Plywood production process schedule Controlled status.
1、Adhesive preparation Gluing of core board
(1) Quality index of urea-formaldehyde glue: solid
solid content % 46～55
pH value 7～9.5
Appearance colorless, white or light yellow uniform liquid without impurities
Free formaldehyde content ≤0.3%
(2) Urea-formaldehyde glue preparation(weight ratio):
glue: flour 100:35
2、Gluing of core board
1.0mm～1.4mm core board double-sided glue application amount: (250～300)g/㎡.
1.5mm～2.0mm core board double-sided glue application amount: (350～400)g/㎡.
(1)The quality of the glued core board must meet the requirements, moisture content of (8 ~ 12) %, temperature below 40 degrees. The core board with uneven thickness, insufficient length, two horizontal edges with curved shape and moisture content greater than 13% should be picked out and put in the designated place from plywood manufacturing companies.
(2) The core staff should clear the debris on the core board, the amount of glue should be evenly applied, the parts not coated with glue should be brushed with glue by hand, no blank spot is allowed; the place where glue is piled up should be cleared of excess glue, the core staff should be responsible for picking out the unqualified core board at the same time and should be put at the designated place from commercial plywood manufacturer.
(3) The core board after gluing should be used first, and the aging time of the glued core board should not exceed 30 minutes.
(4)The use of glued core boards should be reasonable, and the core boards of different species should not be glued and used at the same time.
1,When forming the blank, one side should be aligned with the other side, and each booth should be aligned with the top and bottom, left and right. The trash and other debris attached to the coated core board and the middle board should be cleaned up when arranging the core.
2,Strictly control the aging time of the slab,generally not more than 30 minutes.
3,Prohibit different species, thickness of the core board mixed in the same
layer; slab symmetry layer species, thickness to be consistent.
4,The unqualified core board and veneer picked out in the production process should be put in the designated place and not placed
indiscriminately as birch plywood manufacturers.
5、Fill out the transfer sheet and handover record carefully, and give feedback in time when problems are found.
1、The holes on the slab should be patched with the patch that is consistent with the species of the slab.
2、The overlap on the slab should be cut off with a repair knife, but not repaired into off seams.
3、After the slab has been repaired with a patch if the slab is wider than 2mm and longer than 100mm.
4、The unqualified slabs picked out during repair should be put to the designated place and marked at the defects.
5、The repaired slabs should be stacked neatly according to the species and specifications and marked.
1、Hot pressing process parameters: temperature:(100~115)℃, pressure: (10~12)MPa.
2、Before hot pressing, clean up the wood chips,tape and other dirt on the press board one by one, and even out the temperature of each press board at all corners to reach the required temperature before entering the board production.
3、Load the trimmed slab into the hot press quickly,the position of the slab in each layer of the press should be consistent as far as possible (i.e. up and down, left and right alignment), to ensure that the plywood is evenly pressed and the thickness is consistent.
4、Unload the pressure slowly, especially for pressing multi-layer boards and slabs with large moisture content, otherwise it is easy to cause defects such as open glue and bulging.
5、When stacking the pressed slabs, the thickness of the four corners of the slabs should be checked at any time to see if they meet the requirements; whether the slabs have defects such as open glue and blisters, and the defective slabs should be picked out and repaired in time,phenolic faced plywood suppliers near me.Request a quote.
6、In the process of hot pressing, once the production of inferior products is found to exceed the requirements, it should be immediately reflected to the responsible department to find out the solution before continuing the production, and the truth should not be concealed. In the hot pressing process, the operator is not allowed to change the process parameters without permission.
Attachment: Hot pressing process sheet
Hot pressing time
Hot pressing temperature
Hot pressing pressure
5min to 8min
12min to 15min
(10 to 12) MPa
15 to 20 minutes
20min to 25min
(10 to 12) MPa
25min to 30min
30 min. to 35 min.
Plastering of slabs
1、The pressed slabs should be trimmed in time according to the specifications and species. The cracks and holes of the slabs should be smoothed with putty of similar color to the surface of the slabs, and the excess putty should be scraped off to avoid contaminating other parts of
2. In the process of finishing, slabs with open glue or bulging should be picked out and put in the designated place, and Mark them and send them back to the relevant process in time for rework,vohringer ply suppliers.
3、After the putty of the slab is cured, the slab can only be stacked neatly according to species and specifications and transported to the next process.
4、Putty modulation: Urea-formaldehyde glue, talcum powder and pigments are mixed into a sticky paste.
1、Adjust the distance between the saw blades according to the size of the finished product in storage.
2、After sawing the edge of the plywood allowed length, width size deviation: ± 1.5mm/m, maximum ± 3.5mm.
3、Sawed edge must be reasonable to exclude the plywood side defects, sawed board should be square corners, board edge straight, there shall be no edge and burr phenomenon, saw blade blunt should be replaced in a timely manner,hardwood plywood suppliers near me.
4、Sawed plywood should be stacked neatly according to species and specifications.
1、Sanding according to the requirement of sanding precision, choose the appropriate sanding belt for sanding.
2、Sanding thickness should be uniform and there
should be no defects such as sand leakage, sand penetration, sand jumping and
pollution of the board surface. 3、Check
the thickness of the sanded plywood at any time, if there is an error should be adjusted in time.
4、The thickness of sanding board should meet the standard requirements.
Thickness t ≤ 3mm, allowable deviation: ± 0.2mm
Thickness 3 < t ≤ 7mm, allowable deviation: ± 0.3mm
Thickness 7＜t≤12mm, allowable deviation: +(0.2+0.03t)mm -(0.4+0.03t)mm
Thickness t＞12mm, allowable deviation: + (0.2+0.03t)mm -(0.3+0.03t)mm
5、The sanded plywood should be stacked neatly according to species and specifications russian birch plywood suppliers.
1、The sanded plywood should be carefully inspected and graded according to the standard, and the product name, category, grade,formaldehyde emission and other signs should be added at the lower right corner
of the back of the plywood that has passed the inspection.
2、When flipping the plywood, be gentle, avoid damaging the edges and corners, and do not allow artificial pollution of the board surface.
3、Where the plywood can be repaired, marine plywood manufacturers the plywood should be picked out neatly and put in the designated place, marked at the board defects, and promptly notify the personnel of the corresponding process to repair.
4、Sub-inspection of qualified boards should be neatly stacked according to species and specifications.
5、The sub-inspection standard of the repaired board is the same as the normal standard requirement.
6、Sub-inspection of qualified plywood should be timely warehoused, the number, grade, species, specifications, baltic birch plywood manufacturers etc. should be filled out accurately, and do the product warehousing procedures.
7、The quality of the day’s sub-inspection should be reflected to the relevant departments or leaders in time to make the corresponding treatment.
Finished product packaging into the warehouse
1、Package according to different species, grades and specifications.
2、Pollution, collision and plywood edge problems are not allowed when packing.
3、Packing must be loose and tight to ensure that no loose package and no damage to the edges of the plywood during transportation.
4、The packaging should be accompanied by the name of the product, species,category, grade, manufacturer’s name, specifications, quantity, trademark,product standard number and formaldehyde emission limit signs of the label.
5, different batches, different manufacturers of raw materials should be stored separately to prevent disorderly, mixed, mutual extrusion and folding, minimize the second handling, the height shall not affect the removal and endanger personal safety confirmed by plywood sheet manufacturers.
6, after the inspection and selection of unqualified raw materials, products placed in the unqualified area, shall not be mixed with qualified products.