified, the next discussion could continue smoothly.

2. The answers directly addressed the client’s actual questions
At the early stage, the client did not lack equipment brochures. What affected his judgment was whether his questions could be explained clearly.

During communication, his concerns were not limited to the continuous foam machine itself. He also focused on product direction for the target market, the basic production needs for furniture and mattress flexible PU foam, the connection between foaming and downstream processing, and how the new factory should be arranged under existing conditions.

The replies consistently followed these actual questions and did not stay at the level of general equipment introduction.

3. The solution was developed around the project’s real conditions

This was a new factory project, but the client already had local foaming workers, and the factory conditions were already defined. As communication moved forward, the solution discussion kept following these actual conditions, including how to arrange the factory space, how to introduce the complete line under existing manpower conditions, how to connect the foaming area with the downstream processing area, and which configurations were more suitable for the current project schedule.

What the client saw was not a fixed standard configuration, but a solution approach developed around his own project conditions.

4. The discussion covered practical production use, not only equipment itself

In equipment communication, the client was concerned not only with the equipment itself, but also with how it would be used in real production, such as daily operating convenience, whether parameter adjustment was clear, which links were more likely to cause problems, and how foaming and downstream cutting and processing could be connected more smoothly.

This part of the discussion continued throughout the early communication and did not stop at paper specifications.

5. The topics discussed early could continue into the later solution

The product direction, layout relationship, equipment connection, and processing arrangement discussed in the early stage all continued into the detailed configuration discussion later. The topics raised earlier could continue into the solution without disconnect.

Final Procurement Content

• one complete continuous foaming production line
• one rebonded foam production line, including: rebonded foam machine, steam boiler, foam shredder machine
• one CNC foam cutting machine
• two circular foam cutting machines
• one vertical foam cutting machine

Loading rebonded foam line

Loading continuous foam machine and foam cutting machine

If you are also planning a new PU foam factory, or evaluating continuous foam line, rebonded foam line, and cutting machine configurations, you can send us your product direction, factory conditions, and project plan. We can discuss a suitable solution with you based on your actual situation.

When using a batch foam machine for polyurethane soft foam foaming, have you encountered the following situations?

1.Uneven and numerous foam pores,

2. Rough foam texture.

3. Chaotic pore sizes across the entire foam surface, with slight signs of large pores.

Issues like these are quite common. The main reason for the first issue is that the distance between the mixing impeller of the foam machine and the bottom of the mixing barrel is too great; the second issue is that the mixing blades are too short and narrow: the third issue is that the angle of the mixing blades is too large.

Many manufacturers who design and produce foam machines only understand the principles during the design process, without understanding the significant relationship between a different design in foam production and product quality. A reasonable and perfect mechanical design can only be gradually improved in actual work, and only experienced foamers can achieve this.

Here are some experiences we have had with machine modifications and upgrades, hoping they will be helpful:

First, the installation position of the mixing wheel should be as low as possible, closer to the bottom of the mixing barrel is better. In general, the distance between the lowest point of the mixing blade and the bottom of the mixing barrel should be around two centimeters

Second, the shape of the mixing blade should be fan-shaped, with a moderately wide edge. The advantage of being wide is that it increases the contact area with the liquid material, providing sufficient power and also balances the liquid material.

Third, the length of the mixing blade should also be as long as possible, leaving about three to four centimeters from the baffle inside the mixing barrel.

Fourth, the two edges of the mixing blade should be sloped, with the angle of inclination based on the width of one end and two centimeters difference on both sides. After the mixing blade is modified, proper operation is also crucial, especially the mixing speed. Most batch foam machines nowadays are equipped with high-speed timing frequency conversion devices. However, in actual production, this device is often unnecessary. The operating speed mainly depends on the amount of material in the mixing barrel. If there is a lot of material, the speed should be appropriately faster, and if there is less material, then the speed should be lower.

Beginners are concerned that if the settling plate is not adjusted properly, the liquid flowing out of the nozzle may cause front surging or back surging, affecting the foaming process. Within two minutes after starting the machine, the reaction speed gradually increases, sometimes requiring adjustments to the settling plate. Adjustments to the settling plate are more critical in low-density and high-moisture-content (MC) formulas.

TDI (Toluene Diisocyanate) flow rate can be calculated to correspond to the scale value, but it is recommended to actually measure the TDI flow rate during the first foaming. Flow rate is too important; if the flow rate is not accurate, everything else will be a mess. It's best to rely on the simplest and most intuitive method of measuring the flow rate.

When mixing powders, the mixed stone powder should be left overnight and production should start the next day. For ingredients containing melamine and stone powder, it is recommended to first mix melamine with polyether for a period of time before adding the stone powder.

Foam machine formulas with long mixing chamber in the machine head or more teeth on the stirring shaft usually have less amine and lower material temperature. Conversely, foam machine formulas with short mixing chamber in the machine head or fewer teeth on the stirring shaft usually have more amine and higher material temperature.

For the same formula, when switching between dual-spray swivel heads and single-spray swivel heads with similar nozzle cross-sectional areas, the requirements for mesh thickness and layers are similar.

For the calibration of minor material flow, one method is to measure the return flow of the minor material, and the other is to calibrate it by dividing the total amount used by the foaming time. When there is a significant difference between the two calibration methods, rely on the data from the second calibration method.

Formulas for high-quality soft foam are usually within an unstable range, such as a low TDI index, low water-to-MC ratio, low T-9 dosage, and low silicone oil dosage.

Calculation of foaming distance for continuous foaming machine

Given: Bubble release time for the formula is 108 seconds, conveyor belt speed during foaming is 4.6 meters per minute. Calculate the swinging and trough foaming distances.

Foaming distance when swinging: (108/60) x 4.6 = 8.28 meters

Foaming distance when troughing: [((108-18)/60)] x 4.6 = 6.9 meters

Explanation: For the same formula, continuous foaming machine has a shorter bubble release time than small bubbles. The calculated foaming distance is shorter than the actual foaming distance. This method only provides approximate confirmation of the foaming distance, supporting the adjustment of the settling plate. Troughing: 18" indicates the time in seconds that the raw material stays in the overflow trough.

Calculation of foaming height for continuous foaming machine

Given: Formula flow rate: 80 kilograms per minute for polyether, 20 for white polyether, 60 for TDI, 20 for stone powder, conveyor belt speed 4.5 meters per minute, mold width 1.65 meters, producing foam with a density of 25 kilograms per cubic meter. What is the foaming height in meters?

Total formula weight: 80 + 20 + 60 + 20 = 180 kilograms

Formula volume: 180/25 = 7.2 cubic meters

Base area of conveyor running per minute:

4.5 x 1.65 = 7.425 cubic meters

Foaming height: 7.2/7.425 = 0.97 meters

Explanation: Silicone oil, amine, and tin are not considered here as they offset the amount of carbon dioxide used during the foaming process. Moisture content (MC) is not considered because MC does not increase foam weight when vaporized.

Foaming Daily Operation

Beginners worry that improper adjustment of the settling plate will cause the liquid sprayed from the nozzle to surge forward or backward, affecting foaming. The reaction rate gradually increases within the first two minutes after starting the machine, sometimes requiring corresponding adjustments to the settling plate. Adjustments to the settling plate are more critical in formulas with low density and high MC.

TDI flow rate can be calculated by determining the corresponding scale value for the flow rate, but it is recommended to measure the TDI flow rate during the first foam production. Flow rate is too important; if the flow rate is incorrect, everything else will be a mess. It's best to rely on the simplest and most intuitive method of measuring flow rate.

When powder is being mixed, the mixed stone powder should be left overnight and production should start the next day. For formulations containing melamine and stone powder, it is recommended to first mix the melamine with the polyether for a period of time before adding the stone powder.

Formulas for foam machines with longer mixing chamber or more teeth on the mixing shaft typically have less amine and lower material temperature. Conversely, formulas for foam machines with shorter mixing chamber or fewer teeth on the mixing shaft typically have more amine and higher material temperature.

For the same formula, when switching between dual spray swing heads and single spray swing heads, if the cross-sectional area of the two nozzles is similar, the requirements for the fineness and number of layers of the mesh are similar.

Correction of small material flow rate can be done by measuring the return flow rate of the small material, or by dividing the total usage by the foaming time for correction. When the values obtained from the two correction methods differ significantly, the data from the second correction method should be used.

Formulas for soft foam with better properties are usually in an unstable range, such as lower TDI index, lower water to MC ratio, lower T-9 dosage, and lower silicone oil dosage. Just like in our jobs, there must be effort before reward.