Release agents for rotational molding
Release agents for rotational molding (rotomolding) are used in work environments at very high temperatures. In these circumstances, the use of semi-permanent water-based release agents is undoubtedly the best option. Apart from allowing a high number of demolding cycles after each application, they ensure a safe work environment. In this post you will find everything you need to know about mold release agents for rotational molding. Further on we point out the key factors to select proper release agents for rotomolding.
Characteristics of mold release agents for rotational molding
Mold release agents for rotomolding are specially designed for the processing of thermoplastic resins in rotational heated molds. The special temperature requirements of this industry make that high performance release agents for rotational molding must:
- allow the resin to become attached to the mold wall during the initial heating phase of the molding cycle. In spite of this, the mold release agent must be always present between the mold wall and the plastic resin.
- ensure that the fully molten skin of the rotomolded part remains in close contact with the mold wall throughout the heating cycle and the initial part of the cooling cycle.
- ensure that the rotomolded part remains in close contact with the mold wall until the part has enough cohesion within its structure to resist collapse when the release process begins.
- helping quick release of rotomolded parts without any surface abrasion damage.
Key factors to choose suitable mold release agents for rotomolding
In the choice of release agents for rotational molding we should take into account the following things:
- no transfer (contamination) of the release agent to the rotomolded part. This is something of special importance in the case of high value products that will be painted or glued in later stages of the manufacturing process.
- high amount of molding cycles after each release agent application.
- solvent and alcohol free products. They should not emit CFC or any other volatile organic substances. Due to the high working temperatures, this is a key requirement to ensure a safe work environment.
- chemical stability. The quality of any release agent is very linked to the expiration term provided by the producer.
- low level of in-mold buildup or mold fouling
- wide range working temperatures. Many release agents for rotomolding available in the market require a minimum activation temperature to start working. On the other hand, they stop working when reaching a certain temperature. A wide range working temperatures release agent optimizes molding cycles and enhance manufacturing efficiency.
Rotational molding (rotomolding) requires solvent and alcohol free release agents that ensure a safe working place. Due to the high working temperatures it is compulsory to use semi-permanents water-based release agents adapted to the temperature cycle and mold shape. Thanks to our close collaboration with our partners we assure our clients the experience and the capability to formulate mold release agents suited to meet their specific needs. If you want to know more about this topic, we recommend you read our complete guide of mold release agents.