Question (WOODWEB Member) :
I am working on an A3 troubleshooting project in which the objective is to have no open veneer splicing seam defects and eliminate the need to use veneer tape. We use a hot press to then laminate the veneer to a particle board core. The veneer tape, as you know, must be sanded prior to final finish. We want to eliminate this need by splicing various wood veneers without the need to tape or stitch any defects. Does anyone have any advice?
From contributor C:
I can think of three things. Some people actually zig-zag, then fold the joints open and put a very thin glue-line on the edges, then flatten them. Second, use the lowest temp you can on your press (heat equals shrink which equals open joints). Small shops in Europe use zig-zag machines but press at low temps. The best thing, however, is to get a good Diehl splicer of some similar machine that actually splices with glue on the edges.
Here is a breakdown of our process. We use a double blade jointer to cut all of our veneer leaves. We check for cut quality every day. We then process all of our veneer leaf bundles through an edge glue machine (Kuper) and then through a fanner. A glue thickness check is done 3-times a shift. A Wet gauge wheel is used and we keep our glue thickness between 3.5 and 4 mils. The bundles are stacked on staging tables and are allowed to dry for approximately one-two hours. We then splice the leaves together, in various lengths and widths, with multiple seams. A Kuper Splicemaster unit is used for this operation.
Out settings for the unit are two bars for pressure, 200-220 degrees Fahrenheit for both the upper and lower heater bars. We feed the leaves through the splicer at approximately four-five seconds per seam. All of this is converted from metric and Celsius parameters. From all this, we still see 30-45% of our sheets have splits or open seams on the end of our multiple leaf sheets. We use veneer tape to repair the seams and then process them through a hot press operation.