1. Plastic Bottles The United States produces the following three main production methods: extrusion - blow molding, injection molding - blow molding and biaxial orientation molding. In Western Europe and Japan, in addition to the above three methods, co-extrusion and rotary welding are also used.
The most commonly used blow molding resins today are low density polyethylene and high density polyethylene, polyvinyl chloride, polypropylene, polyethylene terephthalate, polystyrene, styrene acrylonitrile, nitrile polymers and polycarbonate ester. Polyolefins (high-density polyethylene and polypropylene) and polyvinyl chloride have become the main packaging materials on the market. Use of polyolefin containers. From hairdressing and beauty cosmetics to household and industrial detergents, pharmaceuticals, liquids and dried foods, almost every consumer market. The United States now sells 500 million tons of polyolefin resin every year as a blow-molded container.
Polyvinyl chloride, nitrile polymers and polyesters are more resistant to oxygen, carbon dioxide and moisture than other resin containers. Polyester is the only clean food container resin approved by the U.S. Food and Drug Administration. Through orientation, polyester containers have been used to hold carbonated drinks, foods and medicines.
2. Molding - Loading - Sealed Bag (FFS Bag)
Molding - Loading - Sealed bags play an important role in modern packaging. It is a combination of packaging design, materials, and machinery. It can produce effective packaging to meet the needs of modern handling and sales methods.
Molding - Loading - The entire production process of the sealing equipment is automated. The bags are formed from roll stock (single or multi-layer webs and laminates), from the machine's cutting table output pockets, and the bags are sent to On the conveyor, it is transported to the packaging area, heat-sealed after loading, and then counted, tested and mounted. Vertical moulding with a half ounce tomato paste per bag - Loading - Sealer runs approximately 60 cycles per minute (packaging 600 bags/Min). 226.8g (8 ounces) of vertical machine per bag is circulated at 25r/Min (packaging 100 bags/Min). However, higher-grade packaging materials, such as polyester/aluminum foil/polypropylene-laminated too thin steamable bags, cannot generally be packaged at such a high production rate.
This packaging method is suitable for small packaging, accurate control of the weight, and can be mixed with steam in the bag, easy to open. The mixing in the bag is moulded--loaded--insulated in a sealed bag with a breakable film, separating the foods that need to be packed together, and adding water or other ingredients to the food. This eliminates the need for freezing and reduces bulk weight or shipping weight.
Steamable molding - loading - sealed bags in the packaging industry has great potential for development, packaging materials are generally 1/2 cellophane / low density polyethylene / aluminum foil / low density polyethylene four-layer laminate structure competition. Metallized polyesters also provide excellent barrier properties, and UV resistance is comparable to aluminum foil laminates.
For products that are difficult to accommodate, such as iodine is easily infiltrated, the laminated material of the package is delaminated or the aluminum foil is corroded. Many packers are researching and applying the outer layer of aluminum foil, the middle layer of heat-insulating polyester, and the inner layer has 2-8 layers of mil. Rubber-modified high-density polyethylene, used to package sterile saline, can be placed in a retorting tank and heated.
The liquid and semi-fluid foods packaged by the molding-loading-seal bag are ketchup, jam, butter, milk, butter, fruit juice, beef juice and coffee cream etc.; medicines and daily necessities have medical ointment, disinfectant water, Alcohol, detergent, bleach, shampoo, antifreeze, motor oil, etc.
After the liquid bag is opened, it must be dispensed and disposed of. In recent years, a bag with a zipper has been sold, but the cost is high. Now a molding machine with a metering valve manufactured by Knorroff Company in Sweden, which can be filled into a sealed bag, can make the liquid and semifluid in the bag flow out in a certain dose. The injection molded polypropylene valve is heat-sealed in polyethylene. There is also a tightly closed cover on the bag. This form-fitting-sealing bag is now sold in Europe.
3. Heatable hard paper trays In order to save fuel, the United States has used aluminum instead of steel to make automobiles. The supply and demand of aluminum have increased substantially, which has led to an increase in the price of aluminum foil food trays, which has promoted the improvement of hot oven paper trays. Promotion. Now in the convenience food market, foods packed in hard paper trays have largely replaced aluminum foil foods, and can compete with aluminum foil trays in terms of price.
The heat-resisting paperboard is made from solid bleached Sulfate Paper (SBS) or milk board. The thickness of the paperboard ranges from 0.48 to 0.11 cM. The coating usually uses poly(tetramethylene terephthalate), and also uses polyethylene polypropylene, acrylic paint and white clay paint. The coating was applied to the paperboard by melt extrusion. The temperature of cardboard and paint must be carefully controlled. The quality of the finished product mainly depends on the effect of the extrusion method.
Cardboard temperature, coating temperature and machine operating temperature largely determine the maximum temperature that the board can withstand in the furnace and the crack resistance of the board. If the coating breaks, the cardboard will absorb the juice in the food. Therefore, extrusion is a critical process.
The extrusion method is more difficult to control, and the extrusion methods adopted by various board manufacturers are not the same. For example, the international paper company uses a white clay coating, and the building boards are first coated with white clay and then coated with extrusion. Olin Kraft uses acrylic paints and uses a three-stage method of knife coating on a paper machine. The finished product is cheaper than the two-step process.
The ink and adhesive are used in the logo and conversion process of the engraving and printing. The offset printing method, photocopying printing method or printing method is used. The ink and adhesive must be able to withstand the low temperature of the refrigerator and withstand the temperature of the ordinary furnace. . The temperature range tolerated is 232-288Â°C. The furnace temperature of a common furnace is usually higher than the temperature of a microwave oven, but the cardboard itself rarely reaches or exceeds 121 to 135Â°C because the food in the cardboard tray provides a large amount of cooling.
There are currently three methods for making packaging trays from heat-stable cardboard: Pressing, stamping into the lip, and sealing in a straight line on two folding angle machines. The cardboard can be formed into various types of packages, such as cake trays, folded cardboard boxes and small platters.
Since the 1980s, due to the development of the plastics industry, packaging of goods in plastic containers has grown a lot more than it did 10 years ago. As new types of food such as frozen foods and convenience foods are sold on the market, a variety of innovative or modified packaging formats have emerged, among which the packaging bags and the hot platenable hot paper trays that are molded and loaded into the sealing equipment are the most popular. success.