There isn't a forum for paddlecraft construction, excepting Wood/Canvas, so I guess general discussion is our daisy for new developments in boat building!
Innegra Overview
Innegra is a high density polypropylene; an aromatic polyethylene. It has very low specific weight and low tensile strength and modulus mechanicals combined with high elongation to failure. Innegra lowers fabric weight and increases resistance to flexural failure. Compared to Kevlar it is roughly half the weight, hydrophyllic, and bonds better. Fabrics are bulky, or thick, for given weight. Thickness and weight, Innegra floats on resin, are best controlled with infusion to minimize resin content.
It is used to sheath thick carbon race car chassis to control traumatic splintering. We've seen it in a Wenonah canoe and on SUP boards. Most experimentation has focused on thicker ~500 mill laminates, but paddlecraft utilize thin, 35-45 mill, three to five layer laminations. Innegra can be placed on the inside or outside of thin laminations, or both, sheathing stiffer materials, or internally as captured layers. Which choices will optimize paddlecraft laminations?
Innegra S is available as woven fabric in various weights/ thicknesses. Innegra H is bi-woven with E glass, with basalt, a natural material with characteristics between E and S glass, or with carbon. Innegra H is also hybridized with basalt or carbon into bi-spun or co-mingled threads and woven into fabric. There is a broad array of hybridized Innegra S and H configurations.
Basalt/Innegra combinations currently price near Kevlar, Innegra/carbon hybrids near 100% carbon prices, so we need product improvement to justify use. For example, Innegra/Carbon comes closest to a whitewater worthy laminate but at unacceptable price; the basalt hybrid most closely approximating acceptable river tripper pricing. The expense and learning curve of converting to infusion lamination and the cost of attendant discardables further complicates paddlecraft pricing.
Several Canadian composite infusion manufacturers have sample yardage in house and hulls built. We can assume several US infusers are also working with the material for canoes, kayaks and other items amenable to composite construction. There should be quite a creative range of laminations available in the next few years. Lamination schedules will coalesce with industry experience and prices lower over time as volumes increase.
CEW Oct 14
I'll try to get some images of I/B, I/C hulls up
Innegra Overview
Innegra is a high density polypropylene; an aromatic polyethylene. It has very low specific weight and low tensile strength and modulus mechanicals combined with high elongation to failure. Innegra lowers fabric weight and increases resistance to flexural failure. Compared to Kevlar it is roughly half the weight, hydrophyllic, and bonds better. Fabrics are bulky, or thick, for given weight. Thickness and weight, Innegra floats on resin, are best controlled with infusion to minimize resin content.
It is used to sheath thick carbon race car chassis to control traumatic splintering. We've seen it in a Wenonah canoe and on SUP boards. Most experimentation has focused on thicker ~500 mill laminates, but paddlecraft utilize thin, 35-45 mill, three to five layer laminations. Innegra can be placed on the inside or outside of thin laminations, or both, sheathing stiffer materials, or internally as captured layers. Which choices will optimize paddlecraft laminations?
Innegra S is available as woven fabric in various weights/ thicknesses. Innegra H is bi-woven with E glass, with basalt, a natural material with characteristics between E and S glass, or with carbon. Innegra H is also hybridized with basalt or carbon into bi-spun or co-mingled threads and woven into fabric. There is a broad array of hybridized Innegra S and H configurations.
Basalt/Innegra combinations currently price near Kevlar, Innegra/carbon hybrids near 100% carbon prices, so we need product improvement to justify use. For example, Innegra/Carbon comes closest to a whitewater worthy laminate but at unacceptable price; the basalt hybrid most closely approximating acceptable river tripper pricing. The expense and learning curve of converting to infusion lamination and the cost of attendant discardables further complicates paddlecraft pricing.
Several Canadian composite infusion manufacturers have sample yardage in house and hulls built. We can assume several US infusers are also working with the material for canoes, kayaks and other items amenable to composite construction. There should be quite a creative range of laminations available in the next few years. Lamination schedules will coalesce with industry experience and prices lower over time as volumes increase.
CEW Oct 14
I'll try to get some images of I/B, I/C hulls up
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