With the growing domestic demand, packaging plastic thermoforming sheet is also more and more widely used, the amount is also increasing year by year, the prospect is good. With the country's attention to environmental protection, adapted to the production of "environmental degradation sheet production line" has been able to successfully supply the market with various types of "degradation sheet". The use of "nanoplastics" manufactured "nanosheets" has become another focus of attention, but also become a new "selling point" for manufacturers. In order to improve the shelf life of food and shelf life, with "high barrier properties of the sheet" has become the goal of the production companies competing to develop.
Plastic sheet sheet equipment production methods are common calendering method, mainly used in the production of pvc, PVDC and other sheet; another is the extrusion method, used in the production of BOPS, EPS, PET, PP, HIPS and other sheet. This paper refers to the sheet mainly refers to the use of "extruder - T-head - three-roller calendering device - winding" process for thermoforming packaging products produced by the sheet. Domestic production sheet machine industry with the development of packaging sheet also continues to introduce advanced configurations and new machines. Over the past decade, sheet production and sheet machine manufacturing enterprises to cooperate with each other, *** with the introduction, but also improve the overall level of development of the plastic sheet industry. New sheet processing technology, new raw and auxiliary materials in the configuration of advanced equipment to get full play.
The gradual improvement of the domestic sheet machine manufacturing level, promoting the domestic production of plastic sheet enterprises to increase and diversify the varieties of sheet, but also promotes the thermoforming packaging industry unprecedented prosperity. The development of China's sheet machine industry, there are generally the following aspects of the trend: First, a single "separated single screw extruder" configuration "vertical three-roller" sheet production line tends to be saturated with the majority of domestic thermoforming enterprises have this type of sheet production line, it is the first time for the enterprises to capture the market. It for the enterprises to occupy the market in advance, accumulation of funds, technology development has made great achievements. It can basically meet the production requirements of the sheet, but the sheet produced by it, especially the production of HIPS sheet can not produce satisfactory gloss, low grade. This kind of sheet machine technology has been quite mature, easy to assemble, easy to purchase parts, simple configuration, simple operation, inexpensive, very low maintenance costs, has become more popular models. Fierce competition, has forced some manufacturers to other products sheet machine manufacturers into the transformation. Such as "Beijing Shengan" has been the main focus of the "development of aluminum composite panels"; "Shantou Dacheng" to more high-grade sheet production line. There are also some manufacturers from the sheet machine production to the sheet processing, plastic cup manufacturing, blister molding and other industries. With this kind of sheet machine, we can process PP, HIPS, PE egg tray sheet, packaging sheet for blistering, etc. If the calender roller is replaced by a calender roller, we can process the sheet. If the calender roller for the air knife, you can produce thinner sheet for plastic absorption. However, at present, most of the domestic equipment is not equipped with this device, which brings many inconveniences to the production enterprises, and to a certain extent, restricts the development of enterprises in the field of sheet materials and molding products. Second, in a single extrusion configuration of the sheet production line, China's first "electromagnetic dynamic extruder" has been successfully applied in the sheet production line, it has the advantages of energy-saving materials, plasticizing uniformity, etc., can produce a variety of materials, the price is not expensive. This kind of extruder with "Chinese characteristics" should be vigorously promoted and continuously improved, equipped with advanced follow-up equipment and control systems, to the world to introduce our own advanced production line, so as to get rid of the change is always following others behind the development of the state. For example: "Shantou Weida" has launched a number of such sheet production line to the market, the market reflected good. Third, with a single "exhaust - double-stage single-screw extruder" configuration of the sheet machine, equipment manufacturers to match the "environmental protection" and the introduction of a new type of sheet production line. "Shantou Dacheng" and "Xi'an Wanjie" have succeeded in producing biodegradable sheet with starch content as high as 80% after many hard experiments and improvements. Many domestic enterprises have already used the starch degradation material of "Xi'an Wanjie" in the degradation sheet production line of "Shantou Dacheng" to produce environmentally friendly degradation sheet and thermoforming products, which has a promising future. With this kind of sheet production line, we can process high-filled PP/PE sheet, optical/biological double-degradable sheet and bio-starch degradable sheet. However, the domestic "degradable plastics" are not "fully degradable materials", more or less containing "plastic" components. In addition, a wide range of "degradable materials" flood, the existence of the phenomenon of fish eyes mixed up, coupled with the "pulp molded products" competition, as well as by the resurgence of the "foam lunch box" impact, the degradation of thermoformed products market. Impact, degradation of thermoforming products market situation is not optimistic. Fourth, in order to reduce costs and master the market, the production of degradable sheet enterprises to buy a granulation production line, "twin-screw granulation production line" to supply their own "degradable sheet" production line. For example, Shanghai Golden Cherry, Xi'an Wanjie, Xi'an Maxcom and other plastic packaging companies have their own "twin-screw granulation production line". We believe that the market "degradation granules" production technology has matured, the price has fallen to very low, the production of "degradation sheet" enterprises do not have to start their own granulation production line, because there have been a number of granulation production line task is not enough, or even idle equipment. In addition, some sheet machine manufacturing enterprises are developing "twin-screw extrusion degradation sheet production line", the purpose is to eliminate the "granulation" of this intermediate procedure, directly with the allocation of good powder production of sheet, in order to further reduce production costs. Moreover, this "twin-screw extrusion sheet production line" can also process high-filled calcium-plastic degradation sheet as well as extruded PVC, PVDC and other sheet materials. Fifth, K - resin **** mixed transparent KPS sheet instead of PP transparent sheet manufacturing disposable containers, instead of BOPS, PVS production sheet trend. As BOPS, PVC sheet need special equipment to produce, so the general thermoforming enterprises required BOPS, PVC sheet is mostly outsourced. Coupled with the PVC trimmings enterprises can not be utilized by themselves, the recycling price is very low, increasing the production cost of enterprises. Another reason is that PVC recycling material is easy to contaminate other plastics, so in the production of extra attention, which brings some trouble to the production operation.KPS sheet can be processed in the general extrusion sheet production line, the edge of the enterprise can be utilized by their own, but also can increase their own production of sheet, reducing the cost of production. So some enterprises have begun to use KPS sheet to make transparent drinking cups with good hardness and toughness, and some use KPS to make lids instead of PVC sheet. KPS sheet is a ****blend of K-resin and GPPS resin.K-resin is exclusively produced by Phillip Chemical Company, and the price is gradually coming down. The possibility of it replacing PP sheet, PVC sheet and BOPS sheet will further increase. Domestic production of PP sheet equipment can also produce more satisfactory KPS sheet. Six, "multi-layer composite *** extrusion sheet" because of special properties and favored by the market dairy, beverage industry development, the requirements of the plastic cup is also increasingly high. In addition to the requirements of good appearance quality transparent, bright, quite hard, but also requires a longer period of freshness and shelf life, and single-layer sheet can not meet this requirement. Production sheet manufacturers introduced "multi-layer **** extrusion composite sheet", on the one hand, the market demand, on the other hand, is also the need for product upgrading. Single-layer sheet machine investment is small, competitive manufacturers, sheet price is low. The multilayer composite sheet production line investment, few competitors, sheet quality, the production of thermoformed products of high grade, and good market price. Another reason is that the production of composite *** extruded plastic sheet can be more eaten recycled material, reduce costs.