From A to Z
Everything about HPL laminate

Laminate with a highly resistant surface designed for flooring application.

Laminate typology according to EN 438.
A: pearly surface.
C: Compact (≥ 2 mm).
S: standard.

The substance used to bind/glue two surfaces. Adhesives can have natural or synthetic origin and be thermoplastic or thermosetting. Adhesives are typically defined by the kind of adhesion. They can be reactive and non-reactive adhesives. The reactive adhesives chemically reacts to harden: one-part adhesives (light curing materials, e.g. acrylic based adhesives; heat curing materials, e.g. cyanoacrylates and urethanes); multi-part adhesives (acrylics, urethanes and epoxies). The non-reactive adhesive are: drying adhesives (solvent based, e.g rubber cement; polymer dispersion based, e.g. PVAc), pressure sensitives adhesives (e.g acrylate polymers), contact adhesives (e.g natural rubber and neoprene), hot adhesives (hot melt thermoplastic adhesives).

The situation or the purpose for which the laminate can be utilized.

Arpa standard HPL typology: one-sided HPL, whose thickness ranges from 0,7 mm to 1.8 mm.

Arpa postforming HPL typology: one-sided HPL which can be heat shaped toward convex or concave shape. Thickness ranges from 0,6 mm to 1.2 mm.

In the HPL production cycle, the act of putting together the different kraft, decor and overlay sheets. Once overlapped they are put in a press for the thermo-lamination.

The sheet of laminate or other material used on the back of the compound panel to balance the mechanical tensions on the decorative laminate.

During the production of the compound panels is the machining phase that prevents the compound sheets to warp.
It consists in gluing the right sheet of laminate on the back of the compound panel to balance the mechanical tensions and the dimensional changes of the decorative laminate on the front.

Laminate typology according to EN 438.
B: colored core.
C: Compact (≥ 2 mm).
S: standard.

Arpa HPL typology whose surface has been treated for being written on with markers, chalks or felt pens. Thickness ranges from 0.9 mm to 3.0 mm.

During the production of the compound panels is the machining phase where the laminate sheet is glued to a substrate, usually a wood-based one.

Laminate typology according to EN 438.
B: colored core.
T: Thin (Thickness < 2 mm).
S: standard.

Gluing defect due, for instance, to a non uniform distribution of the glue between the laminate and the substrate or to a substrate with defective surface.

Laminate typology according to EN 438.
C: Compact (≥ 2 mm).
G: "General Purpose", which means proper for the greatest majority of applications.
F: flame retardant, that is with improved anti-flame characteristics.

Laminate typology according to EN 438.
C: Compact (≥ 2 mm).
G: "General Purpose", which means proper for the greatest majority of applications.
S: standard.

The final check and the product classification is done at the end of the production process according to the EN 438 Standard.

It is the name commonly identifying the panels produced with wood particles. The chips are mixed with binding material and then pressed to produce the board. Hydrophobic agents, fungicides, etc ... can also be added to the glues.

The HPL classification system, fixed by the European Norm 438, makes use of an alphabetic code identifying the different product typologies with three letters. Here is the meaning of the letters.

First letter: 

• H = proper for horizontal applications
• V = proper for vertical applications
• C = Compact (≥ 2 mm) 
• E = outdoor use
• A = pearly effect 
• M = Metal 
• W = Wood veneer laminate
• B = multicolor
• R = metal Reinforced laminate

Second letter:

• G = General purpose
• D = heavy Duty
• C = Compact (≥ 2 mm)
• T   = Thin (< 2 mm)

Third letter:

• S = Standard
• P = Postforming
• F = Flame Retardant (improved anti-flame properties)

Arpa HPL typology. Compact, self-supporting laminate, which is highly stable and resistant. Thickness ranging from 2 mm to 30 mm.

A composite board obtained by overlapping and gluing sheets of different material, sized as required for use. HPLs typically face wood-based composite: a thin decorative HPL is glued to particleboard or MDF on one or both sides.

Term that generally refers to the direction at right angles to the fibers of the paper which the laminate is made with and to the sanding of its back side.

One of the last steps in the HPL production: after the thermo-lamination phase the panels are cut to the wished shape and size.

Producer declaration attesting the laminates compliance to regulations, technical specifications and standards. It is issued by Arpa upon specific request by order submittal.

The colored or decorated paper layer which confers the laminate its aesthetic properties. The term "decorative" is often used in place of "HPL decorative sheet", to indicate in short a specific high pressure laminate.

Defect of the HPL sheet due to the lack of adherence between the inner and outer layers of the laminate.

Technique transferring in digital decorations, drawings, images, graphic works, logos. It allows an extreme personalization of the high pressure laminate.

Dimensional changes : Expansion or contraction of a material, (in particular a substrate or a laminate) due to changes or alterations of climate and environment.

Characteristic of a laminate sheet to maintain the dimensions, despite the environmental changes of humidity and temperature. It is an essential property to get good results when using a laminate. 

Arpa HPL typology whose surface has been treated for being written on with markers or chalks. Thickness ranges from 0.9 mm to 3.0 mm.

Finishing, bending or molding operation of the edges of a panel.

European Standard relevant to HPLs. Contains the definition of the different HPL typologies, the essential requirements and the test method descriptions to be used for determining the product performances in the different application fields. At present EN 438 consists of 9 parts: part 1 is a guideline; part 2 includes the test methods; part 3 to 6, part 8 and 9 specify the different typologies; part 7 is mandatory only for laminates applied in the Construction field. See also “standard”.

Protective layer used to prevent the HPL sheets (especially the most delicate ones as Metals) from damage during handling and transport.

Both aesthetical aspect and surface quality of a HPL sheet is given by its finish. It can be glossy or opaque, smooth or textured. All 28 Arpa finishes are identified by a name and/or an abbreviation.

Resistance to flame spread. It refers to the material capacity to resist to thermal degradation and to ignitability.

Feature of a material with low flammability reaction, which means that it is able to withstand flame spread. It is important to underline that "flame retardant" refers to a single product, whereas "fire resistant" refers to finished composite item (i.e. door, wall, furniture …)

Arpa HPL typology with a high resistant surface designed especially for flooring coverings in the home and public spaces.

Laminate typology according to EN 438.
H: suitable also for horizontal use.
G: "General Purpose", proper for the greatest majority of applications.
F: flame retardant, with improved anti-flame properties.

Laminate typology according to EN 438.
H: suitable also for horizontal use.
G: "General Purpose", proper for the greatest majority of applications.
P: postforming.

Laminate typology according to EN 438.
H: suitable also for horizontal use.
G: "General Purpose", proper for the greatest majority of applications.
S: Standard.

Decorative laminates obtained thanks to the thermo-pressing of the different layers of impregnated decorative and kraft papers through the combined action of heat (140°/150° C) and high pressure (< 7 Mpa) for about 40/50 minutes. The acronym HPL comes from High Pressure Laminate.

Arpa postforming HPL typology: one-sided HPL which can be heat shaped toward convex or concave shape. Thickness up to 1.2 mm.

In the HPL production process is the operation of preparation of the kraft and decorative papers. They are first soaked (impregnated) in thermosetting resins, then dried. The paper so prepared will give origin to the HPL sheet during the thermo lamination process.

Placing and fixing the finished and cut to size compound panel to its final destination place.

Generally brown raw paper with exceptional resilience and resistance features. The sheets of Kraft paper are impregnated with phenolic thermosetting resins and build up the inner layers of the high pressure laminates.

Semi-finished metal or plastic products obtained through the process of thermo- lamination.

Term that generally refers to the direction parallel to the fibers of the paper which the laminate is made with and to the sanding of its back side.

Application of a laminate edge on the side of the compound panel before (pre-lipping) or after (post-lipping) gluing the decorative laminates on the front and back of the substrate.

Light Reflectance Value. It is the reflected portion, or not absorbed, of the incident light reflected by the surface color when exposed to daytime light. It is mainly influenced by the color. It is measured by means of a specter colorimeter and expressed in terms of Y %, where 100 is the white and 0 is the black.

Arpa HPL typology with magnetized features. Thickness ranges from 0.9 mm to 3.0 mm.

Laminate typology according to EN 438.
M: metallic surface.
C: Compact (> 2 mm).
S: standard.

Medium Density Fiberboard. It is the most famous and distributed of the wood fiber boards family including three categories differentiated on the base of the production process and the density: low (LDF), medium (MDF) and high (HDF).

HPL typology whose kraft paper core is reinforced with a layer of metal layers or nets in order to improve the mechanical performances, reaction to fire and vapor permeability of the finished product.

Arpa HPL typology whose surface is made up of a thin metal layer, generally protected by overlay, lacquers or anodized.

Laminate typology according to EN 438.
M: metallic surface.
T: thin (< 2 mm).
P: postforming.

Laminate typology according to EN 438.
M: metallic surface.
T: thin (< 2 mm).
S: standard.

Arpa HPL typology. Thick, compact, self-supporting HPL with multiple colored layers. A pantograph can be used for engraving. Thickness ranges from 10 mm to 14 mm.

Innovative Arpa HPL typology.
Ecological, as the cellulose fibers, which is made with, come exclusively from certified forests and it is colored with organic dyes. Its elevated density guarantees high performance. It is homogeneous, compact, self-supporting, water-resistant and can support heavy loads. Thickness ranges 6.4 mm to 32 mm.

Higly transparent paper used over certain HPL decors. It confers to the HPL surfaces peculiar features of resistance to abrasion, light, stains...

Feature of a panel to be perfectly flat, without concave or convex warping.

The metal plates are utilized for the production of the high pressure laminates: during the assembly phase they frame and compress the different layers of the kraft and decorative paper which will be then laminated. From their surface features depends the type of finish.

Heating and shaping process for a post-formable laminate to create concave or convex shapes.

Stocking operation of panel and/or substrate at given temperature and humidity environment conditions in order to reduce the dimensional changes of the compound panel.

In the HPL production, the presses for the thermo-lamination typically are multi-daylight. The packages of thermosetting resins impregnated papers are placed In the daylights and the laminates come out of them after the pressing stage.

It is the space of the hydraulic press used for the thermo-lamination of the HPL sheets.

Phase of the HPL production which transforms the materials irreversibly: the impregnated sheets of decorative and kraft paper undergo a process of heat and elevated pressure and give origin to the HPL sheets.

The set of mechanical, physical and chemical resistance features of the high pressure laminate sheets:

• Impact resistant
• Scratch and wear-resistant
• Light fastness
• Easy to clean
• Heat-resistant (up to 180°)
• Hygienic
• Suitable for contact with food

Feature of a finished material, structural element or furniture piece (e.g. door, walls…) to withstand a fire for a given period of time (e.g. half an hour, 1 hour…). The REI class defines the resistance to fire of a finished product. The requested values are indicated by the different national regulations according to the fire scenario and to the final application.

Samples supplied by the Arpa Quick Sample office are always in A4 size.

Step at the end of the production process: the back of the panel is lightly scraped (sanded) to make the surface ready for being glued.

Arpa HPL typology: self-supporting, compact HPL with mono-chromatic core, available in five colors. Thickness ranges from 1 mm to 12 mm.

Term used also in other languages to identify a norm or a specification that describes the test methods and/or the characteristics of a particular product. The standards can be national (Italian UNI, AFNOR French, German DIN, British BS, Spanish UNE, ON Austrian, Dutch NEN, ...), European (CEN) and international (ISO). Unless it is harmonized at European level (HEN) under special mandate by the European Commission and, therefore, with effects of law on the entire territory of the European Community, the standards are of a voluntary.

The support on which the laminates is applied by mean of gluing or fixing system like screws, rivets, frames, .... It can be made of different materials, generally wooden based materials, but it can also be made of minerals, metal or plastic foams.

Also simply called gloss; it is the quantity of the incident light reflected by the surface on certain angles. It is fully influenced by the surface structure. It's measured by mean of a gloss meter and expressed in grades, allows distinguishing the different finishes: towards 0 are the more matt surfaces, towards 100 the more glossy ones.

The term ”telegraphing effect“ means the waves on the surface of a compound panel due to an incorrect gluing process of the laminate to the substrate.

With regards to a finish it means that the surface of a laminate is not perfectly smooth and is enriched by soft or deep embossing, which can be felt by the hands.

The irreversible process which gives origin to the HPL: the impregnated sheets of decorative and kraft paper undergo a pressing and heating process at high levels of heat and pressure (in Arpa: 140°/150° C, at > 7 MPa, for 40/50 minutes).

To heat a material to give it a different shape.

It is the resin used to impregnate the decorative and Kraft papers that create the HPL sheet. They can be phenolic (for the kraft paper substrate) or melamine (for the decorative paper).

Expression to indicate a range of thickness values within which a thickness variation is considered proper to the industrial production process and, consequently, acceptable.

Arpa HPL characterized by laminates with holes in different diameters. It has peculiar properties of mechanical resistance. It is antistatic, durable and resistant to heat.

In the production of the laminate is the phase which follows the cutting to size, in which the edges of the panel are refined.

The laminate typologies refer to the classification of the European Norm EN 438, which defines a product in relation to its properties and application.

Arpa HPL typology: solid single-color laminate. Thickness ranges from 1.2 mm to 12 mm.

Laminate typology proper for vertical applications/grade.

Laminate typology according to EN 438.

V: proper for vertical applications.
G: "General Purpose", proper for the greatest majority of applications.
F: flame retardant, that is with improved anti-flame characteristics.

Laminate typology according to EN 438.

V: proper for vertical applications.
G: "General Purpose", proper for the greatest majority of applications.
P: postforming.

Cross Grain. The wood grain runs through the cross-machine direction.

Progressive deformation of the sheets which tend to curve. It is often due to humidity and temperature changes in the environment.