Fabric dunnage materials include laminated fabrics and coated fabrics that help to protect parts during packaging, shipping, and assembly. Rack bag designers want fabrics that are strong and lightweight, but that are also long-lasting. Depending on the application environment, packaging engineers may also need fabric dunnage materials that are water-proof, puncture-resistant, and easy-to-clean. For financial managers, material selection that helps drive a strong return on investment (ROI) is especially important.
In the first of this two-part series from Hold-True, a Made in the USA manufacturer of sewn fabric dunnage, we’ll examine laminated fabrics for reusable packaging. Part 2 of this series will cover coated fabrics. By understanding how these materials are made and used, rack bag designers and packaging engineers can make stronger decisions about fabric selection. Financial managers can also get a better sense of rack bag ROI and how repairs and maintenance affect the total cost of ownership.
What are Laminated Fabrics?
Laminated fabrics are composite materials with a layered structure. Two or more materials are bonded together with an adhesive to impart benefits like added strength, durability, or a combination of properties such as waterproofing and puncture-resistance. Laminated fabrics act as separate materials within this bonded structure, but they provide greater tensile strength than plain fabrics alone. For rack bag designers and financial managers, raincoats exemplify the benefits of laminated fabrics.
With raincoats, a waterproof membrane is sandwiched between a durable, long-wearing outer layer and a softer, inner layer. Waterproofing is an essential requirement, of course, but people also want garments that won’t tear easily. Yet raincoats can’t be so heavy that they’re uncomfortable to wear. They need to permit movement, too. Even if a garment’s inner layer doesn’t come into direct contact with the skin, wearers still want a fabric that won’t scratch or cut them.
Laminated Fabrics: Advantages and Disadvantages
Like raincoats, laminated fabrics for rack bags can meet multiple requirements. In order for different materials to support lamination, however, each base material must have sufficient weight and adhere to adjacent layers. Plus, each material needs to support the end-use application. For example, PVC laminated fabrics tend to cost less, but they also promote mold growth in fabric dunnage. Weather-resistant HDPE or LDPE laminated fabrics are options for outdoor applications, but delamination remains a risk.
With any type of laminated material, repeated impacts and cyclic stress can cause layers to separate and a loss of desirable properties (such as mechanical strength) to occur. If the edges of sewn fabric dunnage aren’t hemmed properly, the repeated loading and unloading of parts can contribute to this laminate failure. Point loading is problematic, too. Compared to coated fabrics – the subject of our next article – laminated fabrics also tend to weigh more.