CHecked with many factories,in the summer season hot and dry temperature ,normally make more than 6 hours cold pressing time after laminating the HPL sheets on the substrate .
Some mills also less 6 hours ,can you guess the quality of the HPL plywood and all the cold pressing time are decided by the cold pressing machine pressure and the glue .
You can check if any delaminated HPL sheets by hands or tools .
BONDING AND GLUING WHITE LATEX ADHESIVE USED FOR HPL PLYWOOD,COLD PRESSING
white latex adhesive used for HPL plywood,cold pressing
the pressing time and the volume of the white latex adhesive used for HPL plywood cold pressing are much different between the summer and winter to control the delamination .
Do you know how long cold pressing time in Summer and how much pressure for the cold pressing for the PLYWOOD Plywood ?
BLACK – CHINESE IMPORT
18mm – .5mm HPL
2-SIDES18mm x 4’ x 8’ HPL Liner
|18mm 4×8 Cabinet Liner
Imported from China.
Poplar core with E-2 glue.
Face and Back is a .050 Black Liner.
E-2 glue Not Carb Compliant
HPL PLYWOOD DELAMINATION ?THE HIGH PRESSURE LAMINATE (HPL) SEPARATING FROM THE UNDERLYING STRUCTURE SUBSTRATE PLYWOOD PLATFORM
Poor Adhesion or Delamination, the High Pressure
Laminate (HPL) separating from the underlying structure substrate plywood platform ?The decorative layer is not subject to flaking ordelamination .Defect of the HPL sheet due to the lack of adherence between the inner and outer layers of the laminate
1.The glue is too thin to have a good glue bond .
2.The glue is not well prayed and some blank space or without glue.
3.The glue quality is not good .
4.The summer temperature is too hot to have a good glue bond .
5.pressing pressure is not surficient to laminate the HPL .
6. a panel cleaner did not to remove dust and foreign debris from the substrate before the glue-line is applied.
Plywood is made of thin sheets of wood, glued together. When the sheets, called veneers, start to separate, things are definitely wrong. The process of coming apart is called delamination, and causes exist for it. By understanding the causes, you can prevent plywood sheets from delaminating.
De-Lamination of Plywood Water and Moisture
A common cause of plywood delamination is water and moisture. Plywood comes in different moisture ratings, depending on the composition of the glue used to hold the veneers together. If you use an interior-grade plywood for an exterior application, the glue will be dissolved by rain and moisture, and the plies will eventually separate. To demonstrate ply separation due to moisture, do this experiment: Take two, 3-inch square pieces of plywood, one interior-grade and one marine-grade. Place them in a bowl of water and come back in about two weeks. You will see the water has seeped into the interior-grade plywood, and delamination occurred. The marine-grade plywood should be unaffected.
Quality control may be lax at the manufacturing plant, and the glue may have gone bad. The main reasons for glue going bad are age and freezing temperatures. Many glues are water based. If the glue freezes, the water turns to ice, and separation from the chemicals occur. Rather than throw the entire batch of glue away (which can be hundreds of gallons), an unethical operator may use the glue anyway, hoping all will be well.
An unethical plywood manufacturer may try to skimp on costs, by using as little glue as possible. When the plywood is fresh, the glue may be adequate. As the wood dries out with age, the glue also dries out and reaches a point that the stresses overcome the glue, and the plies separate.
A combination effect may take place. First, the plywood was improperly installed, such as using interior-grade instead of exterior-grade plywood. Second, insufficient or bad glue was used in the plywood itself. Combining these two forces result in delamination.
Black Cabinet liner high pressure laminate plywood
High Pressure .7mm Laminate On Poplar Plywood core both sides very strong and light.
Ideal for Lining Walls, Caravans, Camper Vans,Boats making shelving and cupboards kitchen carcases etc….
16MM HPL TWIN PLYWOOD TO ISRAEL MARKETS ,RED GLUE ALWAYS E1 GLUE CERTIFIED
GLOSSY AND MATT FINISHE HPL SHEETS BOTH .MAKE SURE THE HPL SMOOTHLY SANDED BEFORE USING THE white latex adhesive to laminate the HPL sheets .
See the red color Glue used for Israel markets .
In order to make the prices competitive ,some importers already accepted to use non-whole-piece-face-veneer under the HPL sheets to lower the prices and the quality .Very long time ago ,before laminating the HPL sheets,the factories normally would put Natural birch face veneer or okoume face veneer or poplar whole peices face veneer under the HPL and above the short grain to make sure the HPL PLATFORM are smoothly and flat .