The press process in the wood based panel industry

Tobias Schreck June 2016 1

ProTenceProTence

The Press Processin the wood-based panel industry

presented by

ProTence - Tobias Schreck

Competence in Product ManagementProject ManagementProcess Technologies


ProTenceProTenceWho am I, what do I do?

, a competent engineering partner, specialized in

product management

project management

process technologies.

• Provide project-based and flexible technical support for the wood and wood-based

panel industry.

• Be the additional resources to cover peaks in projects and jobs.

• Work out and implement detailed solutions for process technology concepts.

ProTence


ProTenceProTenceReasons for the surface treatment

Surfaces of non coated wood based panels are

unsuitable as visible surfaces or usable surfaces

for most areas of application and therefore need

additional surface treatment.

Requirements of a surface coating:

• Beautifying the surface.

• Increase the utility value.

• Enhance resistance to mechanical, physical

and chemical effects.


ProTenceProTenceReasons for the surface treatment

Pictures on this page: Wemhöner Surface Technologies


ProTenceProTenceMaterials for the surface treatment

Surface treatments

Solid surface covering

Veneer

Paper based foil

Foil / Film

Laminates

Metal, textile etc.

Liquid coating

Stain

Paint

Lacquer

Other coatings

Powder

Flocking


ProTenceProTenceTechnologies to apply solid surface coverings

Application technologies

Continuous systems Discontinuous systems

Calender roll press

Double belt press

Hydraulic moulding press

Hydraulic plate press


ProTenceProTenceManufacturing processes for solid surface coverings

Veneering:

• Thin sheets of wood (approx. 0,5 – 1 mm; 1/64 – 3/64 in)

applied to a panel using suitable adhesives.

• Predominately applied with discontinuously working veneer

presses.

• Additional rework such as sanding and coating of the surface

required.

Laminating (German: Kaschieren oder Folieren):

• Panel surface is covered with a glued-on foil.

• Applied either sheet by sheet in a discontinuously

working press or as roll-fed material applied in a

continuously working process.

• Primer-foil and non coated decorative films are finished

with additional liquid coatings applied after the press process.Robert Bürkle GmbH

STA Travel Service Center


ProTenceProTenceManufacturing processes for solid surface coverings

Pressing (German: Press- o. Direktbeschichten)• Paper sheets impregnated with phenolic of melamine

resins are pressed onto the panel surface without usingany additional adhesive.

• During the pressing process the resin melts and bondsthe paper sheet to the base panel.

• The resin forms the final surface finish of the panel, no additional rework is required.

Covering (German: Belegen)• Laminated sheets (CPL = Continuous Pressed

Laminates or HPL = High Pressure Laminates) areapplied to a panel using suitable adhesives.

• No additional rework required to form a finished surface.• This high-quality surface is used especially for demanding applications (e.g. office

furniture, wall cladding, wet rooms, etc.)

Wemhöner Surface Technologies

Ferdinand Holzmann Verlag GmbH


ProTenceProTenceDiscontinuously working hydraulic plate presses

The process

• Press-plates transfer pressing pressure from hydraulic

cylinders to a covering material and a workpiece.

• Covering material and panel are held in place until the

adhesive links the surfaces securely by adhesion and

cohesion.

Categories of hydraulic plate presses

• Hot press or cold press.

• Single-daylight press or multi-daylight press.

• Light press: press-plate dimension about 1.2 x 0.8 m

(3 x 2 ft) up to 3 x 1.3 m (9 x 3 ft);

pressing force about 400 – 1400 kN.



Categories of hydraulic plate presses

• Medium duty press: press-plate dimension about

2.6 x 1.4 m (8 x 4 ft) up to 4 x 2.3 m (13 x 7 ft);


• Heavy duty press: press-plate dimension about

2.5 x 1.3 m (8 x 4 ft) up to 3 x 2.2 m (9 x 7 ft);


• Down-stroke-press or up-stroke-press depending on

where the hydraulic cylinders are mounted.

• Broadside feeding direction versus narrow-side loaded

presses.


Gottfried Joos Maschinenfabrik GmbH & Co. KG


ProTenceProTenceBasic requirements for all hydraulic plate presses

• Structurally very stable and rigid designed

machine frames to absorb high compressive

forces.

• Number of press frames depends on the

press-plate dimension.

• Good resistance to bending of the

press-plates in order to ensure an even

pressing force across the entire panel

surface. Hymmen GmbH



1. Loading area for base panels and decorative papers

2. Layup area and press feeding system

3. Short cycle press

4. Press unloading system

5. Cooling and stacking area











ProTenceProTenceDiscontinuously working hydraulic moulding presses

Categories of hydraulic moulding presses

• Presses with a fixed three dimensional mould. A work-

piece is formed according to the shape of the mould.

Mainly used for the production of e.g. chairs and lounge

furniture, but not for surface finishing.

• Presses with a flexible membrane. The covering

material is formed to the shape of a profiled workpiece.

• When processing air impermeable covering materials

such as PVC films two types of presses have established:

membrane-presses and membrane-less-presses (the film

itself functions as a membrane).

Deutscher Landwirtschaftsverlag GmbH



The process

• An adhesive is applied to the profiled workpieces prior

to loading these into the press.

• Inside the press first the foil is pressed against the

upper heating plate using compressed air. The

thermoplastic foil is heated up to the required

processing temperature.

• In a second step the heated foil is pressed onto the

profiled workpiece by creating a vacuum underneath the

foil and applying compressed air from the top of the foil.

The foil is moulded to the shape of the workpiece.

• Once the adhesive has dried the pressure is released

and the workpieces are cut out outside the press.

Robert Bürkle GmbH






Robert Bürkle GmbH


ProTenceProTenceContinuously working calender roll presses

The process

• The covering material is unwound from a coil and is glued to

the wood-based panels. These are fed continuously through

the laminating line.

• Covering material can be applied either on one side or

simultaneously on both sides.

• Cold-laminating lines have unheated calender rollers. Used with

dispersion or solvent-based adhesives.

• Hot-laminating (or thermo-laminating) use

heated calender rollers (about 150° -

220° C). Mainly used with PVAC or urea-

formaldehyde adhesives.

• Primarily for decorative printed,

impregnated and pre-painted

paper films (so called finish foil).Robert Bürkle GmbH



Line configuration

1. Brushing machine

2. Hardener applying roller coating

machine

3. IR heating unit

4. Glue applying roller coating machine

5. Transport

6. Calender roll press

7. Unwinding station for surface

covering material

8. Smoothing calender

Optional equipment:

9. Smoothing calender

10. Automatic foil-splicing unit

12. Additional smoothing calender

Robert Bürkle GmbH



Robert Bürkle GmbH


ProTenceProTenceDiscontinuously working double belt presses

The process

• As an alternative to hot-laminating lines double-belt

presses were developed.

• Two endless steel belts are mounted on top of each other.

• Advantages compared to a calender roll press:

- The pressing force is distributed as a surface pressure

and not only as a line pressure.

- Much longer pressing time between the two belts.

• Advantages compared to a short-cycle press:

- Much higher production volume as no production time is lost for loading and

unloading of the workpieces into the press.

• Double-belt presses are mostly used for the production of particleboard and MDF

or to produce decorative laminates.

Hymmen GmbH



Categories of double belt presses

• Isobaric pressure system (= equal pressure):

- Pressure chambers filled with compressed air are located

on the backside of each press-belt.

- An absolutely equal pressure is pressing onto the steel

belts and the workpieces.

• Isochoric pressure system (=equal volume, equal distance):

- Roller carpets are located between the heating plates and

the steel belts.

- The workpieces are pressed together to the fixed opening

width between the steel belts.

- Because of the non-linear pressure application isochoric presses are not

suitable for the application of decorative laminates.



Line configuration for a HPL/CPL production line

1. Film unwinding station

2. Double belt press

3. Cooling station

5. Sanding unit for the backside

6. Edge trimming station

7. Winding station for thin laminates

8. Cutting unit for thick sheet laminates

9. Stacking unit

Hymmen GmbH



Hymmen GmbH


ProTenceProTenceThe End

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The press process in the wood based panel industry