View Full Version : The Definitive Tyvek Article Part 1

02-02-2007, 09:26
The Definitive Tyvek Article Part 1

Discuss (http://www.hammockforums.net/forum/showthread.php?t=526) this article.

Types of Tyvek

Most of the technical information (weights, construction, etc) below came from 2 sources: Dupont (http://www2.dupont.com/Tyvek_Construction/en_US/) <1> and Material Concepts (http://www.materialconcepts.com/pages/dupont-tyvek.asp) <2> websites. The Material Concepts site has tons of info on Tyvek and I suggest you check out the site. Tyvek® is a registered trademark of E. I. du Pont de Nemours and Company or its affiliates.

In this article I focus on the types of Tyvek that can be used in making gear for outdoor activities. The two main types of Tyvek that I focus on are Tyvek for hard sided structures (HS) and Tyvek for soft sided structures (SS). I am by no means an expert on Tyvek and I am doing this mainly to answer questions concerning this versatile material and clear up some misconceptions.

Tyvek was discovered by accident by DuPont researcher, Jim White, who in 1955 noticed white polyethylene fluff coming out of a pipe in a DuPont experimental lab. The flash spinning process took a few years to perfect and in 1967 the commercial production of Tyvek was started.<1>

Tyvek is lightweight, flexible, smooth, particulate free, opaque, and resistant to water, rot and mildew, chemicals, abrasion, and aging. It has a high strength-to-weight ratio and is pH 7 (neutral). Made from 100% high-density polyethylene fibers, Tyvek is manufactured in a unique flash-spinning process without the use of binders. The continuous and very fine fibers of high-density polyethylene are randomly distributed and nondirectional. These fibers are flash spun and then laid out in a web on a moving bed and then bonded together using heat and pressure. No binders, sizers, or fillers are used. Different forms of Tyvek are made by varying the lay-down time and bonding conditions. <1>

Chances are good that you’ve come across hard-structure Tyvek. The two most common examples are Tyvek envelopes used by the USPS and FedEx, and Tyvek HomeWrap, advertised as a windbreaker for your house. Hard structure Tyvek has a paper-like rigidity with a smooth slick surface. If you’ve seen Tyvek protective apparel such as lab coats, jackets, suits, or aprons, you’re familiar with soft-structure Tyvek. It has a soft fabric-like feel, and with use and handling it becomes even softer and more pliable, taking on a silky feel. Tyvek has a unique balance of strength and softness. Durable and lightweight, it has an excellent strength-to-weight ratio.

Tyvek Hard Structure

HomeWrap Tyvek Basis weight, 1.7 oz/yd
This is probably the most common form of Tyvek seen. It can be used to make tents, tarps, waterproof breathable barriers, ground cloths, etc. Many home improvement stores sell Tyvek home wrap in 10 foot wide rolls, though narrower rolls are also available. Rolls are generally fifty to 100 yards long, but eBay is a good source to find this Tyvek in smaller sizes/quantities.
This type of Tyvek is stiff and noisy when new, but if you put the Tyvek in a washing machine on the delicate cycle with no detergent for 2-3 cycles, it comes out soft and much more fabric-like. Washing this type of Tyvek does not seem to affect the water resistance but can cause some shrinkage. Henry Shires (http://www.tarptent.com/) states that 5% should be added to measurements to allow for shrinkage if you are going to wash your Tyvek.

Hard Structure Tyvek Style 1020 Basis weight, 2.0-2.2 oz/yd²
Tyvek style 1020 is used to package, interleave and protect metals, marble, glass & plexiglass, steel sheets, laboratory table tops, and other materials to protect finishes. Tyvek is excellent in applications where protection from water, dirt, and environmental pollution is necessary. Tyvek is also outstanding for furniture patterns and clothing patterns, and is easy to perforate, mark, and cut. Unlike paper, Tyvek is tear resistant and unaffected by water. Style 1020 is not suitable for printing. <2>

Hard Structure Tyvek Style 1016 Basis weight, 1.6 oz/yd²
Style 1016 Tyvek rolls are used for murals, theater backgrounds, photo backgrounds, and other applications where large widths are necessary. These Tyvek rolls are significantly lighter than traditional fabrics or papers. Hard structure Type 10 Tyvek styles have a smooth slick surface with a very low coefficient of friction. They are easy to handle, lightweight, strong, and durable. Style 1016 is not suitable for printing. <2>

Tyvek Soft Structure

Tyvek Soft Structure Type 14

• Fabric-like
• Light Weight & Tear Resistant
• Water Resistant & Breathable
• Durable & Flexible
• Recyclable
• Washable

Type 14 Tyvek is soft and fabric-like, offering excellent barrier protection. Type 16 Tyvek has a pin-perforated structure with high air and moisture permeability at the expense of lower tear strength and barrier properties. Both styles are easily sewn on any conventional sewing machine. <2>

Tyvek Soft Structure Type 1443R 1.25 oz/yd2 ( Kite Tyvek)
Type 14 styles offer excellent wet and dry protection against particulate matter and provide an excellent barrier. Type 14 has high opacity and good surface stability.
Key Features:
• Incredibly strong graphics
• Unique balance of strength and softness
• Stitch ability
• Light weight and durable

Tyvek® Soft Structure Type 16 1622E 1.15 oz/yd2
Tyvek style 1622E is pin perforated with 10-15 mil (0.25mm-.038mm) holes, giving it much higher air and moisture permeability, additional softness, and greater flexibility and drape than the above Type 14 styles, at the expense of lower tear strength and barrier properties. It has a higher quality and is more durable than standard non-woven when used inside sofa and chair cushions, and in limited use products such as pillow cases and apparel. <2>

Style 1673 – 2.10 oz/yd2
Perforated as above with the same permeability as style 1622E, Tyvek style 1673 has a 45% heavier basis weight and is used when added tear strength is necessary. <2>

There are also several other types of Tyvek not mentioned here because of limited application in the construction of outdoor equipment. Here are a few of those types:

Tyvek StuccoWrap, Tyvek CommercialWrap, Tyvek DrainWrap, Tyvek ThermaWrap, Tyvek AtticWrap, DuPont FlexWrap, DuPont StraightFlash, DuPont StraightFlash VF, Tyvek Wrap Caps

Tyvek Tape

I highly recommend using the Tyvek tape. Available at any home improvement store that sells Tyvek, Tyvek tape adheres to Tyvek really well and is almost impossible to remove without destroying the material. It is also highly water resistant. Below is a picture of a piece of Tyvek tape that has soaked in a dye bath for 24 hours, then run through three cycles in a washing machine to remove excess dye. After all this, only a little seepage under the edge of the tape occurred, and most of the area was unaffected. The tape is still firmly attached to the material:
Personally, I would cover any sewn seams with Tyvek tape to strengthen the seam and eliminate water coming in the seam.

hondo_mountaineering from White Blaze had this to say: Original Thread on WB. (http://www.whiteblaze.net/forum/showthread.php?t=9950)

The best solution we have found is an adhesive transfer tape from 3M using the 300LSE adhesive. This tape makes a strong waterproof joint that stays pliable over a large temperature range, making it good for use in mountaineering/backpacking gear. The resulting seam is stronger than the Tyvek itself, and much stronger than a sewn seam. If you can't get the tape (often requires large orders) I recommend using outdoor carpet tape in place of stitching, though not ideal, it's still stronger than thread.

Go to Part Two. (http://www.hammockforums.net/forum/showthread.php?p=6320)
Discuss (http://www.hammockforums.net/forum/showthread.php?t=526) this article.