From a long time the engineering plastics have largely replaced the metal i.e. casting wire to the cost savings and three broad versatility of the molded plastic components. In the field of hot epilator products, the Environmental Stress Cracking (ESC) is a common quality problem. The consequences and the after effects of these failures are often severe and frequently these failures occur right after the products go into the field.
There are many points to be consider while choosing the proper O-rings and rubber seals to use with the plastic components-
- Cross section
To select an O-Ring cross section size from the available standard sizes. If you are unsure about what cross section size to use, then refer to a lot of professional guidance present.
To determine the maximum clear new present in the application, one has to really take care. For a radical seal, subtract the rod (which is a shaft) diameter from the maximum bore diameter. Thus, for a face seal, do subtract the distance between the sealing surface and the motif surface.
- Check the Clearance
Also determine if the clearance is acceptable for the application pressures and the material hardness being used for the checking of the graph. The runner and plastics standard line products are made up from the materials having a hardness of 70 shore A. If the cleaned is unacceptable, then the component tolerance will have to be tightened, harder material will have to specially ordered, or a back-up ring will have to be used. The graph provides the cleaned clues as the radial values, so divide the number obtained in the précising step by the 2 to obtain your radical clearage.
- What is the Environmental Stress Cracking (ESC?)
The Environmental Stress Cracking is definitely a leading cause of failure in the plastic parts. It also occurs that when the cracks form in the molded plastic component as a result of the chemical exposure. The crack formation can grow gradually over the time and the usage, until the plastic component ultimately fails. The chemicals that cause the ESC include oil, fuels, greases, adhesives, solvents, cleaning products and plasticizers.
The Lubricants, Motif and the Rubber Seals, Adhesives and O-Rings need to be compounded and carefully chosen for the use with the Stress sensitive plastics.
Not all the rubber seal ingredients are suitable for the use with the engineering plastics and even very small percentage ingredients in the O-Rings or the rubber seals can impact with these specialized plastic components. the simple exposure of the stress sensitive plastics components to a rubber item made with the incorrect ingredients can start the cracking process with the eventful failure occurring.
Thus, obtaining the proper rubber seal or else the O-Ring for the design doesn’t mean that dramatically to consider the cost or the longer lead time. It just means that the closer collaboration with a seal manufacturer that knows that what one needs and delivers the proper seal for the particular application. An experienced O-Ring or the rubber seal manufacturer should have a number of the elastomers available for the use with the plastics and the ability to develop the special color and the special performer elastomers for the new designs.