Product Announcement from Control Plastics, Inc.
In Gas-assist injection molding , conventional injection molding techniques are utilized in combination with the introduction of gaseous nitrogen. The polymer material is melted and injected into a cavity mold using a standard injection molding press. As the melt begins to solidify the area in contact with the mold walls will harden first. At this point an inert gas is injected into the melt pressurizing it from the inside. This internal pressure of the gas pushes the molten material in to every nook and cranny. Once the material sustains an adequate cure, the nitrogen is vented, the mold is opened, and the part is ejected
An advantage to Gas-assist injection molding is the ability to reduce warpage and distortion by abolishing molded in stress. The gas is used to reinforce ribbed parts eliminating sink marks and surface blemishes. Nitrogen aids with uniform pressure distribution throughout the mold resulting in better packing and a more aesthetically pleasing part.
With the use of the internal pressure provided by the nitrogen gas the outer force needed to hold the part in its shape can be lowered. This provides a condition for larger parts to be produced with less tonnage on smaller machines. This will reduce the molders capital investment when purchasing new equipment.
Diminishing wall thickness and resin consumption will decrease the cure time needed for part production. Curing is the act in which polymer melts harden and hold shape. With Gas-assist injection molding, less polymer is needed which leads to faster cooling and lower cycle times, allowing the machines to increase part output. Nitrogen gas displaces some of the volume that is normally filled by resin. Thus Gas-assist injection molding is faster and uses less material, saving you time and money.
Please feel free to contact Control Plastics, to learn more about the advantages of Gas-assist injection molding, and our other services.