The plastics industry is very aware of the problems associated with airborne moisture, from the formation of condensation on moulds, to the absorption of moisture by the plastic granules.
Injection and blow moulding operations utilize thermoplastics which are heated to plasticity and shaped into forms via the use of a mould. The majority of systems employ the use of chilled water to maintain a cold surface on the mould, resulting in a quicker forming time of the component, and thus higher production volumes. In fact, generally the colder the mould, the quicker the cycle time and greater the production outputs.
Operating at low mould temperatures creates problems with condensation on the mould surface, especially during the summer period. This will result in unacceptable water marks on the product and corrosion on expensive moulds and guide pins, necessitating repair or even replacement.
This problem of sweating can easily be overcome by simply increasing the mould surface temperature. This however will not be the preferred choice as it will mean increasing the cycle time of the components and decreasing output. By incorporating a dehumidifier, mould temperature of 5°C or lower can be achieved, without the risk of sweating.
Greater production output
Due to low mould temperatures, quicker cycle times will be achieved, and in certain cases, reductions in excess of 30% are attainable, resulting in greater production output, irrespective of external ambient conditions.
Storing the raw material
When storing the raw material, normally plastic granules in silos, it is important to protect these against moisture damage. Also, pneumatic systems can benefit from dry air, avoiding mould and the products sticking together. With a Seibu Giken DST dehumidifier, can you control the relative humidity in the whole production line.
Dry air can also be used when storing moulds. No need to put in time and effort in greasing the moulds -they are kept free from corrosion when the relative humidity is below 50%.
FAQ
How do you remove moisture from plastic?
Moisture removal from plastic is critical to prevent defects and maintain product integrity. DST Dryer employs desiccant dehumidification systems that effectively extract moisture from the air circulating around plastic granules and during molding processes. By maintaining low humidity levels, our solutions ensure that plastic materials remain dry and free from moisture-induced issues.
What does humidity do to plastic?
High humidity can lead to several issues with plastic materials. It can cause plastic granules to absorb moisture, affecting their properties such as strength and appearance. During molding operations, humidity can result in condensation on molds, leading to water marks on finished products and corrosion on mold surfaces. DST’s dehumidification systems prevent these problems by controlling humidity levels, thereby maintaining optimal conditions for plastic processing.
Can plastic absorb moisture?
Yes, plastic materials can absorb moisture from the surrounding environment, particularly if humidity levels are high. This absorption can lead to dimensional changes, reduced mechanical properties, and surface defects in molded plastic products. DST’s desiccant dehumidifiers ensure that plastic granules and molded components are kept dry, preventing moisture absorption and preserving product quality.
How do plastic dehumidifiers work?
Plastic dehumidifiers, such as those provided by DST Dryer, utilize desiccant technology to remove moisture from the air. The process involves passing humid air through a desiccant material that absorbs moisture molecules. The dry air is then circulated back into the plastic processing environment, maintaining low humidity levels essential for preventing moisture-related defects in plastic products. This technology ensures efficient operation and high-quality output in plastic molding and processing operations.