Carton sealing

Sealed carton -as tamper-resistant package form [PACKAGING - COSMETICSANDpHARMACEUTICALS] (Voll7)... 

The range of applications includes sealing cartons, bonding packaging films and laminates, fabrications for the motor industry, and applying veneers to chipboard and plywood. 

Is it to be label, a specially designed sealed carton or perhaps watermarked paper or board, chemically marked paper or board security inks, holograms etc. In a large proportion of the potential methods of protection you will need to ensure that the device, print, etc. actually permanently adheres to the substrate. 

It is vitally important that the adhesion between the security system and the final substrate cannot be breached by any means without leaving conclusive easy to see evidence. It is no use using a hot melt adhesive, which can be reheated and allows either a label to be removed and a pass off put on or a sealed carton to be opened. More harm than good may be done with such a system. 

Sealed carton—all flaps of a carton are securely sealed and the carton must be visibly damaged when opened to remove the product. 

Cartons from corrugated board are most often sealed with liquid glues or hot-melt adhesives. However, dextrin adhesives are still used as a result of their low cost and ready availability. Adhesives for sealing cartons must have low and stable viscosity, be able to form strong bonds, and set up quickly. If staining of the carton is not a concern, sodium hydroxide may be added to increase adhesion. A formulation for a white dextrin adhesive is given in Table 5. 

Rigid Film Tapes. Cellophane is the oldest transparent tape backing. It is fairly strong and transparent and is widely used to fasten package wrappings, to seal cartons, and... 

Dextrins are frequently formulated with borax, sodium metaborate, boric acid, or caustic in different proportions to give good tack and higher stable viscosities at moderate concentrations. The pH of the formulations is about 9.0 in most cases. Borated dextrins find use in case sealing, carton sealing, tube winding, and laminating. 

A small quantity of flexible packaging material, usually oriented polypropylene, shrink polypropylene, or polyethylene, is used to overwrap paperboard cartons. The film is wrapped around the carton and sealed by heating. Products such as boxed chocolates, candies, and cookies are overwrapped, sometimes by a printed film. 

Where folding cartons are to contain a product which is sensitive to moisture pickup, barriers are available which can be incorporated into the carton construction. An example of this is polyethylene laminated to paperboard. In some cases an insert bag is used instead, but this requires an additional operation and is usually accomplished by a form-fill-seal machine that makes a bag which is then inserted by another machine into the folding carton. 

Carton sealing is carried out automatically by adhesives, tape, or staples or manually by tape or staples. Carton closer-sealers have... 

Case and carton sealing is a high volume application for hot melt adhesives. Typical formulas use 20-30% wax, 25-40% polymer, and 35-55% tackifier resin. The basic requirements for packaging adhesives will be described followed by formulating guidelines for specific market areas. The focus of this discussion will be on EVA and EnBA-based systems, which are the most common. 

We use extrusion coating to apply thin layers of polymer to the surface of non-polymeric substrates such as cardboard or aluminum foil. Extrusion coated materials are extensively used in food packaging. Products include the coated cardboard used to make milk cartons and the coated aluminum foil used to seal dairy product tubs. The process of extrusion coating has much in common with film casting. 

The coating of polymer that we put on paperboard serves two purposes when we convert it into juice and milk cartons. It prevents the contents from leaking out and it acts as an adhesive so that we can heat-seal the coated paperboard to itself to form a container. Low density polyethylene is the polymer of choice for this application it has sufficient melt strength to... 

Hot melt adhesives based on poly(3HB-co-3HV) have also been described [119]. Hot melts are commonly used in bookbinding, bag ending and case and carton sealing and are mostly based on synthetic materials such as polyethylene, polypropylene ethylene-vinyl acetate and styrene block copolymers [119]. Hot melts based on PHAs alleviate the dependence on petroleum based materials and allow the development of biodegradable alternatives based on natural raw materials. 

Carton liners, industrial liners, bin liners Heat sealing... 

There are a number of well-established systems for the aseptic packaging of liquids. Notable among these are those packs constructed, box form, in situ on the filling line from a cardboard, aluminium, plastic laminate sheet, such as TetraPak or Combi-box. In the TetraPak system, the packing material enters the filling machine from a feed roll the sheet contact surface is sterilised with warm hydrogen peroxide solution it is formed into a tube, and its lower end is heat-sealed across the width the tube is filled, sealed at the upper end, cut and then folded into a box shape. This produces a continuous output of filled cartons with premium utilisation of bulk storage capacity. 

Various alternative configurations can be used, and in particular some manufacturers employ non-aseptic form-fill-seal operations which usually produce either in-line cup packs or cartons such as TetraPak or Combibloc packs. 

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