A pioneer in plastics packaging sees the end of cans and bottles

Laszlo Bonis makes this bold prediction: Within five or six years most cans and bottles will be gone from the nation's supermarkets. They will be replaced by packages of cardboard laminations or coextruded multilayered plastics.

Dr. Bonis is chairman of Composite Container Corporation, a small state-of-the-art plastics manufacturer in Medford, Mass. He's developed a proprietary process to coextrude dissimilar plastics into a film and sheet stock with as many as nine layers of materials at less cost than single-layer sheets and at a yield four times as high. Composite Container is selling its plastic products to packagers. Moreover, the Hungarian-born entrepreneur plans to sell stock to the public for the first time by the end of the year. Publicity can help in that regard.

Nonetheless, he says that can company executives are calling on him frequently, looking for ''insurance'' should he be right about their fate.

What's happened is that the rise in the cost of energy has driven up the price of conventional packaging materials, such as steel, glass, and aluminum. A 12-ounce steel can costs some 9.5 cents now, Dr. Bonis says. He can protect a product with his composite plastic material for 5 cents a package. (Dallas-based Brick Pak Inc., a producer of machines that make a laminate material of polyethylene plastic, aluminum, plastic, and cardboard, from inside to the outside, also offers substantial savings and is selling dozens of its systems for producing rectangularly shaped packages each month.)

Dr. Bonis has major ambitions for his five-year-old company, which first started commercial sales in 1981. He expects last year's sales - at a rate of only $5 million - to quadruple to $20 million this year and reach $160 million by 1986.

Here's his explanation for such a forecast.

At the moment, the metal can is dominant, because it keeps its food contents safe for eating even though they may sit unrefrigerated on a shelf for months. Food is vacuum sealed in the can and boiled for four to seven hours until all the bacteria are killed. This heating has the drawbacks of altering the taste, reducing the nutritional value somewhat, and changing the color. Green beans turn grayish.

Now the Food and Drug Administration (FDA) has approved aseptic packaging, a system developed in Europe. With this, the food is sterilized first. For instance, milk is sterilized at ultrahigh temperatures for such a short time the taste is not changed (at least, that is what is claimed). Then the product is put into a container that has been sterilized separately by a bath of hydrogen peroxide or superhot air, which is sealed. This product also has shelf stability. Milk does not need to be refrigerated, for example.

Dr. Bonis says this package has the advantage of costing less than half of a metal can or glass bottle. One reason is that the metal or glass container uses three times as much energy per cubic inch.

He maintains that his material has the special advantage of requiring no solvent-based glues to join the layers. The layers of various plastics are coextruded from what he terms ''a glorified meat grinder which is heated.'' The layers come out as thin as 2/10000ths of an inch, or one-tenth of the thickness of a human hair.

The layers can be varied according to the needs of the product. But it means inexpensive plastics can be combined with expensive plastics, and the qualities of various plastics in regard to color, heat resistance, flexibility, rigidity, resistance to oxidation, ultraviolet light, odors, flavors, moisture, gases, etc., can be combined to make a suitable package that maintains the product's freshness and integrity.

Dr. Bonis doesn't give details about his proprietary ''black box,'' which turns out a solid cylinder of plastic containing as many as seven plastics. This cylinder is then flattened out into thin sheets. A machine to do this trick costs something like $1.5 million.

Several companies have been working on processes to produce multilayer plastics by coextrusion. Dr. Bonis believes he has a superior method. He was a polymer chemist at a technical institute in Budapest before getting involved in the 1956 revolt and leaving the country. He then did some research in materials science at MIT, specializing in the physics of the interfaces of surfaces. From there he went to Ilikon Corporation, a Chicago-based plastics company, and then, with the help of money from Allstate Insurance Venture Capital, he launched his own company.

By now his plastics are being used to package, for example, Oscar Meyer bologna and salami. A moisture barrier helps prevent the meats from drying out on the shelf. Dr. Bonis says the company has saved 15 percent on costs as well as providing a better packaging material.