The influencing factors of drip plastic anti slip non-woven fabric

Good drip molding does not rely solely on the quality of the adhesive. For the pressure time injector drip molding method, many machine related factors affect the dripability and the formation of adhesive points. The inner diameter of the needle tip is crucial for the formation of adhesive points and must be much smaller than the diameter of the adhesive points on the board. As a principle, the ratio should be 2:1. 0.7-0.9mm adhesive points require a 0.4mm ID; 0.5-0.6mm adhesive points require an ID of 0.3mm. Equipment manufacturers usually provide technical specifications and operating instructions to produce the desired size and shape of adhesive points.
Control the height of the adhesive point by measuring the distance between the PCB and the nozzle, or the height of the stopper. It must be suitable for the drip volume and nozzle ID. For a given amount of glue, the ratio of glue point height to width will increase with the height of the stopper. Usually, the maximum stop height is half of the needle tip ID; Beyond this point, discontinuous dripping and pulling will occur.
High speed equipment can use a timed drip molding cycle that starts before the needle nozzle is in place. The retraction speed and height of the needle tip, as well as the delay between the drop molding and the needle tip retraction, all affect the shape of the adhesive point and the pulling line.
Finally, temperature will affect viscosity and the shape of the adhesive point. Most modern drip molding machines rely on temperature control devices on the needle tip or chamber to maintain the temperature of the adhesive above room temperature. However, the contour of the adhesive points may be damaged, and if the PCB temperature is increased from the previous process, it will affect viscosity and the shape of the adhesive points