Dropping Process In Shoemaking Process

The drop molding technology is based on the state variable characteristics of thermoplastic polymers, that is, viscous flow under certain conditions, and solid state recovery at room temperature, and with appropriate methods and special tools for ink-jet, the shape is shaped according to requirements in the viscous flow state, and then solidified at room temperature. The drop molding technology has been widely applied to various trademark nameplates, cards, daily hardware products, tourism commemorative badges, exquisite handicrafts and the cover of advanced books. Drop molding, also known as micro injection, is a white or colored drop gel on the surface of knitted cotton and all kinds of synthetic fabrics and fabrics. It is a kind of PVC silicone similar products, bags, backpacks, costumes... Most of the brands used are of this type. The processing is rather complicated. We often talk about silicon brand, silicon drop label, drop molding non-woven fabric, and drop molding. TC cloth And so on belongs to this kind of drop molding, PVC drop molding can also be made into plastic shoes. Insole The bottom of slippers, sofa backrest, handrails, table tablecloths, mahjong tablecloth, car interior decoration, etc.

　 Drop molding method

SMA can be applied to PCB by syringe drop molding, needle transfer or template printing. The needle transfer method is less than 10% of the total application. It uses needle arrays to dip in the tray of glue. Then the glue drops are transferred to the board as a whole. These systems require a low viscosity adhesive and have good resistance to moisture absorption because they are exposed to the indoor environment. The key factors controlling needle transfer plastic drop include needle diameter and pattern, temperature of glue, depth of needle penetration and cycle length of dropping plastic, including the time before and after PCB contact. The tank temperature should be between 25~30 and C, which controls the viscosity of the glue and the quantity and form of the glue dots.

　 Factors affecting ductility

Good plastic products not only rely on the quality of glue. For the pressure time injector drop molding method, many machine related factors affect the formation of drop plasticity and glue dots. The inner diameter of the needle mouth is the key to the formation of the glue point. It must be much smaller than the glue point on the board. As a principle, the ratio should be 2:1. The glue point of 0.7~0.9mm requires ID of 0.4mm; the glue point of 0.5~0.6mm requires ID of 0.3mm. Equipment manufacturers usually provide technical specifications and operational guidelines to produce the desired size and shape of glue dots.

PCB control the height of the glue point to the distance between the needle mouth or the height of the stop (stopper). It must be suitable for dropping volume and needle mouth ID. For a given amount of glue, the ratio of glue point height to width will increase with the height of the stopper. Normally, the maximum stopper height is half of the needle mouth ID; beyond this point, discontinuous molding and drawing will occur.

The pressure of the current high speed equipment can start the plastic cycle periodically before the needle mouth is in place. The withdrawal time, the withdrawal height and the time delay between the drop molding and the needle withdrawal affect the shape and tension of the rubber point.

Finally, the temperature will affect the viscosity and glue dot shape. Most modern Dropping machine The temperature of the glue is maintained above the room temperature depending on the temperature control device on the needle mouth or the chamber. However, the outline of the adhesive point may be damaged. If the PCB temperature is raised from the preceding process, the viscosity and glue shape will be affected.