What Makes Good Seal on K Cups

With the development of Single Serve Cup, the requirements for product quality has gradually increased, meanwhile, we also upgraded the performance and hardware of the machine to help the customer being able to produce higher quality products and keep competitive.

Here in this article, we have summarized different models and technologies. Let us see what factors will make the K cup have a better sealing?

Semi-automatic sealing machine

There are two types of semi -automatic sealing machines: pneumatic types and electric types.

First, the pneumatic sealing machine, as the name suggests, needs to connect to an air compressor, use compressed airs and cylinder to make the hot head press down, heating the aluminum foil and the cup mouth to reach the sealing.

Secondly, the electric sealing machine,

after heating the heating tube heating the sealer head, electric type uses an electric driven motor to push down the sealer heads and press on the lids, to seal the lid to the K Cup.

The electric motor model is relatively highly automated. Although the pressure is smaller, it is sufficient for the sealing K cup. You don’t need connect to air compressor, but just a plug to get electricity is enough, while the pneumatic type, you will need electricity to heat up and also compressed air is need to make it work.

This small model is more suitable as a test machine or a small batch production choice like café.

Fully automatic sealing machine-Single seal station

This is a common automated coffee capsule sealing machine.

After the aluminum foil is placed on the cup, we come to the seal station. Here we can see that there is only one seal. Or under a roll film online cut seal, the cut and seal station is combined as one station and seal one time.

Fully automatic sealing machine-twice heat seals

This model is upon our feedback on customers and after research, adding a hot seal on the basis of a single heat sealed. Twice heat sealer or dual heat sealer.

Let’s look at the same and different points of these two sealing machines

Same:

1 it consists of a cylinder or spring, supports positioning components, heat-block parts, and the heat -sealing top cylinder components and heating devices (heating rods, thermal power puppets, temperature control tables). The working process is as:

Heat up to a certain temperature needed.

Cylinder or top drive system (mechanical press) going down and touch the lid and cup and press them.

The finished product comes out.

2 The thermal sealed head is made of special copper material and processed into the size of the cup (the copper material has the characteristics of fast thermal conductivity),

3 The temperature control system can also adjust the temperature by the temperature control table. When the heating reaches the set temperature, it is at the main temperature value of the target.

Curved ring sealing and normal flat seal: The curved ring seal is stronger by making a circle that press the lid melted into the cup plastic material. While the aluminum film is sealed, it is engraved into a circle of dents at the mouth of the cup to ensure that the seal is more closed. The flat sealed surface pressed down the heat.

Especially in a single heat system, although the visual effect of the flat seal will be better, it is still recommended to use a stronger curved ring seal.

The pressure gauge, the pressure gauge dial shows the pressure of this station when it is running. The manual button can be increased or reduced when observing the result of sealing, whether too much pressure cased over melting or not enough and wants more pressure.

Two different working methods as:

Cylinder drive and spring drive, the reasons for using cylinder

Different points: Twice seal system is relative stronger and safer comparing to single seal. After the first heat seal, which can also be called pre-seal with lower temperature and lower pressure, the lids are fixed on the cup, and even if some K cups are not completely blocked, the second heat seal is with higher pressure and higher temperature and seal again even some of cups may be not sealed during the first seal.

Therefore, even when the customer chooses to use flat seal on both seal, the twice heat sealer system can meet the instability of the flat seal.

Also, as first seal and second seal is different pressure and different pressure, so such two-step process, is more fluent during the sealing process, which also makes nice cups, while in a single sealer, you have to use higher temperature and higher pressure because you only have one sealer station and wants to guarantee the sealing, so sometimes you have to accept the unstable result such as over melting, too much pressure etc. and cups are not 100% nice.

Notice for quality sealing:

The first thing is to check whether the film/lid is in the center of the cup and whether there is an offset of the lid. If you get not centered sealing while the lids are placed in center, then you need to check with the sealing process, as sealing process may touch and push the lid away, if you find that the membrane is off or uniformly seal, you need to adjust the position of the heat seal head position. At the same time as the pressure gauge, while increasing the pressure, ensure that the center of the heater heads and the cup center are in the same vertical direction. Including adjustment parameters to change the heat-sealing time.

The problem of ink displacement, which happens a lot on 2.0 ink like purple ink, but especially on the orange ink. The 2.0 type ink is sensitive to temperature, so make sure not using too high temperature during seal, and regulate the horizontal position of the heat head, so that the copper head is maintained vertically and downward during the lower pressure process. No horizontal move is allowed during sealing.

Usually pay attention to keeping the heat -sealed station cleaning. It is very hot so protection is necessary which on EXPAK machines we do install labor-protect covers for heat sealing area and of course it is forbidden to touch it with your hands.