Seam Tape
A seam tape is a tape that is heat- and pressure-bonded to the reverse side of seams in waterproof and breathable materials to prevent water from seeping through needle holes.
Contents6 sections
Definition and Overview
Seam tape is tape that covers needle holes and seams created by sewing, helping to provide waterproofness. It is mainly bonded to the reverse side of seams and used in rainwear, outdoor wear, waterproof bags, and similar products.
In general, the process of covering seams with tape to make them waterproof is called seam sealing. This differs in purpose and bonding method from ordinary tape used to finish seam allowances or for decoration.
Materials and Structure
In many cases, it has a laminated structure consisting of an adhesive layer that melts with heat and bonds, and a base layer that protects the surface and provides strength and conformability. The type of adhesive layer is selected according to the surface material of the fabric and the backing coating or membrane.
Unlike narrow tape made from plain weave, knit, or braid, seam tape is generally film-based. There are thin and flexible types, types designed with stretch in mind, and types that emphasize durability.
- Single-layer types are relatively thin and used for lightweight specifications.
- Multi-layer types are intended to balance adhesion and surface protection.
- For stretch fabrics, consider tape that can follow the fabric's stretch more easily.
Width and Main Applications
Width is expressed in millimeters, and a width is selected that can sufficiently cover the seam and the needle holes on both sides. It is important to avoid widths that are narrower than necessary, taking seam allowance width, seam curvature, and ease of application into account.
Main applications include sealing areas that are likely to be exposed to water or have many seams, such as hoods, shoulders, sleeves, sides, and crotch areas. In addition to straight sections, specifications that emphasize conformability to curved sections are also used.
Selection and Handling Precautions
When selecting, check not only the fabric material but also the backing coating, the laminate or bonding structure, surface irregularities, and stretch. Even with the same waterproof fabric, the tape that can be bonded and the proper processing conditions differ, so preliminary testing is necessary.
For bonding, use a dedicated seam sealing machine or heat press, and properly control temperature, pressure, and time. If the conditions are insufficient, it can lead to peeling or water leakage, and excessive heat or pressure may cause fabric deformation, changes in gloss, or damage to the membrane.
Repeated washing, friction, and bending may cause lifting or peeling at the edges. Before productization, confirm wash durability, the condition of bent sections, and water resistance, and clearly specify edge treatment and overlap in the specification sheet.
Differences from Similar Terms
Bias tape is a narrow tape used to finish fabric edges by binding them or for decoration, and differs from seam tape, whose main purpose is waterproofing seams. Stay tape is an auxiliary material used to suppress stretching of seam allowances and seam lines and stabilize shape.
Bonded sewing refers broadly to techniques that join components with adhesive or tape in place of sewing, or in combination with sewing. Seam tape is a tape specialized for sealing seams within that category.
Frequently Asked Questions
Can seam tape be bonded with a household iron?
Because the required temperature, pressure, and heating time vary by product, uniform bonding may be difficult with a household iron alone. In particular, waterproof breathable materials may be sensitive to heat, so it is important to check the bonding condition and the effect on the fabric using test pieces and follow the specified conditions.
What are the main causes of seam tape peeling off?
Causes include insufficient or excessive bonding temperature, pressure, or heating time; poor compatibility between the fabric and the tape; steps in the seam allowance; and contamination by dirt or moisture. Areas subject to frequent washing or bending are more likely to lift from the edges, so both the process conditions and the application design should be checked.
Can seam tape and stay tape be used together?
Because their purposes differ, they can be used together depending on the specification. However, the thickness or adhesive of stay tape may interfere with seam tape adhesion. Check the auxiliary material structure around the seam and perform adhesion testing under the same conditions as the actual process.
![50000 MOKUBA Silk Petersham Tape [Outlet]](/img/item/thumb/OKURA/1006812_t2.jpg)
