Material guide

This guide explains terms, not test results. It gives no performance numbers, because performance depends on your device, your package design, and your process. Nominal values are on each product's spec sheet, and we can send the manufacturer's technical data, with test methods, on request. For definitions of individual terms, see the glossary. For which methods suit which products, see the sterilization compatibility chart.

Tyvek® grades: 1073B vs 2FS

Tyvek® is a strong, breathable sheet material. Sterilant gas can pass through it, while it acts as a barrier to microorganisms. Medical packaging uses a few specific grades. We work with two as standard. If your spec calls for another, ask us.

1073B is the heaviest and strongest medical Tyvek® grade. Choose it for heavy or sharp devices, where puncture resistance matters most. Typical applications include orthopedic implants and surgical kits. Our coated Tyvek® die-cut lids are cut from heat-seal coated 1073B.

2FS is a lighter grade. It costs less and suits lighter devices and high-speed form-fill-seal lines.

We supply both grades as coated Tyvek® rollstock for rigid-tray lidding, blister lidding, and flexible pouch stock.

Coated vs uncoated Tyvek®

Uncoated Tyvek® will not heat-seal to a rigid tray on its own. It does seal to films that carry their own sealant layer, such as the PE in PET/PE, which is how most Tyvek® pouches and header bags are made. A heat-seal coating is a thin adhesive layer applied to one side. Under heat and pressure on a sealing machine, the coating bonds the Tyvek® to a rigid tray, a blister or a wider range of films. That is what turns a sheet into a tray lid.

Coatings can cover the whole surface or be applied in a pattern. A pattern coating leaves uncoated areas between the coated ones, so the web stays breathable and gas can still pass through. It also gives a clean, visible peel.

Uncoated Tyvek® is the porous web in most Tyvek® and film pouches and in many header bags, where the film carries the sealant. It is also used unsealed, for loose sheets, interleaves, and components placed inside a package. Our uncoated Tyvek® sheets are cut in our cleanroom in custom shapes up to 30 × 30 in (762 × 762 mm).

Typical properties: Tyvek®

Values are typical, not specifications. We can send the manufacturer's data sheet on request.

Medical paper, coated paper, and cold-seal paper

Paper is a porous, printable, and economical sterile barrier material. We supply three types as rollstock.

Medical grade, on this site, means the material maker supplies and controls the material for medical packaging under its quality system, with ISO 11607-1 material statements, and EN 868 declarations for paper, available on request.

Medical-grade sterilization paper is 100% cellulose, in 60 and 70 gsm (37 and 43 lb). Some grades are made for steam. Others are optimized for EtO and gamma. It acts as a microbial barrier once sealed, heat-seals to the sealant layer of films such as PET/PE, and is free of optical brighteners. Paired with a steam-rated film, paper is the usual choice when a package must go through steam.

Coated medical-grade paper comes in 60, 70, and 100 gsm, with a heat-seal coating so it can seal to trays, films, and blisters. The coating can be applied in three ways:

• Grid: a crosshatch of coated lines, with open areas between them
• Allover: a continuous coating across the surface
• Pattern: coating applied in a defined design

The coating is designed to let the paper peel cleanly from the tray or film, with minimal fiber tear when sealed within the right window.

Latex-free cold-seal paper is 40 gsm (25 lb). It carries a cohesive coating that seals to itself under pressure, with no heat. It suits products such as gloves, dressings, and syringes. The coating is not made with natural rubber latex, and we can share the manufacturer's statement for your file.

Typical properties: medical paper

Values are typical, not specifications. Data for film, foil laminates and HDPE card is also available from the manufacturer's data sheet, on request.

Basis weight in gsm and lb

Basis weight describes how heavy a sheet material is for its area.

• gsm means grams per square meter. It is a direct measure, so values compare cleanly across materials.
• lb figures come from the paper industry. They state the weight of a ream at a set basis size. For medical packaging papers the usual basis is a 3,000 sq ft ream, where 1 gsm is about 0.614 lb. Other paper types use other basis sizes, so always check which ream an lb figure refers to.

For our papers, the pairs are:

For coated Tyvek® rollstock, the stated weights of 71 gsm (2FS) and 86 gsm (1073B) include the coating.

HDPE vs LDPE film, and rigid HDPE cards

HDPE (high-density polyethylene) and LDPE (low-density polyethylene) are both forms of polyethylene. HDPE is stiffer. LDPE is softer and more flexible. We offer medical-grade HDPE/LDPE film for flexible parts and webs. On this site, “HDPE/LDPE film” means a coextruded blend of HDPE and LDPE.

Film thickness is given in µm (micrometers) or mil (thousandths of an inch). Our film runs 28–60 µm (≈1.1–2.4 mil). Header bags use a heavier 100 µm (4 mil) LDPE film for bulky or heavy devices and kits, with a porous header strip that lets sterilant in and out.

Film is not porous. It works with gamma and e-beam. For EtO, film parts go inside a package with a porous side, such as a Tyvek® or paper pouch or lid, and a film web is paired with a porous web, so the gas can get in and out.

Rigid HDPE cards are a different product. They are sheets of 100% virgin HDPE, 10–35 mil (0.25–0.89 mm) thick. They are much thicker than film, and they hold their shape. A card sits inside a chevron pouch or rigid tray to hold and protect the device.

Pouch laminates: PET/PE, PA/PE, PA/Alu/PE

Most pouch films are laminates: layers of different plastics bonded together. The notation lists the layers from outside to inside. The inner PE (polyethylene) layer is the sealant, which melts to form the seal.

Foil is not gas-permeable. EtO cannot reach a device inside a sealed foil pouch, so for EtO the foil package needs a built-in porous vent, such as a porous header or breather patch, that is sealed off after sterilization. Ask us for a vented foil header bag.

Foil pouches are typically radiation-sterilized. They suit sensitive devices, diagnostics, and reagents with long shelf-life needs.

Tray substrates: PETG, HDPE, HIPS, PP, and PVC

A rigid tray is thermoformed from a plastic sheet. Lids seal to the tray's flange. These are the common tray plastics:

• PETG: a clear, tough amorphous polyester (glycol-modified PET)
• HDPE: high-density polyethylene
• HIPS: high-impact polystyrene
• PP: polypropylene
• PVC: polyvinyl chloride

Our coated Tyvek® lids are made to seal to all five, with the coating matched to the tray resin: our standard coating seals to PETG, PVC and HIPS, and HDPE and PP trays take a polyolefin-specific coating. Tell us your tray resin when you order. Polyolefin trays (HDPE and PP) are often the hardest to seal well, so run seal trials early. Seal performance still depends on the tray, the sealing equipment, and the settings you use. Validate the seal on your own tray and sealing equipment before you release a package.

Heat and sterilization limits by material

• Tyvek®: compatible with EtO, gamma and e-beam. Steam only in restricted, lower-temperature cycles (up to 127 °C); ask us before you design around it.
• Polyethylene (HDPE, LDPE and PE sealant layers): softens at or near steam temperatures, so it is generally not used for steam.
• Medical paper: the usual steam choice when paired with a steam-rated film. Generally not suited to hydrogen peroxide processes.
• Aluminum foil laminates: radiation, or EtO only with a built-in porous vent.

Confirm every material in your own validated cycle.

Questions to answer before you choose

• How will you sterilize? Now, and any method you might move to later. EtO needs a porous side; radiation needs materials that tolerate the dose; steam narrows the choice to steam-grade papers with a steam-rated film.
• How heavy is the device, and does it have sharp points or edges? This decides between 1073B and 2FS, PET/PE and PA/PE film, and whether you need a card.
• What will you seal on? A tray sealer, a pouch sealer or a form-fill-seal line decides between die-cut lids, pre-made pouches and rollstock.
• What is the tray made of? The lid coating has to suit the tray resin.
• Does the product need a moisture, oxygen or light barrier, and for how long? If so, look at foil, and plan how EtO will get in if you use it.
• Who opens the package, and where? Gloved hands in an operating room need a tab or chevron that starts easily.
• What must be printed? Lot, expiry and symbols may decide between a printed lid or pouch and a label.
• How many do you need now, and at launch? Small first runs suit die-cut parts; a move to form-fill-seal changes the format and needs its own validation.

Still choosing?

Answer a few questions in the material selector to see which products fit your device and process. Or send an engineering question with your spec, tray or pouch type, and sterilization method, and we will help you narrow it down. You can also browse all products.