The development of the first strip thickness gauge worldwide, that could measure the thickness of the strip during the rolling process in cold mills with an accuracy of µm, was the start of our company in 1963.
Vollmer America
High Speed Control
Principles and components
Requirements for a high speed strip thickness control are a quick and well-designed servohydraulic mill screwdown and highly accurate strip thickness gauges with sufficiently fast response times.
The variations of the control scheme are many: Position control, direct roll gap control, roll force control, mass flow control, feedback control, feedforward control and more that combine these modes. Depending on the type of mill, the strip material and other factors, we will create a control scheme for the specific mill that will achieve the required close strip thickness tolerances.
Adaptation of processor concept to the requirements
The performance data of the different mills vary widely from each other. To achieve equally good finished strip tolerances, the requirements for the control are significantly higher for strip speeds of 1000 m/min, for example, than for strip speeds of 100 m/min. Vollmer control systems are also adapted to the requirements of the mill with regard to the processor hardware (from the high-speed VME-Bus processor to the less expensive PLC assembly), so that the customers´ requirements will be satisfied by an optimal solution.
Speed measurement
In addition to the strip thickness, the strip speed is an important factor in many control schemes. We apply non-contact laser speedmeters where necessary. On many mills, the use of rotary sensors on the deflector rolls is sufficient. Which type of speedmeter applied, depends on the strip acceleration, the wrap angle on the deflector rolls and other factors.
Display of information
The graphic user interface provides the human interface to the mill sequences for the operator. Depending on the customers´ requirements, we offer alternatives. Among others, Intouch or WIN CC visualisation systems have often been applied. The multilingual design and the neat display of the strip condition, the control success, the interface situation and many other parameters have been well-proven for many years. Most sophisticated control solutions include diagnosis tools such as crash records, multi-channel strip recorders and other features that have proven to be useful in finding and solving operational problems.
What's New
VIP 08 Flatness Measurement System
While the strip thickness tolerances were a significant criterion for the quality assessment of strip material in the eighties and nineties, significant improvements in controls and automation have made good thickness control a given among suppliers.
First Isotope Thickness Gauge Application in Mexico
During this past fall, we installed our first two – Model A3000 Isotope Thickness Gauges in Mexico. The application was for stainless steel on a heavy-duty reversing mill with 24/7 operation.
Quality and Yield Optimization on Cold Rolling Mills
In order to accommodate for the high demand in accuracy, quality and yield, it is essential to optimize the existing operating equipment. In the past Vollmer has supplied and been known for their high performance thickness gauges in conjunction with the automation of the screwdown system.
News & Events
BFI Article shows new design for shape roll measurement
The well-proven BFI version shape measurement roll has undergone a design change that improves its ability to measure the tensions profile on flat product without marking the strip. The detectors have been redesigned to fit into the roll while leaving the surface of the roll completely clear of machined marks. This eliminates the former problems associated with the axially installed sensors.