STRING TYING
Get the Best out of String Tying process.
What it can and cannot do.
Process: The String Tying process starts when the product passes through the machine, in which, the string is tightened by the lead. And then passing the start of keys point and the string is inserted. The attached head node attaches and the string is cut. A new string will then be ready for the next product. Types of string tying materials are LDPE, PET, cotton, elastomer, elastic, viscous and forms as Poly Tape, Twisted Poly and Spiral Twist. The hard products are bound with elastic cords while the soft products are bound with fixed strings.
String Tying only has a few restrictions, since it has no direct influence on the product outcome. When the cord/string is tensioned, it is important to note that the product needs to have sufficient hardness be able to resist the pull of the string, while ensuring sufficient tension around the product, thus it is subsequently tied in a bundle. Minimum length of bundle typically down to 20-25 mm, but lesser may be possible. The height of the arm that ties the circles gives the outer limit.
Applicable equipment in relation to different processes:
- Manual:
Manual binding of the products have been around since the first jungle rope, this requires no machinery or equipment.
- Semi-automatic:
To my knowledge, there is no equipment for semi-automatic string tying machine.
- Automatic:
- String Tying requires an operator. There are 2 main forms:
- The string is placed around the product and is attached to the underside, rotary type. The machines that implement this process is called Rotary Tyers. These machines are often used in the graphics industry, laundries, etc.
- The string is passed down behind the product after it has been inserted into another string. The string passed into the attached head attached and the cord cutters. This type machines that does this process is called linked arm binders. Example machines are Pak Resort 2000 and Coil Resort. These machines are often used in laundries, gardens, cable manufacturers(coil). Alternatives like the right / left version and tandem also apply.
Typical products have been tied with string:
- Fully Automatic:
- For laundry, horticulture and industry etc. There is a variety of fully automated solutions where the product is loaded in a position facing the conveyor or on the open belt and then the machine binds the product.
Project specific and more advanced string tying equipment and industry-specific processes can be made on request.
Decommissioning:Cord/String comes on core typically Ø76 without the core, with cardboard core ø40-50, in a plastic wrapper, often customised for each machine type.
When ordering, the cord/string layup and type of machine is very important to know. You should know in relation to the string tie the string to be used, the number of meters per rewind, termination method, geometric locked or tape.
Elastic String
Related Areas:
Tying with bands which use a plastic "band" being welded.
Wrapping with ribbon by using plastic or paper "band" that being welded.
Author of Article:
Gunnar Salbæk
CEO / Industrial Design with 20 years of experience in the field.