Although Tyvek® brand material is converted in much the same way as paper or plastic films and on the same equipment, it does require different handling techniques for optimum results. For this reason, we strongly recommend that those who have never worked with Tyvek® before conduct a pilot run to fully test each conversion operation before beginning full-scale production.
Some things to keep in mind:
- Tyvek® cannot be crush-cut as easily as paper. Its filaments are very strong and each must be completely severed; "hangers" will not break off.
- Tyvek® elongates more than paper and will stretch up to 20-30% before breaking. To minimize distortion or neck-down, keep web tension as low as practical -- 0.75 lb/in. (1.3 N/cm) -- during processing.
- Tyvek® may occasionally curl when sheeted because of its inherent "memory." Conventional decurler (breaker bar) equipment can be used at minimum tension."
- Tyvek® has its own natural lubricity and does not contain abrasive fillers or binders. It therefore requires no additional lubricants for processing. In fact, lubricants should be avoided since some contain low-molecular-weight hydrocarbons which can cause swelling and distortion.
- Flying splices can be made with all styles of Tyvek®. A pressure-sensitive tape is recommended for butt splices.
- Tyvek® is a thermoplastic material and it melts sharply at 275°F (135°C).
- When coating or laminating Tyvek®, the web temperature in the oven should not exceed 175°F (79°C).