5 Ways PurgingTo Help Reduce Costs

A machine that is running 24/7 with high yields makes for a happy shop owner for any manufacturing plant, and plastic injection molding is no exception. Meticulous care and maintenance with these kinds of high volume machines will pay for itself over and over, especially in production shops running lights-out manufacturing operations.

Purging plastic injection machines using polymer purging compounds between long cycles can give higher yields, less machine downtime, and overall higher profitability on large batch runs.

The biggest enemy to production-quality plastic injection machines is carbon and particle buildup within the internal cavities of the machines. Because the machines are enclosed, it is difficult for machine technicians and operators to notice particulate buildup—especially if the machine is set to run round the clock. 

If the buildup is not caught early it may be necessary to overhaul the entire machine, so it is important that the machines are properly managed and regularly serviced. There are five key benefits that come with routine purging of a plastic injection machine.

Reduced Machine Maintenance & Service Downtime

With any manufacturing process, having a machine down has an immediate impact on cost and ROI. Simply put, the more time a machine spends being repaired and overhauled, the less profitable a particular job will be.

Decreased Severe Wear & Tear on Injection Machine Components

Purging an injection molding machine helps to eliminate carbon buildup and other harsh chemicals that wear a machine down faster. Charring and black specks are eliminated almost entirely through regular purges, allowing the machine to be flushed of any contaminants that might gum up its internals.

Fewer Scrapped Parts

As a result of reduced downtime and wear and tear, ultimately fewer parts will need to be scrapped. Inconsistencies in material, broken or incomplete parts, and incorrect material mixtures are just a few common reasons why a shop might have to scrap parts. But with the injection molding process running smoothly, the end product will be less likely to have defects.

Reduction in Color Hang-up & Changeover Time

Some of the downtime that comes with plastic injection molding is caused when a different type of resin or material is added, or if a new color is being introduced in the machine. Particulate from one material will typically not mix the same as the other. Purging a machine ensures that the machine is clean and ready for the new material or color.

The Machine Can Run at Optimal Temperatures & Conditions

Some of the overhead associated with running these kinds of machines comes from starting up (heating) initially, and then the cool down period once the machine has run for a significant amount of time. While the machine is still within its normal operating temperature, purging the machine between runs or color or material changes will allow the machine operator to eliminate the heat-up and cool-down of the machine almost entirely.

Purge Consistently & Save in the Long Run

Machine technicians and plant supervisors will find purging especially valuable when changing colors or polymer/resin type when switching over to different jobs. The more variety in their injection molding jobs, the more they should consider having purge cycles built into their overall production schedule.

This is especially true when there is a changeover from materials that are not similar in chemical makeup, as well as when switching over to different colored polymers. There are helpful apps and resources to assist with the injection molding processes and help troubleshoot issues when they arise. Overhauling the internal heated screw and other components within the machine is no cheap matter, and it will be costly to a shop on a number of levels. By building a “buffer” between machine cycles, it is possible to save not only time and headaches, but also a considerable amount of dollars (both tangible and intangible).