In the discussion of flexible containers, will cover the definition, classification, materials used, the process in the field of flexible containers and some popular examples of the application of flexible containers.
Flexible packaging is a form of packaging that is flexible formed from aluminum foil, plastic film, selopan, plastic film coated metal aluminum (metalized film) and paper created one layer or more with or without thermoplastic or adhesive others as binders or coatings construction sheet-shaped packaging can, pouch, sachet or other forms.
This packaging marketing lately become popular to package a wide range of both solid and liquid products. Used as a replacement for rigid packaging containers and cans on economic consideration ease of handling.
Raw materials used:
Usually the materials used as ingredients in the manufacture of flexible containers is among other plastic films, selopan, aluminum foil and paper. To fulfill its functions properly plastic film and aluminum foil and paper in various combinations formed as a multi layer and diextrusion with plastic resin, polyethilen, polypropylene, eva, and so forth, so that it becomes an integral or laminated with specific adhesive.
The combination of these materials, will provide a more complete package than the prosuk. It can be concluded that the materials used are as follows:
Main materials: plastic films, selopan, aluminum foil, metalized films,
paper and so on.
The binder materials: adhesives / adhesive and extrusion of material
Material Helper: among others inks and solvents
The main ingredient :
Paper raw material is widely used in flexible packaging, is one of the essential material. For the foreseeable future,
orientation in order to familiar surroundings, the use of paper in the field of flexible packaging will increase.
There are various types of paper dikenail, with specific properties and with specific applications. The paper is divided into two broad classifications, is cultural papers or fine paper and industrial paper or coarse papers.
Cultural paper: include printing paper, litho paper, artpaper and others.
Industrial paper: among others, kraft paper, manila paper, glassine paper, grease-proof paper and others.
For the purposes of flexible containers, in addition to using paper industries such as kraft paper and glassine paper is also used cultural paper, such as litho paper and art paper. Kraft paper, because it is powerful, flexible containers are widely used in the field, especially as a shopping bag.
Kraft paper used as well in multi-wall shipping bag maker, is also used a lot of paper for flexible packaging is glassine and grease proof paper. The appearance and the special nature of this paper, not because of the addition of additives, but because of the nature of the pulp used.
Aluminum foil occupies an important position in flexible packaging products because it has barriers satisfactory and good appearance. Foil used with a thickness of between 6 microns up to 150 microns in both soft and hard tempering tempering. Soft and hard temper, depending on the composition of the alloy and the treatment of the foil.
Generally, for the benefit of flexible packaging used foil thickness of less than 25 microns. However for certain purposes by example thicker soft tempered aluminum foil that will easily form a dead-fold, and are not easy to come back, and can be shaped as desired.
Foil is no smell, no taste, harmless and hygienic, not easy to make the growth of bacteria and fungi. Because the price is quite expensive, the application of aluminum foil is now widely rivaled by aluminum metalized films. A very thin coating of aluminum, which is carried out in a vacuum chamber, the result is a product that is economical and sometimes function can compete with aluminum foil, in flexible packaging applications and
have a fairly good protection against light, moisture and oxygen.
In general, the application in question include flexible packaging is a plastic film, but the film selopan although not done out of plastic are grouped in plastic film. Foil is defined as a material made of cellophane and a wide range of thermoplastic resins. Films can be made from a variety of ways and processes, which then dicoating, treatment or lamination to obtain a product with a variety of eel physical, chemical, mechanical or electrical.
Certain properties of the film such as tenacity can be obtained by taking the orientation and stretching. Film is widely used, because the barrier properties and resistance to chemicals. Moisture or transimisi gas permeability is the main trait that into consideration in packaging applications. In certain applications the durability of oils and greases are also needed some products, especially food, need transimisi control of oxygen and carbon dioxide gas.
Products such as coffee, tea, potato chips requires good gas barrier, being fresh tomato, cabbage and other products that require respiratory activity, requires permeable film which can release carbon dioxide gas when the breathing process.
Resistance to water vapor permeation and gas permeable of a film can be reduced by increasing the thickness of the film, or by coating with other materials, or laminated with another film or foil.
The physical properties and chemistry are important and taken into account in selecting a product is density, tensile strength, burst strength, impact strength and stiffness.
Besides the above properties, which need to be taken into consideration is dimensional stability, resistant to UV rays, heat seal range flameability, machine ability, gloss and transparency. And printability is important in packaging applications. Selopan in the form of nitro cellulose or polymer coated and other coated rather easily printed. While others require special treatment in the printing process.
Polyolefin to be easily printed once held corona treatment process, nylon, and polyester can be molded easily but require special ink. The film used in packaging
also called polymer, which has a long molecule that is sometimes a combination of monometer between 1,000 and 2,000 units.
Polymerization process can occur over such a process in the making selopan. Average for the plastic film also known as polymer synthesis. In this process, small molecules, called monometer joined together into long chains then called polymerization.
The process of making the film of resin through several stages, there is a simple no rather complex. Steps to be taken are as follows:
Polymer feeding – melting – mixing – metering – filtration. Process vary depending on the characteristics of each resin used.
Production of plastic films is usually a uniform width, the physical properties of a stable, free of bubbles and unwanted color. The process can be carried out in a device simple or sophisticated equipment. Some examples of the plastic film makers can be described as follows:
This process is widely used in the manufacture of PVC and polyurethane films. Is a process of continuous extrusion operation is carried out through a pair of roll cylindris.
Blown-Bubble Extrusion Process
Is an extrusion process that is widely used in the manufacture of polyethylene and polypropylene films. Film diextrude upward through a tube, which is cooled by air is blown, rolled in a roll films tubulais dislit and separated.
Flat Film Extrusion Process
Polymer diextruder through a flat die, chill roll kesuatu which then rapidly cooled. This process is called extrusion casting, and the resulting film is called cast films. Disadvantages film through this process is only pulled in one direction, and the ability less good machine, especially in the transverse direction.
Particular film can be fixed nature by means of temperature-controlled orientation. The result is a better quality films.
Cellophane is a film made of cellulose pulp. Alkali cellulose is reacted with carbon disulfide and dissolved in caustic soda to obtain viscose, and then go through some process obtained cellophane films.
Film can be used in the form of plastic or dicoated with a variety of materials to obtain several properties acquired for a particular application. Cellophane can hold UV light, therefore for UV sensitive products, using colored cellophane. Cellophane has a broad sealing range.
The film is widely used in the packaging of the film than the others, and therefore the lowest cost compared to other films transparent, chemical power resistantnya good enough, and sufficiently resilient to moisture, but the resistance to the penetration of gas is less good.
The surface of polyethylene is non-polar, so it is not easily printed. To have held corona treatment before printing so that the ink can be attached, because it is colorless odorless, widely used for the packaging of food and medicine. Known for their High Density Polyethylene – HDPE and LDPE or Low density Polyethylene.
Created by blown extrusion or casting process oriented PP film can be made or not oriented. Biaxially oriented PP films provide the greatest yield compared to other films. PP copolymer films can make films with heat sealability and good machineability. Coated film can be made with a layer of polyethylene or laquer.
PP films have resistance or more on penetration of gas and water vapor than PE film. Besides the films mentioned above is pretty much known for several other films in the application of flexible packaging. Polystyrene films, films made by stretching a controlled temperature to obtain the appropriate product in flexible packaging applications.
Polyvinyl Chloride Film
PVC can be made via extrusion coating or blown. Some formulations of PVC can be used for food applications, but need rigorous testing to get food grade standard.
Additionally known their nylon films, polyester films have better resistance to temperature. Widely used for boiling or retort bag bag in packaging applications.
Enhancement Pack Flexible
Film sheets to be used as a packaging material, tied with the extrusion coating and lamination. Bolted into a heat sealable layer, can be integrated with other parts, then closed and there was protection of the product contained therein.
The closing process / packaging can be done manually, semi-manually or in masinal. The film will use its binding aided by coating or lamination.
Coating is the process to improve the properties of the film used protection against moisture, gas and others so that the material used for the coating can be thermoplastic or synthetic materials such as lacquer.
The binding process which occurs on two surfaces together, have two different mechanical principle. When the surface of the film is rather porous, the liquid medium will conduct penetration to the substrate, and take place by adhesive filling the molecular length. Occurs physical bond between the two materials. This method is referred to as a physical adhesive or mechanical adhesive. When the surface of the film is flat, and the surface does not go through, then the binder mechanism somewhat different. Then the binding force depends on the molecule is usually called specific adhesive and adhesive. The most popular in packaging applications is extrusion coating and hotmelt coating.
Extrusion is the process of bonding thermoplastic material aligned in a liquid state above a substrate. In this process which is widely used as a medium is LDPE. In addition to the coating process, the binder held lamination process. Known for their wet lamination and dry lamination, and solvent-free process.
In the dry lamination process, the bonding process applied to the sheet film and dried before put together by pressure and heat.
That need attention in the binding process are heat seal strength. The seal strength, can occur immediately tied up while hot, or it may wait a while until they are cold. Seal strength that occurs when the heat is still called hot tack. Hot Tack important if charging towards products that are rather heavy, or the use of machinery
filling the vertical. The bond between layers of multi-layer films, his strength is called bonding strength.
Label and Tape
Label and tape is a product of flexible packaging. The label is an important part of something packaging. The main purpose of the label is to identify the name of a product quantity of the product and the name of the manufacturer. In addition can be explained that the label can explain the essential ingredients contained in the products can also be explained handling of the product that is not easily damaged.
The role of the label as well as a means of advertising and sales promotion. The sale value of a product can be increased several-fold as a result of the proper design of something the label. The application process of the label, means implement the communication function of the packaging, where the content can be identified, and consumers are stimulated to buy, and by this means can be held reasoning about the provision of materials and consumer protection obeyed or not.
In some cases the label of a product can be dipalikasikan directly on the container, through the printing process, screen printing, hot stamping and in mold labels. But in this discussion will be more emphasis on the loose label that is in any form is then applied to the container or bag.
Labels can be obtained in several forms depending on interests. Labels can disupplai in the form of cut or roll, and applied manually or by machine. Most of the raw materials most used are paper, for printing quality, flexibility and price considerations.
Various types of paper and coated or Tisak, can be used for various applications. Foil paper is often also used in conjunction with the nature protection and the sales appeal of foil. Film or plastic label used for such purposes, especially in cosmetic products, gift items and specialty items.
Labels can be printed by any basic printing process, letterpress, offset and flexography generally is a process that is widely used. That the above process provides an economical price and can be done for short-run products. Process gravure economical only for products long run only. Hot stamping and screen printing is only applied to things that are special only.
Varnish or synthetic coating is used as an overprint on the label, so that moisture resistant and improve appearance.
Some Type Label
Glued generally go round label on the label is simple and typically paper, cut to the desired size, adhesive can be applied either at the time of use or time of manufacture, and the adhesive is activated by rinsing water in the container to be used.
Thermosensitive labels, have a thermoplastic coating and applied by the manufacturer, and is activated by applying heat when in use. In general, these products are more expensive than the Glued labels but simpler applications, and high speed can be achieved.
Self ahesive (pressure sensitive) labels in supply in the form of raw materials to be printed, and rolled up and removed with the help of release paper and coating material. Materials that have been printed can be released from this bond will be used soon after.
On the supply in sheet or roll form. Although more expensive operating costs more economical.
Shrink label: general gravure printed on raw materials PVC Shrink. Once printed, molded into the sleeve, then put kedapalam bottles and heated in the shrink tunnel.
Forms of Flexible Packaging
A packaging process is an activity that replaces the handwork. Products that had been held by the hand, charged out of the activity, isolated from outside influences and from secured from possible runoff. Almost all products can be injured as a result of external influences, and this destruction process can be avoided by using the proper packaging.
A few centuries ago flexible packaging, be feasible by allowing the use of paper let alone the price to be quite economical.
Packaging materials can be obtained in rolls or sheets, depending on their needs, and even extruded films in a limited form, then dicut and seal in its application.
In the practice of flexible packaging are widely used is the bag / pouch for products that are not easily stacked, or has the shape of various kinds is appropriate to use as a packaging bag. This product is the only prefabricated containerized
leaving one side open, to be closed after filling. The packaging is produced through an automatic machine reel in a limited form, then closed one side and cut into different shapes according to the application. For applications that are widely used automatic machines.
Packaging field of pharmacy
Strip packaging is a packaging technique that has lasted more than a quarter century. All solid form including general pharmaceutical pills, tablets, capsules, lozenges, packed with this system. But the most common use of this method is tablets and capsules.
The method is packed with two layers up / down, and then sealed and cut. The selection of the material to be precise, so there is no migration of the products out. Products will fall into a hot mold, then molded packaging and facilitate the product. Size and depth of the mold must be sufficient to accommodate the product and form a pocket, and do not get depressed product. It must be checked that the heat seal is effective.
Blister pack: in this process is a thick plastic sheet is passed on the rollers that had been heated, to be terbentu space to be filled product. Items will be packaged and then released through happer, then sheets of foil that has been dicoat with laquer used to cover the plastic sheet that has been formed and contains the product and in the cut. Strip formed in the tray, dicut suitable mold and placed in a cardboard box.
Bulk packaging product
To pack the goods that quite a lot or bulk material are used, multi-wall paper sack. Heavy duty polyethylene bag, woven sack polipropylene and jute bags, jute bags but now it has been less popular. Multiwall paper sack: it consists of several layers of paper that support each other, thus the load supported by the bag will be evenly distributed throughout the layer. The number of layers can be between 2 to 6 layers. By using several layers of paper rather thin is more flexible and powerful than using one or two layers of thick paper. Multiwall paper bag can be used for a variety of products mainly in the form of powder.
Heavyduty polyethylene Bag
First commercial use of polyethylene bags occurred in 1958 for packing fertilizers size 25 Kg. Materials used about 250 microns thick, but with the development of technology, with the same strength, the thickness of which is used less than 200 microns. And another grade that is used not only C4 but the C6 and C8, the advantages of this product is waterproof.
Plastic woven bag
Woven bag made of tape porylene are then sewn and shaped like fabrics and bags made of cloth, and then used a linear PE, causing waterproof woven sack.
Pack a snack food
Snack food market share in the United States: US $ 25 billion, while the food was tasty approximately 40% or US $ 10 billion. The value of flexible packaging used approximately 20% of total production costs. For savory foods as potato chips have a share of about 50%. In order to snack producer huge competition using multiple converters, with each task print different creations as a business promotion.
The enthusiasm of consumers, more regional character and includes the design of the paper used. Although some of the major employers in the field of snack food, operates from several regional plant in the whole country, but maintains the distribution network is relatively short, and requires a shelf life up to six months. For small and medium businesses, has a larger market share, with a shelf life of 20 days up to 40 days. The market share of large employers +/- 20%.
In the development of the snack food market consumers sometimes rather quickly saturated. Therefore necessary ideas and innovation to produce various kinds of products in small lots, to anticipate market demand. And that is important in the effort mengdiversifikasi packaging without damaging the product image.
Various kinds of functions have to repair, protection and preservation of the products, packaging operations, sanitation and economics.
Packaging fruit and vegetables
After harvesting physologi functions like breathing in fruits and vegetables is still ongoing. One way to preserve the product, are controlled atmosphere (CAJ) preservation method. In this way, the gas that is in the product environment
controlled at low temperatures, reduce the levels of O2 and CO2, to control breathing and to maintain the quality of the product for long periods of time.
When fruit is packed in polyethylene bags, the air composition in the package would change the breathing excessive, wrinkled fruit and fruit such as product value will decline. When the levels of O2 increases, the color of the fruit changes, and when the CO2 level increases, the flavor will change.
Low density polyethylene film with a thickness of less than 20 micron somewhat tolerable for packaging vegetables, due to the high permeability to gases and water vapor. However difficult to apply, the film is rather fragile and easily torn.
According to research high-density polyethylene with a thickness of 10 microns has given satisfactory results in the packaging of citrus fruit. There should be more research into the application of packing fruits and vegetables as a method CA, using LDPE and HDPE films faced humidity is quite high in Indonesia.
Today the flexible packaging is the main alternative in the packaging of coffee powder, sei terms of price, weight and space consumed. At the time of roasted coffee beans still contains CO2 gas trapped inside. During the third ground into powder CO2 immediately evaporates, was third again for about 45 minutes apart from the coffee powder bond.
Within Tisak too long, the product must be packed in tightly, to avoid the intervention of oxygen gas would react with konstituer of coffee aroma that will generate unpleasant taste.
During the process before it is packaged, a small portion of coffee aroma evaporates joined together with CO2 gas. which required attention in coffee packaging is to avoid the problem of oxygen gas into the product. And boxed the recommended heat sealed laminate, PET / PE / aluminum foil / PE.
Polyethylene is used as a heat seal layer. Aluminium gas barrier role. Average polyester film than as a tough outer layer, in order to avoid leakage, also serves as a gas barrier. Before packaging should be cooled in a stream of fresh air, to reduce the amount of CO2 trapped.
Upon consideration of costs, the aluminum foil is usually replaced with metalized PET while LDPE LLDPE is replaced with boxed in order to obtain a more robust, being a good heat seal, LLDPE mixed with LDPE.
Manufacturing of retort food, consisting of equipment to utter product, filling and sealing machines and equipment retort.
Setup Boxed retort pouches can be in the form of fabricated or, pouches filled and formed in the engine of the film stock. Basic materials used for this product to be a packaging material that is heat resistance.
The material generally used is a wide variety among other variations of compositions of aluminum foil, polyester, polyprolylene, polyvinylidence chloride and vinyl acetate copolymer. For the packaging of relatively large, typically using four layers and should withstand a drop test.
Standing pouches typically use aluminum foil but also with a four-layer laminate. Standing pouches that do not use aluminum foil, using a polyester film for the outer layer to improve the position of self standingnya. For adhesive and others many cases using a polyurethane type adhesive. Semi-rigid container using aluminum foil laminated with polypropylene and epoxy resin as a protective coating. Being similar in composition to the container lid. Lid iniharus made easy-open.
Baca juga : Jual Mesin Kemasan Plastik
The stability of the product with Flexible Packaging
The influence of water vapor on the packaging
Therefore, the water vapor is above this, each product is either packaged or in the free, moisture content therein. The moisture content is defined as the weight amount of water contained in the material and is described as a percentage of the weight of the material in a state of free water.
Each water levels of something material, varies with the state of humidity of the room, where the material already has a balance. The air at a certain temperature, will contain water in the form of water vapor. When the amount of water contained is a maximum, said vapor pressure is saturated. But if abortion is not the maximum, then the water vapor is called relative humidity. Relative humidity moisture content, which amount than when in a state of lower saturated and otherwise
in percentages. If the room does not have a relationship with other sources of water vapor, the temperature increase will cause the relative humidity to fall, due to the increased temperature the room is able to contain more water vapor, otherwise when the temperature decreases, the relative humidity will increase. When the air in contact with hygroscopis material, such as paper and bread, the quality improvement resulting in decreased H.R. diatmosphere surrounding material, resulting material releasing water content, while the new balance will be reached between the material and the atmosphere.
The balance value for each material varies in content of water vapor, as an example in the paper will contain 8% of water vapor in equilibrium with air on H.R. 65%. When the air cools and the balance going on H.R. 80%, then the paper will absorb moisture more so for the balance and the water content of paper money will be 12%.
But when the temperature rises so the balance in 48% H.R. then the paper will contain water vapor 7%. When the open air the material would absorb or release water vapor, the space inside the enclosed space in the packaging will happen the same thing. Water vapor will penetrate the barrier contained in the packaging, and Relative Humadity that occurred in the packaging, called the Equilibrium Relative Humidity (EHR).
When packing with the EHR concept placed in the atmosphere that has R.H. higher than ERH, then the packaging will absorb moisture. The opposite will occur when the container is placed in the atmosphere is lacking.
Protection against moisture, one of the factors that influence on shelf life of a product. The durability of the packaging for the protection of water vapor to note: By slowing the water vapor from the air into the packaging, the product deterioration can be delayed due course. If the quality of the packaging is appropriate, then the product will be used at the right time. Barrier does not have to be perfect all the product can be maintained as far as the extent of the expected usage time.
The amount of water contained in a wide variety of food will vary according to the condition of the environment, and the water content in certain procentase will not affect the product something. For example on something biscuit will contain limited to 2% of water when finished cooking, and there will be the effect on consumers.
Sugar will not absorb moisture from the air when the moisture content is lower than 85%. The above content of sugar will absorb water from udaara until melted.
Penetration of oxygen gas into the packaging, will give unwanted consequences on the product being packaged, for products containing oil will oxidize. It is important to keep the penetration of oxygen into the packaging as small as possible because the oxygen in addition to a role in the oxidation of the parts of the product, it will also help the development of bacteria and fungi.
Fats and oils derived from vegetable contained in food, is very sensitive to the influence of oxygen gas. When the vegetable fat disensitif by the influence of sunlight, which is the active part will be formed by absorbing oxygen gas. The result will be formed peroxide is unstable and turned into a more stable aldehyde, which will change the nature and flavor of the fat and mnyak will become rancid.