Many companies are now utilizing injection molding in their manufacturing process. This is because injection molding is an effective, efficient, and low cost way to produce their products. That being said, manufacturers are always looking for ways to improve their process and drive down costs. There are various ways that manufacturers can make alterations to decrease expenditure, but not all methods are created equal.
When it comes to decreasing costs for manufacturers, decreasing the cycle time is the name of the game. This is because a decrease in cycle times allow manufacturers the ability to produce more parts in less time. In manufacturing, time is money, so faster production cycles lead to increased potential profits.
Out of all the processes involved in the cycle time of a part, cooling is by far the most tedious. In many cases, cooling takes up more than 80% out of total cycle time, while tool-opening/closing and material injection/ejection typically take up less than 20%. Knowing this, a reduction in cooling time is the most effective way for manufacturers to accelerate their process and drive down cost
In order to reduce cooling times, manufacturers design in cooling channels. These cooling channels should be focused on hotspots and areas susceptible to warpage. Unfortunately, the traditional method for creating these cooling channels is by gun drilling directly into the injection mold tool. Because these cooling channels are limited to straight lines, they are not nearly as effective. In a perfect world, companies would be able to design conformal cooling channels that follow the unique geometry of each individual part – this is where additive manufacturing comes in.
Novel advances in additive manufacturing have allowed for new ways to manufacture conformal cooling channels. Direct metal laser melting or sintering (DMLM / DMLS) is a form of additive manufacturing that uses a laser to melt / sinter metal powder and create a metal insert based on a 3d CAD design. DMLM/DMLS creates the metal insert layer by layer, which allows for engineers to design complex cooling channels without being limited to straight lines.
By utilizing predictive engineering models, engineers are able to identify hotspots and areas with high warpage potential. Knowing this, engineers can create a 3d CAD of the metal insert with complex cooling channels and then use DMLM/DMLS to manufacture the part with these channels already installed. By utilizing predictive modeling before producing the physical part, design engineers can ensure peak performance at the time of manufacturing.
Although the most significant process change that manufacturers can make to drive down costs is by optimizing their conformal cooling channels, that doesn’t mean that there aren’t other things that can be done. These next four topics are all areas manufacturers can target to lower costs and increase productivity.
Larger parts require larger molds, and take longer to produce. This means that typically, the larger a part is, the more expensive it is going to be to produce. In order to reduce costs, manufacturers should do everything they can in the design stage to make the part smaller with less complex features while , as this will lead to a significant cost reduction.
The chosen mold material and pigment selection can both impact the cost it takes to produce a part. This means that manufacturers should be thoughtful about their material needs and choose the lowest cost material and pigment necessary to accomplish the desired performanceof the part.
Optimize Mold Design
By designing the mold with the specific part in mind, manufacturers can reduce the time necessary to produce a part and decrease costs. This is done by strategically planning the positioning of the part, paying attention to how the mold will fill and how scrap can be reduced. Strategic design can also eliminate the existence of leftover material, which would require a sprue and runner to remove.
Another method for reducing costs is by altering an existing mold to produce a new part. This process is called retrofitting and can dramatically reduce costs as it negates the need to pay for a brand-new mold.
Although complex conformal cooling lines are the most effective way to drive down cycle times and subsequently, cost, there are clearly multiple ways that manufacturers can optimize their process. By thinking strategically in all of these areas and making informed decisions, manufacturers can keep costs low and rate of production high