Plastic injection: adding value thru flexible robotics

Are you manager of a company operating injection presses? If so, you fully understand that money flows in only when plastic is being injected, right? How often do we hear from customers: “As soon as the mold opens, I’m not making money until it closes again and injects plastic!” It’s usually a matter of a few seconds only, but it’s a shame that there is no magical way to exit parts without stopping the injection flow.

This is why plastic injection companies are investing so much time, effort and money in optimising the cycle times thru different strategies:

  • Reducing opened mold time
  • Accelerating plastic injection speeds
  • Improving temperature controls for faster cooling

 

These are all very valuable and legitimate aspects to consider for better competitivity on the market. But what about adding the maximum value possible to the parts after they are injected?

Calculating gain with only one variable (speed) is pretty straight forward, it’s a simple ratio. But there is a point where trying to gain anything more will just take too much effort and put both work force and equipment under huge pressure, jeopardizing the profitability of the whole thing.

Calculating gain with auxiliary operations is not always straight forward, but it is never complicated either. It may vary from one project to the other, requiring some brain power to find the numbers, but these gains are usually way more significant than gains from speed alone. It would be a mistake not to look at it seriously.

If you recognize your situation in one of the following statements, you should definitely consider reading the whole thing!

    • ▸ I rather quote for parts requiring no auxiliary operations, or the fewer the better
      ▸ Once parts are injected, we store them in bulk and we later perform manual auxiliary operations and final packaging
      ▸ 100% inspection is costly, or simply impossible

 

How can auxiliary operations become more profitable than the injection process itself?

Quick spoiler:

  1. Add value to parts for free while the mold is closed, at each cycle
  2. Take advantage of the fact you have an accurate control of the parts positions in the mold
  3. Use the most flexible automation cell available on the market to manage multiple SKU auxiliary operations
  4. Bring every party around the table for macroscopic view and think out of the box!

Make money in parallel of the mold closed time

Instead of having your automated handling system just waiting for the next opening of the mold to deliver new parts to you, why don’t you use this free time to perform valuable auxiliary operations for free?

    ▸ You already do perform some automated auxiliary operations on your parts right at the press? You are on the right path! Ask us to look at them or any future part for cost-reduction/profit-increasing automation with our expert’s eye.
    ▸ You do perform auxiliary operations, but later down the line? We can help you reduce costs by eliminating redundant handling and find clever ways .
    ▸ You don’t perform auxiliary operations? Ask your customers which operations would create value for them.

 

Don’t leave money on the table, there are so many very affordable automation technologies available. The rest is a matter of calculating the ROI, and the exercise is so much worth it.

Make every second count, twice!

 

Save time and money by keeping track of the parts positions in 3D space

As you know, an injection mold is a quite accurate piece of equipment. Every single cavity has a steady position in 3D space. It means you can easily automate the exit of parts using an automated handling system. You might already be using some of these systems. But sadly, too often the exit of parts and entering of inserts is about the only purposes served by automated handling systems. If we drop the parts in bulk to later on grabbing them back for auxiliary operations, this is nothing less than money lost.

Hey, you had the part in control at the mold exit and you let go of it! Now you have to use a vision system or other mechanical/electrical feature to locate them and grab them back into controlled position. Or even worse, you have to do it manually! That loss has a potential to be converted into gain if well engineered.

Be creative! What can I do IMMEDIATELY with this part while I have it under full control instead of doing it later? Why not brainstorming with your engineering team? Ask yourself: in an ideal world, what would magically happen to the part after injection? Technology is available, like speaking with somebody half-way around the globe used to be magic… it’s no more.

 

Bet on flexibility

Well, I mean bet like you would bet on a SUV over a 2 seated convertible to be the best adapted vehicle for the transportation needs of a 3 children family, there is no uncertainty here.

Why limit yourself to 3 or 4 axes robots’ capabilities? Don’t put handcuffs on your ROI! If you plan on making money with auxiliary operations, 6 axes robots will easily open so much doors that 4 axes robots can only dream of opening… in their likely low creativity robotish dreams.

Once a plastic injection supplier truly realises the potential of 6 axes robots, there is no turning back to cartesian robots except for very specific situations such as year long single SKU production on a single injection press, with no auxiliary operation ever required.

Also, why permanently fasten your automated handling system on top of a single injection press? These robots mounted on top of the presses are one way to clear the floor for better access by operators and mechanics. But they still have to be serviced once in a while and access to them is not the easiest thing.

There is a better way: 6 axes side entry mobile cells. By being mobile, with quick and clever setup features, one can use its mobile cell for instance at press A for 4h of production, then move it to press B for 8h of production, then… well you get the picture. Setup times within 15 minutes are the standard.

 

Get everyone implicated in finding the best global solution

We have lived it numbers of times. When we gather the designer of the part, the mold maker, the injection manufacturer and the automation supplier, great things happen. With the right persons participating, every minute invested in group for thinking is exponentially producing cheaper, simpler and more profitable solutions.  The sooner we get to sit all together to brainstorm, the more efficient and easy the whole process is. Many companies have already understood how important it is for the designer and the mold maker to sit together early to work out a new design. But seldom are there companies who know that the same benefits are present with the automation aspect.

 

Final thoughts:

More and more final customers are asking their plastic injection suppliers to provide turn key parts with added value thru auxiliary operations, ready to assemble on their production line, guaranteed to meet quality requirements.

If they don’t ask for it, then you might take advantage of offering it over your competition.

What is the cost of your inaction? Every hour you keep postponing to look at automation solutions is an hour that could have been more profitable for you company!

Technical reps at CFM Robotics would be more than pleased to share their experiences with you and help your company reflect on implementing the best practices in plastic injection automation.