Wrapping with Lachenmeier hood stretch technology consists of applying a flexible and stretchable plastic hood, which firmly holds the pallet load til its unwrapped. The plastic hood is stretched to fit the outer measurements of the pallet load and then vertically applied and dropped under the the pallet. This secures that the goods will stay on the pallet during transport and keeps it free from dust and water.
The machine product range consists of Lachenmeier Power Flex, for wrapping of one pallet size, to Lachenmeier Multi Flex, for wrapping of 1/4-, 1/2-, och 1/1 pallets in the same machine. A fully automatic hood stretch system gives a numerous of advantages, some of them are listed below:
- Optimal load stability due to horisontal and vertical support from the hood
- No use of heating during the wrapping process
- High capacity, up to 200 pallets/hours
- Few shift of film while the role weigh 500-600 kg
- Sturdy construction which gives long life time
- Few wear and tear parts, low service costs
- Visually neat package
- Possible to apply logotype or barcode on the plastic film
- Savings of man time
- No stability impact in the pallet load if air pockets arise, the film will adapt.
- No risk that the film adhere with other plastic (anti lamination)
- Many plastic film suppliers
- Water and dust free hood
- Hotline at all hours 7 days a week
- Possible to get perforated film if the product needs air
Function and technical facts
How does a hood stretch machine work and how is it designed? The simple but, in particular, genious design is described below, from pallet entry to exit.
When a pallet load entries the machine the height is first measured via photocells, placed on the vertically moving frame. This measurement triggers the film feed device to wind up the proper film length from the 600 kg heavy role to the opening system. The opening system opens the film with a patented combination of vacuum from suction boxes and mechanical fixation. When the film is opened, 4 specially designed grippers join the opening system which wind up a part of the film. The film is then welded and cut off. After the weld has cooled a couple of seconds, the rest of the film is winded up on the grippers. The film is now ready to be stretched with hydraulical power to fit the outer measures of the pallet. The hood is vertically unwinded and placed over the pallet load. This gives superior stability with optimal vertical och horisontal stretch. The unwindig process is electronically controlled to achieve smooth stretching (patented) over the product corners. The grippers make it possible to place the hood under the pallet, which gives superb transport safety. Of course the film can be placed directly on the sides of the pallet, with a tolerance of ± 1 cm.
The outer parts of the machine consists of 4 vertical steel beams with a quadratical assembled frame. The frame is controlled by 4 engines with chain-drive for vertical adjustment, one in each corner. This gives the advantage to maintain a synchronized vertical movement via the lengthways located axels in it´s own coordinate plane (xy plane) with minimum wear and tear as a result.
The opening system, placed in the upper part of the machine is, through the feed device, fed with film from the film role/roles, placed aside of the machine. It has 4 suction boxes with mechanical fixation of the film during the opening processen. This patented system is very reliable.
A well functioning opening system is noting without the important gripper units, which the frame is equipped with. Every one of the 4 grippers are geared with an electric motor, used to wind up the film. Stretching with the hydraulic system gives the possibility to stretch more than 1000 kg/gripper and is unaffected in the most dirty enviroments. In practice this means that every type of film on the market is compatible with the system.
The film roles, which are fixed in a rail system, are located beside the machine. The maximum diameter is 1000 mm and the weight (stretch wrapping role 16-18 kg). This big difference results in less shift of film role i.e. less production stops. When the role begins to run out of film, a clear indication is sent out.
Service and maintenance has to Lachenmeier always been a central part during the development phase. The few moving wear and tear machine parts are easily accessed and changed. One example of this is the film feed device which consists of cutting blades and welding line. This change requires only one tool.
The entire hood stretch system is held together by an electronics system which can be controlled with a HMI-interface.
For further reading, click on Datasheet.