There is no perfect thing in the world, as is the FRP filament process machine. In the use of the FRP filament process machine, defects sometimes occur in the production process of products. Today, analyze the causes of these defects and their countermeasures:
1. Color spots, uneven color, and discoloration Cause: The pigments in the resin are mixed unevenly, and the pigment decomposition temperature resistance is not good. Measure: Strengthen stirring to make the resin glue evenly mixed. If no effect, replace the pigment.
2. Contamination and Foreign Matter Mixing Cause: Foreign matter is mixed in the resin glue and the surface of the glass felt is contaminated. Foreign matter is entrained when entering the FRP pultrusion die. Measures: Carefully check the mixing of foreign materials during molding, replace contaminated raw materials
3. Rough and dull surface Cause: The mould surface has a high roughness value. The effect of the release agent is not good. The resin content on the surface of the product is too low. The pressure in the cavity during molding is insufficient. Measure: Select mold with low surface roughness value, use good mold release agent, use surface felt or pass continuous felt and knitted felt through dip tank to increase yarn content or add filler.
4. Causes of surface dents: Too few yarns or local yarns are lost, and the mold sticks to cause debris accumulation, scratching the surface of the product.
Measures: Increase the amount of yarn, clean the mold, restart after a brief shutdown, and use a good mold release agent.
5. Insufficient coating of glass mats Cause: The width of the glass mat is too narrow, and the positioning device of the mat is inaccurate, resulting in the offset of the mat in the forming.
Measure: When designing the felt width, a certain lap length should be taken into consideration. Before the felt enters the mold, the preform mold must have a precise guide felt seam, and a limit card is added at the entrance of the mold if necessary. The
6. Causes of surface wrinkles: The glass surface felt is too hard to be discounted when entering the mold. Polyester surface felt or non-woven fabric is too soft. There is a certain degree of inclination when entering the mold. When the surface product is pultruded, it gathers and wrinkles under the action of traction. .
Measures: Use a softer glass surface mat, use polyester surface mat or non-woven fabric carefully, if necessary, set the fixture at the die mouth to accurately position.
7. Droplets on the surface Cause: The product is not cured completely, the fiber content is small, the shrinkage is large, the product surface and the mold wall produce larger gaps, and the uncured resin migrates. Measure: Raise the temperature or reduce the casting speed to make it fully cured. This is especially important for thick-walled products. Increase the yarn content or add low shrinkage agents and fillers.
8. The surface of the skin, broken Cause: The surface of the resin-rich layer is too thick, there is creeping peristaltic at the breakaway point, the difference between the gel time and the curing time is too large, the breakaway point is too far ahead of the solidification point. Measures: Increase yarn content to increase mold pressure, adjust initiation system, and adjust temperature.
9. Cause of white powder: poor demoulding effect, glass fiber reinforced plastic pultrusion die mold sticking on the inner surface of the product, scratching the surface of the product, the surface roughness of the mold surface is too high (manufacturing reasons or scratch, rust corrosion during use. Measures: Select a good off Molding agent, cleaning, repair or replacement of qualified molds, shutting down the machine for a few moments, and pulling out the chips from the mold to achieve the purpose of cleaning.
10. Significant parting line, wear at the parting line Cause: The size of the mold manufacturing is not accurate enough. When the mold is closed, the positioning of each module is large, and the parting line has a sticking mode to cause the white line. Measure: Repair the mold, disassemble the mold and reassemble, and stop for a while to restart.
11. Exposed surface fibers, fiber fluff Cause: This defect generally occurs on products that are only reinforced with fiber yarns, such as rods, possibly due to too high fiber content or resin chips on the inner walls of the mold cavity. Measures: Reduce the fiber content and restart the machine after the machine is suspended.
12. Not aging, fading Cause: There is no addition of light stabilizers and heat stabilizers. The pigments have poor light resistance. Measures: Add anti-aging agents, use high-quality color paste.
13. Insulation is poor Cause: Resin, fiber insulation is poor, poor interface adhesion performance. Measures: Improve raw material selection and use coupling agents to enhance interfacial properties.
14. Insufficient strength and poor mechanical properties Causes: The mechanical properties of raw materials are low, and the degree of cure is not sufficient. Measures: Select high-quality raw materials, such as high-strength fibers, high-strength resins, and reasonably control the process parameters to ensure the degree of cure and post-curing.
15. Dense pores Cause: The raw material quality is poor and the temperature control is irrational. Measures: Use a good material and control the temperature not too high.
From the above few defects, it is not difficult to find out the reasons for these problems in the
FRP filament process machine, and how to solve the problems can be prolonged the service life of the FRP filament process machine as long as the problem is solved.
