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| COMPLAINT HANDLING PROCEDURES |
Introduction
Preventing Problems
Tackling Problems
Complaint Checklist
Evidence Checklist
| Introduction |
Over the past twenty years or so, huge progress has been made in the measurement and control of the physical and aesthetic properties associated with paper making.
As a result, manufacturing tolerances are much narrower, and products are far more consistent in their appearance and performance from one making to another. However, although defects during manufacture are less common, they of course still occur. Where a customer has cause to complaint about one of our products, it is our policy to attempt to resolve the the problem as quickly as possible.
How quickly and efficiently a complaint can be resolved, depends largely upon the quality of the supporting information and evidence made available to us. This is particularly important where a customer is seeking to recover costs in relation to downtime etc.
Whilst the vast majority of paper manufacturers supplying the UK market will consider reasonable claims sympathetically, the “burden of proof” lies with the merchant and his customer.
Perhaps the most useful analogy to adopt when collecting/retaining evidence is that of making an insurance claim.
The purpose of this section is to provide guidelines and check lists to assist in the gathering of relevant evidence and information.
| Preventing Problems | page top |
As in most fields, preventing paper problems is usually far less costly and time consuming than correcting them.
The following pointers are generally considered to be good practice:
a) Ideally, paper should be allowed to reach near press-room temperature PRIOR to unwrapping (ideally 48 hours).
b) Please retain ream/pallet labels until the job is accepted by the client. It would be very helpful if the paper's making references were recorded on the job bag just in case there is a complaint from the client. Knowledge of the making reference is vital for two reasons: firstly, to enable us to avoid sending out the suspect paper either as a replacement or as a fresh delivery to another client; and secondly, to allow the mill to inspect their records of the suspect making as soon as possible.
c) Always MINIMIZE the delay between unwrapping and printing/processing. This will limit the effect of any imbalance between the condition of the paper and the ambient conditions of the printing works.
d) Where paper is to be subjected to multilpe passes on the press, always ensure that any stacks in process are protected by close-fitting, moisture-proof material.
e) If, once printed, the paper is likely to be subjected to laser printing, or laminating/varnishing, please refer to your ink supplier to ensure the inks are fully compatible.
f) When guillotining paper, please ensure that a true, clean edge is presented to the stack. Trimming with a worn blade may not only cause edge-padding or burring, but it can also lead to edge dust (one of the most common sources of print interference).
g) Always protect the stack with moisture-proof material IMMEDIATELY after guillotining to avoid the risk of wavy/tight edges.
| Tackling Problems | page top |
There are a limited number of measures that can be explored in order to “get the job home” even if there are paper problems suspected. For example;
Surface Picking:
This is a problem usually associated with the laying down of solids. It is unusual for a sheet to equally prone to picking on BOTH sides. In many cases, therefore, printing on the reverse of a seemingly problematic sheet may see a picking problem reduce or even disappear altogether. Another remedy is to use the first unit to “scavenge” by running on impression with fount but no ink. This should remove most of the debris, and allow you to achieve a better result. Finally, reducing ink-tack, altering pressures and adjusting the ink film density may all alleviate picking.
Paper Mottle:
Again, the tendancy to mottle is rarely identical for both sides of the sheet. If possible, when you experience mottle, try printing the reverse side and compare the results.
Set-off:
Such problems are as often due to the inks used as the paper itself. Widespread use of poor drying so called “stay-fresh” inks have many advantages however there can be downsides. Such inks avoid “skinning” because their tendancy to oxydize has been chemically reduced. Many paper stocks (especially those with smooth hard surfaces such as Ivory Boards, and Cast Coateds) rely heavily upon oxydation of the ink for the image to dry properly. This is because, the surface is so “closed” it is difficult for the ink to penetrate and thereby to dry by absorption alone. Where you encounter poor ink drying/set-off, check to see if the inks are of the “stay-fresh” variety. If they are, try switching to conventional inks which will oxydize; it is likely that the drying performance of the ink on paper will improve significantly.
Blade lines :
These lines are usually caused by small hard particles that become trapped between the paper and the coating blade as the base paper is being coated at the paper mill. Such defects are almost impossible to detect until an ink solid is printed on the affected area of the sheet. Usually, blade lines are intermittent and only a very small proportion of the pallet will be affected. Indeed, only one side of the sheet is normally affected. Depending upon the design of the job, it may be worth printing on the reverse side when blade lines are discovered on the top side.
Wavy edges / tight edges :
Where the edges of the paper have become wavy, the ambient conditions in the press room have a tight edges significantly greater relative humidity than the paper itself. Because the paper is “dryer” ; than the environment it is exposed to, the paper will try to equalise itself with the surrounding air. It will therefore absorb moisture along its egdes and swell/stretch. This will cause major difficulties in feeding on press, and if the paper has already been subjected to one pass prior to the edges swelling, then misregister will be inevitable on subsequent passes. Where you discover wavy edges you may be able to retrieve the situation by securely wrapping the stack in moisture resistant material, and then leaving the wrapped stack at a constant temperature for 36-48 hours. In many cases the sheet will revert close to its original mill condition. Beware that prolonged exposure to a higher RH environment will see the return of the edge wave. The perfect solution is to have the facility to adjust your press room conditions (ie temperature AND humidity). Paper is normally manufactured to be in balance at an ERH of 55 at 21C and the ERH range at 21C is usually 40-60. Only where the paper falls outside this range will a mill accept that the paper is the primary cause of a wavy edge problem. Best practice would be to keep the paper WRAPPED and at the press room temperature and to only unwrap it immediately before use; where multi-pass/process work is involved, ALWAYS wrap the paper in moisture resistant material between processes. The converse of wavy edges are TIGHT EDGES; here the press room conditions are dryer then the paper. Exposed edges will therefore give up moisture and dry out and shrink as the paper seeks to equalise itself. The remedies and solutions are exactly the same as those described for WAVY EDGES. As a rule of thumb, TIGHT EDGES are most common in winter where the outside air is cold and press rooms are heated-this causes the air to expand and become dryer as a result; WAVY EDGES are more common in summer where outside air temperatures are much higher and generally more humid.
Static :
The “sudden” appearance of static within a stack of paper can be a nightmare. It is true to say that the causes are not fully understood, what is clear is that it is rarely a problem due entirely to the paper alone. All stacks of sheeted paper will contain redidual electrostatic energy. It is rarely noticed, because in “normal” conditions it naturally discharges into the air. However, hot press rooms in winter months mean the surrounding air is very dry and will therefore not act as an effective conductor. Sheets will be prone to sticking together and even sticking to metal parts of the press. The best solution is to raise the press room humidity and lower the temperature; unfortunately, this is not always possible. The next best solution is to fit static eliminator bars/ionising bars to the press. Some success may be possible through fitting foil strips/tinsle above the feed and allowing this material to trail on top of the paper; this will “earth” the paper to a degree but it is just what it seems-a “Heath Robinson” solution which is largely unreliable. Vigorously fanning the stack can also help, but the discharge of static will only be temporary because if the surrounding air remains warm and dry, the static will soon build up again. It is UNLIKELY that a replacement of fresh paper will help if the press room conditions remain the same.
Curl :
No paper will ever be perfectly flat due to the way it is formed
and then dried on a paper machine. So all mills have a defined tolerance
for acceptable curl for each of their products. If the edge of a sheet
is lifting by over 5mm above the plane, this will generally be considered
to be excessive curl.
Curl can be a symptom of paper out of balance with its environment (see
wavy/tight edges above); it can also be a deliberate paper property
such as 1-side coated boards, where a down curl across the grain is
induced to ensure the long edge is flat when gripped on the press. More
usually, however curl is attributed to a fault during the manufacture
of the paper.
Where paper has an excessive curl, the best course is to replace it.
However, where time does not permit, and the job is printed one side
only, the paper will feed better if presented curl down. For duplex
jobs there is really no effective remedy, although rolling the paper
and slowing the press may help. Using wedges/chocks can help angle the
paper to ease feeding; reducing the stack height at the feed and the
delivery could also lessen the inconvenience.
Cracking :
A common problem where boards, espectially coated boards, are folded into covers. Surface coating will on the fold have quite different elasticity and fold resistance to the base paper beneath, so cracking on the fold is an inevitable fact of life when folding such products. The key is to limit the extent to which it cracks. Prevention begins during the planning of the job. As far as possible, avoid folding over a solid of ink or varnish because the cracking will be far more obvious where the white base is exposed within a dark solid. When folding it is essential that the three variables of mechanical creasing machines are optimally combined; they are: the WIDTH of the creasing channel, the DEPTH of the creasing channel, and the BREADTH of the creasing knife. Considerable dividends will be gained by exercising the same degree of care with creasing that was given when originally printing the job.
| Complaint Checklist | page top |
If the paper is the most likely source of a problem, please advise your supplying merchant of the following as soon as possible:
* Paper details - brand, size, weight/thickness, colour.
* The making number of the paper (usually found on the label or wrapper).
* A brief description of the problem.
* Are BOTH sides of the sheet affected? If not, try the other side if appropriate to the job (NB. It is unusual for a sheet to “pick” on both sides).
* When was the problem FIRST encountered?
* How much paper was supplied, and how much of this appears to be affected?
* What actions have been taken so far in trying to overcome the problem?
* If the job is still “on press”, can it be lifted?
* Is a replacement required? If so, what is the absolute deadline?
* What is the type, make and model of the press?
* What is the ink sequence? (Please advise ink brand and references).
* Type of blanket? (eg Hard, Soft, compressible).
* Planned running speed (Impressions per hour).
* Achieved running speed.
* Details of any time lost and the reasons for this.
| Evidence Checklist | page top |
* Please ensure that you retain ALL the defective material.
* Please obtain, at least, twelve consecutively numbered printed AND unprinted samples.
* If the problem is intermittent, please retain consecutive samples of BOTH suspect and acceptable output for comparative analysis.
* Where there is debris on the blanket(s):-
- please take at least TWO sellotape pulls across the FULL WIDTH of each affected blanket, and clearly indicate the sequence and number of impressions since the last wash-up.
- please fasten the sellotape to a sheet of acetate or PVC, or alternatively fold the sellotape back on itself so as to trap the debris collected. Please NEVER stick the sellotape to the surface of any paper or board material.
- if surface picking from the surface of the paper is the most likely source of the debris, please check back through the printed matter in the delivery stack to see if you can locate a sample which contains a “white” cavity. This is known as a
“primary pick” and ALL mills consider such evidence as VITAL in proving that the paper was the principal cause of the blanket debris. Without the support of a sample containing a primary pick, there will always be an element of doubt as to whether the debris has come from that particular product.
* If the problem is likely to be “moisture related” (eg. Curl; wavy edges; tight edges; cockle; distortion of the sheet etc.), please isolate at least 20 consecutive sheets and FLAT WRAP them securely in moisture resistant material.
* Where blankets have been damaged, it is ESSENTIAL that they are all retained along with any material which may have contributed to the problem (eg. sheets with concealed roll-ups; lumps; holes; extraneous trim etc.). Appropriate printed samples illustrating the effect of the blanket damage is also important. Please be aware that where the paper is accepted by the mill as the cause of the damage, the value of the credit usually relates to the estimated useful life remaining in the blanket at the point it was damaged.
* Where the paper problem is “physical” (eg. variations in: shade; size; grammage; thickness; surface smoothness; or where creases, blade lines etc are present), please retain 20 consecutive samples to illustrate the problem.
* Where the printed image fails to meet expectations (eg. mottle, poor ink lift, unacceptable dot gain, poor register, image doubling, set-off/inferior drying etc), it would be helpful if a few sheets from another stock were run through the press. If the problem disappears, then the original paper has to be considered highly suspect. By having comparitive samples of another paper, the mill's task in evaluating the suspect material will be far easier, and by the same token the complaint will be more difficult to dispute.
| page top |
