Revival: Flexible Packaging Of Foods (1970)

Aaron Brody

• Publisher: CRC Press
• Year: 2017
• eBook ISBN: 9781351365833
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Biology
• Index: Technology & Engineering

This review encompasses one segment of food packaging – foods. That include flexible materials in their package. It is intended as a systems view point: designing product requirements and markets, and describing the present material and machine methods for filling those requirements.

By any measurement, packaging is a large industry in size, diversity and complexity. Mere enumeration of the amount of materials consumed, or dollar volume of machinery sold, would fail to depict the numbers of persons who package products each day. Entire industries are in reality not manufacturers but packagers of products made by or assembled by others. Almost all goods reaching the industrial or consumer level are packaged. To ascribe a dollar volume in excess of $25 billion to packaging would be to miss much of the value.

Clear segmentation of so large a group of industries is difficult. Packaging might be divided into cans, glass, paper, paperboard, plastic and flexible. This classification, based on materials, overlaps and lacks clarity. Most paper and some plastic packaging is flexible. A rigid plastic tub with a laminate lid is a rigid container, but it might perhaps have greater flexible value than rigid material. Aluminum foil laminated to paper is used as label stock on cans and glass, but it is generally not considered to be flexible packaging.

A precise definition of flexible packaging is not important. To assure that the significant uses of flexible packaging are examined, a number of areas which might be marginal are covered. Flexible packaging, then, includes a broad range of papers, plastics, aluminum foils, coatings, bondings, and various combinations which generally are not self-supporting in flat form and which can be shaped.

Estimates have placed the volume of flexible packaging used annually in recent years at 1.6 billion pounds valued at $1.4 billion. The growth rate has been estimated at 7% per year.

Although multi-wall bags are usually not considered flexible packages, a large volume of material is employed to contain bulk materials such as fertilizers and chemicals. Similarly, relatively small quantities of expensive and sophisticated flexible materials are used by the pharmaceutical, cosmetic and toiletries industry to protect their products. The tobacco industry uses large quantities of flexible materials, including cellophane, paper, and aluminum foil laminations to keep products fresh. Clothing is wrapped in considerable quantities of flexible packaging. Durable consumer goods, such as phonograph records and toys, employ flexible materials both for protection and decoration.

However, the largest single use category is probably food. The costs of raw materials and commodities for food products, coupled with a fierce competitive situation among processors, has led to generally low profit margins among food industries. Efforts to maintain or improve profitability by food companies have ranged from mechanization to reduction of labor.

Flexible packaging has benefited from this pressure for lower cost. Much food packaging was in rigid containers which have persisted. Rigid glass and metal are protective, impermeable and, when properly coated and closed, inert to the contents. Further, rigid glass and metal are able to withstand the stresses of thermal or freezing processing. Because of their structure, rigid containers lend themselves to high-speed automatic equipment. Rigid containers are, however, among the highest cost packaging used for foods. The fact that rigid containers are difficult to fabricate has mitigated against the food industry manufacturing, and dictated that these containers be fully formed at the packaging suppliers' plants. The volume of fabricated glass and metal containers used requires large warehouse facilities or skillful logistics to assure adequate supplies. Although some food processors have their own facilities for can manufacturing, cans and glass demand long run quantities for efficient operation and lower cost.

All of these factors have worked in favor of flexible materials which are inherently cheaper than rigid materials. Flexible packaging is also flexible from a business standpoint. Although efficiencies can be realized from long runs, even short runs are not difficult to manufacture at moderate cost. A broad range of properties may be built into flexible packaging with appropriate components. Size, for example, can be varied, sometimes at the packaging site. And, since flexible materials are made in the flat, they do not require large inventory facilities.

Flexible materials may be obtained in preformed configuration which is filled and closed by the food packager, or in roll or sheet form. The food packager may manufacture the package in-plant from roll or sheet stock, thus eliminating part of the price of vendor package fabrication. A considerable amount of this package fabrication equipment forms the package around the product or forms the package and fills it in sequence. Such machinery allows for integration of product manufacture directly into the package and thus reduces costs.

There may be some sacrifice of structural strength, inertness and permeability which limits the applications of flexible packaging to foods. For example, no known coating is as inert as glass. Being lighter in weight, flexible materials might be thinner and weaker than rigid.

Because of the multitude of basic paper, plastic and ink suppliers, and the similarity of flexible packaging converting to the printing trade, there are many more flexible packaging vendors than suppliers of rigid containers. This leads to a lesser dependence on a few sources of supply. Many converters provide a specialized line of flexible materials to a limited part of the food packaging industries. Some converters have direct interest in raw materials such as a plastic or paper. No converter, however, has infinite capability in a field as complex as flexible packaging of foods.

The field of flexible packaging of foods is dynamic. Nevertheless, however accurate a picture of an existing situation is, the picture is transient. At present, the relatively limited number of commercial plastics, papers, foils, coatings and adhesion systems give rise to an estimated seven million possible combinations of flexible materials.

Polymer chemists have developed many more materials which are not commercial; however, applications have been detailed for these materials. Large research efforts have been directed toward coatings to change the properties of the basic films. Even paper has been the subject of intensive research. Basic material suppliers are seeking new means for upgrading their output and for widening potential applications. Working in cooperation with their customers (the converters) and the ultimate customers (the packagers), basic material suppliers are constantly creating new combinations of flexible materials. Converters, caught between basic material suppliers and customers striving for lower cost and higher performance materials, are developing packaging to better their position.

The packagers, in their quest for new products and better means for presenting them, are making increasing demands upon their suppliers. These statements of customer need are leading the suppliers to develop new flexible packaging.

Equipment manufacturers, most often small and highly specialized, create part of the pressure which leads to new flexible materials. Concepts of higher speed and more efficient packaging machinery have directed converter and basic supplier attention to flexible materials suitable for the equipment designs. The need for assuring the proper marriage of material to machine has led to increases in joint ventures and in organizations which operate in both areas.

Two areas of government have played a prominent role in package specification. Safety, by virtue of materials in contact with foods, is the province of Food and Drug Administration. Also under FDA jurisdiction are consumer protection and communication elements, such as assurance of fill and adequacy of information on the label. By its nature, flexible packaging may not appear to contain the declared quantity of contents if filled on high speed automatic equipment. Government has also instituted a program of package shape and size standardization in an effort to help the consumer shop without a runaway proliferation of combinations and permutations of sizes and weights for similar products.

With these many and diverse resources lending themselves to problems of flexible packaging, improvements and solutions are regular inputs to food packagers. In the new product area, new packaging systems are the rule.

Certain fundamentals, such as requirements for containment, protection and decoration, remain. Several of the original films have survived as basic materials to flexible packaging. These include papers, cellophanes, polyethylenes and aluminum foils. All have been improved for specific uses. Other materials have entered the market, and, of course, more will become part of the packaging world with the passage of time.

Both basic material suppliers and converters constantly review the flexible packaging situation. Their useful documents are proprietary to those who have prepared them, and focus has been on the specific and obviously relatively narrow interests of the companies preparing these reports. Users have occasionally been privileged to study portions of these reports relative to the immediate and direct product interests of the users.

Examination of a detailed review would present opportunities for cross-fertilization not generally afforded users. Presentation of the totality of flexible packaging of foods in one place for users would offer both users and their suppliers perspectives which might clarify certain problems and define solutions based on experiences in other segments of food packaging. Presentation from the standpoint of the food, rather than from the packaging material, might offer a view that has not been afforded either the user or supplier. Even though this field is constantly changing, there is purpose to documenting the situation at a single point of time.

As implied, flexible packaging industries include basic material suppliers, converters, machinery manufacturers and packagers. In general, basic material suppliers manufacture paper, plastics, inks, coatings and metal foils. Converters are those who make the basic materials useful by coating, laminating, printing and cutting. Machinery makers design and build equipment which transforms the converted flexible materials into filled packages. The packagers are those who bring product and packaging material together and produce the package.

Generally, science is found among the basic material producers. Applications orientation is most often with the packager. Converters are generally concerned with building properties into materials. The converter may be considered a middle man, attempting to use what is available to satisfy the needs of the users. Thus, the converters' problems may be greater than those of the industries which surround them. The magnitude of converter responses to the pressures exerted from two sides has often restricted converter development to immediate problem solving. Only a few large converters have the resources for long-range development.

As a result of this natural division of interests, the limited number of technical and trade publications are generally devoted to materials, their components, properties and manufacturing. Similarly, machinery designers' literature focuses upon the mechanical characteristics of the equipment. The many basic material producers' technical publications describe many technical properties of the chemical compounds.

The packagers themselves are usually concerned with the results of packaging and often have little knowledge of the identity of the material/machine combinations used for their products. Technical publications on food products usually treat packaging in a most cursory fashion, if at all. Product technologists often leave packaging to purchasing or marketing people.

This paucity of published information on technical interactions of product and packaging has limited commercialization of some important packaging developments. For example, perhaps the greatest number of technical publications on flexible packaging deal with fresh red meat. Most students of this topic concede that despite the many publications there are enormous voids of information. Some of the needed data is believed to have been prepared by various suppliers, but little of this has been integrated for users. One reason for this lack of dissemination is that those who possess needed information may not know the potential market.

This background demonstrates the lack of a comprehensive source of applications information on flexible packaging. Such a review would not be an instruction manual on flexible packaging analogous to those on canning, paperboard packaging equipment or corrugated case design. Rather, this review is aimed at describing food products employing flexible packaging, the requirements dictating the flexible packaging being used and the current state of flexible packaging in the food industry. Materials and their properties are included as needed, but emphasis is given to stated and inferred marketing needs which influence the selection of materials and their graphics. Machinery is indicated in terms of describing the packaging that it makes and the rationale for including it in a production line.

It is expected that this attempt to cover a vast field will lead to some omissions, but perhaps the inclusion of a broad range will lead to later insertion of the missing parts.

Because of the dynamics of flexible food packaging, some of this review will be obsolete by the time this article is printed. In these areas, this document serves as an historic record and thus might still interest and stimulate the persons with direct packaging responsibilities.

In few other reviews would it be so difficult to classify the subject areas. In an attempt to minimize reader difficulty in reviewing and referencing, this report is classified in alphabetic order according to food categories:

Bakery

Bread, cakes, soft goods, pies

Biscuit and cracker

Cookies and crackers

Canned foods

Sterilized flexible packaging

Film multipacking

Cereals

Ready-to-eat and hot breakfast

Coffee

Roasted and ground, and instant

Confectionery

Candy and nuts

Convenience foods

Food service and retail

Dairy

Fluid milk, ice cream, dry milk, cheese, butter and margarine

Dehydrated mixes

Formulated mixes, cake mixes, dinner mixes, rice, flour, pasta, soups, salad dressing and sauce mixes.

Desserts

Mixes and refrigerated

Frozen foods

Fresh and precooked

Meat

Red and processed

Poultry

Produce

Snacks

For each product category, the products included, their manufacture, distribution and marketing are briefly outlined. From the marketing or ultimate user standpoint, the packaging requirements are reviewed, pointing out the important needs served by packaging. Present packaging for each product group within the classification is described, with the detail on flexible packaging. There may be omissions from the descriptions because information is

FIGURE 1 Definitions for Some Flexible Packaging Materials Used for Foods

From Modern Packaging, Oct., Nov., and Dec., 1967. With permission

proprietary to supplier and user. Where important and appropriate, some conclusions as to the nature of the packaging are drawn based on professional observation.

Because machinery and materials are so closely intertwined, the equipment used, usually used or probably used is described. It would indeed be a happy circumstance to be able to wrap...

Table of contents

• Cover
• Title
• Copyright
• Author's Introduction
• The Author
• Contents
• Bakery Products
• References