Frequently Asked Questions
- I have been told that it is a good idea to take the wrappers off my paper or board and allow it to breathe before I print it. Is this advice correct?
No. This would be very bad practice. All paper that a printer receives will be contained in moisture proof wrappers. Paper will be stable at a particular equilibrium relative humidity usually around 50% at 20°c, once it is removed from the wrapper the paper will react to the conditions in the immediate environment. If this environment is very dry or humid then the paper starts to distort. When the paper or Board is delivered it should be allowed to acclimatise to the press room temperature within the wrapper. The wrapper should only be removed immediately prior to printing and the printed stacks should be recovered with plastic or similar.
- How do I cut coated board without generating edge debris?
Based on practical experience we would recommend that this type of board is double dressed or back trimmed to remove the debris from the edge of the sheet.
- What is corona discharge treatment?
The purpose of corona discharge treatment is to improve the adhesion between the base material (especially plastics and metals) and liquids applied to it such as inks, coatings, adhesives etc. This is achieved by bombarding the surface with electrons which are accelerated under the influence of high voltages. The electrons have so much energy that when they hit the surface they alter the molecular structure and increase the surface energy. This makes the surface more 'wettable' and so, for instance, a liquid might now spread to form a uniform skin on the surface whereas previously it would have pooled into many tiny drops.
- I am silk screen printing display board and when I come to cut down to the finished size the edges of the board split or chip away. How can I overcome this?
This problem occurs when large areas of board are trimmed away during finishing, we recommend a double dressing procedure with the initial cut leaving perhaps 3-4mm for a second and final cut. This will alleviate the problem.
- Why do sign panels made with PERSPEX™ warp?
There are many possible reasons including (a) lack of expansion allowed, (b) sign not being top hung, (c) PERSPEX sheet too thin, (d) moisture absorption or (e) poor quality sheet. In most cases the failure of a sign in service can be traced to one of the above problems. Heat within the sign box, unless the sign is inset into a wall, is unlikely to be a cause of the problem.
- What is crazing of PERSPEX?
Crazing of PERSPEX sheet, or products produced from it, is due to the material becoming stressed. This can occur either due to fabrication or in service and being contacted with an organic chemical. Under most circumstances cast PERSPEX is substantially more resistant to stress crazing than extruded PERSPEX.
- What is a U-Value?
It is a measure of how well a material insulates against the loss of heat.
- How do I clean my conservatory roof?
Luke warm water with some washing up liquid in it. For stubborn dirt, allow it to soak. Rinse thoroughly with clean water.