Test & Measurement, Education & Training & 3D Printers

Tensile Testing of Contact Lenses in a Temperature-Controlled Bath

First of all, learn the characteristics of contact lenses and why need to test them?

Try pulling contact lenses for what? First, we learn some information about this type of glass. Contact lenses, also called eye lenses, are very small glasses with the same diameter size as our eyes. Compared with conventional frame glasses, contact lenses overcome the disadvantages such as entanglement, inconvenience and it also increases the aesthetics of the eyes.

The initial effect of this type of lens is to adjust the vision of people with nearsightedness, farsightedness, … Later contact lenses were improved, varied in color, size and strain. type to meet the aesthetic needs of people.

Today, there are millions of people worldwide using eye lenses that make them the most popular and widely used medical devices in the world. Eye lenses are preferred over rimmed glasses, as they use a variety of eye drops and are manufactured in a variety of lens types that are hard to soft lenses.

When testing lenses, loading the specimen into the grips can pose many problems: the soft lens material is slippery and delicate, and fractures at very low forces; and the test specimens are extremely small, providing a limited amount of gripping surface. Contact lenses must also be tested in an environment that best simulates physiological conditions; ambient testing results in the drying out and cracking of the material.

The most common method to characterize contact lenses is a basic tensile test.

For this test, we used a single column electromechanical test frame configured with a 10 N load cell and 250 N submersible pneumatic grips with extra long surfalloy faces for this test. Additionally, we used the BioPuls™ Submersible Pneumatic Grips and Temperature-Controlled Bath to keep the contact lenses hydrated and at body temperature.

Specimens are cut into pieces to obtain accurate data when conducting pull tests. Testing speed is 5mm / minute. Bluehill® 3 software has been used to assess maximum load, tensile tension at maximum load and module for two lens models.

Test results show that the system configuration was successful in checking contact lenses and we were able to accurately demonstrate the low forces needed to measure the error of the specimen. In short, eye lenses can easily be tested using the configuration described earlier. We recommend that the faces used for this test allow separation of the grip by 0 to match the small overall length of the contact lens sample.

Refer to a number of related material strength testing systems:

  • Universal testing machine Instron 5900 series
  • Bluehill Universal Software

This post is also available in: viTiếng Việt

Share this post
  , , ,