Precise Gluing Application

In the small auto lamp assembling application, the required hotmelt amount of each lamp is very little (about 5g to 10g). If use reactive adhesive such as Reactive Polyurethane in 20L pail or 200L Drum packaging could lead to deterioration due to long usage time. Therefore, the 300ml packaged adhesive is a more suitable choice for small auto lamp hotmelt dispensing application.

In the auto lamp industry, the finished products need to pass strict inspection, the CPK values have to reach 1.33 within tolerance of ±3%; otherwise, the export sales channels to the US and Europe will be limited. Therefore, the accuracy requirements like dispensing quality and precision of the glue amount are very strict in the production of the lamps. As a result, whether a dispensing machine can precisely control the amount of adhesive is a very important index to auto lamp factories when evaluating equipment.

When using 300ml packaging hot melt adhesive, it is difficult to control the dispensing tolerance of small auto lamps within ±3% with a pneumatic pressure control needle or a pneumatic hot melt valve, that the repeatability of which is about/over ±10%. The traditional pneumatic control needle dispensing requires precise control of the air pressure to maintain the stability of the hot melt volume, and it often causes dripping and cannot stop dispensing because of unstable air pressure, viscosity change of adhesives and insufficient suction force.

Norda AccuValve metering valve is able to maintain the dispensing tolerance within ±1% when the dispensing width is less than 2mm. The CPK value of the quality inspection result is greater or equal to 1.33, which is required by the lamp manufacturer. The uni-body design of dispensing valve and metering system makes AccuValve to achieve the precision, stability and immediacy of hotmelt dispensing operation. The dispensing valve can stop the adhesive immediately when the operation is completed, with no dripping occurs. The gear pump driven by servo motor is able to provide metering, keep the dispensing amount consistent, and not influenced by air pressure or changing of hotemlt viscosity. AccuValve can be used with the commercially available 300mL cartridge packaged hotmelt, which can be directly placed into the system. The HMI display dispensed glue amount and remaining amount, as well as issue a warning when the amount of glue is low.