Specific implementation process of nylon tie

Specific implementation process of nylon tie
Nylon tape caprolactamine has strong water absorption, and will absorb a large amount of water during storage, and will react with NaOH during casting polymerization to generate water. Moisture must be removed during casting polymerization. Dehydration methods can be divided into nitrogen method and vacuum method.
Nylon tie nitrogen method
Add caprolaphthalamine into the dehydration vessel, heat it to 110C, add caustic soda, add nitrogen under stirring, make it react and dehydrate for 30min, then heat it to 140C and add cocatalyst, quickly add nitrogen and stir for 15min, then quickly pour it into the 160 ` C mold, and polymerization can be completed within 20 '- 30min. Finally, take out the product. The disadvantage of nitrogen method is that it needs to consume a large amount of nitrogen, and a large number of monomers are brought into the air to pollute the environment, and the quality of products is also difficult to control. This method has been gradually replaced by vacuum method.
Nylon tape vacuum method
Add caprolaphthalamine into the dehydration vessel, and heat it until the monomer starts to melt (melting point 70C), then start to vacuum. After all the monomers are melted, add NaOH and raise the temperature to 130 -- 140 ° C, continue vacuuming for 10 ^ - 15 minutes, then add cocatalyst, mix evenly and pour it into the mold at 150 -- 160 ° C quickly, and the polymerization can be completed within 15 minutes. The mold can be demoulded after holding for 1h.