Rigid Packaging Material

A wide variety of rigid packaging materials has been developed over a period of time. The most important packaging material like metal container have been widely used for the packaging of milk powder since long due to certain important properties like complete barrier to light, oxygen gas and moisture. In addition, glass bottles are also used for the packaging of flavoured milk and fresh milk. But now-a days,the application of flexible pouches have gone ahead to glass bottle for the packaging of pasteurised chilled milk. The plastic bottles are also used to a great extent for the packaging of dairy products. The corrugated fibre board boxes are considered to be the most important transport packaging materials for all processed food products including dairy products.

i) Glass Containers

Glass is the oldest packaging materials and used as containers for over 3000 years. The first glass container was made in Egypt in 1500 B.C. Despite of having certain inherent characteristic like fragility, tare weight, the glass containers have made an established application in packaging of dairy products.

PROPERTIES OF GLASS

Chemically Inert, Non – Permeable, Transparent, Mouldable, Excellent impact strength, light Weight, unlimited Supply and see through property

Advantages of Glass Packaging

High or low temperature resistance, do not contaminate the contents with crystals or fibres, climatic variation do not affect the glass container, see through property, can be made in any size shape and capacity, does not taint, pollute or affect the quality of product, there are Various types of closures for glass container made of metal, plastic, cork or rubber and Impermeable to moisture and gases thus suitable for processed food products.

COMPOSITION

The main constituent of glass are sand, lime stone and soda ash. The sand used is known as silica or glass sand. In some cases, arsenic, selenium and cobalt oxides in proper proportion are added to make clear glass. The green or brownish shade in glass comes from the impurities in natural sand, mainly iron. Boron from boraxis added to glass to make the container stronger and to increase its resistance to acids. Colours are added to glass, of (small quantities of chromium, cobalt, iron and other colorants depending on the colour required). For amber (brown) glass, carbon and sulphide are added.

TYPES OF GLASS

The three universally accepted standard are :

All soda lime glasses are mainly Type III.

Type II : This is the same glass as Type III but the inside of the glass container is coated at the time of manufacture, usually with sulphur.

Type I : This is Borosilicate glass which has the added property of almost complete neutrality.

APPLICATION OF GLASS CONTAINERS

Glass containers have wide application for the packaging of pharmaceuticals, dairy, liquor, breweries, food products, soft drinks, cosmetics, chemicals, inks and other industries.

ii) Metal Containers

Metal containers could be made from either aluminium, tinplate or tin free steel.But the tinplate container have got extensive application in packaging of dairy product especially skimmed milk powder.

There are two types of tinplate container namely :

a) Open Top Sanitary Can.

b) General Line Can

a) Open top sanitary can.

These cans are made of three pieces i.e. body, top and bottom ends. Hence, this OTS cans are also called as 3 piece can. These containers are normally round in shape, extensively used for skimmed milk powder.Normally, the metal can of size 1 kg or 500 gms are used for the packaging of milk powder. These metal cans are also used for the packaging of condensed milk of either 500 gms or 1000 gms capacity.

b) General Line Container

General line containers are ranging from tiny containers to 15 lts capacity containers for packaging of milk based biscuits or vanaspati.

PROPERTIES OF METAL CANS

This materials are completely opaque, Complete barrier to moisture, oxygen gas as well as light, Amenable to print with multicolour decoration, Provides longer shelf life to dairy products, High impact strength to withstand stress during transit and Lighter in weight as compared to glass container.

iii) Plastic Containers

Plastic containers are also used as an alternate rigid packaging materials for the packaging of dairy products mainly milk powder and ghee.

PROPERTIES OF PLASTIC CONTAINERS

Could be manufactured in different size, shape and capacity, High barrier to moisture and oxygen gas, It is possible to manufacture the containers in different colours, Impact strength could be improved, Plastic containers could be manufactured with handle to facilitate to carry, Could be made either opaque or transparent, Amenable to make surface printing and it is possible to make leakproof container.

APPLICATIONS

i) Packaging of milk powders, ghee etc.

ii) PET bottles are also used for the packaging and storage of butter under refrigeration.

iv) Corrugated Fibre Board Boxes

Corrugated fibre board boxes are the world’s most popular and environment friendly packaging materials. The intelligent use of corrugated fibre board boxes can replace some of the use of wood, thermocole and plastics.A single layer of kraft paper is passed through the corrugating machine to get the corrugations or fluting media and then stuck into a plain layer of kraft paper by means of adhesives or gum to form 2 layer or 2 ply corrugation roll.

 Subsequently, the 2 ply corrugation roll could be converted into 3 ply corrugated fibre board by pasting an another Kraft liner or facing material. In the same manner, corrugated fibre board could be made either of 3 ply or 5 ply or 7 ply by means of pasting the corrugation roll and facing material. This could be illustrated with the following diagram.

 5 Ply or DOUBLE WALL CORRUGATED FIBRE BOARD

7 Ply OR TRIPLE WALL CORRUGATED FIBRE BOARD.

The corrugated fibre board is converted into corrugated fibre board boxes by considering the following steps.

 ADVANTAGES OF CORRUGATED FIBRE BOARD BOXES

i) Availability of raw materials i.e. Kraft paper and adhesive.

ii) The technology of box making is simple.

iii) Availability of box making machineries.

iv) Cost effective.

v) Amenable to make display package.

vi) Tare weight of box is less resulting to the reduction of freight cost.

vii) Maximum utilization of storage space due to collapsing nature of boxes.

viii) Recognised as Eco-friendly packaging materials.

ix) Facilitates to have excellent printing on the outer surface of the boxes.

x) Easy to handle in the shop floor due to collapsing nature as compared to wooden box.

LIMITATIONS

i) Strength properties are influenced by the environmental condition.

ii) Requires special condition for storage to maintain the strength properties.

iii) Shortage of best quality of kraft papers in India.

iv) Lack of technology in the converting machineries.

APPLICATIONS OF CFB BOXES

Visual merchandising, danglers, and promotional material, Die-cut box for display pack, Extensively used for office stationery items like- trays, pen-stand, filing cabinets, folders for conferences etc., Explored around the world by various designers in its application in furniture item, Wide application for making educational aids, toys etc., As a unit pack for the packaging of horticultural produce, Popularly used as transport packages for all types items including dairy products.