Kap Keep Prototype Development
The design proposed in the ideas phase just showed a simple recess designed to accept the rim of the cap. However, in practice this did not get a good enough hold of the cap and also left the cap exposed and vulnerable to be knocked off.
Prototyping Objectives
- Ease of use with different sized hands and gloves etc
- Positive hold for the cap but still easy to place in the KapKeep and remove
- Design suitable for injection blow moulding on existing production lines and machinery.
8 prototype designs and tested. This was done by 3D printing a small section of the bottle and sticking that portion onto the side of a standard bottle with a hole cutaway to accept the recess.
Two different design routes were pursued.
Firstly the ‘post’ concept designed to hold the cap on the inside where the threads are as the internal details may be able to provide some good grip.
Secondly the ‘recess’ concept is designed to grip the cap on the outside which has a more uniform shape.
Post Designs
Post Concept 1 – Simple round Post (11mm * 27mm) in shallow recess. This didn’t grip the cap very well as the threads inside seemed to get stuck on the post. Finger access to remove also not good.
Post Concept 2 – Elliptical post to allow cap to deform and grip better. Added finger grooves either side. This gave better grip but the threads still didn’t seem to grip on the post. Closer inspection of the threads showed that since they are on a helical pattern the orientation of the lid relative to the major axis of the ellipse cause variation.
Post Concept 3 – As 2 but taller post in deeper recess. Better grip but still inconsistent
Obviously a thread detail on the post would provide good retention but this would be difficult and expensive to manufacture. Other comments were concerned that the inside of the cap could be contaminated with whatever is on the outside of the post.
Recess Designs
Recess Concept 1 – Simple 5mm deep circular recess. This gave good grip but was difficult to remove sine the cap was since fingers couldn’t grip the side of the cap after it was in the recess
Recess Concept 2 – As 1 but with similar finger grooves to the Post Concept 2. This worked well being easy to grip for removal usingthe finger grooves. However, the addition of the grooves removes the sides of the recess so the grip is slightly reduced.
Recess Concepts 3,4 &5 – With these prototypes the recess was deepened step by step ending up with concept 5 that both gripped and released the cap positively.
During testing, it was noted that with the cap on the bottle the finger grooves made it easy to carry and hold. That ergonomic thinking was developed to add an additional finger hold groove on the opposite side to the cap which gave a more comfortable hold.
FINAL DESIGN WITH EXTRA FINGER GROOVES
Detail photos of hand interactions.
3 hand types and prototypes from left to right; Post Concept 1, Recess Concept 1, Recess Concept 5 and Recess Concept 5 with extra finger groove.