1. Sizing: select adhesives with different properties according to the properties of products and base materials. According to different materials and properties, water-based polyurethane adhesive or acrylic adhesive can be selected. For example, when rubber, plastic, steel, glass, wood, etc. are the base materials, the main consideration is the bonding fastness. For clothing materials, not only the fastness to washing, but also the softness of hand, air permeability and moisture permeability should be considered. If the viscosity is too small, the villi may incline. If the viscosity is too large, it will hinder the depth of implantation and reduce the strength. If the amount of coating is large, the hand feel will be poor, and the drying time will be prolonged; if the amount of coating is small, the friction fastness will be reduced. The quality of flocking can be ensured by adjusting the proper viscosity and coating amount.
2. Flocking: there are four main methods of flocking: lifting, falling, side planting and upper and lower planting. Lifting type: the fluff enters the electric field on the conveyor belt, and under the action of static electricity, the fluff rises from bottom to top and inserts into the adhesive in the adhesive coating of the substrate. The ascending vegetation is above, and the falling artifacts are below. The lifting method requires two conveying devices, i.e. the conveying of processed fabric and the conveying of fluff. The structure is complex and the tension is large when conveying. If the strength of the fabric is not strong, it is difficult to process. In case of discontinuous production, the lifting method is better, because some of the fluff is implanted into the adhesive under the action of electrostatic field, the redundant fluff will fall naturally, and the fluff on the flocking surface is less. In addition, a Downing device is added to the Downing rule to absorb the floating pile on the pile surface. At present, most flocking machines adopt the Downing type. The side planting method is suitable for flocking of massive objects, and the lifting and falling planting method is suitable for flocking of linear objects.
3. Thermosetting: after flocking, heat treatment shall be carried out to make fluff, adhesive and substrate firmly combined. Generally there are two stages: pre baking and baking, depending on the type of adhesive. There are many ways of heating, usually the hot air circulation is better, which can not only reach the crosslinking temperature of the adhesive, but also make the moisture in the adhesive separate as soon as possible. The drying temperature should also pay attention to the properties of the base material to prevent the material from deforming at a higher temperature. The quality of heat treatment has a great influence on the flocking fastness. In order to ensure the temperature and time of heat treatment, if the speed is fast, the length of the oven should be lengthened properly.
4. Brush hair: after flocking, although the floating hair is sucked off, there is still residual hair in the gap. Generally, the way of brush moving against the direction of base material is used to clean the brush hair once. Mechanical beating, blowing and other methods are also used for treatment, so the effect is better. If finishing is not required, the finished product can be obtained after brushing.