What are Stripper-Crimpers needed for? （英文）

Crimping & Crimp Quality - Issue 5

The greatest advantage of a Stripper-Crimper is that stripping and crimping are carried out by the same machine. This enables both higher quality and higher productivity than when these two processes are carried out separately.

The choice of the correct machine depends largely on the type and quantity of wires/cables to be processed, as well as the quality which must be achieved. The possible types of processing are different for single-conductor or multi-conductor cables. A Stripper Crimper offers important advantages for the efficient processing of multi-conductor wires.

Cut-to-length	Stripping	Crimping
PowerCut 3700 Cutting machine	UniStrip 2100 Stripping machine	UniCrimp 200 Crimping machine
PowerCut 3700 Cutting machine	StripCrimp 200 Stripper-Crimper
EcoStrip 9320 Cut & Strip machine		UniCrimp 200 Crimping machine
CrimpCenter 63 Fully automatic crimping machine

Single-Conductor Wires

With the processing of single-conductor wires, there are many possibilities for stripping the wire and to crimp with a terminal. For the processing of small quantities of wire, this can take place on a stripping machine followed by a crimping press (with crimp applicator). However, it is simpler and more efficient to use a Stripper-Crimper so that both processes are carried out on the same machine. Both processing types are semi-automatic as the cable is inserted into the machine by hand.  

With larger quantities, processing using a fully automatic crimping machine is possible and makes sense. The cable is cut to length, stripped and crimped either at one end or at both ends. This process is fully automatic. Depending on the machine, the output can reach over 3800 wires (with both ends crimped) per hour.   

Multi-Conductor Wires

The processing of multi conductor wires is significantly more difficult, as the ability to automate is heavily dependent on the complexity of the cable construction and also because the jacket stripping requires an additional processing step. The wires must be separated and individually inserted by the operator. This can take place in two steps (strip followed by crimp) or in one step (strip and simultaneously crimp) with a Stripper-Crimper. The inner wires of the multi-conductor cable are thereby stripped and crimped on the machine without the need for the operator to let go of the cable. A fully automated processing of multi-conductor wires (more than 2 inner conductors) is only possible with special, specifically constructed systems.

Processing of a jacket-stripped multi-conductor
cable with a Schleuniger StripCrimp 200 Stripper-Crimper

1. Jacket-stripped cable
2. Separated inner conductors
3. Stripped & crimped cable

Productivity & Quality

High productivity can be achieved by using a Stripper-Crimper. With cycle times of less than 1 second, experienced operators achieve 1300 – 1400 crimps per hour.  This production rate is 50-60% higher than when using a stripping machine in combination with a crimping press (sequential processing). The cost for both machines together, however, is generally 20% lower than for a Stripper-Crimper. The single-conductor wires or the inner conductors of a multi-conductor cable are stripped on the machine and crimped with the terminal directly.  

Another important argument for the use of a Stripper-Crimper is quality. As soon as a wire is processed on a stripping machine, the individual strands are unprotected. Although, this can be prevented if the insulation isn’t completely removed (partial strip) so that it remains as protection on the strands.  The partial strip must then be removed manually before insertion into the crimping press. It can happen that these strands are folded backwards. This happens if the operator inadvertently touches the edge of the safety cover whilst inserting the wires. The folded strands then fail to be crimped into the terminal, resulting in a defective crimp.   

With a Stripper-Crimper, the stripping process takes place directly in the machine and the cable is held by a clamp. Operator induced damage to the strands is not possible here. A further advantage is that since the stripping is done in the machine, the position of the wire in relation to the crimp terminal remains constant, which increases the quality of the crimping. In a crimping press, this position is influenced by the operator, who places the wire directly in the terminal. Especially with small wire sizes, which are increasing in volume in recent years, it is virtually impossible to place the wire accurately in the correct position. With the Stripper-Crimper, the wire is held on a start-sensor and then clamped. The wire is always stripped in the correct place in relation to the terminal and accurately placed in the terminal by the machine. Stripper-Crimpers such as the Schleuniger StripCrimp PP3 can process small wire cross sections up to 0.05 mm² (AWG 32).

Types of Stripper-Crimpers

There are three basic types of Stripper-Crimpers:

Particularly with multi-conductor wires, additional movements lead to reduction in quality. As the entire cable makes the movement, it can happen that the operator, who is holding the cable during the entire process, pulls the wire out of the clamp, thus influencing the insertion position. The best solution is a Stripper-Crimper design where the cable doesn't make any movement throughout the entire process. This requires a symmetrical closing of the crimping press, which is technically complex and therefore expensive. 

A solution with vertical movement of the cable in the machine is technically simpler. Stripper-Crimpers of this type achieve high quality and are significantly cheaper to produce. Stripper Crimpers where the cable makes both a vertical and a horizontal movement make sense when stripping isn’t possible in between the applicator opening (unlike with the other 2 variants). 

With modern Stripper-Crimpers, all processing parameters are programmable and functions, such as integrated crimp force monitoring, automatic bad part destruction, blade retraction to protect the wire or various re-cut options to achieve an accurate strip length, contribute to quality assurance. An important criterion with multi-conductor wires is the minimal break-out length (distance between opening in the safety shield and the stripping blade), as this determines the minimum length inner conductors can have from the stripped jacket.  

Stripper-Crimpers, such as the StripCrimp 200 from Schleuniger, are used where high efficiency and a consistent high quality are necessary in the processing of multi-conductor wires. These characteristics, combined with high flexibility, the possibility to use side- and rear-feed banded terminals and the attractive price of such a machine, provide an ideal production medium for every cable processor.

Next Issue: How Good Are Your Crimps?