• Vacuum Formed Packing Trays

    Custom designed moulds which are suitable to insert the customer's products are formed using Plastic sheets such as Rigid PVC, APET, HIPS, HDPE and ABS.


  • Blister Packing

    A transparent sheet of PVC/APET sheet is formed in the shape of the mould, then cut to shape and given to the customer for heat sealing of their products.


  • Material Handling Trays

    Vacuum formed trays from Thick Plastic sheets are used by customers to transport products within their factory or from one factory to another


Products
Products Photo Gallery



Blister Packaging using Thermoforming Technique

Blister pack is a term for several types of pre-formed plastic packaging used for small consumer goods, foods, and for pharmaceuticals.

The primary component of a blister pack is a cavity or pocket made from a "formable" web, usually a thermoformed plastic. This usually has a backing of paperboard or a "lidding" seal of aluminum foil or plastic. A blister that folds onto itself is often called a Clamshell.

Thermoforming is a manufacturing process where a plastic sheet is heated to a pliable forming temperature, formed to a specific shape in a mold, and trimmed to create a usable product. The sheet, or "film" when referring to thinner gauges and certain material types, is heated in an oven to a high-enough temperature that it can be stretched into or onto a mold and cooled to a finished shape.

In its simplest form, a small tabletop or lab size machine can be used to heat small cut sections of plastic sheet and stretch it over a mold using vacuum. This method is often used for sample and protoype parts. In complex and high-volume applications, very large production machines are utilized to heat and form the plastic sheet and trim the formed parts from the sheet in a continuous high-speed process, and can produce many thousands of finished parts per hour depending on the machine and mold size and the size of the parts being formed.

Thermoforming differs from injection molding, blow molding, rotational molding, and other forms of processing plastics. Thin-gauge thermoforming is primarily the manufacture of disposable cups, containers, lids, trays, blisters, clamshells, and other products for the food, medical, and general retail industries. Thick-gauge thermoforming includes parts as diverse as vehicle door and dash panels, refrigerator liners, utility vehicle beds, and plastic pallets.

In the most common method of high-volume, continuous thermoforming of thin-gauge products, plastic sheet is fed from a roll or from an extruder into a set of indexing chains that incorporate pins, or spikes, that pierce the sheet and transport it through an oven for heating to forming temperature. The heated sheet then indexes into a form station where a mating mold and pressure-box close on the sheet, with vacuum then applied to remove trapped air and to pull the material into or onto the mold along with pressurized air to form the plastic to the detailed shape of the mold. (Plug-assists are typically used in addition to vacuum in the case of taller, deeper-draw formed parts in order to provide the needed material distribution and thicknesses in the finished parts.) After a short form cycle, a burst of reverse air pressure is actuated from the vacuum side of the mold as the form tooling opens, commonly referred to as air-eject, to break the vacuum and assist the formed parts off of, or out of, the mold. A stripper plate may also be utilized on the mold as it opens for ejection of more detailed parts or those with negative-draft, undercut areas. The sheet containing the formed parts then indexes into a trim station on the same machine, where a die cuts the parts from the remaining sheet web, or indexes into a separate trim press where the formed parts are trimmed. The sheet web remaining after the formed parts are trimmed is typically wound onto a take-up reel or fed into an inline granulator for recycling.

Most thermoforming companies recycle their scrap and waste plastic, either by compressing in a baling machine or by feeding into a granulator (grinder) and producing ground flake, for sale to reprocessing companies or re-use in their own facility. Frequently, scrap and waste plastic from the thermoforming process is converted back into extruded sheet for forming again.

Vacuum forming (vacuuforming), is a simplified version of thermoforming, whereby a sheet of plastic is heated to a forming temperature, stretched onto or into a single-surface mold, and held against the mold by applying vacuum between the mold surface and the sheet. The vacuum forming process can be used to make most product packaging, speaker casings and even car dashboards.

Normally, draft angles must be present in the design on the mold (a recommended minimum of 3), otherwise release of the formed plastic and the mold is very difficult.

Vacuum forming is usually - but not always - restricted to forming plastic parts that are rather shallow in depth. A thin sheet is formed into rigid cavities for unit doses of pharmaceuticals and for loose objects that are carded or presented as point-of-purchase items. Thick sheet is formed into permanent objects such as turnpike signs and protective covers.

Relatively deep parts can be formed if the form-able sheet is mechanically or pneumatically stretched prior to bringing it in contact with the mold surface and before vacuum is applied.

Suitable materials for use in vacuum forming are conventionally thermoplastics, the most common and easiest being High Impact Polystyrene Sheeting (HIPS). This is molded around a wood, structural foam or cast/machined aluminum mold and can form to almost any shape. Vacuum forming is also appropriate for transparent materials such as acrylic which are widely used in applications for aerospace such as passenger cabin window canopies for military fixed wing aircraft and "bubbles" for rotary wing aircraft.

Usage

Unit dose packaging of Pharmaceuticals:
Blister packs are commonly used as unit-dose packaging for pharmaceutical tablets, capsules or lozenges. Blister packs can provide barrier protection for shelf life requirements, and a degree of tamper resistance. In India, blister packs are mainly used for packing physician samples of drug products, or for Over The Counter (OTC) products in the chemist shops. In other parts of the world, blister packs are the main packaging type since pharmacy dispensing and re-packaging are not common.

A series of blister cavities is sometimes called a blister card or blister strip as well as blister pack. In some parts of the world the blister pack is known as a Push-Through-Pack (PTP). The main advantages of unit-dose blister packs over other methods of packing pharmaceutical products are the assurance of product/packaging integrity (including shelflife) of each individual dose and the possibility to create a compliance pack or calendar pack by printing the days of the week above each dose. Blister packs also hinder the use of OTC drugs in the manufacture of illegal drugs.

Blister packs are created by means of a form-fill-seal process at the pharmaceutical company or designated contract packer. A form-fill-seal process means that the blister pack is created from rolls of flat sheet or film, filled with the pharmaceutical product and closed (sealed) on the same equipment. Such equipment is called a blisterline.

Consumer goods:
Other types of blister packs consist of carded packaging where goods such as toys, hardware, and electrical items are contained between a specially made paperboard card and clear pre-formed plastic such as PVC. The consumer can visually examine the product through the transparent plastic. The plastic shell is vacuum-formed around a mold so it can contain the item snugly. The card is brightly colored and designed depending on the item inside, and the PVC is affixed to the card using heat and pressure to activate an adhesive (heat seal coating) on the blister card. The adhesive is strong enough so that the pack may hang on a peg, but weak enough so so that the package can be easily opened (in theory). Sometimes, with large items, the card has a perforated window for access.

Clamshell:
A hinged blister is known as a clamshell, used for a variety of products. It can be used as a security package to deter package pilferage for small high-value items, such as consumer electronics. It consists of one sheet folded over onto it and sometimes fused at the edges. They can be securely heat sealed, making them difficult to open by hand to deter tampering. A pair of scissors or a sharp knife is often required to open them (although these are often sold in similar packages). Care must be used to safely open some of these packages.

Medical Blister:
Medical Blister trays differ from Pharmaceutical blister packs in that these are not push-through packs. The thermoformed base web is made of a thicker plastic sheet, generally between 500 to 1000 and cannot be collapsed, thus forming a solid tray. The lidding film provides a peel-open feature and is generally porous to allow sterilization. Such medical blister packs are used for medical devices, used in hospitals.

Raw Materials Use

PVC (Polyvinyl Chloride):
The most basic material for the forming web is PVC or Polyvinyl Chloride. The principal advantages of PVC are the low cost and the ease of thermoforming. The main disadvantages are the poor barrier against moisture ingress and oxygen ingress; moreover PVC has a negative environmental connotation due to its chlorine content.

In the case of blister packaging the PVC sheet does not contain any plasticizer and is sometimes referred to as Rigid PVC (RPVC). In the absence of plasticizers, PVC blisters offer structural rigidity and physical protection for the pharmaceutical dosage form.

On the other hand, the blister cavity must remain accessible by the push-through effect and the formed web may not be too hard to collapse when pressed upon; for this reason the PVC sheet thickness is typically chosen between 200 to 300 depending on the cavity size and shape.

Most PVC sheets for pharmaceutical blisters are 250 or 0.250 mm in thickness. Typical values for the Water Vapor Transmission Rate (WVTR or MVTR) of a 250 PVC film are around 3.0 g/m2/day measured at 38C/90%RH and the Oxygen Transmission Rate (OTR) is around 20 cc/m2/day. In order to overcome the lack of barrier properties of PVC film, it can be coated with PVDC or laminated to PCTFE or COC to increase the protective properties.

Multi-layer blister films based on PVC are often used for pharmaceutical blister packaging, whereby the PVC serves as the thermoformable backbone of the structure. Also, the PVC layer can be colored with pigments and/or UV filters.

The European Pharmacopoeia (EP) references the requirements for PVC blister packs for pharmaceutical primary packaging in the monograph EP 3.1.11 "MATERIALS BASED ON NON-PLASTICISED POLY(VINYL CHLORIDE) FOR CONTAINERS FOR DRY DOSAGE FORMS FOR ORAL ADMINISTRATION".

In order to be suitable for pharmaceutical blister packs, the PVC formulation also needs to comply with the US Pharmacopoeia <661>; EU food legislation; US 21.CFR and Japanese food contact requirements.

PET (Polyethylene terephthalate):
PET is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination with glass fiber.

Because PET is an excellent barrier material, plastic bottles made from PET are widely used for soft drinks (see carbonation). For certain specialty bottles, PET sandwiches an additional polyvinyl alcohol to further reduce its oxygen permeability.

Biaxially oriented PET film (often known by one of its trade names, "Mylar") can be aluminized by evaporating a thin film of metal onto it to reduce its permeability, and to make it reflective and opaque (MPET). These properties are useful in many applications, including flexible food packaging and thermal insulation, such as "space blankets". Because of its high mechanical strength, PET film is often used in tape applications, such as the carrier for magnetic tape or backing for pressure sensitive adhesive tapes. Non-oriented PET sheet can be thermoformed to make packaging trays and blisters. If crystallizable PET is used, the trays can be used for frozen dinners, since they withstand both freezing and oven baking temperatures.

When filled with glass particles or fibers, it becomes significantly stiffer and more durable.
    Copyright 2011 VEL PACK Industriesdesigned by FQI