Common problems and solutions for the quality of TPE extrusion granulated pellets

Common problems and solutions for the quality of TPE extruded granulated pellets are as follows:
1. The modified material is granulated. By granules is meant that two or more pellets of the binder are joined together side by side. The reasons for the production of modified materials are mainly due to the absence of timely striping or broken strips during driving, the insufficient length of water immersion, and the high temperature of the head.
The main solution:
1) When extruding the strip, use a nylon roller with a suitable width to separate the strips that are stuck together;
2) Adjust the appropriate cooling immersion length to prevent the strip from overheating, thus reducing the granules;
3) Properly reduce the temperature of the head and adjust the temperature of the strip;
4) For the occurrence of continuous granules, sieves can be sieved with a suitable sieve.
2, long strips. Larger than normal pellets, twice the length can be considered as strips. The main reasons are the starting strip or broken strip, the direction of the strip is not straight, the strip is not suitable for water immersion, the cutter of the pelletizer is worn or notched.
The main solution:
1) Adjust the direction of the strip entering the pelletizer and adjust the length of the immersion during normal production;
2) The production process is severely required to adjust the extrusion process;
3) Pay attention to the inspection of the pelletizing motor knife; replace the damaged moving knife in time;
4) For the long strips that appear, a suitable vibrating screen can be used for sieving.
3, purlins. The cut surfaces of two or more pellets are not completely cut, and they are called together as a purlin. In fact, the reason for the category of the binder is mainly the speed of the trolley when the speed is slow, the twin-screw extruder The material of the material is not enough, the length of the water immersion is insufficient, the cutter of the granulator is worn, or the gap between the fixed knife and the movable knife is too large.
The main solution:
1) The operator should draw a uniform speed when pulling the bar to avoid the material being too thick;
2) Adjust the appropriate extrusion process to avoid dropping material at the feed opening;
3) Adjust the appropriate cooling immersion length to avoid overheating of the strip;
4) Adjust the clearance between the fixed knife and the movable knife, and then do not replace the new tool.
4, black spots. There are black speckle particles on the surface or inside of the particles. The main causes of black spots are: the screw is not clean, the black spots in the raw materials, the carbonization of the screw, the environmental pollution, and the intrusion.
The main solution:
1) During the process of converting the product, the screw is not cleaned and the screw can be re-pulled; the cleaning point: “three ports”, the stencil behind the filter and the large head;
2) Strengthen the inspection of incoming materials, especially those filled with mineral powder or flame retardant, which are more prone to black spots and impurities; for example, Z30S or T30S particles containing wood chips in the package, low-grade filler mineral powder or flame retardant; Cannot be used to produce modified plastics with strict black spots;
3) Pay attention to control the temperature of the barrel and the residence time of the material in the barrel to prevent the processing temperature from being too high; that is, the corresponding extrusion process should be designed according to the formulation of each product.
4) Pay attention to the surrounding environmental sanitation and keep the ground moist. It is necessary to do the isolation and protection between the machines that produce different colors.
5) Regularly clean the auxiliary equipment of the extrusion equipment such as: sink, pelletizer, etc.;
6) When changing the net, clean the remaining materials on the moving stencil and the template to prevent the carbonization from being too long;
7) Note that the floor strips are strictly prohibited from entering the pelletizer to prevent dust from being introduced;
8) Anti-static static electricity is generated, and static electricity is easy to absorb dust.
5, discoloration. It is manifested that the color of the product changes suddenly during the production process, and there is obvious color difference. The main cause of discoloration is uneven mixing or incorrect mixing; the cleaning machine is not clean; the temperature is too high; the shearing is too strong; .
The main solution:
1) In strict accordance with the mixing process to ensure the uniformity and correctness of the mixture;
2) After the completion of the cleaning machine, check the personnel to ensure that the cleaning machine is clean;
3) Control the extrusion temperature to prevent the toner from decomposing due to excessive temperature;
4) Select the appropriate screw combination to avoid too strong shear;
5) Make sure that the backstock is free of impurities.
6. Poor vacuum. There are two or more vacuum eyes or foaming on the grain cut surface. The main causes of poor vacuum are insufficient vacuum, vacuum return, bad vacuum system, and poor sealing.
The main solution:
1) Regularly check and maintain the vacuum pump and vacuum pressure gauge;
2) Clean the vacuum tank, vacuum chamber and vacuum pipeline in time;
3) Properly control the flow rate of the circulating water of the vacuum pump;
4) Solve the vacuum return and ensure that the vacuum cover is sealed.
7. Iron filings or other metal particles have iron filings or other metal particles on or in the middle of the plastic pellets.
The main causes are screw wear, broken knives, iron filings or other metal particles in the material.
The main solution:
1) Check if the screw, moving knife, vibrating screen, etc. are damaged;
2) Check whether there are corresponding metal particles in the raw materials;
3) For poor products, strong magnetic or other metal separators can be used to screen out metal particles;
4) Add a filter to the non-enhanced car.
8. Poor plasticization. There is a refractory material from the grain cut surface, or the surface is black and has a skin-like phenomenon.
The reasons for poor plasticization include low heating temperature, impurities in raw materials, excessive feed rate, too weak screw shear, and too much lubricant in the formulation.
The main solution:
1) Control the temperature according to the process regulations, and find that the temperature is appropriately increased when there is plasticization;
2) Check whether there are impurities and insolubles in the raw materials or in the process;
3) Properly control the feeding speed to increase the time during which the plastic is heated and plasticized in the screw;
4) Select a screw combination with a moderate shearing capacity;
5) Adjust the formula appropriately.
9. If the water is too high, look at the shiny water from the surface of the strip, or feel the tide of the material by hand, or drip under the pelletizer.
The reason why the water is too high is that there is too much water in the material strip. When the car is driven, it is not divided in time. The speed of the pelletizer is too fast, the wind speed of the air knife is too small, and the distance between the pelletizer and the air knife is too close.
The main solution:
1) Properly adjust the length of the immersion of the strip;
2) When the strip is pulled, the strip is divided into strips immediately after entering the pelletizer;
3) Adjust the speed of the pelletizer appropriately, and at the same time properly adjust the height of the strip holder;
4) Ensure that the wind knife wind is large enough and use two air knives if necessary;
5) Adjust the distance between the pelletizer and the air knife appropriately.
10. After the granules are granulated by the pelletizer, many tiny granules are produced.
Due to the static electricity of plastics, the main reason for their adsorption at the bottom of the vibrating screen is that the strips are too immersed in water, the cutter of the pelletizer is worn, and the filler is too hard.
The main solution:
1) Properly adjust the amount of water immersed in the strip;
2) Replace the new pelletizing tool;
3) Adjust the formula appropriately to reduce the distance between the pelletizer and the air knife.
11. At the carbonization die, the coke is turned into a black substance, and the main cause of the carbonization of the granular scorch on the surface of the plastic is that the heating temperature is too high, causing the melt to be scorched; the screw is used for a long time without cleaning, and the scorch is accumulated. The downtime is too long and there is no cleaning head and screw.
The main solution:
1) Always check if the heating system is normal, if the heating system has problems, solve it in time;
2) Regularly pump the screw or clean the machine head and clean it thoroughly;
3) The die, stencil and filter should be cleaned in time to prevent carbonization. If carbonization is found, the machine head and screw should be cleaned immediately.

Spanish Roof Tile is a new type of building material which is widely used now. It has the advantages of anticorrosion, durability and rich color. Spanish Roof Tile is widely used in flat to slope, resort, rural building, villa and other buildings. In terms of production material, resin tile is ASA material, which has the characteristics of load resistance, corrosion resistance, weather resistance, water resistance, fire protection, etc. Synthetic Resin Roof Tile  has the characteristics of long-lasting color, even if long-term exposure to ultraviolet, moisture, heat and cold conditions, it can still maintain its color stability.

Spanish Roof Tile

Spanish Roof,Spanish Tile Roof,Plastic Shed Roof,Plastic Spanish Roof Tiles

PINGYUN INTERNATIONAL , https://www.pingyunconstruction.com