How to do a heat test

Properly manufactured Thermofoil doors will not delaminate without exposure to heat. To determine if a door has a good bond and the glue line was activated simply pull a part from production and do a pull test. In a pull test you cut a triangle shaped amount and pull the vinyl off the corner of the door. If the bond is good you will notice that there will be fibers on the film and also it will be very difficult to pull off the vinyl as pliers will need to be used. 

If you are pulling heavy fibers then you almost certainly will pass heat tests. If you are not pulling heavy fibers you may need to give extra spray to the sides of the door or increase heat or preheat to give total heat exposure to fully bond the glue line.

So what about heat delamination?

The two most common places of delamination from heat are directly above a tea kettle or beside a self cleaning oven. Keep in mind that these temperatures are so hot that they will strip lacquer off wood doors too however with thermofoil its more noticeable because the vinyl will actually shrink and will expose the MDF. This is not a defect in the door.  Tea kettles should be pulled out from under the upper cabinets and the doors should be hinged away from the oven during self cleaning mode with the doors open and drawers open during self cleaning operation. One other helpful tip is to have your cabinet manufacturer use a heat shield next to ovens.

As a thermofoil door manufacturer how do you test your heat resistance?

Firstly, a 1 part glues resistance is typically 150 to 175 degrees F and for a 2 part glue 170 to 200 degrees. Simply heat an oven up to 150F for one hour and then raise the temperature by 5 degrees  until failure or delamination occurs. You will notice the delamination as the vinyl will pull up revealing the mdf.  If your oven doesn't go that low simply utilize a digital thermometer and run the cord beside the part. Heat your oven on low and crack the door if necessary to keep the temp at 150 and raise at intervals to get the highest temp reached before delamination occurred. You may also use heat strips on your test to ensure accuracy of the highest temp reached.

The proper machine to professionally test is a Blue M lab heat test machine however they are quite expensive. One other tip is to ask your glue supplier to run a heat test on your parts.

I hope that this information is useful and remember that the most important thing is to purchase your components from a reliable producer in which you have a good relationship.