1、 Insufficient melt strength
Performance: The bubbles are too large, clustered, or elongated in the longitudinal section; Poor rebound and easy breakage after pressing the board
Cause: Insufficient dosage or substandard quality of foaming regulator; Excessive foaming agent leads to excessive gas expansion; Excessive processing temperature or poor plasticization
Solution measures; Add high viscosity foaming modifiers (such as P-503) to enhance melt strength; Adjust the proportion of foaming agent (AC/modified foaming agent) to reduce excessive gas production; Optimize plasticizing temperature to avoid local degradation
2、 Lubrication imbalance
Insufficient external lubrication: The temperature in zone 5 of the extruder is out of control and rising, causing overheating of the merging core; There are large bubbles, series of bubbles, yellowing in the middle of the board, and the surface is rough;
Excessive external lubrication
Serious precipitation (visible oily substances or “whiskers” on the mold structure/surface)
Internal lubrication imbalance: insufficient: uneven plate thickness (thick in the middle and thin on both sides); Excessive: The temperature of the merging core increases, causing yellowing
Solution: Accurately regulate the ratio of internal and external lubrication; Internal lubricants (such as G60) improve flow uniformity; Select high melting point and high-efficiency varieties of external lubricants (such as J-1020P OPE wax); Choose OPE wax with a stable viscosity of around 10000 to avoid excessive sticking of the material
3、 Temperature and plasticization out of control
High temperature: yellowing of the board/core layer (due to stabilizer failure or local degradation); The foaming agent decomposes in advance, and gas escapes from the feeding hole
Low temperature: Poor plasticization, low melt strength leading to bubble rupture
Solution: Reduce processing temperature (especially in the merging core/head area); Choose stabilizers with good initial coloring and strong thermal stability (such as MS-101/WD-300); Regularly test the performance of stabilizers at 180-200 ℃
4、 Synergistic failure of foaming agent and regulator
Performance: Layered or abnormal cross-sectional pores; Incomplete foaming or gas escape 7
Cause: Imbalance between regulator and foaming agent ratio (such as insufficient regulator); Improper stabilizer dosage affects the decomposition temperature of foaming agent. Solution: Adjust the dosage of foaming regulator to match the gas release rate of foaming agent; Accurately control the stabilizer dosage according to the resin grade (such as S-700/SG-8) to ensure that the plasticizing temperature is synchronized with the decomposition temperature of the foaming agent
Post time: Jun-19-2025
