NANJING LESUN SCREW CO.,LTD

What Are the Technical Requirements for Barrel and Screw Manufacturing Quality?

Ⅰ. Quality and technical requirements of extruder barrel


1. The barrel of the extruder should be made of anti-corrosion and wear-resistant alloy steel. China is currently mostly made of 38CrMoAL, 40Cr or 45 # steel.


2. The extruder barrel blank should be forged.


3. The extruder barrel should be quenched and tempered after rough processing, hardness ( HB ) = 260 ~ 290.


4. After the extruder screw barrel is machined, the wall thickness should be uniform, and the machining accuracy of the inner hole should conform to the 7 -level accuracy in the GB 1184-1996 standard.


5. The surface of the inner hole of the extruder barrel should be nitrided, and the depth of the nitrided layer should be within the range of 0.40-0.70mm. Surface hardness ≧ 950HV.


6. The roughness Ra of the surface of the inner hole of the extruder barrel after processing should not be greater than 1.6µm.


Ⅱ. Quality and technical requirements of extruder screw


1. The extruder screw blank is forged with 38CrMoAL or 40Cr alloy steel.


2. The extruder screw should be quenched and tempered after rough processing, hardness ( HB ) = 260 ~ 290.


3. The outer circle accuracy of the extruder screw after finishing should meet the H8 level accuracy requirements in GB/T1801-1999.


4. The roughness Ra of the screw thread part of the extruder is not greater than 1.6µm on both sides of the thread, and the bottom groove surface and outer circle of the thread are not greater than 0.8µm.


5. The surface of the thread is nitrided, the nitrided layer is 0.3 to 0.6mm deep, and the hardness is 740 to 840HV.


6. The brittleness of the extruder screw is not more than 2 grades.


Third, the structure of the extruder barrel is divided into several forms?


The extruder barrel is on the periphery of the screw body, and the extruder screw rotates in the barrel.


The structure of the extruder barrel can be divided into three types: integral type, bushing type and casting bushing type. The most widely used is the integral barrel structure.


Integral barrels are mostly made of 38CrMoAL or 40Cr alloy steel. Nitriding treatment is performed on the inner working surface after finishing to improve working hardness and wear resistance. The machining accuracy of this barrel structure is easier to ensure. The assembly precision is high, the barrel is heated evenly, and the process temperature is better controlled, but it is more difficult to repair after wear.


The bushing type barrel structure and the casting bushing type barrel structure are mostly used in the large extruder barrel structure, mainly to save more expensive alloy steel, and the wear and repair cost of such an extruder barrel structure is also relatively low.


As a leading screw and barrel manufacturer, our company is specialized in the production of parallel co-rotating modular screw elements, barrels and screws, covering various models from Ø20mm to Ø300mm. After ten years of vigorous development, our company now has a number of advanced CNC machine tools and special processing equipment for screw manufacturing. Now our machining operations are basically intelligent and automated. Advanced processing methods, strong technical force and sophisticated processing technology ensure that the quality and technical indicators of each production fully satisfy customers. If necessary, welcome to consult.

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