What do the protection professionals answer to the question: does the seam technology of disposable coveralls as personal protective equipment have any significance for the user? The clear answer: yes. In this article, the security professionals will go into detail about this topic and explain it below.
Versions of disposable protective coveralls
Disposable coveralls must meet or exceed the requirements of the European PPE Directive. They are part of the category 3 personal protective equipment. The desired protective effect depends on several influencing factors: the material used, the intended purpose, the intended protective effect, the comfort for the wearer, the fibre release, the manufacturing process, etc.
Above all, the intended use is the main reason why there are different designs. As a garment, disposable overalls must naturally correspond to the physical proportion of the wearer. The technology to achieve this has always been assembly, in other words, the cut pieces must be assembled into a wearable garment. The production of the garment is done in the simplest form by sewing. The disposable coverall usually has seams, but new suturing techniques (e.g. welding or laser technology) are becoming increasingly important. What should the user know about suture technology?
Disposable protective coveralls: Stitched seams
This is the simplest form of a suture. The cheapest and therefore least elaborately manufactured overalls are often made with such a seam. Protective coveralls produced in this way must meet the minimum requirements of Category 3 Type 5 and Type 6 certification. The price is decisive. Naturally, this limits the technical effort involved in production. The most important requirements are: the seam must withstand a certain load pressure and must only allow substances from the surrounding area to pass through within the framework of the standard.
Examples of simple sewn seams are: internal and external seams. The basic condition is that the suture must hold. The thickness of the seams is measured in Newtons (N) according to ISO 13935-2. The values of large manufacturers such as Dupont reach values of more than 50N, top products (including those of other manufacturers) more than 75N. The thickness of the thread material used also plays an important role in achieving higher strength, as does the sewing technique:
- Elaborate sewing technique
- Sewing technique 2 stitches/cm
- Simple sewing technique only approx. 1 stitch/cm
Due to the fact that hazardous substances act on the overall from the outside, external seams are preferable. Felled seams offer more safety than simple seams in terms of mechanical strength and a better barrier against liquids and solid particles.
Disposable protective coveralls: taped and welded seams
In an effort to further improve the tightness of the overalls, the focus is once again on seam technology. Naturally, therefore, such techniques are used in chemical protective coveralls of category 3 types 1, 2, 3, and 4. The bonding of the previously sewn seam significantly increases the tightness of the seam. In addition to the time-consuming subsequent bonding of the sewn seam, the tightness of the seam is also achieved by direct bonding (without sewing). The strength of the seam can be tested by a shear or peel test.
Recently, suturing technology has been evolving. In addition to Ultrall welding, laser welding is also used. In addition, some manufacturers glue over or taped the welded seams to achieve a particularly high level of tightness and strength. Suturing technology is also important for coveralls used in cleanrooms. It is essential to avoid that fibers/particles detach from the seam and thus reduce the quality of the application.
What can the user learn from the above suture technology?
The higher the quality of the chemical protective coverall, the more complex the seam technology must be in addition to the basic material of the protective coverall. Taped (or taped over) seams are more secure and are therefore almost always used on type 4 and lower coveralls. For the user, such a coverall is more expensive than a type 5 and 6 coverall, but it also offers more protection. Price cannot be the sole criterion for decision. The protective effect must be evaluated first and only then the price.
Choosing the right disposable coverall
The protection professionals therefore recommend a precise risk assessment. With the large number of protective coveralls of the 6 standardised types available on the market, the selection of the suitable product may require a more in-depth analysis of the product data, and not only because of the seam technology. Seek advice from a specialist dealer for personal protective equipment so that you can choose the overall with the right protective effect.