Button Attachment Strength

Definition and Evaluation Scope

Button attachment strength is a test that pulls a sewn-on button in the direction of separating it from the garment to check the durability of the attachment area. Evaluation covers not only the button’s own hardness and resistance to breakage, but also the sewing thread, sewing conditions, and fabric strength.

If a button comes off, it can impair the garment’s function and appearance, and small buttons can also create hazards such as accidental ingestion. For that reason, it is important to set the required performance from the planning stage, taking into account the application, wearer, and button size.

• The main defects checked are button detachment, sewing thread breakage, chipped holes, broken shanks, and fabric tearing or pullout.
• During evaluation, the results vary depending on the pull direction, holding method, and condition of the specimen, so the test conditions are standardized.

Influence of Material and Structure

For hole buttons such as two-hole, four-hole, and cat-eye buttons, the basic approach is to distribute the thread evenly according to the number and arrangement of the holes. With buttons that have thin hole edges or are made of brittle materials, overtightening can cause chipped holes or breakage.

For shank buttons, load tends to concentrate at the base of the shank, so the thickness and shape of the shank and the way the sewing thread is passed through should be checked. When attaching to thick fabric, making a thread shank with a neck wrap creates space for the fabric thickness and helps prevent excessive force from being applied to the button.

Shell, natural materials, resin, and metal each react differently to impact, heat, and chemicals. At the same time as securing attachment strength, check for cracking, corrosion, and discoloration in the actual sample under the intended use environment.

Size Indication and Application-Based Considerations

Button size is generally expressed in millimeters or lignes. Lignes are a unit used for button dimensions, and if the unit is mistaken, it can cause problems with matching buttonholes and sewing specifications, so the unit must be clearly stated in purchase orders.

Small buttons for shirts and blouses, front closure buttons for jackets and coats, and waistband buttons for pants and skirts each face different levels of force and frequency of use. In particular, in areas that are pulled strongly during dressing and undressing, the combination of fabric and button must be considered.

For kids' clothing, uniforms, and workwear, the risk of detachment should be carefully checked according to the usage conditions. Larger buttons are not necessarily stronger; shape, weight, sewing method, and fabric thickness all have a combined effect.

Attaching Method and Handling Precautions

For sewing, choose thread with the appropriate thickness and strength for the button, and make sure the amount of thread used for each hole is not uneven. If the fabric is thin, coarse, or prone to stretching, methods such as using a backing button on the reverse side can be used to distribute the load. Check with a sewing sample before mass production.

During washing and dry cleaning, rotation and collisions with other garments repeatedly place loads on the button and the sewn attachment area. Handle according to the care label, use a laundry net if necessary, and check for detachment or thread loosening.

The heat and steam from an iron can cause deformation, changes in gloss, or discoloration of resin buttons. Do not apply the iron directly to the button; choose the temperature and method appropriate to the material, such as using a pressing cloth.

• Do not continue using a button that has become loose; resew it promptly.
• Before washing, fasten front closures and pocket buttons to reduce snagging.
• For metal buttons and highly decorative buttons, also check for discoloration and surface scratches caused by moisture, chemicals, and friction.

Differences from Similar Terms

Button attachment strength indicates that a button attached to a garment is less likely to come off. Unlike the impact resistance of the button alone, it cannot be judged by the button material alone. It is the performance of the entire attachment area, including the sewing thread, fabric, presence or absence of reinforcement, and sewing quality.

Button pull test is often used to refer to the test used to confirm button attachment strength. On the other hand, tensile strength may refer to the strength when the material itself, such as fabric or thread, is pulled, so the evaluation object and test method are distinguished and stated in the specification.

Frequently Asked Questions