Polyester color masterbatch procurement: Why is it that "the color is correct" but "it gets clogged up when put on the machine"? 

When purchasing Polyester color masterbatches, the most dreaded situation is this: during sample testing, the color was confirmed to be satisfactory. However, once it was put into spinning, the filtration pressure rose rapidly, the breakage increased, and even the screen got clogged. The color was fine, but why did it "get clogged as soon as it was put into production"? The problem often lies in the dispersibility and heat resistance. Below, we will help you analyze the reasons from these two aspects. 

1. The dispersion is not good enough, and the filtration pressure "soars like a rocket" 

The dispersion state of the pigments in the color masterbatch directly determines the filtration performance during the spinning process. 

Particle agglomeration is the main cause: If the pigments in the masterbatch do not fully depolymerize and there are large-sized agglomerated particles, they will be intercepted when passing through the filter screen of the spinning component, resulting in a rapid increase in filtration pressure and even clogging of the filter screen. This is usually caused by insufficient grinding fineness or an incompatible dispersion system. Jiangsu Meizilin adopts a nano-level breaking and refining process and a super-dispersant coating process to refine the pigments to the nanometer level, reducing the risk of agglomeration from the source. 

How to verify: During the procurement process, you can request the supplier to provide the detection data of the filtration value (DF value). The lower the DF value, the better the filtration performance of the masterbatch. During the on-machine trial use, you can record the time from the start to when the pressure reaches the mesh-changing value, and compare it with the reference data provided by the supplier. Using products such as nano-sized ultrafine carbon black particles, due to their finer particle size, the spinning cost can be significantly reduced. 

Carrier compatibility: The carrier has poor compatibility with the polyester substrate, which can also lead to the formation of incompatible gel particles in the melt, exacerbating the clogging of the screen. For the masterbatch used in PET spinning, a carrier with good compatibility with PET should be selected. 

2. Insufficient heat resistance, the color "changed" and it also clogged the net 

The spinning temperature of polyester fibers is high (usually ranging from 280℃ to 300℃). If the heat resistance of the color masterbatch is insufficient, problems will follow one after another. 

Pigment decomposition: Pigments that are not resistant to high temperatures will decompose at the spinning temperature. This not only causes color differences and air wrinkles, but the decomposition products may also form carbides or char substances, directly leading to clogging of the screen. 

Additive volatilization or carbonization: The dispersants, lubricants, and other additives in the masterbatch, if they do not have sufficient heat resistance, will volatilize or carbonize at high temperatures, which will also increase the filtration pressure and even contaminate the hot rolls. Jiangsu Meizilin has matched corresponding heat resistance grades and additive systems for different substrates and processing temperatures of PET, PA, PP, PE, PLA, etc. 

How to verify: During the on-machine trial, observe the speed at which the component pressure rises, the breakage rate, and whether the filament color is uniform and free of air bubbles. You can also ask the supplier to provide the color difference data of the same specification masterbatch under different temperatures to assess its heat resistance stability. 

Summary and Selection Suggestions 

When purchasing Polyester color masterbatches, it is recommended to follow the following steps to avoid the risk of "getting clogged upon machine operation": 

Provide process parameters: Inform the supplier of your spinning temperature, speed, and filtration accuracy, so as to match the appropriate heat resistance grade and dispersion fineness. 

Request for filtration performance data: Require the supplier to provide the filtration pressure value (DF value) or the filtration pressure test data as a reference for selection. 

First, conduct a small-scale trial run on the machine: Before starting the full-scale production, conduct a small-scale trial spinning on your production line to observe the changes in filtration pressure and the breakage rate. Once stability is confirmed, then increase the order size. 

Jiangsu Mizlion Nano Technology Co., Ltd. adopts nano grinding technology and focuses on coloring and functional masterbatches for polyester, nylon, polypropylene, polyethylene, PLA and other substrates. It can provide masterbatches with low DF value and high heat resistance. Please feel free to request samples for testing. 

Official website: http://www.mizlion.cn