Impregnation process

Impregnation line

Impregnation line is used for secondary processing of board. It is suitable for the board processing industry. To impregnate and dry surface paper, balance paper, wear-resistant paper; furniture décor paper, HPL surface & core papers for laminating, with melamine resin or its modified glue or urea resin.

Parts of Impregnation Line

According to a different processing technique, the Impregnation line is divided into one step impregnation line and a two-step impregnation line.

●One step impregnation line

Raw paper roller → unwinder → tractor → pre-wetting → penetration → impregnation → doctor roller → smoothing roller → dryer → cooler → web aligner → paper tractor with big cooling drum unit→ cutter → conveyor → stacking lifter.

* Impregnation material: phenolic resin, melamine resin, urea glue

* Main product: decorative paper、cement formwork panel paper, balance paper, insulating paper

* Applicable products: veneering of MDF furniture board, the decorative paper of HPL sheets, veneering of cement template, laminated flooring, CCL impregnated paper for FR1 and FR4

●Two-step impregnation line

Raw paper roller → unwinder → tractor(first) → pre-wetting → penetration → impregnation → squeezing roller(first) → smoothing roller(first) → dryer(first) → cooler(first) → web

aligner(first) → coater → mesh roller (secondary) → smoothing roller (secondary) → dryer(secondary) →cooler(secondary) →web aligner(secondary) → tractor with tap water drum→ cutter → conveyor → stacking lifter

* Impregnated material: high or low-pressure décor printed paper for MF resin, UF resin, and PF resin.

* Main product: Wooden grain paper, abrasion paper, kraft paper

* Applicable products：laminated flooring，fireproof plate，bending plat, compact grade laminate, physical and chemical plate for laboratory.

A detailed description of two-step impregnation line equipment

1, Unwinder:

Placed at the front of the inlet part of the unit, is a piece of special equipment for leveling paper. In our current design, we apply horizontal and arm-radial models, with a tap or fully automatic paper jointer unit.

2, Impregnation section:

Impregnating the raw paper.

● S roller: 2 chrome rollers are driven by a 1.5kw motor, which is controlled by 1 inverter, transfer the paper from the unwinder to impregnation section.

● Coated back: 3 chrome galvanized rollers, 2 wrap angles which can adjust paper and backer roller by handwheel. It is driven by 1 set of converters.

● Sky banana roller section: consists of two bending rollers that can be raised or lowered by the motor. The speed of the bending roller is controlled by a frequency converter.

● smoothing roller: 3 chromed wiping rollers are controlled by 3 sets of motors and 3 sets 1.5 converters, it is used for improving the gluing evenness of the impregnated paper surface.

● The plastic basin lifter is driven by an air cylinder.

● Glue bath: Double layer structure design, inner layer with 3mm stainless steel, outer with 4-10mm carbon steel, maintain the glue temperature through hot water or cold water, the bottom with 4 wheels can be conveniently dragged out to clean it.

3, Automatic dryer section:

3+5 total 8 sections, each section as 3.75m

 Oven section includes upper and lower airbox, 1 set hot windpipe, set upper and lower nozzle, 2 automatic doors lifted by cylinder,1 set air heater, HONEYWELL Brand Pt100 thermal resistance for temperature measurement, 1 HONEYWELL temperature control meter to show and control the oven temperature. 2 pieces radiators.

4, Mesh roll coating machine:

The Upper is coated by measuring rollers, and the lower is coated with an anilox roller. The paper roller is driven by the cylinder up and down. The wiping roller is used to improve the surface quality of the impregnated paper.

5, Cooler:

3 air doors: 1 air door is placed at the air inlet to control inlet air volume .2 others are placed at windpipe with a connected nozzle.

6, Web aligner:

● 1 deviation adjusting frames driven by an electric motor

● 2 chrome driven rollers

● Use 2 photoelectric switch detection and driven by the motor to adjust.

● 1 cylinder for lifting or lowering the roller

● A tension control mechanism is used to automatically control the tension when the paper running

7, Paper pulling machine:

● 1 root ? 200 mm chrome pulling paper roller.

● 2 rubber rollers are used to press the paper, which is raised or lowered by 4 cylinders.

● 1 set of pulling paper chain for tensioning device

● 1 set 4KW motor is used to drive the pulling paper roller, and it is adjusted by inverter

● 1 set 2.2 KW motor is used to drive the pulling paper chain, which is adjusted by the inverter

8, Cutter system:

● Cutting Max length: 2500mm

● Cutting Min length: 150mm

● Sample length<200 mm

● Cutting precision: ±3mm

● Conveyor table: customized

9, stacking system:

Fixed, with two shelves, produced as customer requirement.

10, Electric system

The main control cabinet is about 2880 x 650 x 2,100 mm, internal switch button, PLC, inverter, temperature control meter, voltage meter, fuse, intermediate relay, contactor, indicator light, etc..

4 operation screen:

● 1 impregnation station operation screen

● 1 coater station operation screen

● 1 paper pulling operation screen

● 1 paper cutting operation panel

11, Performance guarantee:

Average operating speed: over 30 m/min based on the following conditions:

● Decorative paper 80-90gsm.

● Glue quantity/pick-up 100%.

● Glue solid content of glue is 55% / 60%.

● Volatility 7 %

● Evenness degree of gluing: lateral accuracy ±2%

● The temperature of the drying oven: about 130-130 ° C

● Quantity of moisture: 12,000m3 /h

● Power demand: about 70 KW

● Oven heating time: about 20 min

C: Control method of glue pick-up quantity

Glue pick-up quantity refers to the glue weight on the unit area of the coated substrate surface, usually expressed in g/㎡. There are several different ways to measure the amount of glue.

1, on-line thickness gauge to detect.

2, Weight the glued sample sheet.

3, statistical methods to determine the amount of gluing coated.

4, the compound machine calculates to a similar amount of glue coated.

5, impregnation unit and coating unit parameters to estimate the amount of glue.

D: Finished product of impregnation line

Melamine impregnation paper

 Melamine impregnation paper (Melamine-Urea-Formaldehyde Impregnated Bond Paper）is a kind of adhesive paper, which is made by raw paper or printed decorative paper to be impregnated with Amino resin (Melamine formaldehyde resin and urea-formaldehyde resin), then after the dryer, cutter system. It can be glued together or laminated with the base material of artificial board as MDF/HDF/PB etc.

1, Product classification 

1.1, Wear-resistant surface paper -- mead or other raw paper with Al2O3 impregnated MF, used for laminating flooring

1.2, Impregnated decorative paper - special decorative paper impregnated MF, used to laminate flooring and furniture (impregnated MF or UF)

1.3, Balance paper –special paper impregnated MF, used for laminating flooring

2, Quality control in the production process of melamine paper veneering board.

2.1 Paper quality and impregnation process

 In order to ensure the quality of impregnated paper, unqualified paper cannot be adopted in the next production line. During the impregnation process, sampling inspection every half an hour, to confirm the glue pick-up quantity in the range of 130% ~ 150%, the volatile content from 6% to 7%, pre-curing less than 65%, after impregnation and drying, the coated paper immediately packed with plastic film and use a glue stick to seal; storage temperature at 20 - 25C, 55% to 65% humidity, the warehouse should have air-conditioning, storage time should not exceed 3 months till its expire.

2.2 Substrate quality

 The base material of veneer man-made board of MDF/HDF/PB/Plywood commonly used medium-density fiberboard and particleboard. For particleboard, should according to the different requirements of customers purchased, particleboard products must meet GB / T4897-92 standard.

Requirements for substrate quality:

2.2.1, The surface should be smooth and clean, water stains and oil stains are not allowed, make sure the right size.

2.2.2, The thickness deviation of the sheet shall be no more than + 0.2mm, and the sandblasting is uniform, and sand leakage is not allowed;

2.2.3 The water content of the plate should be controlled within the 6%-10% range.

2.3 Hot-pressing process 

 The hot pressing temperature is mainly catalyzed the chemical reaction of the impregnated resin that is for accelerating curing in high temperature. High temperature is also beneficial to release after pressing and can shorten the cycle of hot pressing and increase production capacity. The proper pressure can ensure a good combination between the substrate and impregnated paper. The time of hot pressing depends on the curing speed and temperature of the resin. Generally, it should be between 20 and 25s.

INNEXPORT Sources, Indents on behalf of companies and Distributes a wide range of product and has specialized in:

• Print Base Paper
• Décor Paper (solid color & Printed décor paper)
• OVERLAY PAPERS
• Recycled Absorbent Kraft Paper & Phenolic surface film
• PVC foil
• BALANCE, BARRIERE PAPERS
• Press Plates
• CUSHION Pads
• Impregnation & Printing machinery
• LVT, SPC, WPC production line
• DET MACHINES
• High-Pressure Laminates
• Machinery for Wood-Based Panel Industries MDF-HPL & flooring line
• SHORT CYCLE PRESSES
• Specialty Fastener & Tools
• PLYWOOD & BLOCKBOARD (Melamine faced & vinyl-covered)
• Chemical: UV LACQUERS & Printing INK & Primer &Pigments & Glue     
• Providing technical group for launching a production line

Inquiries for products outside of these categories are welcomed as the above list offers only a minor insight into the company’s sourcing capabilities.

For more information kindly visit our website: www.innexport.com

If you are interested, please do not hesitate to contact us, and discuss for further steps