Page 211 - Biomedical Engineering and Design Handbook Volume 2, Applications

190 MEDICAL DEVICE DESIGN

bottom web material and the chosen sterilization process. The top web material must therefore be
selected on the basis of the following three factors:
• Type of device—environmental or product barrier requirements
• Method of sterilization—gas, radiation, steam
• Method of dispensing—peel, cut, tear, puncture

7.4.3 Flexible Nonformed Pouches
The most common package in this category, and probably for most single-use medical devices, is the
two-web peel pouch. The package form is very common for a variety of medical devices, including
gloves, catheters, tubing, adhesive bandages, dressings, sutures, and other low-profile and lightweight
products. This flat pouch design is suitable for high-volume, low-cost devices as they provide the
basic protection for devices. The most popular form of flat pouch is known as the chevron pouch. It
gets its name from the peak-shaped end of the package where the initial peeling of the seal begins.
This design provides ease of peeling as the peel forces are distributed angularly along the seal line
rather than across the entire seal end. Other forms of the flat pouch can be achieved by forming seals
across the corner of the package, leaving a tab to initiate the peel.
The typical peel pouch used for devices is made from two separate web materials that are heat
sealable or adhesive coated. Since these packages usually contain sterile disposable devices that are
terminally sterilized inside the primary package, a porous material is required for one of the webs.
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Either paper or Tyvek is used as one of the web materials along with a plastic film such as a lami-
nated polyester and polyethylene.
Some of the benefits of the peel pouch are
• Relatively low cost
• Suitable for small-run or high-volume uses
• Can be fabricated from a wide variety of materials
• Can be prefabricated or formed in-line
• Provide a sterile delivery capability
• Product visibility
• Easy opening
• Printable with product information and instructions
Some of the disadvantages are
• Not useful for high-profile devices
• Not suitable for high-mass products
• Low dynamic protection capabilities
• Not suitable for irregularly shaped devices
• Not suitable for kits or multicomponent devices
Another type of peelable pouch is known as the header bag. This package is essentially a two-web
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pouch in which a portion of one web is a peelable Tyvek or paper vent. The header bag provides
high permeability, ease of opening, and convenient product dispensing. An advantage of this pack-
age type is that a basic flexible bag can contain a high-profile device.

7.5 PACKAGING MATERIALS

This part provides a basic overview of some of the more common packaging materials used for medical
device packages. Since entire books are published describing the chemical characteristics, applications,
and performance properties of packaging materials, it is beyond the scope of this chapter to provide all