Why Your Komori Press Is Streaking (And Why Your 'Quick Fix' Isn't Working)
So, Your Komori Is Streaking Again.
You call it 'banding.' The operator calls it 'ghosting.' The client just calls it 'unacceptable.' Doesn't matter what you name it--that inconsistent line across the sheet is costing you time and money. And if you've already tried the obvious fix (new blankets, fresh ink, another cleaning cycle), you're probably frustrated as hell.
I've been on site for this exact scenario more times than I can count. In the last year alone, I've triaged 40+ press issues where 'streaking' was the symptom listed on the ticket. And what I've found is that 90% of the time, the internet advice you find is either incomplete or just plain wrong for a high-speed offset press. It's not your blanket. It's not your ink. It's usually something deeper, and the longer you ignore it, the more it costs.
Let's get into the real reasons your Komori is streaking, the cost of the 'quick fix' mindset, and what actually works.
The Real Culprits Behind the Streak
When a customer calls about streaks, they usually have one of two theories: it's a worn-out blanket or a bad batch of ink. Those can be the cause, but I'd say they're the culprit maybe 20% of the time. The other 80%? It's a system issue that a simple blanket change won't fix. Here's what I actually look for.
1. The Roller Settings Are Drifting (It's Not a Conspiracy, It's Physics)
The most common cause of mechanic streaks isn't a dirty roller--it's improper roller settings. Over a few thousand impressions, bearings wear, brackets shift, and the kiss between the ink roller and the vibrator changes by fractions of a millimeter. That's enough to cause a cyclic streak that appears every 4 or 5 inches.
I worked with a shop in Chicago last fall that had swapped out their roller sleeves three times in six weeks. They'd spent nearly $2,000 on parts and labor trying to fix a streaking issue. When I arrived, the first thing I checked was the roller pressure. It was set at 0.18mm on one side and 0.12mm on the other. No wonder they were streaking. A 30-minute adjustment with a feeler gauge solved it. Cost of the fix: nothing. Cost of the wrong fix: $2,000 plus downtime.
2. The Dampening System Is Fighting You
This one is sneaky. If your Komori uses a conventional dampening system and you're seeing what looks like a water-based streak (sometimes called 'tinting'), it's rarely a flood of water. It's usually uneven metering. One end of the dampening roller is touching the plate harder than the other, creating a localized imbalance. The result? A streak that shows up in the mid-tones and gets blamed on the ink.
I don't have hard data on industry-wide rates of this issue, but based on the calls I've taken, I'd estimate that a quarter of the streaking complaints I hear are actually dampening-related, not ink-related. It's a classic case of treating the wrong symptom.
The Hidden Cost of Chasing Streaks
So your press is streaking. You try a new blanket. Still there. You try a different ink. Still there. You run a cleaning cycle. Still there. Now you've got 2 hours of downtime, a bin of wasted sheets, and a client waiting on a proof. That's the real cost.
Let's put some numbers on this. Based on publicly listed prices, a standard set of Komori press blankets for a 6-color machine runs about $3,600. If you change them trying to fix a streak that's actually a roller setting issue, you just spent $3,600 for nothing. Plus the 2 hours of labor. Plus the 500 sheets you ruined while testing. That's a $5,000 'quick fix' that didn't fix anything.
Had 2 hours to decide on a fix for a client's rush order last year. Normally I'd run a full diagnostic, check pressure settings, and test the dampening system, but there was no time. The job had to ship that afternoon. I went with a blanket change based on a hunch. In hindsight, I should have pushed back on the timeline. The blanket change didn't work, we missed the courier pickup, and the client hit us with a $2,000 penalty for late delivery. All because I didn't have the 40 minutes to do the right diagnostic first.
The KHS Hyper System: Not a Magic Wand, But a Real Help
This is where the KHS Hyper System (the automation suite on newer Komori machines) changes the conversation a bit. It doesn't make streaks impossible, but it does make the diagnosis a lot faster. The system tracks roller pressures, temperature, and dampening rates in real-time. So when a streak appears, you can look at the data from the last 500 impressions and see if something drifted.
Is it a magic fix? No. I've seen a press with KHS streak because someone forgot to clean the dampening pan. The system is only as good as the operator who maintains it. But what it does well is eliminate the guesswork. You don't spend 2 hours wondering if it's the ink or the blanket. You check the KHS logs, see that the dampening rate jumped by 8% on unit 3, and you know exactly where to look.
If you've got an older press without KHS and you're chasing streaks regularly, it might be time to look at what the newer presses offer. Not because they never break down (they do), but because the diagnostic data alone can save you thousands in wasted downtime.
The Bottom Line on Streaking
If your Komori is streaking:
- Don't change parts first. Check roller pressures. It's free and quick.
- Look at your dampening system. Make sure the metering is even side-to-side.
- If you have KHS, use the data. It's not just a fancy dashboard. It's your diagnostic log.
And if you're shopping for a part or a press and the first thing you ask is 'what's the price?'--just remember that the cheapest blanket is going to cost you way more if it's the wrong solution. The TCO of a part isn't the sticker price; it's the cost of the downtime and the wasted material and the lost customer trust.
Trust me on this one. I've paid for that lesson a dozen times over.
