When screen printing silicone on 100% polyester material, the following matters need to be noted:
1. Material and equipment preparation
Polyester material pretreatment:
Ensure that the surface of the polyester material is clean and free of pollutants such as grease and dust.
Consider using methods such as plasma treatment or alcohol wiping to increase the roughness of the material surface and improve adhesion.
Screen selection:
Choose a suitable screen mesh, usually recommended between 80-120 mesh, depending on the accuracy and requirements of the printed pattern.
The thickness of the screen photosensitive glue also needs to be properly controlled, generally between 0.1mm-0.3mm.
Ink and diluent:
Use silicone screen printing ink suitable for polyester materials to ensure that the ink has good compatibility and adhesion with the polyester material.
The addition ratio of diluent needs to be adjusted according to the viscosity of the ink and the printing requirements. Usually, for thick lines and thick printing, the addition ratio of embossed silicone and diluent can be 1:1.3; for thin lines and thin printing, the addition ratio of liquid silicone and diluent can be 1:0.9.
2. Printing process control
Ink preparation:
When adding color paste or gold and silver powder, stir evenly to avoid waste.
Diluent or adjusted textile silicone needs to be added to the screen every 5 to 10 minutes to increase the leveling of embossed silicone and prevent liquid silicone from agglomerating and affecting screen printing.
Printing operation:
The scraper pressure needs to be dynamically adjusted according to the hardness of the polyester material and printing requirements.
The screen needs to be kept clean during the printing process to avoid blocking.
Curing treatment:
After printing, it needs to be naturally dried within 6-10 minutes, and then the material can be collected after half an hour.
The curing temperature and time need to be set according to the curing requirements of the silicone ink. The general temperature is between 120-160℃, and the time may be 10-30 minutes.
3. Problem prevention and treatment
Bubble problem:
The bubbles generated during the stirring process can be eliminated by putting it in a vacuum machine for 8-10 minutes.
If vacuuming is not possible, use a diluent to dilute the screen printing silicone to speed up the bubble removal speed.
Fastness problem:
Make sure that the curing agent is added in sufficient amount to fully cure the slurry.
For smooth fabrics or fabrics that have been waterproofed, you can use rounded corner primer silicone or silicone adhesive primer to enhance fastness.
Hiding power problem:
When the hiding power of silicone is not enough, you can increase the amount of color paste added appropriately.
When printing patterns on dark fabrics, it is recommended to use white primer first and then scrape and print.