TA3004. Food Packaging Lesson 3: Paper and Paper-based Packaging Materials M.S. Ashanty Miguel Piña Rodriguez ampina@itesm.mx Module 2: Food Packaging Materials Campus Queretaro Spring 2012
Objectives To learn about the different types of paper To learn about the different uses of paper products To learn basic processes of manufacturing paper To discriminate among commonly used paper packaging materials for food products
Food Packaging Materials 4 major materials: Metal Glass Paper / Cardboard Plastic Cans Bottles Boxes/cases Flexible Bags Films / liners Films Jars Bags Rigid Containers Cases/cups Bottles Tubes/cups Biobased materials
Attributes of paper and paper-based packaging Recyclable Mechanical resistance Flexible Printable Available raw materials Inexpensive
Raw Materials Paper, paperboard, corrugated board, and other paperbased materials Pulp - cellulose Additives Pigments Polymeric liners ~97% of paper and board is made from wood pulp 85% wood pulp: spruces, firs and pines (coniferous) (Source: USDA Agricultural Research Service)
Pulping Separate the fibers without damaging them Softening or removal of Lignin Chemical Process Mechanical Process Semi-Chemical Process Chemi-Mechanical Increases cellulose content (Source: USDA Agricultural Research Service)
Mechanical Pulps Groundwood High cost (energy usage) Preserves most of the lignin Smaller and weaker fibers Higher in opacity Low mechanical strength Mainly used for newsprint and magazine paper
Refiner mechanical pulping (RMP) Utilizes various supplies of wood chips, sawmill residues, and sawdust Thermomechanical pulping (TMP) Pre-steams chips to 110-150 C Chemi-thermomechanical pulping (CTMP) Mild pretreatment with sodium sulfite and a pressurized refining
Chemical Pulps Degrades and dissolves away the lignin Alkaline Processes Soda process: sodium hydroxide at 170 C Sulfate (Kraft) process: Sodium sulfate Acid Process Sulfite processes: Bisulfite + sulfurous acid Recent modification involves anthraquinone and methanol
Paper packaging 3 major groups: Packaging papers Cartons Corrugated box
Paper Types Coarse papers i.e. packaging In general, good grease and water resistant Not so good as gas barriers Resist oil penetration for as long as a food product s life
Paper Types (coarse) Greaseproof paper Vegetable parchment Glassine paper Waxed paper
Adhesives Starch solutions Rubber latex Acrylic-based (for paperboard) Odor free Barriers To water vapor and environment gases (oxygen, volatiles, etc) Paraffin (vs water vapor) Polyethylene Cellulose derivatives, rubber derivatives, vinyl copolymers, polyamides, polyester, and butadiene-styrene copolymers. Pigments ~70-90% of dry solids in paper coatings
Cartons From paperboard Paper >224 g/m 2 Multi-ply boards one or more web plies into a single sheet of paperboard Boxes Folding cartons Beverage cartons Other products
Folding Cartons Paper material Foodboard Cartonboard
Beverage Cartons Paper material foodboard
How cartons are made? http://www.youtube.com/watch?v=jnbkic8td5i 7:24 min
Molded Pulp Containers Paper material Chipboard Base board http://www.youtube.com/watch?v=ha1bu77tdt s&feature=related
Corrugated board Cellular structure High compressive strength / relative low weight Two components Liner outside planar sheet Medium fluted center portion Different fiberboards from various combinations
Single face 1 liner, 1 flute Single Wall Board 2 liners, 1 flutes B, C Double Wall Board 3 liners, 2 flutes BC Triple Wall Board 5 liners, 3 flutes BCB, BCC
Flutes 4 flute sizes Height flute Number flutes/unit length (Source: Smurfit, www.packaging-gateway.com)
A maximum cushioning and good top-to-bottom compression B smooth printing surface C compromise between A/B, the most common E for retail boxes, with good printing quality
Double Wall Board: B+C Flute B Height 2.46mm 47 flutes/30cm linear Oriented to the outside Good printing quality Flauta C Height 36mm 39 flutes/30cm linear Oriented to the inside Good compression resistance
Corrugated Boxes Functions Contain a product Protect the product during distribution Resistance to stacking Communicate content characteristics Reduce weight and cost http://www.youtube.com/watch?v=nspngatufok
Factors involved in the selection of corrugated boxes Identify the contained product Identify the distribution and transport systems Identify the geographic areas of distribution Elaborate prototypes Testing: travel, compression, stacking Elaborate final specifications of corrugated box
Designing a corrugated box $ COST $ Material to construct a box (m 2 ) Dimensions L W H % wasted material More material more expensive
Cost reduction Material saving i.e. 3 boxes with same cubic contents, different waste factor (P) 70-80% total cost = raw material
Space saving Different stacking arrangements, shape arrangement i.e. 24 cartons (11 4 15cm), different arrangements using 0.494-0.675 m 2 board, latter P=36% Metrication Favors packs of 10 s Economy Favors packs of 6, 12, 24, etc.
Monograph for calculating wastage (%P) of board for regular slotted containers
Corrugated boxes styles
Interior fitments Pads Fill spaces Cover the bottom Separate layers Tubes Double protection Partitions Separate cell
Stacking Resistance Corrugated board caliper Box dimensions Volum density Stacking levels External factors Humidity Nominal forces Mishandling
Effect on stacking strength lower in a much economical box proportion Most economical relations: Box Style Length Width Height 0201 2 1 2 0204 1 1 2 0301 1 1 0,25 0320 2 1 1
Compression Resistance Several situations may cause a loss on the compression resistance -29% When there s no uniformity in the vertical stacking
Boxes hanging over the edge of the pallet. The two vertical edges of the box not hanging over the pallet edge are primarily supporting the load -32%
Use of interlocking stacking patterns -45%
Printing Method Printing rollers (i.e. flexography, lithography) and the type of ink could reduce compression resistance up to 15%
Mediciones de Resistencia ECT (Edge Crush Test) Measures the maximum compression strength of a combined board. Used to calculate the stacking resistance Lbs/in
McKee Formula A formula that can estimate the compression strength of a given box Total caliper H (cm) Box Perimeter Z (cm)= (L+ W) x 2 ECT Pm (Kg/cm 2 ) http://www.cartoncorrugado.com.mx/herramientas.html http://www.harperlove.com/files/documents/newsnovember10.p df
Product-Packaging Interaction Paper and paper-based materials Product Packaging Environment Consequence Sorption Packaging deterioration Permeability Product degradation Migration Possible toxic effect; Packaging corruption
Environmental Repercussions Paper is recyclable Recycled paper can be used to make More paper Furniture Construction materials KEYS Sustainability Responsibility
How many trees??? 1 ton printing and office paper uses 24 trees (Kraft method) 1 ton newsprint uses 12 trees (Groundwood method twice tree efficient) 1 tree makes 16.67 reams of copy paper or 8,333.3 sheets 1 ton of magazine paper uses a little more than 15 trees 1 ton of newsmagazine paper uses nearly 8 trees
1 ton (40 cartons) of 30% postconsumer content copier paper saves 7.2 trees 1 ton of 50% postconsumer content copier paper saves 12 trees. 1 ton of recycling paper Saves 17 trees 380 gal oil won t be used 4000 KW of power are saved http://www.youtube.com/watch?v=rzl7kaessaa