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Home , Paper sack

AND PAPER BOARDS

Prepared by Mrs.M.Janani Department of Commerce (International Business) Government Arts College, Coimbatore – 18. Reference: Fundamentals of Packaging Technology Authors: S.Natarajan M.Govindarajan V.Kumar

TYPES OF PAPER Paper is truly a renewable resource used for packaging. Paper and paper board packaging comprises about 30 per cent of total use of packaging materials in India. Two broad types of paper used in packaging are coarse paper and fine paper.

I. Coarse Paper Nearly all the used for packaging come into the category of coarse paper. The classifications of the coarse paper used in packaging are:

•

• Vegetable

• Sulphite paper

•

II. Fine Paper Fine paper are classified as:

•

• TYPES OF PAPERS AND THEIR CHARACTERISTICS Types of paper Thickness in mm Characteristics Applications Kraft 0.1-0.8 A strong paper that is brown when unbleached, can be bleached white and 25-50 kg sacks used for containing printed. Usually used in multiple layer or ‘plies’ (3 or 4 ply are most flour, sugar, dried fruits, vegetable common) in order to give the necessary strength. Can also be laminated to and cement polythene or wax treated paper to give greater moisture protection. Sack material is designated from the outer ply according to the number and weight of the layers. For example, 2 /90-1/80 kraft, means that there are 3 plies, the two outer ones having a weight of 90 gsm and the inner having a weight of 80 gsm. Vegetable 0.05-0.1 Kraft paper that has been further treated with acid during its preparation to Fats, such as butter or fresh / dried parchment make the surface smoother and more resistant to penetration by oils or fish water (more greaseproof and greater than kraft paper). Negligible barrier properties to air or moisture and not heat sealable. It is not used for food package that require protection against air or moisture pickup. Sulphite paper 0.04-0.06 A lighter and weaker paper than kraft or parchment, usually made with a Used as small or wrapper for glazed surface to improve the appearance and to increase wet strength and biscuits or confectionery oil resistance. (When glazed it is known as Machine Glazed (MG) sulphite paper). The glazed surface can be printed using flexographic methods, but for higher print quality the paper should be coated. It is also used to laminate paper with plastics or foil. TYPES OF PAPERS AND THEIR CHARACTERISTICS Types of paper Thickness in mm Characteristics Applications Greaseproof 0.05-0.08 Made by beating fibres more thoroughly during the Fresh fish or meat, liner for paper manufacture of sulphite . The smaller fibres make a shipping , butter / denser surface which is more resistant to oil. However, this cheese, liner for packs of resistance is lost when the paper becomes wet. biscuits, fats and other oily foods.

Glassine 0.03-0.05 A translucent sulphite paper gives a high gloss surface. The Liner for biscuits, cooking fats gloss makes it more resistant to water when it is dry, but if and fast foods the papers become wet it loses resistance.

Tissue paper 0.035 A thin, weak sulphite paper, it is often machine glazed on one Wrapping fresh fruits to side (known as MG tissue). A special type of tissue paper prevent bruising, making dip with small regular perforations is used to make tea bags. tea bags TREATED PAPERS Paper are generally treated with wax or laminated with poly material to improve barrier properties. Two types of treated papers are wax treated and laminated paper.

1. Wax Treated Paper Papers can be treated with wax to improve their barrier properties and make them heat-sealable. These papers are used to package cereal products, bread and spices. The methods of applying wax to paper are as follows: • Coating is applied after the paper has been made. However, the coating is easily damaged by folding the paper or by abrasive foods (e.g. dried foods). Damage can be avoided by laminating a layer of wax between two layers of paper or between a layer of paper and a layer of polythene.

TREATED PAPERS • Dry waxing During manufacture, the hot paper is treated with melted wax so that it penetrates into the fibrous structure of the paper. This improves the durability of the wax barrier. • Wax sizing The wax is added to the pulp during the initial stages of preparation and becomes fully integrated into the structure of the paper. This method of waxing enables the ingredients to become deeply ingrained into the paper and therefore, it is not easily damaged by folding the paper or by abrasion. 2. Laminated Paper Paper can be laminated to low-density polythene to make it heat sealable and to improve its barrier properties (air and moisture). to or to other types of plastic can also be made. However, in each the cost is increased. Laminated paper are used to pack herbs, coffee powder, dried soup, spices and other dried foods which requires a barrier protection to moisture, air and to give longer shelf-life.

ADVANTAGES / LIMITATIONS OF PAPER BASED PACKAGE MATERIALS Advantages Limitations Lowest unit cost Poor mechanical properties Lowest ratio Non-supporting character of paper body

Securely closed on all sides Poor durability Bags/Pouches tailored to fit snugly Wrinkles and folds makes the package around the product unattractive Less storage space Susceptible to fail under mechanical hazards and climatic hazards Sizes to suit conceivable product Breakage factor ½-2% to be considered in the design problems in warehouse stacking FOLDING Folding cartons are popular in food and pharmaceutical packaging. The folding cartons are also used as primary package to contain collapsible and similar products. The folding cartons give adequate mechanical protections as well as good shelf stability for the collapsible tubes. The flat die cut board can be folded to make of the required shape and style. The folding cartons are also called as Collapsible Folding Cartons (CFCs). The reasons for wide choices are: • Very economical in cost of material as well as in fabrication and assembly. • Being collapsible, it can occupy minimum space in shipping and in storage. • Good and embossing can be done on the surface. • Attractive designs, value-added features and sales appeal to the carton can be provided. • Versatility of the packaging is evident with different size and styles. • Special features like windows can be cut into blank with little or no additional cost. Some limitations of folding cartons are: • Folding cartons are rather flimsy in comparison with setup box or plastic . • Less rigidity of the folding cartons. • The maximum size and weight of the package is relatively low and hence, it is not suitable for containing heavy and bulky objects. FOLDING CARTONS Style and Designs of Boxes • Several boxes with elegant design can be printed on single sheet and can be die cut on single sheet and creased at the same time. Mixed size printing and operation to make varied boxes is called as combinational run. • The carton quality can be adjusted by the number of ups on the board or by drops-off. • The folding cartons are kept in flat position and erected during use. • The folding cartons can be handled with automatic machines for folding, glueing, filling the products, sealing and palletizing operations. • A great variety of style, size can be made, with built-in-platform, extended panel, curved scores and other novel treatments. • The folding box is a useful versatile packing form. The folding cartons are also called as tubular cartons. In this construction, the board is folded on four parallel lines with a small overlap, which is glued down to form a tube. The ends of cuts are creased to provide flaps and lock in place. DIFFERENT TYPES OF FOLDING CARTONS Parallel tuck-in end Reverse tuck-in end Skillet end cartons base Crashlock base Six spot corner glued Pillow pack glued FOLDING CARTONS Depending on the design, end of a carton and type tuck, the cartons are classified as parallel or reverse and skillet end cartons. The tuck end cartons are not generally sealed. In a sealed end carton the outer flaps are glued down after filling. These types of cartons are called skillet end cartons and contain product like powder, liquid, solid and granular items, special locks are also provided at bottom flap of cartons to contain heavy object. Extra tongues and slots are provided on the envelope base cartons to ensure that they will not open during transit. The other styles like cutouts, extensions are also used to increase the visibility or for holding objects in right position. The design of the folding boxes can be enhanced with perforations, hinges, slots and sleeves with little additional cost. FOLDING CARTONS

Selection of Material for Folding Cartons • The used for should not crack along score lines. • The different thickness and grade of board are used for varied application. These boards usually have 140-200 gsm with outer layer for better quality printing. • If the carton is used to protect the contents mechanically no special requirements are imposed. • For pasty liquids or frozen food materials, the board must be treated to give protection and impermeation to water vapour and gas. • The board must be modified with paraffin wax or hot melt coating or laminated with or polycarbonate. These materials also permit easy heat sealing qualities and provide hermetically closed ends. • The board stiffness is a function of elasticity of a material in grain and cross grain direction of the board. Since most fres are oriented in machine directions, the stiffness is FOLDING CARTONS

• The grain of the board for a good design of cartons usually runs around the box and perpendicular to the main scores. This provides more stiffness across the span from one score line to the other and facilitate main panel to lie flat. • Bulk carton with granular products will bulge due to internal pressure of contents. The panel area is an important factor for such cases. The degree of bulge also has little effect in increasing thickness of the board. • The humidity also affects performance of the board and may reduce the stiffness. As the caliper of the board increases, the moment of inertia increases in proportion to square of the distance from the centre of the board to the outside surface. The outer plies, therefore, have the highest effect on the surface. • Chipboard is generally used for packing dry fruits, cereals and cake mixes. It is also used for non-food items like toys and hardware supplies. For direct contact with food and cosmetics applications, high quality surface is required. The bleached board is generally used for such applications. The clay board is used for ultra fine printing of half tone images.

CARTON DESIGN CONSIDERATION

• The choice of material, style of the box will depend on the type of product and market requirement of particular item. • The selection of the cartons may be based on factors such as cubic volume, weight, standard shelf size (dimension), convenience feature and cost. • The cost is a prime consideration, if the carton structure is utilitarian, such as customer pack or institutional or industrial package. Besides, providing protection against mechanical hazards, the carton must give good display and stability in shelf. It should also give good appearance when stacked in mass display. • The physical dimensions of cartons should be proportioned to give good impression, but it should not be deceptive. The strength of the carton board, quality of the board and press work all contribute to good appearance on shelf. The package should also provide customer convenience by giving easy to pick up and hold facilities. CARTONING SYSTEM

A cartoning system combines a special carton with the machinery to erect it from a flat position, filling it with a product and closing it. The machinery may be semi-automatic or fully automatic in operation. In cartoning system, main operations performed are: Forming or erecting the carton: The material may be fed to the carton erection point as continuous web, as flat carton blank or as folded carton flat with a manufacturer's joint secured. Loading the carton: Product loading can be done by top loading or side loading. Top loading system has only one face open at the point of filling. Closing or sealing of the cartons: The factors listed below are considered for selection of the cartoning system. Machinery consideration • Production rate and expected peak load • Range of pack size involved • Frequency of the change in size • Whether the existing system can accommodate changes in the pack size

CARTONING SYSTEM

Product factor • Product variation-easiness to control and product compatibility with machine. • Availability of material handling-equipment like conveyor, monorails, lift truck and cranes. • Board and carton requirement-required barriers properties to odour, moisture and oxygen • Loading techniques -top loading is better than side loading Board and carton requirement • Board requirement in terms of decoration and selling power • The degree of protection the carton must provide to content General consideration • Compatibility of the proposed machine with the existing system SETUP BOXES

The setup boxes are rigid boxes made from fibreboard. These boxes cannot be collapsed. This is in contrast to folding cartons which is shipped flat and erected at the point of filling.

Advantages

• Less use of sophisticated machines and tooling .

• Complicated and expensive dies are not required .

• Better versatility and rigidity of the box

• Good appearance to provide better display values .

• Easily accommodate small production runs and unusual forms

Limitations

• Occupies large floor area in shop floor and warehouse

• Cost is higher than folding cartons STYLE OF SETUP BOXES

CORRUGATED BOARD Corrugated board consists of a central member-medium (flute). These flutes are glued with one or two flat sheets of paper or paper board (facing) to form different types of corrugated board. The corrugated board is classified based on the number of liner or medium used The configuration of corrugated board is based on the principle of arch.

BASIC COMPONENTS OF CORRUGATED BOX TYPES OF CORRUGATED BOARD PROPERTIES OF CORRUGATED BOARD The corrugate board is the dominant in transport packing. Corrugated board has achieved its position due to: • Using wide variety of paper and board material to give a wide range of properties – structural and graphic • Creating a large number of structural designs adopted to the needs of both products and distribution system • Mechanical properties of the paper in corrugated board being comparable to other basic materials like and polystyrene • Strength / cost value of board is outstanding • Ease and flexibility of changing structural and graphic designs depending on display and information needs • Suitability to meet the varied production needs • Flexibility to change structural designs depending on consumer needs and other PROPERTIES OF CORRUGATED BOARD

The corrugated medium may be made of kraft, bagasse or straw board. Liner boards are generally cylinder kraft, filled sheet made from scrap paper. The process of adhering to the flat sheet with corrugated medium is called combining. The machine used for this purpose is called combiner. A Corrugated board package is usually built so that the flutes are oriented in the direction of the compression load of package. If the load direction is parallel to corrugation, the board provides maximum stacking strength. The rigidity of the board is influenced by the factors, such as:

• Height of flutes,

• Frequency of flutes,

• Integrity of flutes,

• Elastic stiffness of the liners, and

• Fibre orientation of the paper used. FLUTE SELECTION

• Corrugated board is normally made in four flute sizes designated as A, B, C and E. • The type of flute to be used depends on the product contents and their fragility, density and self-supporting characteristics. • If top to bottom compressive resistance is important, A-flute is better choice. Fragile products needs better cushioning effect from A-fluted board, except for denser product which create flat crush. • For greater crush resistance, B-flute with more lines, contacts between the corrugated medium and the facing, is a better choice. It also gives greater strength at the score line and better end to end crush resistance. B-flute fold more easily and makes a neat looking package for small boxes. • C-fluted board is an economic compromise between A and B-flute. C-flute uses less material than A-flute. It gives the cushioning quality of A-flute and flat crush value of B-flute. It also gives reasonably good stacking qualities and stiffness properties. • E-flute provides an excellent printing surface and works well with automatic equipment. It provides better strength than comparable carton board for the same weight. The E-flute can combine with other flutes to give improved properties. Combination of different flute provides a large number of alternatives for varied applications. For providing good compressive strength and printing surface, E-flute board may be combined TYPES OF CORRUGATED BOXES

• The corrugated box is the most widely used . These

are generally collapsed to make it flat.

• The most frequently used style of box is the regular slotted container, which are

popularly called as RSC.

• In addition to its use as shipping container, corrugated board is also used for

bracing, blocking and cushioning applications. Partitions inside the box are

provided to hold the products in place or apart from each other.

• Stacked sections inside the box act as cushion for heavy products.

• Corrugated board provides the cost-effective protection to the products. It gives

major contribution to the modern distribution system. TYPES OF CORRUGATED BOXES • The corrugated shape offer rigidity to board and cushioning properties. The most frequently used style of box is Regular Slotted Container (RSC) in which all the flaps are of the same length and the outer flaps meet in the centre. It is made from single piece of fibreboard and is shipped flat to the user plant. • Normally the direction of corrugation in a box is vertical. This provides the maximum strength in stacking. The liners have corrugation usually in horizontal direction, to withstand the shock from sliding down from the chutes. The end of blank box can be joined in several ways. The edges may be joined by metal stitches or stables. This joint is called manufacturer joint. TYPES OF CORRUGATED BOXES TYPES OF CORRUGATED BOXES STYLE OF INTERIORS USED IN CORRUGATED BOXES STYLE OF INTERIORS USED IN CORRUGATED BOXES STYLE OF INTERIORS USED IN CORRUGATED BOXES STYLE OF INTERIORS USED IN CORRUGATED BOXES TYPES OF MANUFACTURING JOINTS FIBRE Fibre drum is used for shipping bulk chemicals and other industrial products like , pastes, paints and certain food products with proper lining. Fibre drums are generally used for dry products. It can also be used to contain pastes and certain kind of liquids with suitable liners. Fibre drums are light weight. and have good strength in proportion to their weight. Although a fibre drum is a single trip container, it can be reconditioned and used for several trips. Fibre tubes and composite cans are made from paper board to contain cosmetic and hard ware items. FIBRE DRUM

Advantages of Fibre Containers • Light weight and less tare weight • Shipping weight can be reduced • Fibre drum have a strength to weight ratio as long as they are stacked upright • Provides excellent protection against spoilage • Easy opening and closing features • and easy disposal • Fibre drum is the most economical rigid shipping container for bulk packaging of powder and granular materials. FIBRE DRUM • Three methods of producing fibre containers are spiral winding, lap seaming and convolute wounded containers. • In the spiral winding system. the paper board is slit into narrow width and wound into roll of 75 to 100 mm diameter. The outer stock forms a . The printing is inclined, so that when it is wrapped around, the tube printing becomes straight and matches where edges built together. The roll containing paper is mounted on unwind stand. The paper board is threaded in the glue pot, where it is coated with the adhesives like silicate and dextrin. • Convolute winding of several layers coiled on the top of spiral wounded bodies. Liquid products are shipped in fibre drum with special liners. All fibre drums are made as straight cylinders. The end pieces are either made of 24-30 gauge steel or water proof fibreboard. The outer layer of fibreboard and end disc may be water proofed using wax coating. • The barrier material, such as asphalt or polyethylene is applied between the plies. • Steel covers are secured by locking ring with a toggle to draw it up tightly against metal rim of the drum. A gasket in the cover provides . • Toggle action of the lever makes it easy to close and pilfer-proof. Wire seal can also be used for MULTIWALL PAPER SACKS

• Multiwall paper sacks are made of kraft paper or extensible kraft paper. • The sacks are made of multiple layers of paper ranging from 2-6 layers of different with different strength. • The diferent types of paper sacks are: pillow type. guset type. etc. Multiwall paper sacks provide a good print. • They can be made waterproof by providing waterproof on the outer layer or protecting the product from moisture by using polyethylene on the inner side of the sack. • Multiwall paper sacks are gaining popularity in recent times. They are being used for keeping products, like cement, fertilizers, carbon blocks, bulk drugs and plastie granules. • The selection of multiwall paper sack depends on nature of product, handling methods and storage hazards. PLASTIC WOVEN SACKS These sacks are becoming popular as an alternative to jute bags. They are used to pack food grains, chemical fertilizers, bulk drugs, cement, plastic and granules. PAPER BAGS

Paper pouches or bags are used to contain powder granular products. Laminated papers are also used in making pouch to contain liquid and pasty products.

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