The are many different types of whiteboards, which have different manufacturing processes.
The types of whiteboards manufacturing we will discuss are, flexible film laminates, porcelain, glass, melamine and HPL.
Flexible films are made from molten PVC which is extruded under a rubber blade, called a knife into micron thin sheet and rolled onto itself. Separately, the backing sheet is produced which is a silicon coated liner, or polyethylene (PE), sometimes with a double PE liner, which means that is coated on both sides. Coating the liner on both sides keeps the liner flat under humidity and heat. These liners sometimes have patterns embedded into them to create the air-release channels in the adhesive which it is laid on to the backing paper. The PVC and backing paper are then combined, before they are combined a primer layer is applied to the film to make sure that the adhesive stays on the film when the film is removed, instead of the backing sheet. When producing whiteboard laminates, the film needs a non-stick coating. These films can often be made from polyester as they are harder than PVC and less porous, very similar to graffiti guard films. Our laminate has a hardened coating which makes it more rigid than PVC, and better than other whiteboard laminates. If you accidentally use permanent marker then, instead of whiteboard marker, you can still wipe it off with IPA.
Our stick-on whiteboards are made by printing on the PVC base film with latex inks, which are water-based and contain less than 1% solvent. After this they are put through a lamination process, where the base film is fed between 2 rollers from behind, and the whiteboard laminate is fed from above through to combine with the PVC base film. When the laminate is fed from above the rollers, the backing sheet is simultaneously removed to expose the adhesive layer, this is what makes them stick together. The rollers apply pressure which activates the adhesive, called wetting-out, and the films are combined. After the lamination the films are kiss-cut through a vinyl plotter, this machine moves the vinyl, back and forth, whilst moving a knife across the film. The combined motion cuts the shapes out the film without cutting through the backing sheet. The whiteboard is then weeded, whereby the excess film is taken away, and the excess backing sheet is trimmed.
Porcelain Enamel, or Vitreous Enamel is made with a process of combining powdered glass and metal under very high heat. The word Vitreous has its roots in Latin, and stems from the word, vitreum, meaning “glass”, and the word “enamel” comes from several different source languages, the old German word to smelt is smelzan, which comes through the old French word esmail, which comes from Latin smaltum.
Enameling is essentially a process of overglazing. The process starts with an Enamel Frit, which is a glassy state silicate, otherwise known as a borosilicate. This is made into an enamel slurry by adding water to the enamel frit. The substrate to be coated, in the case of whiteboards it is sheet metal, is then evenly coated with the slurry. This can be done by dipping, pouring, spraying or bepowdering, which is where the glass coating is put on dry to a extremely hot ground coat so that the coating and firing is one process. There is also electrostatic coating which is when the substrate is given a negative charge and the coating is fired at it with a positive charge; the two meet and combine under heat.
The coating is then fired. This happens under high temperatures, around 800°C – 900°C depending on the substrate. The temperature and exposure time is critical in getting the product to look and perform correctly. The whiteboard is then laid on to a backing board, usually hardboard, or particle board so that it is rigid. Mounting the sheet on a backing board also helps the manufactures build up the depth of the whiteboard, so it can be thicker or thinner for various applications. Once completed these boards are usually stacked so that to help activate the glue and provide pressure over the entire surface. The boards are then cut to size, framed and shipped to distributors.
Glass whiteboards are often made from tempered, or toughened glass. Tempered glass is annealed glass which has been through additional heat treatment; this additional heat treatment makes it about 4 times stronger than it was before. The reason tempered glass is used is because it is stronger, and when it breaks, is shatters, instead of breaking into dangerous shards. There are 5 steps to the process, cutting & edging, inspection, heating, and quenching.
Cutting and Edging is done prior to the glass being toughened. This is because tempered glass cannot be cut. The glass is cut to the desired size, then the edges are sanded off with a special sandpaper. The glass is examined for any flaws, and then washed. Flaws need to be identified in the glass before the heat treatments as the glass could break at any stage of the tempering.
The glass then is taken through a tempering oven at circa 620°C. after this the glass is put through a high pressure cooling system called quenching. Quenching cools the putter edges of the glass faster than the centre, this put the glass under tension, which gives it strength. Standard glass will take 6000psi, whereas tempered glass can take 24,000psi.
Whiteboards made from glass are ordered at the desired size, them then are usually painted on the rear of the glass to create the colour, some have a galvanized sheet of steel on the rear to give the board magnetic qualities. However, you usually need to use neodymium, or rear earth magnets to be strong enough to hold on through the glass.
Melamine is a hard resin and is manufactured as a low-pressure laminate (LPL). Melamine is an organic compound that when combined with formaldehyde forms a durable thermosetting plastic. The plastic is then added to a kraft paper and is bonded directly to either MDF (medium density fiberboard), chipboard, or plywood. This produces a whiteboard which will be economical but will ghost sooner than the other products discussed here. It’s a popular choice for a lot of companies as you can buy finished sheets, cut them to the size needed and sell them.
Low pressure laminates can be known as pre-finished boards. They are manufactured at 200-350kg per square meter of pressure, at 170°C, unlike high pressure laminates (HPL) which are produced at a lower temperature, but higher pressure.
HPLs are comprised of an overlay paper, a decorative paper, and a kraft paper, these are brought together in a thermal lamination process with resins and mounted to the backing board. In total 6-8 layers can be used to form the laminate. These layers are combined by saturating them in phenolic formaldehyde and melamine formaldehyde.
The overlay paper is a laminate which serves to add durability to the composite. The overlay paper increases the products abrasion, scratch, and heat resistance. When making a whiteboard from melamine this becomes the dry erase surface.
The decorative layer, as you would guess is where the design is. In the case of most whiteboards, a blank white sheet. Although as their primary use is benchtops and other décor products, the bulk are produced with a pattern.
Kraft paper is used to control the thickness of the laminate, sometimes known as the core. You may see these products most commonly as whiteboards desks. They are durable, and works well, the downside is that they are expensive.
As you can see there are many different ways to manufacture a whiteboard. At Tosh & Leod we decided to do flexible film laminate because it works well, you can decided what surface you want to put it on, fridge, desk, wall, window, or a board. We also liked that it ships much easier and fascter than traditional whitebaords.