تعمل معظم مصانع الدرفلة الباردة الترادفية التقليدية في وضع الدفعة ذات الملف الواحد. يقوم المشغلون بتغذية ملف فولاذي واحد في كل مرة من خلال منصات دوارة متعددة. لا يمكن لهذا الإعداد تقديم إنتاج مستمر حقًا.
يؤدي تدوير الدُفعات إلى إنشاء مراحل انتقالية غير مستقرة. وتشمل هذه المراحل خيوط الشريط, إسقاط الذيل, تحولات السرعة والتباطؤ في طبقات اللحام. They cause dimensional errors on cold rolled strip and cut the mill’s working efficiency.
Full continuous cold rolling mills solve these weaknesses of intermittent single-coil rolling. They let steel strip run nonstop for high-volume stable production.
## 1. Equipment Composition
A typical production line uses a five-stand full continuous cold rolling mill. Workers send raw steel coils to the uncoiler after high-speed hydrochloric acid pickling.
The line levels the strip head and trims the strip end. A high-speed flash welder joins the tail of one coil to the head of the next coil.
The line fits a loop storage warehouse. This unit stores extra strip to keep the mill running at constant speed during coil welding.
Weld detectors sit at the inlet and outlet of the loop warehouse. They spot thickness changes around welds. The detectors send signals to the control computer. The computer adjusts rolling parameters to keep stable product quality.
## 2. Working Process
The mill installs a pinch roll and rotary cross flying shear between the fifth stand and two tension reelers.
The pinch roll holds steady front tension for the final stand during strip cutting and reel switching. It stays away from the strip under normal rolling conditions.
The rotary flying shear cuts strip to split coils. Two tension reelers take turns to wind strip, so the line can change coils without stops.
This mill keeps strip inside the machine during roll change. Teams restart rolling right after they finish roll replacement, without full line shutdown.
## 3. Core Advantages of Full Continuous Cold Rolling Mill
### 3.1 Boost Working Time Utilization
Full continuous rolling removes time loss from repeated threading and tail dropping. It cuts roll change frequency and reduces acceleration and deceleration time.
The mill runs at stable high speed after startup. Operators only slow it to 5-10m/s for product specification changes or flying shear cutting. This setup maximizes effective production time.
### 3.2 Raise Finished Product Yield
Batch rolling often creates out-of-spec thickness and trimming waste at coil heads and tails. Continuous rolling avoids these thickness fluctuations. It cuts scrap and improves the yield of cold rolled steel strip.
### 3.3 Improve Roll Service Conditions
Intermittent rolling often damages roll surfaces. Strip folding during threading and impact during tail dropping create surface defects. Frequent speed changes also speed up roll wear.
Continuous rolling stabilizes the rolling state. It reduces impact and abrasion on rolls. Teams change rolls less often. They spend less time on roll grinding and storage management, and the strip surface quality improves.
### 3.4 Reduce Labor Demand
Full continuous cold rolling mills rely on computer automatic control. Operators do not need manual threading, tail dropping or manual parameter tuning.
The control system monitors and adjusts the whole production flow automatically. The factory needs fewer on-site workers and achieves labor-saving intelligent rolling.
