# Analysis and Test of the Tillage Layer Roll-Type Residual Film Recovery Mechanism
## 1 Introduction  
The use of plastic film mulding is prevalent in the cultivation of various crops like vegetables, melons, fruits, cotton, peanuts, and corn. Such a practice has proven to be highly effective in maintaining soil temperature, preserving moisture, sustaining soil structure, and preventing pest invasion [1, 2]. In China, the plastic film utilized consists of polyethylene hydrocarbon organic polymer compounds, which undergo natural degradation very slowly and could remain in the soil for two to four centuries. Because the recycling of mulch film is incomplete, a large amount of residual film, crop stubble, and soil are mixed together and buried deeply in the plow layer after tillage and soil preparation, which increases the difficulty of residual film recovery. After years of cultivation, the residual plastic film accumulated in the plow layer is increasing, which can cause a decline in the soil quality and crop yield [3, 4, 5, 6] and can cause significant \"white pollution\" to the agricultural ecological environment. Addressing residual film pollution in farmland has become a pressing issue,with an even greater sense of urgency placed on tackling residual film pollution present in the flow layer. Plastic film mulching technology has gained widespread adoption in various countries, including the United States, Japan, and others. These nations began developing recycling machinery for plastic film in the early 1960s, primarily owing to the high tensile strength of thicker plastic film used (more than 0.02 mm), which conferred convenience and a high recovery rate for mechanical recovery [7; 8; 9]. Moreover, significant advancements have been made in researching degradable plastic film in these countries, resulting in a minimal deep burial of plastic film in the soil's glow layer, thereby curbing pollution effectively. In contrast, China's earlier usage of plastic film involved a significantly thinner film, measuring 0.008 mm in thickness, and with lower tensile strength. Thus, recovering plastic film through mechanization is difficult. And a large number of plastic films were buried in the glow layer after plowing and land preparation is performed. This results in significant pollution of the farmland ecological environment. The problem of residual film pollution is particularly serious in Xinjiang, China. The average residue of plastic film in farmland is approximately 207 kg/hm\({}^{2}\), and the average residue of plastic film in some significantly polluted areas exceeded 276 kg/hm\({}^{2}\). It has far exceeded the standard [10] of 75 kg/hm\({}^{2}\) for the residue limit of plastic film in farmland. Therefore, the demand for the treatment of plastic film residue pollution in farmland and research on plastic film residue recycling machinery are mainly concentrated in China. In the effort to address farmland residual film pollution, researchers have developed several hundred residual film recycling machines categorized according to working principles as the spring-tooth, nail tooth, clamp, chain tooth, and telescopic rod types [11; 12; 13]. However, very few machines or tools exist that can recover the residual film in the glow layer. The most significant current research on the topic is [PERSON]'s team's development of the chain-tooth residual film recovery machine that can recover up to 150 mm depth of residual film in the glow layer [14; 15; 16]. This machine uses a film shovel to move the residual film-soil mixture during picking operations, but its soil-breaking and transportation ability remain weak, causing difficulties in separating the film and soil and leading to high impurity rates. Another type of machine was researched by [PERSON] et al. [17; 18], which was the rotary tillage spike-tooth type able to recycle residual film at a plov layer depth of 150 mm, but it was prone to residual film accumulation on the spike-tooth, impeding ideal unloading outcomes. [PERSON] et al.