In this construction, a scrim or strands (inserts) are sandwiched between layers of film. Thus load-bearing members are laid straight, which maximizes the high modulus of the fibres, where a woven material will have some inherent stretch to the weave. Laminating film to film around the strands creates a very strong and dependable bond reducing the amount of adhesive needed. In high quality cloth, the strands or scrim are tensioned during the lamination process.
Strands are combined from fibre yarns. Scrim is a loose weave or lattice of strands, typically bonded where they cross to maintain a grid pattern. Scrims are used to strengthen or reinforce sailcloth characteristics to synergize the qualities of each.
Using films reduces stretch in all off-load directions.
Lamination also allow fibres to be placed in uninterrupted paths.
Films are a thin sheet material extruded from synthetic polymers and are used in laminates. PET film is the most common film used in laminated sailcloth, extruded and biaxially oriented. In the US and Britain, the most well-known trade names are Mylar and Melinex. The film is normally Mylar (a film Polyester), but could be Tedlar.
To day, the taffeta most commonly used is Polyester, since it has less load bearing duties to perform, its role in laminates is largely to provide durability.
Taffeta-Film-Scrim-Film-Taffeta.Taffeta fabric with high UV and abrasion protection is added to the Film-on-Film. This combines the best of a laminate, but is more costly, heavy, and stiff. This is an attractive method to combine high modulus fibres that have poor UV resistance.
Adhesives are applied to the surfaces, before the layers are laid in contact with each other – a pre-preg component.
These components are laminated using high pressure rollers and heat. The scrim (and/or the taffeta if present) used defines whether the fabric is an Aramid, Polyester, Carbon or Dyneema laminate.
Laminate – Film on Film
Laminate – Taffeta
Materials Performance over Time
Performance compared to Aramid
Film-Scrim-Film or Film-Insert-Film (Film-on-Film)