Laser, EVA or PUR glue?

Edgebanding can be a minefield these days with the ever-increasing types of tape and methods of applying the tape. In this article Simon Hornby from Jacks looks to declutter the options and dispel some of the myths.

Two obvious edgebanding trends are towards a “zero” glue-line and the use of 1mm tape on cabinet doors and drawer fronts to achieve a seamless slimmer modern profile.

PUR glue

Advantages include a thinner glue-line and the extremely strong bond and waterproof qualities - up to six times stronger than EVA glue. This makes it ideal for use in cabinetry destined for high moisture areas and where extra durability is required. PUR is a moisture-reactive adhesive - requiring atmospheric humidity to harden. Curing begins as soon as PUR is exposed to the atmosphere. The volume of glue and humidity at the time will determine how long the glue will remain usable. Best practice is to apply PUR as soon as possible once the packet is opened. Cleanliness is also vital.

Edgebanding with PUR requires more gluestation maintenance than EVA. Arguably one of the greatest enemies of edgebanding with PUR is the problem of dried PUR contamination within the system. Glue station maintenance and flushing the system are two practices which must be consistently and faithfully performed. Unless the gluing station is completely sealed, when the edgebander is switched off for the day, flushing or storing the gluing station in a purpose-built unit is necessary. PUR can’t be left to sit in the edgebander over the weekend. If it does, it may harden and possibly require replacement of the gluing station. For these reasons, PUR lends itself to larger workshops with higher volumes whereby the edgebander is run most days for extended periods of time.

EVA glue is the most common glue type used in New Zealand. With a suitable glue colour the glue-line isn’t obvious but it is thicker than a PUR glue-line and therefore more difficult to disguise. The bond strength of EVA is also not as strong as PUR and when reheated or exposed to moisture the edge tape can delaminate. The advantage of EVA over PUR are its handling properties. Unlike PUR, EVA can be reheated multiple times and left in the glue application unit of the edgebander for weeks between jobs. These properties reduce maintenance and make EVA easy to work with.

Laser tape

Laser tape is quickly becoming the most popular method to apply edge tape for both smaller and larger workshops. The two main advantages of laser tape are the “zero” glue line seamless join between edge and face material, and the simplicity of applying the tape. Bond strength sits somewhere between EVA and PUR.

As consumers become more accustomed to furniture without glue-lines, demand for the higher quality finish increases. Unlike conventional edge tapes, laser tape consists of two layers. A hard décor layer and a meltable function layer. The function layer consists of polymers which enable it to melt faster than the décor layer. When the function layer is heated and pressed against the edge of the board, the tape fuses to the edge to create a seamless join. The absence of glue in this process has significant processing benefits over PUR and EVA glue. Less maintenance and cleaning of the edgebander, faster readiness for operation of the machine and no requirement to change glue colours.

As demand for laser tape increases so does availability. All major suppliers of edge tape in New Zealand now offer a wide range of laser tapes. Competition in this space is also making laser tape more economical. Many Kiwi manufacturers with edgebanders capable of processing laser tape are not just processing doors and drawer fronts with laser tape but also carcasses. Once the cost of glue, extra cleaning and maintenance are factored into the overall costs of edgebanding, the costs of processing with conventional tape and laser tape are very similar. And let’s not forget the advantages of the zero glue-line appearance and strong bond qualities of laser tape.