Angel Hair - You may know the problem, but what is the solution

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Angel Hair – You may know the problem, but what is the solution?

The converting process can pose many challenges for the machine operators, but one that comes up time and time again is Angel Hair. Not as heavenly as it sounds, Angel Hair is the thin strands of board created during the converting process. These strands are classed as contamination by all carton convertors, but in particular, those who deal in the food and drinks industry.

Who is affected by Angel Hair contamination?

Carton Convertors are the first in the chain to see this problem. As the manufacturer of packaging for the food industry, they need to remove the risk of Angel Hair. If Angel Hair goes unresolved, then the Carton Convertor runs the risk of losing a contract with the food producer as they are unable to use packaging which poses a risk of contamination to the food consumer.

Why is Angel Hair such a big problem?

Strands of board are sometime created during the converting process. These are classed as contamination by the food packaging supplier. If any of the strands of the board enter the food chain, the food suppliers are open to having a law suit pursued against them.

How and why do we get angel hair?

Machine operators are often placed under immense pressure, management are conscious that an unproductive machine cost money. This is considered as down time and is costly.

Good working practice can be overlooked to reduce down time on the converting machines, which unfortunately, can cause further problems later down the line.

Over pressuring the cutting die to speed up the set up instead of undergoing a steady patch up procedure is going to cause damage to the tool. If the cutting blade is over pressured, you effectively blunt the knife, causing a pinching effect of the substrate between the tip of the knife and the steel cutting plate during the converting process. The pinching of the substrate during the conversion causes fine strands of board to break away,  the results is Angel Hair contamination.

There are some corrugated packaging suppliers are currently looking into ways to measure and set a limit against this type of board contamination.

Are there any other contributing factors to Angel Hair?

The main thing is to keep the blade from being over pressured, apart from too much weight on the machine and a bad patch up, the machine operator must also ensure that the cutting plate is in excellent condition. If they are uneven, pitted or worn, the plates will add to the pinching effect. If the plate is worn, then it must be replaced. Poor rubbering processes on the cutting die can also cause the sheet to cut unevenly resulting in bursting of the sheet. If the sheet has short recycled fibres, they will burst apart and cause board contamination. However, this isn’t exclusive to recycled material. Control of factory humidity, and moisture content in the board is extremely important, if you have dry board with short fibres, again during the converting process, the board is susceptible to bursting apart, resulting in poor cutting.   In corrugated board, it is important to control moisture, starch and liner content (although I believe this is more difficult than it sounds) as dry board is susceptible to breaking up during the converting process.

It is also important to understand the correlation between the width of the strands of the Angel Hair and the damage to the tip of the blade. The more damage that the blade has incurred, then the wider the Angel Hair will be.

Where has Angel Hair been an Issue and how can it be resolved?

I recently received a phone call from a die maker, one of their customers was doing some important packaging for a beverage company. The die maker asked if I could do a joint visit as the angel hair problem was becoming a big issue. The packaging company was at risk of losing the contract with the drinks company, therefore, the die-maker would have lost their tooling contract with the packaging manufacturer.

A joint visit took place to the packaging facility and I was greeted with a “what are you going to do about it” situation. The manager of the packaging company was adamant that it was down to poor tooling and bad rule.

Before making any suggestions, I went to look around the machine area along with the die maker. I must admit, I have never seen Angel Hair in such large quantities or strand widths before. I spoke with the machine operator and asked to look at the tool to assess the damage.

The machine tooling was thumping through the board and the cutting rules were very flat, both signs of overpressure, but the manufactured tool made by the die maker was made to a very high specification. I had a look at the patch sheet, the patch sheet had very little patch tape on it, that along with the heavy thumping of the machine is another sign of over pressure. Everything pointed towards over pressure on the machine.

During the patch up process, no calibrated patch sheet or industry specific patch tape had been used. Instead the patch up had been performed using selotape, masking tape and even brown parcel tape. It was obvious to me at this point where the problem lay. It was a case of too much initial weight on the tool and a bad patch up process. There were no signs of the 80/20 patch up process that the machine manufacturer usually recommends.

While speaking with the packaging manufacturing manager, and discussing what I had seen on the machine, I explained that I felt that the machine operator would benefit from training on performing a correct patch up process. The managers view was a machine standing still costs money – “let’s get the machine running”. The operators, who didn’t have the understanding of the damage that they were causing to the rule or tooling continued to increase the weight on the platen so that they could run the machine quicker.

I suggested to the packaging manager that he should put some time aside to give training to the machine operators on good machine set up practices, and quality patch up techniques. The reason for this was to help the Operator understand the damage they will cause to the cutting die, and that if they insist on over pressuring the cutting rules they will inevitably end up causing the Angel Hair problem.

The training provided by the Diemaker resulted in a huge reduction in Angel Hair over the next few months, and the packaging company kept their contract with the beverage company.  The machine set up training was conducted using recommendations made by the machine manufacturer for initial machine pressure and patch up process. Although quality steel isn’t the answer to eliminating Angel Hair, after all one impression can kill the cutting rule, I always advise die makers to use a hardened tip. In this case Bohler Steel rule was recommended to the Die Maker, to provide extra strength in the tooling.

The advice and training have elimiated Angel Hair, this has further benefited the packaging company as they are now saving money on tooling. The £250 down time is offset with the fact that the packaging company no longer requires tooling to be replaced as frequent.

23rd January 2017, 14:59