With the increasing domestic demand, the applications of thermoformed plastic sheets for packaging are becoming more widespread, and the usage is increasing year by year, showing promising prospects. With the country's emphasis on environmental protection, "environmentally friendly degradable sheet production lines" adapted to production have successfully supplied various types of "degradable sheets" to the market. "Nanosheets" made from "nanoplastics" have become another focus of attention and a new "selling point" for manufacturers. To improve the shelf life and shelf life of food, "sheets with high barrier properties" have become a target of competition among various manufacturers.
Common methods for producing plastic sheet equipment include calendering, mainly used for producing PVC, PVDC, etc.; and extrusion, used for producing BOPS, EPS, PET, PP, HIPS, etc. The sheets mentioned in this article mainly refer to sheets produced using the "extruder-T-die-three-roll calender-winding" process for thermoformed packaging products. The domestic sheet machine manufacturing industry is constantly introducing advanced configurations and new machines in line with the development of packaging sheets. For over a decade, cooperation between sheet material manufacturers and sheet forming machine manufacturers has led to the introduction of advanced technologies, raising the overall development level of the plastic sheet industry. New sheet processing technologies and raw materials have been fully utilized with advanced equipment.
The gradual improvement in domestic sheet forming machine manufacturing has spurred the increase in domestic plastic sheet manufacturers and the diversification of sheet varieties, while also contributing to the unprecedented prosperity of the thermoforming packaging industry. The development of my country's sheet forming machine industry can be summarized by the following trends:
The production line using a single "separate single-screw extruder" with a "vertical three-roller" is approaching saturation. Most domestic thermoforming companies possess this type of sheet forming production line, which has played a crucial role in helping them initially capture the market, accumulate capital, and develop technology. While the sheets produced can generally meet production requirements, the sheets produced, especially HIPS sheets, lack satisfactory gloss and are of lower quality.
This type of sheet forming machine technology is quite mature, easy to assemble, with readily available parts, simple configuration, easy operation, low price, and very low maintenance costs, making it a widely used model. Intense competition has forced some sheet extrusion machine manufacturers to shift their focus to other products. For example, Beijing Shengan has concentrated its efforts on the development of aluminum-plastic composite panels; Shantou Dacheng is moving towards higher-end sheet production lines. Other manufacturers have transitioned from sheet extrusion machine production to sheet processing, plastic cup manufacturing, and blister packaging.
This type of sheet extrusion machine can process PP, HIPS, PE egg tray sheets, and blister packaging sheets. Replacing the calendering roller with an air knife allows for the production of thinner blister sheets. However, most domestic equipment lacks this device, causing inconvenience to manufacturers and hindering their development in the sheet and molded product fields.
In sheet production lines configured with a single extruder, my country's pioneering "electromagnetic dynamic extruder" has been successfully applied. It offers advantages such as energy saving, material saving, and uniform plasticization, can produce various materials, and is reasonably priced. This type of extruder with "Chinese characteristics" should be vigorously promoted and continuously improved, equipped with advanced downstream equipment and control systems, to introduce China's own advanced production lines to the world, thereby breaking free from the development status of always following others. For example, Shantou Weida has already launched several such sheet production lines to the market, and the market response has been positive.
Third, sheet extruders configured with a single "vented-type double-stage single-screw extruder" are a new type of sheet production line launched by equipment manufacturers to support "environmental protection."
Shantou Dacheng and Xi'an Wanjie, after numerous arduous experiments and improvements, have successfully trial-produced biodegradable sheets with a starch content as high as 80%. Several domestic companies have already used Xi'an Wanjie's starch-degradable materials on Shantou Dacheng's biodegradable sheet production line to produce environmentally friendly biodegradable sheets and thermoformed products, with promising prospects.
This sheet production line can process high-filled PP/PE sheets, photo/biodegradable sheets, and bio-starch-degradable sheets. However, domestic "degradable plastics" are not "fully degradable materials," still containing some "plastic" components. In addition, the proliferation of various "degradable materials" and the existence of counterfeit products, coupled with competition from "pulp molding products" and the resurgence of "foamed lunch boxes," make the market situation for degradable thermoformed products less than optimistic.
