1) Resin selection
In winter construction, a resin with relatively low viscosity should be used. When the temperature is lower than 10 °C, it is still difficult for the general resin to meet the process requirements. In this case, the resin is usually heated by a water bath method, and a cover is added to prevent excessive volatilization of styrene.
2) Curing system selection
In winter, the temperature is low, and the reactivity of the commonly used methyl ethyl ketone peroxide curing system is difficult to meet the process requirements. The curing agent with higher reactivity should be used. In winter, benzoyl peroxide and high-activity methyl ethyl ketone peroxide are usually used. When adjusting the curing speed in winter, the curing speed should be adjusted by adjusting the dosage of the accelerator. The curing speed cannot be adjusted by adjusting the curing agent, so as to prevent micro-cracks or cracks when the resin is cured, which affects the performance of the product.
3) Glue configuration
The configuration of resin glue in the molding process of FRP products is a very important process. When configuring unsaturated polyester resin glue, the initiator and resin should be mixed and stirred according to the formula ratio, and then the accelerator should be added and stirred evenly. The storage period of the resin glue added with the initiator should not be too long, and the amount of glue should be It depends on the size of the construction area and the number of construction workers. In the winter construction process, insulation measures should be taken for the configuration of glue utensils.
4) Resin curing
After the pipe is wound, it is placed on the curing station and rotated, and the baking plate is heated evenly by the far-distance external line; the far-infrared heating and curing method is used in the pipe fitting and interface resin curing project, and it is required that the position should be changed frequently during the curing process to prevent centralized heating. Cracking phenomenon; for small area molding, iodine tungsten lamp or hair dryer can be used to heat and cure molding process.
5) Temperature control
Due to the low temperature in winter, if conditions permit or conditions are mature, the production environment should be relatively closed, and electric heating or water heating should be used to heat up the working area, increase the molding temperature of the working area, and require attention to ventilation.
6) The mold heats up
Due to the metal structure of the mold, FRP products dissipate heat quickly in winter. Combined with the small thickness of the inner lining, the heat generated is less. In order to ensure the quality of the inner lining, warm air can be used to heat the mold to improve the curing of the inner lining. Spend.
7) Curing after finished product
Due to the low temperature in winter, the curing degree of the finished product after curing is relatively low, and the strength of the product is relatively low.