ONE NEW KIND OF THE HIGH SPEED BLISTER PACKAGING MACHINE

1. FIELD OF THE INVENTION

The present invention relates to solutions for developing blister packaging machine in the medicine and healthcare industry, particularly to solutions for developing high speed blister packaging machine.

2. BACKGROUND OF THE INVENTION

Currently, the production capacity of a blister packaging machine in the medicine and healthcare industry is relatively low. Usually many enterprises have more than one aluminium-aluminium/aluminium-plastic blister packaging machine. Only by increasing the number of packaging machines can those companies increase their production capacities. Apparently, adding new machines will need extra workshop space and increase running fees of both machines and workshop.

With increasing demand for the stability of medicines/healthcare products, requirements for interior packaging materials are becoming stricter. Currently, the aluminium-aluminium blister package is one of main packaging forms for pharmaceuticals. Because medicines are sealed in blisters and protected from both air and light, the expiration date of medicine is prolonged effectively. Also, this kind of package makes medicine easy to take from blisters. The time for pressing aluminium- aluminium blisters is longer than that for pressing aluminium-plastic blisters, which limits the production capacity of an aluminium-aluminium blister packaging machine. Currently, the production capacity of an aluminium- aluminium blister packaging machine is only about one tenth of that of an aluminium-plastic blister packaging machine.

The current aluminium-aluminium/aluminium- plastic blister packaging machine only presses one row by positive moulds/high pressure air per time at room temperature. Thus, only by increasing the lines of each row can a packaging machine increase its production capacity, as it shows in Figure 1. In Figure 1 it

shows that blister moulds press aluminium foil into blisters, heat and seal them which are filled with medicine, and finally cut them into packs. Each pack includes several blisters and each row includes several packs.

Currently, an aluminium-aluminium blister packaging machine presses 6 packs (per row) per time and presses about 30 times per minute. Its capacity is determined by the inherent mechanics characters of aluminium foil and those characters are hard to improve.

Currently, there are thousands of pharmaceuticals factories in China and most of them are overcapacitied. Current blister packaging machines can basically meet their production demands. Especially, high speed aluminium-plaster blister packaging machines can meet most domestic production demands. However, most medicines in China are non-patented, so the price of them is very low. The adoption of aluminium-aluminium blister packaging machine is disadvantageous for the sake of the price competition. Therefore several hundred factories are using aluminium-aluminium blister packaging machines.

The medicine invented by the inventor is now using the aluminium-aluminium blister package. However, the current production capacity of several packaging machines can not meet the increasing production demand. More machines will be needed in the near future. If the production capacity of one packaging machine is increased by severalfold, medicine manufacturers will only need one machine and save the cost to expand workshop space. But when the inventor talked with several packaging machine design companies about this idea, they either felt hard to accept this new design idea or they didn't have the desire to meet customers' demands immediately. Thus, the inventor initiates the thought to develop a new high speed blister packaging machine.

3. CONTENT OF THE INVENTION

3.1The project of developing a high speed blister packaging machine

The production capacity of an aluminium-aluminium blister packaging machine is composed of the following factors:

> Pressing/sealing/cutting time The shortest blister shaping time T ₁ is related with the metal characters of aluminium foil. The shortest sealing time T ₂ is related with the temperature and the transmission speed of heat. Cutting speed

can be set very fast, so its shortest time T ₃ can be very short. Generally speaking, T _! >T ₂ > T ₃ .

> Moving speed of aluminium foil The moving speed of aluminium foil can be set very fast. Thus, the shortest moving time of aluminium foil T ₄ is also very short.

> Line number of blister packs, N Currently, N=3~6. If N changes, the control parameters for moving speed don't need to be changed.

> Row number of blister packs pressed/sealed /cut per time, M. Currently, M=I. If M=2, 3..., the production capacity will be increased by severalfold. However, the control parameters of advancing process need to be changed. The design of the related parts is more complicated than that in the line number's increase.

Aluminium-plastic and aluminium-aluminium blister packaging machines are basically similar. The blisters of prior one are pressed by high pressure air without positive moulds.

This invention is to develop a high speed blister packaging machine by making M =5= 2. Increasing the row number M is more complicated than increasing the line number N. To realize this project, the key point is to ensure that every blister is pressed into the same height, sealed under the same pressure and cut precisely. Otherwise, the qualification rate of the quality will decrease. When M=2, the whole packaging process is shown in Figure 2. In Figure 2 it shows that the machine presses, seals and cuts two rows of blister packs per time.

3.2. Technical obstacles possibly incurred in implementing the project

The technical obstacles incurred in developing a blister packaging machine from normal speed to high speed are evenness of pressure, sealing performance and cutting precision. If pressure is not even, blisters will be shaped in different heights and sealing performance will be not good. While in the sealing process, blisters should be positioned precisely. Otherwise, they will be misshaped. If cutting is not accurate, it will not only influence external sizes of blisters, but also lead to bad sealing performance.

3.3. Solutions to technical obstacles

3.3.1. The obstacle of the unevenness of blister pressing pressure

Solution 1 Current existing blister packaging machines transmit forces from the rotation of 1-2 cams to pressing moulds so as to press aluminium foil

into needed blisters. When the number of blisters is increased, every blister should be ensured to be pressed under the allowable pressure range. Otherwise, the height of blisters will exceed the required size range. Increasing the number of cams to increase forcing points on pressing moulds can ensure that every blister bear the same pressure.

Solution 2 When the blister number is increased to certain degree and Solution 1 can not solve the problem of unevenness of blister pressing, combining several sets of moulds narrated in Solution 1 can ensure that every blister bear the same pressure.

Solution 3 When implementing the above solutions, the bad inosculation between the positive and negative blister moulds can still lead to the unevenness of the blister pressing. Thus, installing springs or other elastic devices on the moving direction of pressing moulds can solve the inosculation problem. Also, this solution can be combined with Solution 1 and Solution 2. 3.3.2. The obstacle of the unevenness of blister sealing pressure

Solution 4 Solution 1 can solve the problem of unevenness of sealing pressure. Good blister sealing is very important. It requires sealing devices to implement identical pressure on aluminium foil/plastic film. Only when sealing devices implement identical pressure, the sealing can be tight enough.

Solution 5 When the sealing area of the sealing device is increased severalfold, the unevenness of pressure still might happen. Combining several sets of ordinary sealing devices can solve this problem.

Solution 6 Installing strings or other elastic devices on the advancing direction of sealing devices can make the two moulds of sealing devices inosculate very well so as to implement even pressure. This solution can be combined with Solution 4 and Solution 5.

4. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic flow chart showing the aluminium foil via pressing , sealing , cutting. Figure 2 is a schematic flow chart showing a process of pressing blister in the case ofM= 2.

Figure 3 is a schematic view showing a structure of a pressing mould. Figure 4 is a schematic view showing the forcing points need to be increased

on pressing moulds in the case of M=2. Figure 5 is a schematic view showing the combination of blister moulds in the case of M=4 Figure 6 is a schematic view showing the elastic devices installed between one side of blister pressing moulds and mould base. Figure 7 is a schematic view showing more forcing points exerted on sealing devices in the case of M=2

Figure 8 is a schematic view showing the combination of sealing moulds Figure 9 is a schematic view showing the elastic parts installed between sealing mould and mould base.

5. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Example 1 The project to ensure pressing moulds bear same pressure - increasing forcing points

One set of current ordinary moulds only presses one row of blister packs per time. Thus, there is no problem of the unevenness of pressing forces, as it shows in Figure 3.

This invention changes the row number of one set of ordinary moulds from one to two or more. To ensure pressing moulds bear the same pressure as before, forcing points need to be increased on pressing moulds, as it shows in Figure 4.

The row number in Example 1 relies on the precision of mould devices.

Example 2 The project to ensure pressing moulds bear same pressure — combining several sets of moulds in Example 1.

In Example 1, when the blister number pressed by one set of moulds increases to certain degree, the precision of mould devices may decrease. By combining several sets of moulds can solve the problem and improve production capacity, as it shows in Figure 5.

Example 3 The project to ensure pressing moulds bear same pressure — adding elastic devices on one side of pressing moulds

Elastic devices can be installed between one side of blister pressing moulds and its mould base to ensure pressing moulds bear same pressure, as it shows in Figure 6.

Example 4 The project to solve the unevenness of sealing pressure — increasing forcing points

When the pressing row number increases, the sealing area will increase correspondingly. To ensure the same sealing pressure as before, more forcing points should be exerted on sealing devices, as it shows in Figure 7. Thus, the aluminium foil can be ensured to receive same pressing forces and seal evenly.

Example 5 The project to solve the unevenness of sealing pressure — combining sealing devices.

Good sealing performance of blisters is the guarantee of medicine stability. Heat is transmitted from heated sealing plates to aluminium foil to make the macromolecule films on the surface of aluminium foil conglutinate together. The sealing performance crucially relies on the evenness of forces exerted on the surface of aluminium foil. Currently, the surface of heated sealing plates that seal aluminium foil is composed of raised lattice. Thus, the metal surface should be very flat. However, even though the surface is very flat, when the sealing area becomes too big, it is hard to promise two sealing plates contact each other fully and evenly. As it shows in Figure 8, two sets of separate sealing devices are combined to reduce the possibility incurred by increasing heating area to reduce the sealing performance.

In Figure 8, the number of rows that are sealed by each mould is M=I, 2..., the upper limit is determined by the flatness of sealing moulds' surface and the evenness of pressure that sealing moulds receive.

Example 6 The project to solve the unevenness of heat sealing — installing elastic devices between heating plates and the mould base

As Figure 9 shows, blister sealing performance can be improved by adding elastic devices between the heated plates of sealing mould and the mould base.

6. INDUSTRIALAPPLICABILITY

This invention can increase the production capacity of a current blister packaging machine by severalfold and at the same time save workshop cost and running fees of both machines and workshop. This new invention of a high speed blister packaging machine is a technical breakthrough in the packaging machinery industry and it will bring a huge benefit to society.