Multi dispensing application with the PU bicomponent material SPECFIL FD 402 from Dow Chemical
Units A310 for preparation and feeding materials to a metering head provide an optimal solution for processing and dispensing fluids, especially highly filled bicomponent products and moisture-sensitive dispensing media. They consist of non-pressurized tanks, in which vacuum can be applied, as well as temperature control, material agitation and recirculation simultaneously to the feeding process to improve the homogenization, avoid fillers sedimentation, and ensure bubble-free dispensing. A proper preparation of the material components is essential to avoid air bubbles coming into the metering dispenser producing a modification on the mixing ration, irregularities and rejections.
We show here a new application for bonding a ceramic surface with a plastic part using the two-component polyurethane based product SPECFIL FD 402 from Dow Chemical.
The main parameters of the performed process are as follows:
- Parts dimension: 450 x 450 mm
- Dispensing volume: 210 mL
- Cycle time: 15 seconds / part
- Atmospheric-pressure dispensing
DISPENSING SYSTEM CONFIGURATION
The system used for this application consists of the following units:
- Material preparation and homogenization unit: A310
- Multiple piston metering head with 7 outlets: type Dos P016-2C/07
- Automation: CNCell with three motion axis
MAIN TECHNICAL CHALLENGES
Technical challenges to be highlighted from this application are as follows:
- Integration of the process in an assembling line.
- Very short cycle times.
- Movement of the multiple metering head with 7 outlets simultaneously and synchronized with the execution of the doses.
- Material pot life only between 2 and 3 minutes.
- Proper material preparation to avoid sedimentation of fillers in the poliol component and crystallization of the hardener (isocyanate).