Joie: Juice Box Holder for Kids (2019)

3d product design / design research 
Joie is a juice box holder for kids. Since kids cannot control their hand power, kids spill their drink easily, which typically leads to parents or teachers unfolding the juice tab to make a small handle. However, it can be annoying for parents and teachers, while also being hard to grab appropriately for children. To solve this problem, Joie has 3 functions; stable, stackable, and easily washable.

A team led by myself and 2 others decided to re-design a juice box holder for kids to solve this problem. As leader, I directly contributed to direct modeling, rendering, visualization, and ideation of the product.


When I worked for a daycare center, I discovered that teachers had to constantly unfold the top of milk packs to make a little tab for children to hold. These little tabs prevented spills from kids’ squeezing, but it’s really uncomfortable for kids to hold and annoying for teachers to do.

“Why do kids have to drink the juice pack with tabs?”

To define a problem space, we did several types of research. 

Research 1


Place: UNIST Education Center, South Korea
Date: Sep 24, 2019 - Sep 26, 2019
Sessions: Lunch time, Brushing teeth, and Small activity

*All the observation was conducted with the consent of children's parents and UNIST daycare center.
For a deeper understanding, we had to observe it firsthand, and wanted to know why kids drink it that way. Since we wanted to cover all the activities by kids hands, we planned to observe divided into 4 sessions; lunchtime, brushing teeth, and the activity.
We also wanted the kids to feel more natural and so we avoided using DSLR cameras, and chose to use our smartphones instead. 

There was a teacher per table with about 6 to 7 kids. However, they spilled so much food, even while using tools. After lunch, the kids washed their hands and brushed their teeth. They used a variety of toothbrushes, with a few teachers helping them, while other teachers cleaned up the classroom. After washing and brushing, the kids did some activities with toys or books.
On the last day, we could check the actual experience of kids holding on to the tabs of juice boxes. One teacher unfolded the tabs, and another teacher put straws into the boxes. Kids would hold with tabs, but it looks that there are some troubles like bending the neck, or not even holding the box up and drinking.

Research 2


Place: UNIST Education Center, South Korea
Date: Sep 25, 2019 
Duration: 60min
  1. Why do teachers have to unfold the tabs rather than the kids?

  2. Which age group do teachers have to unfold the tabs?

  3. Is there any trouble for the kids to hold tabs?

  4. Is there any other product to hold the boxes?

  5. When we observed, we did notice the clothes would get quite dirty. Don’t the students get uncomfortable?

  1. Some kids use chopsticks, and others use forks, is there any difference?

  2. We discovered that kids struggle to scoop their rice. What do you think about it?

  3. When the kids eat the soup, we’ve seen them flipping the spoon out of the bowl. Why does that occur?

  1. Why do the teachers brush the kid’s teeth once again at the end?

  2. We saw the teachers’ pumping some lotion for each student. Why is that?

  • Because of their age, the kids haven’t developed enough of the proper muscle, making it difficult for them to control their strength since they try to use their entire palm to grab the juice box. Therefore, they are more likely to spill the juice if they don’t use the tabs. There is also a different degree of development depending on the individual. Controls are developed in the order of arm – palm – fingertips.

  • At first, kids cannot catch on to it and they eat while putting their elbows on the desk. It takes a long time to adapt to tabs. But rather than letting them spill and cleaning it up, teachers are using this method.

  • Annoying to unfold a milk pack (for teacher), but it’s better than clea up the floor/tables more often


Research 3

Desk Research

We discovered and analyzed existing products and found out their disadvantages. Those are unstable since it’s just a hollow plastic box. Even if it has an adjustable function, it doesn’t cover the various sizes of milk packs and still unstable. Our future product should not only solve these disadvantages but also become fresh and innovative.

According to the observation, interview, and the desk research, we were able to find the problem space and set the target.

Main Problem Space


Uncomfortable posture

DIFFICULT TO ADAPT TO TABS 2Bend their neck forward to drink juice

DIFFICULT TO ADAPT TO TABS 3Put elbows on a table for stable posture





Korean age of 3 to 4 years old kids, kids’ parents, and teachers


Make the milk pack holder that is stable, stackable, and easily-washable, preventing kids from spilling and teachers from wiping.

To decide the proper size of the juice box holder, we conducted additional researches.

Research 3

Market Research

We collected different sizes of juice/milk boxes in South Korea.

By observation of the market, we could find out all the common sizes of milk and juice boxes. Thus, we chose to cover 80% of it, cutting the smallest and the biggest ones (in terms of diagonal size).

Research 4

Measure Kids Hand Size

The next step was to understand and measure the kids’ hand size. As it will help to define the dimensions of our future product. We calculated the average size of 10 kids. It helped us a lot, we could specify the height and handle the size of our product.

Place: UNIST Education Center

First Sketches

Starting with the clay manipulation, we moved step by step from handle shape to the overall form to refine and modify our model. Also, we sketched various forms, considered interesting and comfortable. For example, we wanted to make it easy to use in terms of putting a box by kids themselves, easy to fold to be stored well, and interesting form- like a monster.

User Scenario

Slowly, we came to our first defined form and user scenario. As the main feature, we were thinking that it should be easy to wash and easy to store (it should be stackable) as it is used in the daycare centers where there are many kids. It was decided to have three legs instead of two, as it was more stable and interesting. Then, we understood that our handle is too thin and flat, so we tried to make a more round and comfortable handle. Additionally, overall form should be changed to be more familiar with kids (be easier and fun).


We started over with sketches, now more round form was used and stackable part was considered better. Now, the top part was not a single silicone but two different parts: one is a plastic ring and the other is silicone (on top of it). Laser cutting was used to help us define the top and the bottom part (size and form), 9 different forms were considered and examined. We wanted to see how it looks, and to know the minimal size for stacking and holding. After several trials with real milk packs, form with number 6 was chosen, as it had optimal size, not too big not too small. Moreover, the silicone part had the same process as all shapes of cutout behaved differently. The best option was star-like shape (5 necklines with round tips to prevent damage as cracking), it holds various types of milk boxes better than others.

Second Sketches 

A new form became more round and was better from an ergonomics point of view, but still inherited the main feature of our first form. We found out that our model is too bulky and big: upper bumps (for stacking) should be revised, handles might be more straight without curves and the bottom part is not used efficiently.

Final Design 

We made our model smoother and more aesthetically pleasing. Handle shape was inspired by a wide toothbrush (special brush for kids, as kids use their palms to hold, not fingers), so we decided to imply wide handle features. Next, we used two layers of silicone: one on the top and one to the bottom. The function of the top one is, as before, hold the juice/milk packs tightly. The cutout was changed to the circular (instead of star-like), because with the new model it looked better and more beautiful, moreover, it was functioning fine, so we did not sacrifice functionality. The bottom silicone part was added, as it provides more stability to the juice/milk pack (no sliding). The new form is a combination of every piece from the start to the end. It has carried out all the features we wanted to adapt: stackable, easy to wash and stable. It moved a lot further than current existing products, solving their disadvantages.