Acrylonitrile butadiene styrene. This synthetic thermoplastic resin is obtained through the copolymerisation of acrylonitrile, butadiene and styrene. It has a good level of resistance to acids, but not to chlorinated solvents, it does not attract dust or become deformed; these properties make ABS a suitable material for the production of furniture and furnishings. It is also used to manufacture edges and veneers for coating surfaces.
Acrylic resins are used in combination in impregnation baths when a flexible product is required.
In finishing, balance sheets are unrefined impregnated papers used on the nonvisible back side of panels to balance out warping.
BOARD ON FRAME
Wooden core-based panel, composed of a central two-section core joined together through adhesion and hot pressing. The frame is made out of wood, usually spruce, or out of wood-based derivatives and is filled with an alveolar (honeycomb) structure made out of cardboard or aluminium, or by a lattice of strips of plywood. The two sides are usually formed of wood-based panels or sheets of HPL plastic laminate. From a technical point of view, honeycomb panels are the best solution for obtaining structural elements that are both light and mechanically strong.
Veneer obtained from growths that sometimes develop on tree trunks where grafts have been made, in areas that have undergone trauma and, most of the time, near the roots.
A certification process for formaldehyde emissions introduced in the state of California in 2007. The “Airborne Toxic Control Measure” (ATCM) regulation is approved by the “California Air Resources Board” (CARB) with emission limits for panel products based on ASTM E1333-96 known as the “large chamber” with two separate phases known as P1 and P2. Since 2011, the level for everyone is P2. The limits are slightly more stringent compared to the European E1.
Since 2013 the Cleaf showroom at Lissone headquarter with 1.250 m2 of exhibition space.
Wood-based panels formed by particles of wood (flakes, fragments, etc.), joined together through adhesion using thermosetting synthetic resins and hot pressing. Chipboard panels are made out of mixtures of less valuable wood and by-products of other processes. For this reason, it is a very interesting product from an ecological point of view. You can make different types of chipboard panels (for example, homogeneous, laminated or multi-layer chipboard), by varying the geometrical dimensions of the particles and their distribution, the type and amount of resin, and the operational parameters of the production process, such as temperature, pressure or time.
Wood-based panel on whose surfaces one or more sheets or films of the following materials have been pasted for aesthetic or technical reasons:
• Papers impregnated with synthetic resin
• Decorative plastic HPL or CPL laminates
• Resin film
• Finish foils
• Decorative veneers.
The purpose of the coatings is to improve the aesthetic appearance of the panel whilst also giving the surface itself specific technical properties, for example hardness, abrasion resistance, scratch resistance, resistance to stains and chemical agents, heat and moisture resistance, etc.
This composite surface material is manufactured by DuPont, and is composed of 1/3 acrylic resin and 2/3 mineral substances. The main component is alumina trihydrate, derived from bauxite. This compact, non-porous material does not absorb stains and is warm to the touch. It can be easily worked and heat-moulded, and also enables you to create almost invisible joints.
Wood-based panel whose sides have been covered with cellulosic support materials (papers) or polymeric foils (PVC foils, ABS, etc.).
Continuous press laminate. See Low pressure laminates
Mono-coloured paper or printed with patterns. With these papers you can produce melamine surfaces such as covered panels, laminates, CPLs and painted surfaces such as door seals and finish foils. Grammage ranges from 60 to 140 g/m2. Before being pressed, they need to be impregnated with suitable resins. See Impregnation resins
Custom drilling is completed on part-finished products using numerically controlled machines. The holes will then be home to hardware such as handles, hinges or plugs for shelves etc.
E1 FORMALDHEYDE CLASSIFICATION
The European standard EN 13986 establishes class E1 with the EN 717-1 chamber test, according to which panels must release less than 0.1 ppm (equivalent to lt;0,124 mg/cu.m).
The process through which the edges of panels are finished. The process involves applying a plastic edge, usually made out of ABS as well as PP or PVC, to a panel by successive steps including adhesion, trimming and finishing. Conventional edgebanding uses hot-melt adhesives. Recently developed glue-free technologies use a suitable active layer on the back side of the edge, which is then fused together using a laser, hot air or infrared and becomes the adhesive for the panel.
Most edges available on the market are treated with solvent-based primers, but there are also water-based primers. There are many adhesives on the market and primers should be compatible with all of them. The main types of adhesives are: EVAs (Ethylene-vinyl acetate) are some of the most common adhesives. They are cheap and easy to use because they do not react or require complicated equipment. Their bonding to primers is mostly physical. They have little resistance to temperature (<90°C) and water. They are not recommended for use in kitchens or bathrooms. Polypropylene adhesives. Compared with EVAs they have more resistance to temperature, but not to water. They are less widely used than EVAs. Polyurethane adhesives. They have the best performance, with excellent resistance to both temperature and humidity. Their better performance compared to EVAs and POs is explained by the fact that the polyurethanes crosslink and therefore the adhesion mechanism is chemical as well as physical. They are more expensive and difficult to use precisely because they are reactive, so they require special fusers that require more diligent cleaning.
Decorative plastic films, normally made out of ABS as well as PP or PVC, which are applied onto the panel using edgebanding technology (see Edgebanding). They are extruded in thicknesses of between 0.3 mm and 2.5 mm, and can be printed, varnished, embossed and treated on the back for adhesion.
Wood-based panels formed of fibres or bundles of wood fibres, obtained through high-temperature thermomechanical defibration, joined together with or without the use of thermosetting adhesives and hot pressing. There are two manufacturing processes: the “wet” process and the “dry” process. With the first process adhesives mixtures are not required; it actually uses the mechanical felting of the fibres and the adhesive power of the lignin contained in the wood itself. Sometimes a small amount of thermosetting phenolic resin is added to improve the mechanical properties. Panels made using this method are called “hard fibre panels” (for example, hardboard, Masonite, etc.) and HDF panels (High Density Fibreboard). With the second process, fibres are joined together by using thermosetting synthetic resins as adhesives. Panels made using this method are called MDF (Medium Density Fibreboard). Raw materials of low commercial value and by-products of other processes are also used for wood fibreboards. However, the wet process poses serious water pollution problems.
Materials used for coating surfaces; they are single-layer papers impregnated with a mixture of urea and melamine thermosetting resins, with the addition of plasticisers. They are the low-cost version of laminates for coating surfaces. Sold as finished, pre-painted, semi-finished with a primer coating, or untreated.
FIRE RESISTANT BOARD
Wood-based panel to which chemical compounds or mixtures of chemical compounds that reduce flammability and delay the propagation of flames have been added during the production process.
Surface coating process for panels using a rolling press. The film or sheet of covering is usually glued to the panel surface with hot-melt adhesives (polyurethane, PP, EVA), and is applied onto either the panel or the back of the covering, depending on the type of system. The panel then passes under a rolling press to complete the bonding process. Panels can be coated with a wide range of coatings through lamination, including finish foils, CPL, HPL, sliced wood veneers, decorative plastic films and glossy plastic films.
This literally means folding. Manufacturing process for three-dimensional part-finished products, where the back of a panel is scored using V-shaped cutters to form grooves along which the panel is then folded, similar to the way in which cardboard boxes are made. This process enables you to simulate thicker panels or to produce low-weight box beams.
Organic gaseous compound with a pungent odour that is used as a component in most thermosetting adhesives for wood-based panels (UF, MF, MUF, PF). The free formaldehyde emission, i.e. of the part that has not been polymerised, is governed by legal regulations. In fact, formaldehyde causes irritation of the upper respiratory tract and is potentially carcinogenic. A formaldehyde concentration of over 0.10 ppm (parts per million), equivalent to 0.12 milligrams per cubic metre, is considered dangerous in domestic spaces. This value was determined with reference to people who are in high-risk categories (children, the elderly, asthmatics, hypersensitive people, etc.)
The acronym FSC stands for the “Forest Stewardship Council”. The FSC is an international non-governmental non-profit organisation founded in 1993. Its members include environmental and social groups (Greenpeace, WWF, Legambiente, Friends of the Earth, Amnesty International, etc.), indigenous communities, forest owners, industries that process and sell wood, large distribution groups (B&Q, Castorama, Home Depot, Ikea, etc.), and researchers and technicians who work to promote the proper management of forests and forest plantations worldwide. The FSC has introduced a non-mandatory certification described as standard FSC-STD-40-004, which affects all products derived from wood (furniture or structures made using solid wood or wood veneer, wood-based panels, paper or products derived from cellulose, etc.) The rationale behind the certification is to promote the use of wood from forests that meet the requirements of eco-sustainability and low environmental and social impact.
Parameter that measures the glossiness of surfaces. It is measured using an instrument called a gloss meter, which emits light rays at specific angles (20°, 60° or 85°) and records the amount of light reflected. Matte surfaces have a 60° gloss of less than 10, whilst glossy surfaces have a 60° gloss of more than 80.
Important property of decorative papers. It is expressed in grams per square metre and relates to the coverage capacity of the decorative paper. Mono-coloured papers generally have a higher grammage (90-140 g/m2) than those with decorative prints (60-80 g/m2).
High density fibreboards. See Fibreboards.
HIGH PRESSURE LAMINATES
High pressure laminates are materials used for coating surfaces and are made of a series of papers impregnated with phenolic and melamine thermosetting resins joined strongly together by high-temperature hot pressing. Papers impregnated with melamine resins usually make up the decorative surface, while the support is made out of a series of Kraft papers impregnated with phenolic resins. They were the first materials used for coating surfaces and are still known today under the trade name “Formica”. The surface of HPL plastic laminates is very hard, and is resistant to boiling water, chemical reactions, scratching, abrasion, heat and cigarette burns, among other things.
This synthetic adhesive is applied in molten state and has adhesive strength thanks to the physical solidification process that occurs during cooling. Once solidified, the adhesive softens and temporarily loses its adhesive power if it is placed in a temperature of between approximately 60°C and 100°C, therefore the process is reversible.
See High pressure laminates.
Decorative papers, both mono-coloured and printed, must undergo the impregnation process in order to be loaded up with enough thermosetting resin for it to react during pressing. The resins are primarily melamine (melamine – formaldehyde), and may also have a proportion of urea resins (urea – formaldehyde). Kraft papers are usually impregnated with phenolic resins (phenol – formaldehyde). The impregnation process is performed continuously on lines that provide an immersion bath in which the paper is saturated in liquid resin, before squeeze cylinders remove excess resin and drying ovens help the water to evaporate. Following impregnation, the papers have more than twice as much weight.
In the impregnation process of decorative papers water-based thermosetting resins are used. Thermosetting resins used for impregnation all contain formaldehyde as a binding agent. There are melamine-formaldehyde and urea-formaldehyde resins. The surface layer must be composed of melamine resin, whilst the inner layer can be entirely melamine or can be mixed with urea resin. The mixture of thermosetting resins includes a latent catalyst which develops an acid that speeds up crosslinking when at a high temperature.
Produced using the Kraft process (also known as the sulphate process), which chemically extracts cellulose from wood in order to obtain so-called “cellulose pulp”. They are very durable, but not white. After phenolic impregnation, it is used to produce barriers for covered panels or, in multiple layers, forms the body of high-pressure laminate (HPL).
Surfaces can be for internal or external use. Depending on the case, they are tested with equipment that simulates aging caused by light through accelerated exposure to UV lamps. After performing the series provided for by the reference standard, colour variation is measured and compared with the resistance of certified fabric skeins (blue wool scale). Resistance is then classified on a scale ranging from 1 (poor) to 8 (excellent). For internal use a blue wool scale grading of 6 or more is usually required.
LOW PRESSURE MELAMINE LAMINATES
Materials used to coat surfaces, formed by two or three papers impregnated with melamine thermosetting resins to which plasticisers are added. The papers are joined strongly together by hot pressing at low pressures. The physical and technical properties of these materials are inferior to those of high pressure laminates, but are more than adequate for coating furniture components that will not undergo much stress and, in particular, are suitable for producing edges.
See Scratch resistance
MATERIAL SAFETY DATA SHEET
A material safety data sheet (MSDS) is a legal document that lists all the dangers that a chemical product may pose to human health and to the environment. In particular, the list includes the ingredients, the manufacturer, the risks for transportation, for humans and for the environment, instructions for disposal, Hazard statements and Precautionary statements, TLV/TWA exposure limits and the personal protective equipment (PPE) that employees who come into contact with the substance must wear.
Medium density fibreboard. See Fibreboards
Melamine resins are synthetic thermosetting resins obtained through the polycondensation of formaldehyde with melamine. They crosslink when exposed to heat and are accelerated by acids. When exposed to pressure the resins form a very resistant and transparent crosslinked compound. They are used in the impregnation of decorative papers.
Metamerism is the effect through which a colour that appears to be the same shade as another, under certain conditions, may appear completely different under different conditions. The most common case is that in which two colours look the same in daylight and different in artificial light. The effect is caused by the different compositions of the two dye formulas.
Evolution of the preforming process in which, through angling cutters in a specific way, you obtain a joint that enables you to get very small radii.
Milling is a process for removing material that enables the production of a wide range of surfaces (floors, grooves, shoulders, etc.) using a multicutting tool with defined angles.
“Manmade” material made by breaking wood down into thin sheets. These are then dyed, coated with adhesive and pressed to form blocks and boards. Decorative veneers and sawn wood can then be obtained by further processing these blocks.
Oriented Strands Board. Wood-based panel, formed of three layers of more or less rectangular and often thin particles (strands). The particles that form the sides are oriented vertically, while the particles of the core layer are oriented horizontally. This arrangement gives the panel good bending resistance and rigidity, particularly lengthways. In 2015, Cleaf launched Quidyl, the first coverable OSB panel with fine layers of shavings, consisting of poplar wood and formaldehyde-free adhesives.
Transparent paper consisting of pure cellulose without fillers. The grammage of overlay is usually between 20 and 30 g/m2. It is impregnated with melamine resin and, once superimposed on standard impregnated decorative paper, increases its abrasion resistance (see Taber abrasion). With the addition of overlay, colour changes slightly, with dark colours in particular becoming less glossy. There is also a version that contains corundum, which meets the requirements imposed by flooring regulations.
Layer of sulphite cellulose that is used as support instead of Kraft paper in the production of thin continuous pressed laminates (CPL). It does not need to be impregnated and gives the laminate flexibility and a barrier effect without needing to be polished.
Wood-based panel formed of more than three sheets of wood stacked so that adjacent layers’ grain is oriented at a right angle
Wood-based panel formed by a set of sheets of wood, usually an odd number, made solid through adhesion using thermosetting synthetic resins and hot pressing. The sheets of wood (veneers) are stacked so that adjacent layers’ grain is generally oriented at a right angle. When there are more than three layers, the panels are called plywood.
Synthetic thermoplastic resin obtained from the polymerisation reaction between a diphenyl and phosgene. It has a high melting point and is extremely hard. It is used as a substitute for glass or as safety material.
A family of synthetic resins obtained through the condensation polymerisation of a carboxylic acid and an alcohol. Due to their physicochemical properties they are used in many sectors (furniture, textiles, aeronautics, shipbuilding, construction, etc.) as ingredients for paints, plasticisers, fibres and as an array of composite materials.
POLYMETHYL METHACRYLATE (PMMA)
Polymethyl methacrylate is an acrylic resin whose monomer is the methyl ester of methacrylic acid. It is a low-density resin that is hard, transparent, shiny and resistant to solvents. It is referred to commercially as Plexiglas and Perspex, amongst other names, and is used instead of glass when particular safety features are required. It is also used as a matrix for some composite materials, such as “Corian”.
A family of synthetic resins obtained through the addition polymerisation of isocyanates and polyols. Polyurethane is used in almost all productive industries thanks to its extremely versatile formulation; in practice, you can produce polyurethane systems aimed at meeting specific application requirements, including liquids, pastes, solids, and both rigid and flexible expanded foams.
Edge coating process in which the pre-shaped rough board has already been coated on the flat surface using flat lamination (see flat lamination) leaving a part of the coating protruding, which is then shaped and glued onto the edge using heat and rubber rollers.
In contrast to postforming, in preforming the panel covered on the flat surface is carved beneath the decorative layer with appropriately designed cutters and the excess section is curved to cover the edge using heat and rubber rollers. Preforming enables you to obtain soft contours and radii of just a few millimetres.
This is decorative paper impregnated during production by the same paper factory. In this case, any printing is applied to already impregnated paper, unlike traditional printed paper that is post-impregnated after printing. These papers are suitable for making finish foils.
The plates are made out of steel and are etched with lines of acid to obtain the desired structure or texture. During the finishing process, the structure is transferred in negative to the melamine panel surface.
Polyvinyl Chloride. Synthetic thermoplastic resin, obtained through the addition polymerisation of vinyl chloride. PVC is one of the most commonly used plastic materials in the furniture industry. It has been seen as a toxic and non-environmentally friendly material. However, with regard to toxicity, the problem relates solely to the production phase of the polymer as the carcinogenic properties are due to the vinyl chloride monomer that, once polymerised, becomes entirely non-toxic. The environmental problems are related to the disposal-by-burning stage, but if PVC is properly incinerated in special combustion chambers, practically no dioxin is produced. As PVC is a thermoplastic material it is not very resistant to heat; it softens between 75°C and 95°C and deforms between 140°C and 160°C.
These papers are treated with a special surface coating that has a three-dimensional structure. Pressed between decorative paper and the continuous press belt, they make it possible to obtain HPL or CPL laminates with surface structure. Unlike with engraved sheets, release papers can reach lower depths and cannot be in-register with decorative paper.
Resin substances are characterised as blends of many simple molecules known as monomers. The product of the blend of monomers is called a polymer, which is a high-molecular weight macromolecule. Resins can be natural, artificial or synthetic.
Most decorative papers used in the furniture industry are produced using Rotogravure printing. Rotogravure printing is a direct process of intaglio printing (the graphics or the part that will be printed is recessed compared to the non-image areas, the parts that are not being printed), and rotary printing. The ink is transferred to the paper through a modular system of recesses of different depths. The deeper each recess is, the more ink it will be able to contain, and therefore the denser the printing will be. Decorative effects are created through the superimposition of several printing cylinders, each of which applies a different coloured ink. The cylinders are controlled by cameras in order to ensure synchronised printing and avoid any effect of blurring (out of register).
This is one of the most important properties of surfaces. In the furniture industry, surfaces must be resistant to the stresses of use and cleaning. In the industry’s standards there are various methods for measuring scratch resistance, such as: resistance to scratching with a diamond needle, with the result expressed in N or Newton (1N is around 100g), which refers to the amount of weight on the needle that the surface resists without scratching. Martindale: rotating tool onto which Scotch-Brite abrasives are mounted. Following a number of rotations, the surface is compared with standards and is categorised within classes.
Process of cutting a panel to the requested measurements. It is carried out using various machines, from manual saws to highly productive automatic saws. Depending on the order, panels are cut according to a cutting pattern that minimises waste.
Veneer obtained from a tree trunk or part of a trunk using the slicing process.
Process for coating contours using flexible films such as CPL or finish foils and hot-melt adhesives.
SOLID WOOD PANELS
Wood-based panels composed of sheets or slats of wood, usually in rectangular sections. The components are joined together solidly using thermosetting or hot-melt adhesives, before the tops are comb-head milled (finger joints, minizinken joints). They can also be joined using just adhesives, without using finger joints. Single-layer or three-layer panels are usually used, overlapped with 90° curly grain. This method produces plywood solid wood panels.
When the texture is coordinated with the decorative paper’s design this is called a synchronized product. Achieving this feature is not technically insignificant as the expansion of the decorative paper must be managed during the impregnation process, and the impregnated paper must then be inserted exactly underneath the finishing plate at sizes of more than 5×2 metres with a margin of error of just a few millimetres.
TABER WEAR RESISTANCE
Resistance test that indicates surfaces’ ability to resist abrasions. The name comes from the instrument itself, called the Taber, which has weighted abrasive wheels. The level of abrasion resistance is expressed in the number of rotations required to achieve the level of abrasion specified by various legislations. Different categories of abrasion usually signify different uses. For example, in increasing order of resistance, they can be used vertically, horizontally (on worktops) and as flooring.
TECHNICAL DATA SHEET
A technical data sheet is a voluntary document in which the manufacturer includes some technical performance information about the manufactured item that might be useful for the customer or end user. They often include recommendations for use, storage, maintenance and cleaning.
The texture is the finish of TSS products. It is characterised by a three-dimensional structure, obtained by pressing engraved sheets for covered panels, release sheets for laminates and mechanical embossing for edges.
This synthetic adhesive has adhesive power thanks to chemical polymerisation reactions that are activated by heat and catalysts. Once polymerised, the adhesive is no longer meltable or soluble as the process is irreversible. The most widely used thermosetting adhesives are: urea-formaldehyde (UF), melamine formaldehyde (MF), melamine-urea-formaldehyde (MUF), and phenol-formaldehyde (PF).
Material used for coating surfaces; made out of a very thin polyester foil on which a decorative layer and a layer of thermoplastic adhesive have been placed. Using a hot rolling press the polyester foil transfers the thermoplastic adhesive and the decorative layer to the panel surface. The decorative layer may be mono-coloured or may have a wood grain design. Then, to protect the decorative layer and improve surface properties, a finishing coat of varnish is spread on top.
TSS or Thermo Structured Surface.
This is the name that Cleaf gives to its panels made using a press with thermosetting resins. TSS are set apart from common melamine products thanks both to the careful combination of decorations and finishes, as well as the depth of the latter.
The panels’ high-quality performance comes from the use of both well-selected raw materials and state of the art machinery.
The layer placed between the decorative layer and the support, necessary for preventing imperfections when pressed with deep or structured finishes. In this case, the barrier acts as a cushion by also distributing the pressure to the surface’s hollows. In the case of panels, the barrier can also be used for preforming as it helps to thicken the surface layer, enabling it to bend. It is usually made out of Kraft paper impregnated with phenolic resin. For the finishing of thin single-sided panels, barriers impregnated with urea are used to help flatness.
Used for the production of both impregnation resins (see Impregnation resin) and adhesives for the production of particleboards or MDF. They are formed of urea and formaldehyde, and crosslink when exposed to heat and pressure. Compared to melamine resins they are less precious, cheaper, more hygroscopic and they release more free formaldehyde.
Wood-based panel whose sides have been covered with decorative veneers (sliced or rotary cut)./p>
Thin sheet of wood, less than 7 mm thick, obtained from a trunk or part of a trunk, through slicing, rotary cutting and, in special cases, sawing.
WATER RESISTANT BOARD
Wood-based panel made using melamine and phenolic thermosetting adhesives that are resistant to humid environments and a paraffin emulsion that restricts water absorption.