Seam types are the place where two pieces of fabric are joined by application of a series of stitches or stitch types with a defined geometry. Over the years there are a number of different types of seams that have been developed to do different jobs. Many have largely been superseded by the development of machine stitches that finish as you sew them, and by the development of the over locker (or serger in some parts of the world), it is useful to know some of the basic seams types and finishes.
The place where two pieces of fabric are joined by application of a series of stitches or stitch types with a defined geometry to one or several thicknesses of fabric material is defined as Seam. There are different kinds of seam constructions, used depending on whether the seam is a decorative element of the design, the kind of fabric used, or how much stress is placed on the seam. Some of the most commonly used seam types are superimposed seams, lapped seams, bound seams, flat seams, edge finished seams, ornamental seams. There are subdivisions depending on the fabric layers and direction of stitching.
Significance and use of seam
Significance and Use
Selection of correct seam type for a particular assembly is very important as improper selection of stitch type, seam type or thread type can result in failure of the sewn seam and failure of the garment. The most important aspect of a properly constructed sewn seam is strength, elasticity, durability, security and appearance. These characteristics must be balanced with the properties of the material to be joined to form the optimum sewn seam. The selection of the seam type and stitch type should be based upon these considerations.
Strength: The seam efficiency of the sewn seam should be so that sewn seam strength is balanced and can withstand the everyday usage of the garment.
Elasticity: Elasticity of sewn seam should be slightly greater than that of the material which it joins. This will enable the material to support its shape of the forces encountered for the intended end use of the sewn item.
The elements effecting the elasticity and strength of a sewn seam depends upon fabric type and strength, seam type, stitch type, stitch density (SPI), thread tension, and thread strength and elasticity.
Durability: Durability of a sewn seam depends largely upon its strength relative to the elasticity of the seam and the elasticity of the material. For making durable sewn seam, the thread size and stitch density must be carefully chosen to avoid puckering.
Security: Security of sewn seam depends chiefly upon the stitch type, SPI, and its susceptibility to become unravelled. The stitch must be well set to the material to prevent snagging that can cause rupture of the thread and unravelling of certain stitch types.
Appearance: Appearance of a sewn seam generally is governed by the proper relationship between the size and type of thread, the stitch density, and the texture and weight of the fabric.