How many kinds of plastic PVC hose tractors are there?

How many kinds of plastic hose tractors are there?
There are three common types of plastic hose tractor: rubber belt type, roller type and caterpillar type. The requirement of plastic hose tractor is to provide certain traction force and traction speed, and the traction speed can be adjusted, the traction force can be kept constant, and the clamping force of tractor to plastic hose should be adjusted.
Rubber belt type
It is composed of rubber conveyor belt and compacting roller. The plastic hose is pressed onto the rubber conveyor belt by compacting roller. The plastic hose is pulled by the friction produced by the compacting force between the two. The conveyor belt is driven by power. The compacting roller is a passive roll. The compacting force can be adjusted. The traction force of the tractor is small and suitable for drawing small diameter plastic hoses.
Roller type
It consists of several upper and lower traction rollers. The plastic hose is pulled by the upper and lower traction rollers. The outside of the traction roll forms a waist roll shape to increase the contact area with the plastic hose. The lower active roll is steel roll, the upper passive roll is rubber roll and can be adjusted up and down. However, the traction force is not too large, suitable for traction of small and medium diameter plastic hoses.