# Analysis and Test of the Tillage Layer Roll-Type Residual Film Recovery Mechanism
## 2 Materials and Methods
### Analysis of the Operation Parameters
#### 2.2.2 Analysis of Film Collecting Process  
The function of the pickup roller is to drive the winding roller to revolve around the pickup roller and continuously pick up the film-soil mixture thrown by the film-lifting device. Therefore, the movement of the pickup cylinder depends on the advance speed \(V_{m}\) of the implement and the film-lifting depth \(h\). The larger the forward speed \(V_{m}\) is, the higher the rotational speed of the pickup drum, and vice versa. The larger the film-lifting depth \(h\) is, the greater the mixed amount of film and soil entering the pickup roller per unit time is, and the speed of the pickup roller is correspondingly increased to improve the clean rate of the residual film. However, the minimum critical value of the pickup cylinder  
Figure 3: Motion analysis of the membrane cutter. rotation speed \(n_{1}\) is that the linear speed of the outer circle of the pickup cylinder is equal to the forward speed, that is:  
\[n_{1}=\frac{V_{m}}{\pi D_{1}} \tag{6}\]  
where \(D_{1}\) is the diameter of the pickup drum, m; \(V_{m}\) is the forward speed of the unit, m/s; and \(n_{1}\) is the rotational speed of the pickup drum, r/min. When the forward speed \(V_{m}\) is calculated to be 2.5-5 km/h, the angular velocity of the pickup cylinder speed \(\omega_{1}\) is 2.29-4.58 rad/s. During operation, the advancing speed \(V_{m}\) determines the amount of the soil mixture entering the film collecting area. The greater the speed is, the greater the amount of the soil mixture entering the film collecting area, and vice versa. Therefore, to improve the picking rate of the residual plastic film, the rotation speed of the picking roller is calculated according to the maximum amount of the film-soil mixture entering the film-picking area, and the angular velocity of the rotation speed \(\omega_{1}\) of the picking roller is 4.58 rad/s. To increase the effective film collecting area of the roller and reduce the reverse resistance of the soil to the residual film, we determine that the effective film-picking area of the roller is 120\({}^{\circ}\) in the forward rotation film collecting area, as shown in Figure 4.  
When the pickup cylinder rotates at \(\omega_{1}\), the time for the pickup cylinder to rotate one circle is \(t_{1}\), and the time for the winding roller to enter the positive rotation film pickup area is \(t_{1}\)/3. According to the design of the winding roller structure, a single spring-tooth on the winding roller just rotates one circle in \(t_{1}\)/3. The rotation speed \(\omega_{2}\) of the winding roller is 13.74 rad/s. The picking mechanism is the core of the plastic film recycling machine, and its performance directly affects the pick-up rate of the plastic film recycling machine. During operation, the film-lifting device throws the plow layer film-soil mixture into a positive rotation film-picking area, and under the action of the mechanical force of the spring-teeth, the residual film in the mixture bears the hooking and picking action of the spring-teeth to separate the residual film from the soil. There are two kinds of mechanical forces of the spring-tooth on the residual plastic film. One is the film-picking effect of the spring-tooth on the residual plastic film, and the other is the film-hooking effect of the tooth tip of the spring-teeth on the residual film. During the picking of the plastic film residue, the acting force of the soil and stubble on the residual film and the wind resistance affects the process in addition to the gravity of the plastic film residue, the friction force of the spring-tooth on the plastic film, and the centrifugal force during movement. Because the force of the soil and stubble on the residual film and the resistance of wind are random forces, the magnitude and direction of the force cannot be determined. Therefore, the acting force of the soil and stubble on the residual plastic film and the wind resistance are not considered in the force analysis of the process of picking up plastic film by spring-teeth.