In automated product labelling processes, the adhesives used to affix the labels are sometimes prepared just before the label application step. To ensure maximum quality of label adhesive, Suurmond has developed a module that incorporates two dispensing pumps, three flow meters and a static mixer.
Adhesives come in many varieties. Some are standard commercial products, ready for use. Other adhesives have multiple components that are mixed either just before, or during the labelling process.
Two-component adhesive
One of Suurmond’s customers has developed its own two-component adhesive. This adhesive is composed of a watery component mixed with an additive that ultimately determines the bonding properties of the glue.
These fluids must be dosed and mixed with the greatest of precision. The process therefore requires both automation and fine control. Given the positive experience with a previous machine from Suurmond, this customer asked the company to develop a dosing and mixing module specifically for their new adhesive.
Arrangement
The final design employs two dosing pumps that deliver the two components into the mixing process pipework.
The flow rate is measured and monitored by two independent flow meters. A static mixer is mounted in the same pipe to combine the two components to form a homogeneous fluid.
Reijer van den Bosch, Project Engineer: “The customer also asked that we include a third flow meter to measure the final product in the pipe. This creates an extra monitoring step in the process, enabling detection of any leaks, as well as a check for possible failure of one of the two upstream component flow meters. The mixture, a highly concentrated ‘glue’, is then pumped through the delivery line to where it is used to bond the labels to the actual product container.
Membrane pumps
In addition to the dosing pumps and flow meters, Suurmond also supplied all the pipework, as well as two membrane pumps. One diaphragm pump is used to fill a buffer vessel with additive. This buffer vessel takes over when the main additive supply tank is empty, enabling the exchange of supply tanks without interrupting the process. The second diaphragm pump is intended to flush the pipe system when the machine is idle.
