PACKAGING OF DAIRY PRODUCTS

Lesson 15 C

15.10 Aerosol Containers

The aerosol can generally a 3 piece or 2 piece tin plate or aluminum container that has been specially designed to hold a product under high internal pressure and to dispense the product through an aerosol valve.

The precise meaning of the word "aerosol" is a "production of minute solid or liquid particles so fine that they remain suspended in the air for long periods of time." The more commonly accepted definition is a "container of liquid under pressure that is released through a pushbutton valve."

• Aerosol containers are used to dispense a product by means of a pressurized gas (CFC Free) or liquid that is held in the same container.

• The basic components of the package are the valve, the container and the protective cap.

• The container must be gas-tight and may be constructed from steel cans, aluminum cans, glass, plastic, or a combination. Choice of material must be related to safety (ability to hold pressure and lack of fragility), size, and product compatibility.

• There are several types of aerosols which can dispense products as fine mists, sprays, dusts or foams depending upon the type of valve used and the product/propellant arrangement.

• A Single phase aerosol contains a liquid product layer and a compressed gas propellant layer.

• A two phase aerosol contains a liquid product with dissolved propellant layer plus a compressed gas propellant layer.

• A three phase aerosol contains a layer of liquid propellant, a layer of product and a layer of propellant vapor. Removal of product causes the liquid propellant to boil and replenish the vapour phase.

• Piston aerosols contain a flexible plastic barrier between the product and the propellant gas.

• Co-dispensing aerosols disperse two products through the same nozzles.

• Use: Aerosol containers have been used for beverage concentrates, cocktails mixes, cake icings, pan cake mixes, syrups, salad dressings, seasonings, whipped cream, pan release spray and cheese spread.

15.10.1 Advantages and disadvantages of aerosol cans

• The convenience of dispensing materials from aerosols at the touch of a button is an outstanding feature of this type of package.

• The other advantages are premixing, lack of evaporation and exclusion of air even when partly used.

Disadvantages

• High costs (100-200% of the cost of product), risk of explosion, breakage or leakage are main disadvantages.

15.11 Rigid Plastic Packages

A wide variety of rigid plastic can be used in the form of thermoformed, injection - molded or blow molded containers.

15.12 Blister Packs

• It is a thermoformed package and it is obtained by using transparent sheet and cardboard.

• It is a pack which encloses an article between a formed plastic cover and a flat backing paperboard.

• These blister packs provide a great success in merchandising.

• Blister packaging is self selling and tends to reduce pilferage.

• The blisters may be obtained in many desirable options - single, double or multiple blisters and in desirable shapes and sizes.

• Based on product, a blister pack can be tear open type for repeated use.

• The backing card is an important component of the blister pack. While the transparent blister shows the product, card on its part tell the customer about brand, manufacturer’s name, instructions for use, area of application, price etc.

• A colorful graphic design on the blister card attracts the consumer from a distance and puts his eyes on the product through transparent blister.

15.13 Transport/Shipping Packages

15.13.1 Master packages

• Normally they are outer containers in which the commodity in bulk or packed units is placed to give protection against transit hazards.

• These master packs also could be unitized into a palletized load of 500 to 2000 kgs or loaded into containers of 5, 10 or 20 tons capacity, which ensures minimum handling of unit packages.

• The unitization either in pallets or containers results in considerable economy, since the cost of the master pack will be considerably less than for the package designed for transport on its own.

• The transport packages could be broadly classified into following categories:

• Depending upon the nature of protection required by the product, the necessary properties could be built into the package.

• Solid and corrugated fiberboard materials are used to fabricate shipping cartons and cases used extensively in wholesale and Industrial shipping.

• They are not usually used as direct containers for foods but are extensively employed as after shippers for food packages i.e. cans and bottles.

• Both are made from heavy fibrous craft paperboards.

• Solid fiberboard is made by gluing several plies of paperboard together. By using asphalt or special resin adhesives, such as urea formaldehyde, enhanced moisture resistance may be built in. Selection of weight, fibrous construction and number of plies is related to the desired burst, tear, puncture and bend resistance.

• Corrugated fiber board is made from similar base materials but is generally thinner, as it is then constructed by combining facing (flat sheet) and liners (corrugated or fluted sheets) by means of adhesives.

• There are four major types of corrugated paperboard:

• Unlined single faced,

• Double faced,

• Double walled, and

• Triple walled.

• The first two types are used for wrappings of fragile objects or as interior padding of boxes.

• The latter two types are used where exceptional strength and rigidity are essential.

• Double - faced corrugated is the most commonly used type for boxes liners and partitions.

• Each flute has particular properties with respect to load support in each of the three possible directions.

• In double wall construction different flutes can be combined.

• Corrugated containers are now available with easy open tear strips, self locking assembly and smooth white liners permitting flexographic printing on the exterior. Special reinforcements can be employed. Where strength is less important molded pulp has been used for liner material.

• Other special corrugated boards or fiberboard constructions include foil laminated facings and plastic foam fillers between paper facings
  

15.13.1.1 Advantages and disadvantages

• Corrugated board packages are versatile, light weight, strong, disposable and having low cost.

Disadvantages

• Low wet strength - newer techniques of manufacture and new coatings are eliminating this disadvantage.

15.13.2 Cylindrical shipping containers

• Cylindrical containers have high stacking strength and can be rolled in handling.

• They may be made from fiberboard, glass, metal, plastic or wood.

• A barrel is a cylindrical container of greater length than breadth, having two flat ends of equal diameter and bulging at the waist.

• A drum has straight sides and flat or bumped ends.

• A pail is a cylindrical or tapered (truncated cone) shaped container with or without a wire handle or bail.

• Small pails may be called cans.

• A keg is a small barrel.

• A cask is a large tight wooden barrel.

• Barrels may be made of wooden staves bound together with hoops and may be tight or slack.

• Metal barrels are made of steel or aluminum.

• Drums may be made of metal, plywood or fiberboard, fiberboard drums may have wood, metal or fiber ends.

• Fiber drums and cans are made from spiral or convolute wound paper or paperboard bodies and may be closed with metal, plastic or fiber ends. With interior facings of special papers, foils, or plastics such as glassine, parchment, aluminium foil, polyethylene, or pliofilm, they may be used successfully for bulk shipment of foods as the linings prevent contamination of the food or weakening of the container. Other barrier components can be built into the side wall at time of lamination. These may be asphalt, foil, or polyethylene to achieve a moisture barrier.

• Steel drums are used as single trip or returnable containers. Drum heads may be removable or fixed. Fixed heads may be fastened to the body by brazing, welding or double seaming. Some drums are formed in two halves and joined circumferentially at the waist.

• Drums may be fitted with removable covers which are of the friction lid type or which may be held in place by locking rings or lugs.

• Tight head drums or pails are furnished with small capped or screw plug openings for easy of pouring. Additional vents and drains may be specified.

• Aluminum drums are designed to have similar features to steel drums. Stainless steel drums are used where corrosion resistance or high levels of sanitation are required.

• Latest types of drum constructions are blow molded polyethylene drums as the primary container and a steel shell for added protection and rigidity.