The Pressroom Environment – Material Temperatures
Some time ago we discussed the importance of ambient temperature control in your pressroom and explained why below 65°F or above 90°F can cause serious problems. However, there is more to temperature control than ambient temperatures. Anything that is brought into the environment becomes part of the environment. Producers may keep their pressroom at a consistent, comfy 72°F. Yet, if substrate and laminate are brought into the pressroom at well under 65°F, all that effort was for naught.
The principles for substrate and material temperatures are virtually the same as ambient temperatures with some qualifications.
Avoid Temperature Extremes:
Just like ambient temperatures, materials below 65°F can cause serious problems. Glue activation becomes extremely difficult as cold core materials absorb the heat too quickly, cooling the glue before it has a chance to activate. Operators will be forced to overheat the laminate in order to reach acceptable glue line temperatures, leading to surface quality changes, “blowouts”, and more. If you want to see scrap rates that will make your bottom line turn red, keep your pressroom nice and cold.
When it comes to the upper end of the spectrum, things are a little different. Though it is possible to press successfully in a room that is 90°F, pressing with substrate that warm is extremely difficult. Glue line temperatures need to drop to somewhere around 120°F or below before pressure is released or the laminate will begin to lift away from interior profiles and edges. The glue has simply not solidified enough to do its job.
Avoid Temperature Swings:
As is the case with ambient temperatures, major swings in material temperatures are never a good idea. Material temperatures should remain as constant as possible. Keep the target stationary if you want your operators to hit it consistently.
QC Tools That Help:
Smartech has a few tools that will help your operators stay on top of these issues before scrap rates and returns become a major headache. The Extech Infra-red thermometer is frequently used to check substrate, laminate, membrane and platen temperatures. It is also useful in checking temperatures as the product exits the press to make sure it’s not coming out too hot. Our paper thermometers are an excellent way to make sure acceptable glue line temperatures have been reached.
Consistency and accuracy in the pressroom environment will go a long way in assuring producers are able to deliver a quality product in a cost-effective manner. As always, “hope so” optimism is not the approach to take. Certainty and confidence go hand in hand.
Up Next: Operators and the Environment!