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حِرَف

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الهندسة العكسية

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الأجهزة القابلة للارتداء

J.P. C. (Wikimedia Commons) · CC BY-SA 2.0

أنشأه

Mary

22. سبتمبر 2026

Repositionable Microsphere Adhesive

In 1968 Spencer Silver at 3M, trying to make a very strong adhesive, made the opposite: an acrylate that formed tiny tacky spheres and held only lightly. For years it had no product. In 1974 his colleague Art Fry coated it on bookmarks for his church hymnal so they would stay put without tearing the pages; the sticky note reached shops in 1980. **US 3,691,140**, "Acrylate copolymer microspheres", Silver, filed 9. March 1970, granted 12. September 1972: "inherently tacky", elastomeric microspheres of an acrylate ester such as iso-octyl acrylate with a small share of an ionic monomer. **You measure what makes it different from tape**: the peel force over twenty re-sticks, side by side with masking tape, and the spheres themselves under a microscope.

مبتدئ

1 hour

التعليمات

Look at the stripe

Put a sticky note's adhesive stripe under the digital microscope at high magnification. Beside it, a strip of masking tape. Capture both; measure the bead size and spacing on the note.

المواد لهذه الخطوة:

أوراق لاصقة قابلة لإعادة اللصق1 pad

شريط لاصق ورقي1 لفة

الأدوات المطلوبة:

مجهر رقمي

Clean the glass

Wipe a glass sheet with isopropyl alcohol and let it dry. Cut the masking tape to the same 25 mm width and 75 mm length as the note's sticky area.

المواد لهذه الخطوة:

كحول إيزوبروبيلي 99 %10 مل

منديل ورقي1 ورقة

الأدوات المطلوبة:

لوح زجاجي

مقص

مسطرة

Peel at 90 degrees

Press the note and the tape onto the glass with one firm thumb stroke each. Clip a paper clip to each free end, hook the spring scale, and peel straight up, slowly. Record the steady force.

المواد لهذه الخطوة:

مشابك ورق2 قطع

الأدوات المطلوبة:

مقياس قوة (ميزان زنبركي)

Re-stick and repeat

Stick the same pieces down again in the same place and peel again. Record peel 1, 2, 5, 10 and 20.

الأدوات المطلوبة:

مقياس قوة (ميزان زنبركي)

Peel ladder and contact area

جارٍ تحميل دفتر Jupyter…

History & Context

**What the patent specifies:** inherently tacky, elastomeric, solvent-insoluble acrylate copolymer microspheres made by suspension polymerisation with an ionic comonomer. **Modern build (derived):** a commercial sticky-note pad, tested. The same idea now holds repositionable labels, wall graphics and removable flags. Its limits: a weak grip by design, fading tack as dust and fibre collect on the spheres, and poor hold on rough or damp surfaces.