Traditional pressure-time adhesive dispensing systems are suitable for many automated bonding and sealing applications but they are not a good choice where an exact amount of product needs to be applied regardless of ambient temperature or viscosity. This is why Henkel has introduced a comprehensive range of LOCTITE dispensing systems based on the principle of volume change, a process which ensures consistent dosing.
Commonly, these LOCTITE Volumetric Dispensing Systems are used in automatic workstations, transfer lines and in robotised assembly for precise dispensing of adhesive dots and beads onto mating surfaces or flanges. This is particularly important to those in electronics and medical device assembly who also often require the integration of light cure equipment in the process.
As Henkel can supply both the adhesive and the volumetric dispensing system, the combined solution is optimised for the purpose. Consistent, high-quality bonding and sealing is assured, with very high repetition accuracy even in variable environment conditions.
At the heart of the LOCTITE design is an eccentric rotor pump, the main components of which are a stainless steel rotor that rotates within a self-sealing elastomeric stator. As it dispenses the adhesive volumetrically and virtually free from pulsation, it gives far greater control of the amount of adhesive released.
Volume flow depends on the size of the pump and the number of revolutions; direction of flow is reversible to eliminate the possibility of post-dispense dripping. As flow is directly proportional to the speed of rotation, the system allows for the continuous, variable adjustment of the dispensing rate via motor speed adjustment.
The standard, single pump, Henkel Volumetric Rotor Dispenser is designed for flowable, single component LOCTITE anaerobic adhesives/sealants and light-curing acrylics. A maintenance-free, brushless DC motor is used to drive the system and an integrated pressure regulator is provided for connection to an optional reservoir. The system comes complete with a dedicated controller whose menu navigation and graphic LCD display makes it easy for users to select either the amount of product dispensed, in millilitres, or the dispense rate in ml/min.
Henkel's LOCTITE Dual Rotor Pump Dispenser is based on exactly the same operating principle but is mainly designed to handle two-part epoxy resins. It is suitable for processing low and high viscosity materials within the ratio of 1:1 to 10:1 and typically specified for dispensing continuous beads or for time-controlled potting applications in manual work stations.
Two separate servo drives allow continuous adjustment of the ratio mix and the system can also process some abrasive products. As the pumps are built directly into the follower plates with wipers, they can also be used for feeding and dispensing non-levelling, thixotropic products.
Both Volumetric Dispensing Systems are in the standard LOCTITE range but, in common with all dispensing and automation equipment, they can be tailored to the precise needs of the application. Additional choices in the range include the LOCTITE Benchtop Peristaltic Dispenser for volumetric dispensing from a bottle and the new Jet Valve for non-contact dispensing. Go to www.loctite.co.uk for further information.