Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Springy plastic

  1. Mar 27, 2016 #1
    I need a light weight plastic material, like a string that is no more than 1/8 inch in diameter, that can be sewn into fabric alongside a zipper and spring open when the zipper opens. I would greatly appreciate any suggestions anyone is able to give. I have been trying to solve this design problem for months.
  2. jcsd
  3. Mar 27, 2016 #2


    User Avatar

    Staff: Mentor

    Welcome to the PF. :smile:

    It would seem like you could just use two pieces of plastic ribbon that are formed in the shape of a curve, and sewn into the fabric next to each side of the zipper in the orientation where the curve is parallel to the plane of the zipper. How long will the zipper be? Does it zip closed going up or going down? Is this for a schoolwork design project, or a personal project?
  4. Mar 27, 2016 #3
    Hi, thank you for your post, I hadn't thought of that. It's a personal project where the zipper is a two way zipper opening in the middle in both directions such that the opening get larger from the center outwards as you open the zipper. The opening only needs to be about 3-4 inches, but I do need maximal resistance somehow to maximize the width of the opening. Do you know of a specific type of plastic ribbon that I could use. Thanks again.
  5. Apr 2, 2016 #4
    There are two types of strands that should be considered: 1. A polyester monofilament (available in different diameters); and a wrapped wire if more rigidity is needed (this would probably have to be specially made by a textile company with a wrapping machine). You could probably do this yourself, but be sure to use two layers wrapped in opposite direction.

    To coordinate the strand with the zipper's opening and closing you might consider modifying the slider. Small eyelets could be attached to guide the strands.

    What exactly are you trying to do? Is it a one time action or one that's repeated. Is it for a garment? If so, do it have to be washable?
  6. Apr 2, 2016 #5
    Hi, thank you so much for your thoughtful response. What you are describing sounds very close to what I need. Yes, it is for a washable, repeatable action garment. It has a 2-way zipper, such that when opened there will be a hole in the center that needs to stay open for injections. Could you please provide me with a little more information on the polyester monofilament, or any other ideas you might have. I really like your suggestion about modifying the zipper slider.
  7. Apr 4, 2016 #6
    Lots of places sell monofilament yarns. Polyester is usually available and is probably the best polymer for your application. Just Google monofilament yarns and find one with the correct dimensions. Another thought - if you need an opening for injections, your might consider a Velcro closure rather than a zipper. That would give you more flexibility in designing the garment.
  8. May 2, 2016 #7
    Hi Slideruler, regarding my question above, I have an international patent deadline coming up in two short months, and have to make some important decisions before that happens. Would you available to consult over the phone. I have a paypal account, and would, of course, be happy to pay for your time.
  9. May 2, 2016 #8
    Not sure you could do this with a string or filament (but as always I reserve the right to terribly wrong). If I understand, you need something that will create tension so that when the zipper is unzipped, it flays open and stays open. You'll need something like a girl's hair beret...??...berette?...whatever...metal hair retaining clip gizmo. Only made of a stiff-enough plastic with sufficient cross section to provide the spring-open force you need. Could be formed, could be injection molded, could be printed...in the open shape. When the closure is zipped, it requires the spring to bend under tension. Tension is released when zipper opens.
  10. May 2, 2016 #9
    Thank you, that is precisely the right idea! Do you have any suggestions as to where I may be able to find such a material.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted