Monitoring paper transport on a sheet-fed printing press with DKS40

Monitoring paper transport on a sheet-fed printing press

On a sheet printing machine, paper is transported through several colour towers, at high speed. In many cases, the printing material range is only 0.04 mm. The rollers transporting the paper must run in absolute synchronization, otherwise the sheets may be misprinted. The rotation of the rollers must therefore be monitored, and the number of roller rotations per minute must be communicated to the controller. The device used for monitoring must withstand heavy vibrations.

The SICK DKS40 incremental encoder was selected. One of the main reasons was the favorable price, compared with other products in the same quality class. With numbers of lines from 1 to 2048, the DKS40 determines the speed of the rollers and sends the data to the controller. Thus, if the rotation value of a roller differs, this will be corrected by the controller. The encoder housing consists of solid die-cast zinc and with an outer diameter of 50 mm, it is extremely compact, thus saving valuable mounting space. Its core contains the highly successful mini disk technology, making the DKS40 with its IP 64 protection rating supremely robust in respect of shock and vibrations.

Low price, high reliability through robustness and proven technology make it easy for the customer to choose this encoder, which is also used for rotation monitoring and positioning in many other market areas.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
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Protection of the handling area of gantry cranes

An S3000 protects the handling area on gantry cranes between printing presses and a printing cylinder store.

Challenge
In a large printing works, the approx. 6 m deep handling area for a gantry crane must be protected. The area is also crossed by people. An existing, high maintenance sensor solution, that often requires adjustment and can only be reactivated manually after interruption of the protective field, is to be replaced with a more cost-effective, automatically re-starting, low maintenance system.

Application Solution
The SICK S3000 safety laser scanner is setting a new technological standard and provides a high level of security of investment. Improved performance data and integrated functions provide the user with more benefits. Less mounting and wiring effort, less space required, and in comparison to the past, minimized maintenance effort on the safety system are considered to be significant advantages by this user.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
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SICK DME5000 laser distance measuring sensor

Protection field switching of rail-guided transport trolley for rolls of paper independent of position and direction using DME5000.

Challenge
For a rail-mounted truck that travels in two directions, a precise and robust system was sought for switching between and activating the protective fields of two safety laser scanners mounted on the truck.

Application Solution
Two SICK DME5000 laser distance measurement systems mounted on the truck are used. When the truck is moving, the two sensors continuously measure (redundantly in the related direction) the time taken by the light pulses emitted to travel to the end of the track and back. From this information the electronics determine the position of the truck and provide this information to the truck’s PLC over Profibus. The data are processed in the PLC and the related binary signals generated. These signals are used for protective field switching on the laser scanners.

The proximity switches originally used for the protective field switching did not last long, as the switching lugs for the proximity switches were bonded to the floor and were frequently damaged by the fork lift trucks in the building. The DME5000 + PLC solution has proven to be extremely reliable in comparison. Furthermore, the measurement accuracy is extraordinarily high at +/- 2 mm with a reproducibility of 0.5 mm. A current measured value is output every millisecond – it is hardly possible to measure distances more precisely in such applications.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
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Reading of barcodes on paper coils

Reels of paper are transported to various printing presses in a printing works. As the paper thickness and color varies from reel to reel, it must be clearly identified which reel needs to be taken to which machine. The barcode to identify the reel can be at any position on the front of the reel. Comparable requirements exist in paper mills.

Application Solution
Two SICK CLV490 barcode readers are used; these devices are arranged with their scan lines at 90┬░ to each other. The scan lines move over the front face of the reel of paper due to the movement of the reel. With the maximum read distance for the scanners of up to 2100 mm at a modulus width of 0.5 mm and the autofocus function, the coils can be clearly identified and the controller for the conveyor line receives the necessary information to be able to guide the reels to the correct printing press.

Benefit
Using the CLV490 with autofocus, it is also possible to reliably read imprecisely positioned codes at varying read distances. As a result the fully automatic transport of the reels of paper can be undertaken rapidly and reliably.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
Contact Tri-Phase Sales or Get A Quote

Protection of a punching machine

One safety light curtain protects an automatic punching machine and at the same time increases the machine performance by approx. 30 % in PSDI mode.

On a punching machine for labels, brochures, credit cards, children’s books and savings books, protection must be provided against people reaching into the running machine with its sharp knives and punching pressures of 5.7 metric tons. This protection is to be designed such that the operation of the machine is not hindered.

Application Solution
The punching machine is equipped with a C4000 Standard safety light curtain with a protective field height of 300 mm and 14 mm resolution. The signals from the light curtain are evaluated in the UE402 switching amplifier.

Benefit
Using the C4000 electro-sensitive light curtain, safety according to type 4 is achieved together with significant production advantages. The direct access to the machine when it is not in operation saves a considerable amount of time and shortens the machine’s cycle time. It was possible to increase the machine’s productivity by up to 30%; depending on the item punched.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
Contact Tri-Phase Sales or Get A Quote

Protection field switching with DME5000 laser distance measurement system

Protection field switching of rail-guided transport trolley for rolls of paper independent of position and direction using laser distance measurement system.

For a rail-mounted truck that travels in two directions, a precise and robust system was sought for switching between and activating the protective fields of two safety laser scanners mounted on the truck.

Two DME5000 laser distance measurement systems mounted on the truck are used. When the truck is moving, the two sensors continuously measure (redundantly in the related direction) the time taken by the light pulses emitted to travel to the end of the track and back. From this information the electronics determine the position of the truck and provide this information to the truck’s PLC over Profibus. The data are processed in the PLC and the related binary signals generated. These signals are used for protective field switching on the laser scanners.

The proximity switches originally used for the protective field switching did not last long, as the switching lugs for the proximity switches were bonded to the floor and were frequently damaged by the fork lift trucks in the building. The DME5000 PLS solution has proven to be extremely reliable in comparison. Furthermore, the measurement accuracy is extraordinarily high at /- 2 mm with a reproducibility of 0.5 mm. A current measured value is output every millisecond – it is hardly possible to measure distances more precisely in such applications.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
Contact Tri-Phase Sales or Get A Quote

Counting of newspapers in a printing press output

Newspapers and magazines produced in printing works must be counted as they travel on fast moving conveyors.

Challenge
Newspapers and magazines produced in printing works must be counted as they travel on fast moving conveyors. Here the printed products are transported in an offset, i.e. overlapped arrangement. Currently mechanical switches are used for this task, however there are subject to wear and require maintenance. It is also not possible to exclude incorrect counting or the failure to count.

For counting newspapers and magazines in the printing press, the offset stack counter DMH is used in many cases, predominantly with a scanning range of 110 mm. The height profile acquired by the sensor is evaluated based on the step reductions in height caused by the layers of newspapers. Here the step changes in height can leave the measurement field in the direction away from the sensor (mode 1) and in the direction toward the sensor (mode 3). At the point when a step change in height from one newspaper to the next, a so-called offset stack, is detected, the offset stack counter DMH outputs the corresponding count pulse. Newspapers and magazines of varying thickness can be correctly counted after one-off adjustment.

Using this non-contact system, the maintenance required on mechanical switches due to wear is avoided. The error rates when counting are also significantly reduced. Even height fluctuations on the conveyor or interrupted flows of offset stacks do not affect the measured result.

This is an application from SICK.
Tri-Phase Automation is a SICK distributor in Wisconsin.
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Damper Control for Paper Products Facilities

This application note highlights the benefits of replacing pneumatic actuators with Exlar’s Tritex II AC actuators for control of dampers in paper products manufacturing facilities.

This note illustrates benefits many customers with a variety of applications can appreciate, especially if their actuators are located in hard to access areas of their facility. Read below to find out how Exlar’s actuators address and reduce the application challenges related to damper control in paper products facilities.

Challenge:
In paper products manufacturing facilities, regulating the humidity in the plant is a key procedure due to the effect it has on the quality of the final product, as well as the amount of energy used in the paper making process. Too much moisture in the manufacturing environment can result in poor drying or curling of the paper rendering it unusable. In addition, if the humidity levels are too high,energy costs can rise by way of increased dryer usage. To properly regulate the humidity in these facilities, precise control of the dampers is required to ensure excess moisture is kept out of the manufacturing environment.

Solution:
In order to improve damper control, engineers are replacing their pneumatic actuator solutions with more precise and reliable Exlar electric actuators. With Exlar’s Tritex II AC actuators, controls of the dampers is instantaneous, with small incremental moves possible for precise positioning and ultimate control.

Tri-Phase Automation is a distributor of Exlar in Wisconsin.
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Safe Stack Turners and Logistics Systems in the Printing Industry

Modular safety system exploits rationalization potential

Due to increased printing capacity, automation of logistics processes is critical. Printed sheets must arrive at the feeder and be delivered without process delays. With every unnecessary machine stop, the printing and ink parameters must be reset and optimized, adding time, waste, and cost to the process.

Application Solution:
All operator-accessible points on the machine are monitored with light barriers and light grids. Pepperl Fuchs SLA29 sensors are permanently active safety light barriers. Their detection range is extended by means of adjustable mirrors as far as this is useful. Depending on the risk potential, SLC30 safety light curtains may be required as an option for hand protection.

Benefit:
Previously, Krifft & Zipsner had used four different switching devices by two manufacturers for every machine, for example, the SLVA-4K evaluation device for the permanent light barriers and the SLVA-8K for the muted light barriers. All of these functions are now performed by the Safebox in an easier and more rational way.

Tri-Phase Automation is a distributor of Pepperl+Fuchs in Wisconsin.
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Quality in Manufacturing: Double Sheet Detection for Plastic Plate and Film Sheet

Double Sheet Detection

Cost effective processing of plastic plates and film sheets is very important in manufacturing print products. Quality requirements for high gloss products are very demanding. Even the smallest scratch on the surface or manufacturing steps that are not completely clean can result in waste. Plastic plates and film sheets are separated from a stack into individual units for further processing. Before the individual plastic plates or film sheets are cut to size, a check must determine that only one plate or sheet has been supplied. If not, the equipment can be damaged and the material will be unusable. Double sheet detection increases equipment life and minimizes material waste.

The Solution:
The Pepperl+Fuchs UDC-18GM-400-3E3 ultrasonic double sheet detector checks for the presence of an item before it reaches the blade. The presence of more than one unit, due to static electricity or other reason, triggers an alarm. The UDC-18GM-400-3E3 reliably identifies the presence of no sheet, single sheet, or double sheet, ensuring reliable, quality processing.

Double sheet detection has previously been triggered by a simple mechanical switch. Measurement that involves contact can mar the high-gloss plates or sheets. The change was made to no-contact ultrasonic detection to increase quality. Scratches are now a thing of the past. The Pepperl Fuchs UDC-18GM-400-3E3 ultrasonic double sheet detector is designed for a wide range of applications and is able to check all materials, from transparent film and thin film sheets to plastic plates 2 mm thick. For thicker media, such as sheet steel, the UDCM-30GM-085-3E3 ultrasonic double sheet detector is available.

Tri-Phase Automation is a distributor of Pepperl +Fuchs in Wisconsin. Contact Tri-Phase Sales or Get a Quote