QingdaoFoam packaging manufacturerExpounding the raw materials and pre delivery mechanism of foam packaging manufacturing

1、 Raw materials:

1.1 Process control of fast materials and standard materials (ordinary materials)

Rapid materials: Low molecular weight and volatile substances, mainly used in automatic machinery, also used in soil machinery.

Low foaming agent and short curing time. During operation, the heating time is short, the cooling time is short, the forming cycle is short, energy consumption is saved, and production efficiency is improved.

1.1.1. Under normal circumstances, due to the small amount of foaming agent, it is necessary to heat it in a short period of time and fully utilize a small amount of foaming agent to bond bubbles. This shortens the heating time and saves time. Use high pressure and heat for a short period of time.

1.1.2 can save energy consumption and improve efficiency. High temperature demolding can reduce the difference between forming temperature and demolding temperature, thus saving steam.

The molding temperature of the mold is 115-130 ℃. After cooling with water and vacuuming at 90 ℃, the surface expansion rate of the product decreases to a certain value

85 ℃ demolding.

Standard materials: High molecular weight and volatile substances, mainly used in earthmoving machinery, but less used in automatic machinery from the perspective of energy consumption control.

1.2 Rapid Materials - Rapid Prototyping and Steam Saving

1.2.1 Quick material types: BASF CP303, Dragon King B-SB, Daxing 303, Chengda PK303, etc.

Features:

Rapid cooling speed leads to rapid prototyping cycles, typically 20 to 30% faster than ordinary materials

Rapid material demolding temperature is high, reaching 80-85 ℃

The demolding temperature of traditional materials is low, ranging from 60 to 65 ℃

Therefore, rapid feeding can save up to 30% of steam

In the rapid prototyping process, the combination of products should be controlled between 60% and 80%, which can better reflect their rapidity.

Rapid material control technology: Adopting high-pressure short time heating.

1.2.2 Common material types: BASF CP203, Dragon King E-SB, Daxing 302, Chengda PK302, etc.

Commonly used material control technology: Due to its high molecular weight and high volatile substances. Expansion is prone to occur during the production process. Low pressure heating should be used for a long time.

2、 Pre release mechanism:

2.1 Foaming agent:

The foaming agents for expandable polystyrene are mainly pentane, n-pentane, and isopentane. The olefin content in industrial pentane has a significant impact on the processing performance of expandable polystyrene. High olefin content can easily lead to product shrinkage.

The content of EPS foaming agent is not as high as possible. Standard: 4.8-7% (≤ 6.8%) is usually around 5%.

The content of foaming agent is too high: pre foaming, uneven, deformed, and cracked.

Low foaming agent content: reduced foaming rate, prolonged heating time, poor adhesion of EPS particles during the molding process, and easy shrinkage and detachment of particles in the product

2.2 Advance principle:

During the pre foaming process, the beads containing foaming agents will not foam until 80 ℃, but the foaming agent in the beads will diffuse outward, and the beads will not expand at this time. When the temperature exceeds 80 ℃, the beads begin to soften, and the foaming agent distributed within the beads is heated and vaporized to generate pressure, causing the beads to expand and form disconnected bubbles. At the same time, steam also permeates these cells, increasing the total pressure inside the cells. As time goes on, the steam deepens, the pressure increases, and the volume of the beads also increases. This process continues until the thin-walled cell ruptures. Therefore, it is important to increase the total pressure in the pores due to the continuous penetration of steam during the pre foaming process. For example, foaming agents can be opened and steam can expand. In order to make the steam enter the foam cell faster than the foaming agent escapes from the cell, the polymer will be stretched into a rubber state with sufficient strength to balance internal pressure, so that the beads can be pre foamed. This is the simple mechanism of PS foaming.