/ep_edm/en/contect_991.html SHINI PLASTICS TECHNOLOGIES, INC.

Special Reports

2015 Quarter 4 Issue 25

Application of Air-cooling Chamber on Plastic Molding

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The air-cooling chamber can substitute for a highly efficient dehumidifier. At the same time it reaches the reduced cooling time, simplifying the technological process. It ensures highly efficient and reliable production as well as improves the product’s quality and output at the same time.

Working Principle of Air-cooling Chamber

Concrete working principle of the air-cooling chamber: it should start the connected cooling water system before the air-cooling chamber starts up. Then by adjusting the flow and temperature of cold water, requirements of different outlet-air temperature can be reached. Cold water processes heat exchange with air in the heat exchanger. After the centrifugal blower starts running, it drives the air flow to reach cooling and the dehumidifying effect. While the temperature of cold air output via temperature sensors, feed back to controller is necessary for control and display.

Features and Applications of Air-cooling Chamber

The air-cooling chamber adopts side air suction by using a simple structure. It occupies a small space for easy movement. It should be used with a cold water system or water chiller. Air-cooling chambers are mainly applicable for applications like cooling of large PE film production, cold-air stereotyping for bottle blowing machines, and preventing mould from moisture condensation. In areas with high humidity, it is possible to use a closed air loop. Following are the analysis of air-cooling chambers used in different occasions. 

1.Blown Film Extrusion Molding

During plastic blow molding, air ring, internal bubble cooling system (IBC) is the key component in blown molding and cooling. The cooling of bubble is dependent on the cooling system inside the air ring, bubble and ambient temperatures of blown molding equipment. An air ring is an essential part in the blown molding process and cooling for bubbles. The soft airflow and suitable temperature around bubbles are a fundamental condition for bubble after-stage cooling. Internal cooling is a kind of advanced technological solution for bubble molding and accelerating cooling.  Cooling principle of blown film: In plastic blown molding, it adopts the air ring which employed air as a cooling medium to process outside cooling at the blowing zone of bubble (between the dye and condensation line). When cooling air via blower through air ring with a certain angle and speed, it is blown into the bubble that came out from the extruder. A high temperature bubble contacts with cooling air, large amount of heat from the bubble exchange with the air and taken away, making the bubble (the cylindrical tube film) cooler, consolidation, and the temperature decreasing. In order to improve the mechanical properties and output of the film, it can adopt the air-cooling chamber to provide constant frozen air to the internal cooling system of air ring and film bubble.  


2.Cold Air Stereotyping of Blow Molding Machine

The current blow molding machine adopts a two-step process in which the plastic material is usually made into performs first and then blow molding finishes afterwards. Processes of blow molding can be divided into two steps: First, performs are exposed to high temperature tubes to soften the body parts. To keep the shape of a bottleneck, it is unnecessary to heat up the perform mouth. Thus some cooling aspects are needed to cool down the mouth part. Then, by placing the preheated performs into moulds and air-inflating with high pressure will lead to finishing the blow molding. For the sake of controlling the cooling time and ensuring outstanding quality, keeping a constant ambient temperature and enough moisture is very important. 

3.Prevent Mould from Moisture Condensation

In plastic molding too much air moisture would result in condensation on the mould surface and affect the finished product quality, leading to water-drops on the surface of goods. Therefore, moulds’ ambient humidity needs to be controlled to ensure the products quality. The launch of air-cooling chambers provided the game changing to these applications. The air-out dew-point is10℃, and temperature can be adjusted between 11℃~16℃, which effectively controls air temperature and moisture round moulds. This ensures dry air would be fully around the mould to avoid dew drops during mould cooling.

The application of the air-cooling chamber is not limited in one side or one field, as long as the occasion requires the control of ambient temperature and humidity, it can all have beneficial applications.   


SACC-3000 Shini Air-cooling Chamber