Peelability

For skin packaging, ionomer films provide outstanding protection, especially for sharp objects. Films can be drawn down tightly around regular shapes without penetration. Characteristics of heat seals can be adjusted so that convenient peelable seals are obtained (31—35). 

The finished outer surfaces of the assemblies may be coated with a peelable coating compound which can be easily sprayed and air dried. The coat forms a translucent peelable film, suitable for protecting the finished surfaces during assembly, transportation and installation from scratches, oil marks, grease and dirt etc. The film can be neatly stripped after the equipment is finally installed. Approximate spraying data are ... 

Peelable film in case-ready ground beef package add color and shelf life. As an example Cryovac Div. of W. R. GRACE CO uses a peelable barrier lid and foam tray system. It is two packages in one there is an oxygen barrier structure, which is peeled off, leaving an oxygen-permeable film over the meat. 

The incompatibility between polybutene and polyethylene is used to make peelable film seals. 

EthyPharm, disintegrating based, taste Peelable opening... 

TPX shows an excellent peelability from a wide variety of materials. Therefore, TPX is used in applications in that separating properties are important. For this reason, it can be used as a release material in the process of curing thermosetting resins. In Table 4.4, the separating force expressed as surface tension of various materials against an epoxy resin are shown. 

PB film is usually made by the blown film process, but also can be cast oil drill lolls. Film applications include food and meat packaging, compression wraps, and hot-fill containers. The material can be formulated to provide a wide range of seal strengths for peelable or easy-opening packaging. 

The other major uses of acrylic latexes are in textile finishing (e.g., stain and wrinkle resistance), adhesives, and floor polishes and waxes. Adhesives are used in many applications, including pressure-sensitive tapes, contact adhesives, and construction adhesives for carpeting and floor tiles. Peelable labels and stamps probably got their start with the Post-it note, invented by Spencer Silver and Art Fry at 3M company many years ago. 

Pkotocurable materials for photographic films contain pentaerythritol and dialkyiamino and/or nitrile compounds, which have good adhesion and peelability of the layers, and produce clear transfer images (97,98). 

Cereal box liuers Film HDPE/auhydride modified PE/EVOH/auhydride modified PE/peelable adhesive bleud with iouomer or EVA... 

Flexible medical packaging is well suited to SBC for use in form, fill and seal machines. SBC have excellent formability, which allows for nearly perfect replication and filling of molds. To make a peelable seal, the SBC would need to be co-extruded with a lower melting substrate to act as the adhesive layer. The SBC structure provides good web formability and good toughness. It then has the versatility to be sterilized by 7-radiation, ethylene oxide or electron beam. 

Drenching, spraying or dipping are also commonly used methods for applying liquid smoke to the surface of meat products. Provisions for smoke application are located at the entrance of the oven in the first section or zone of the system. As the stuffed product enters the oven, it is conveyed through a shower of liquid smoke that totally wets the surface of the product. The liquid smoke not only acts to produce a uniform colour but it also contributes to skin formation on the product surface through coagulation of protein. This in turn aids peelability. 

Aluminium overcaps may have a perforated metal, plastic fhp-off or peelable foil cover. Figure 6.21 shows typical combination and conventional seals. Vials have also been introduced for unit dose packs using either an aluminium two-piece tear-off closure with a Saran coated pulpboard liner or a peel-type seal. 

Finally, containers can be diaphragm sealed using heat (including induction sealing) or adhesive either as the sole closuring means (i.e. peelable tops for unit dose preparations) or in conjunction with any of the other closures previously mentioned. Diaphragms can be a useful means of forming a tamper-evident seal, e.g. used in conjunction with a child-resistant closure. 

Polybutylene is another new member of the polyolefin group, being similar to polyethylene but exhibiting better tensile strength. It is frequently used blended with polyethylene or polypropylene to modify the properties of films, i.e. to give a controllable peelable seal, and a good future as copolymers is predicted. 

In some instances the heat seal ply of a lamination has to be peelable. These should be checked for peel strength over the shelf life of the product as in some instances the peel strength may reduce and so jeopardise the seal or increase it to a point where a permanent non peelable seal is obtained. The use of pattern lacquers also assists peelability. 

A later type of formed container was made by using matched male and female dies with sufficient clearance between them to permit the metal to slip and form wrinkles rather than be stretched. A much greater versatility in shape is available in this container. Smooth drawn flanged containers which accept a peelable lidding have been used for unit dose packs of liquids and semi-liquids. These packs may be lacquered or unlacquered. 

Pharmaceutical blister packs are mainly used with a foil lid which may be pushthrough (as used in Europe) or peelable (as used in the USA). Push-through foil lidding is made from either hard foil (15-20 Pm) or soft foil (25 Pm). Laminations using these may also be used to increase child-resistance. 

Seals may be permanent, semi-permanent, or peelable. Peelable systems usually consist of ethylene copolymers, possibly modified with polyethylene, or other films, lacquers or dispersions. Some are resealable, hence are not strictly tamper-resistant. Cold seals, typically based on a rubber latex, are usually non-resealable. These may employ the cold seal only in the area of the seal, hence avoiding any or limited product contact. Pattern systems are widely used for surgical materials and instruments. 

Ease or difficulty of opening depends on the properties of the materials, the design and seal pattern. Polyester, Nylon and polypropylene may give rise to difficulties, hence it may be necessary to incorporate a propagation aid feature such as a V-shaped notch, a cut or slit. The other alternative is a peelable seal. The seal strengths of permanent and peelable seals are measured by a similar process. 

With glass the contact ply depends on whether the glass is treated or untreated and whether the product is dry or wet. In certain circumstances special treatments may be necessary to give either a weld or peelable seals. 

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