Thermoforming blister-package

By the mid-1950s, thermoformed blister packages and food containers of polystyrene were found in most grocery stores. In 1962, approximately 77,000 t of plastic was thermoformed in the United States. By 1998, approximately 2.9 million metric tons of plastic were thermoformed in North America (6) (Fig. 1). This is a sustained annual growth rate of about 10% over nearly four decades. An additional 4.55 million metric tons are thermoformed worldwide. The total world market is estimated to have a value of about US 35,000 million. 

Butyric acid, the simple oxidation product of -butyraldehyde, is used chiefly in the production of cellulose acetate butyrate [9004-36-8]. Sheets of cellulose acetate butyrate are used for thermoformed sign faces, blister packaging, goggles, and face shields. 

SB copolymers are produced via anionic polymerization by sequential addition of styrene and 1,3-butadiene monomers. These clear, tough plastics are easily processed with conditions and equipment similar to those used for HIPS. Various amounts of GPPS are usually mixed with the SB copolymers during sheet extrusion to maximize rigidity and economics in the thermoformed parts. Typical applications include drinkware, medical packaging, lids, containers, and blister packages. 

The modern food supply chain uses many forms of thermoformed articles meat trays, microwave and deep freeze containers, ice cream and margarine tubs, delicatessen tubs, snack tubs, bakery and patisserie packaging, sandwich packs and vending drink cups are just a few of the food related applications. Other non-food applications include manufacturing collation trays, blister packaging and point of sale display trays. 

Use For blister packaging and thermoformed containers for refrigerated/frozen foods, candies, and sundries. 

In many applications of conventional thermoforming, low-cost tooling is used compared to that of other processes, particularly in cases of limited production and/or the forming of very large parts (Fig. 5-2). Thermoforming of thin parts has an advantage over most other processes, where very thin walls cannot be produced. An example of its use is in skin and blister packaging. 

Blister packaging n. The enclosing of articles in thermoformed, transparent bhsters shaped to more or less fit the contours of the articles. The preformed blisters, usually slightly oversized to provide ample room, are made of thermoplastics such as vinyl, polystyrene, or cellulosic plastics. They are placed inverted in fixtures and loaded with the articles, and then cards coated with an adhesive are applied and sealed to the flanges between and around the blisters by means of heat and pressure. 

The process also is used for blister packaging. Thermoforming can be continuous by using rolls of sheet or batch by using precut shapes. 

Blister n (1) An imperfection on the surface of a plastic article caused by a pocket of air or gas beneath the surface. NOTE — A blister may be caused by insufficient adhesive inadequate curing time, temperature or pressure or trapped air, water, or solvent vapor. (2) A thermoformed canopy or pocket roi hly hemispherical, for example an aircraft cockpit cover or a shape used in Blister Packaging. 

Skin Packaging A variation of the thermoforming process in which the article to be packaged serves as the mold. The article is usually placed on a printed card prepared with an adhesive coating or mechanical surface treatment to seal the plastic film to the card. See also Blister Packaging. 

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