Flexible packaging industry practitioners are clearer, the origin of flexible packaging is extended through the canned products instead, commonly known as "soft cans". In the composite flexible packaging products, the most representative of the soft cans of a product is the suction nozzle products.

This representation is mainly determined by the characteristics of the pipette bag itself: pipette bags in the strict sense, is a combination of hard and soft package of a product, and can not simply think of it as a soft package of products.

This combination of hard and soft parts is the most characteristic part of the pipette bag in the flexible packaging category.

First, the common structure of the pipette bag

Composite flexible packaging suction nozzle pouches have a very wide range of applications, whether in the food field, or in the field of daily chemical products, pharmaceuticals or health care products, have a very large share. In these applications, the nozzle products according to the content is divided into three major categories of powder, fluids and liquids, the structural design is different.

For powdery type products, 2~3 layer structure is generally adopted, such as:

PET/PE

NY/PE

BOPP/VMPET/PE

Used to package flavouring materials, granular sugar, toner and other lightweight products, the use of 3-layer materials are designed to achieve a certain decorative effect.

Fluid products generally use 3~4 layer structure, such as:

PET/AL/PE

PET/NY/PE

PET/AL/PET/PE

PET/AL/NY/PE

Used for packaging salad dressings, fruit and vegetable sauces, jellies and other fluid products, using 3~4 layers of material structure to ensure that the physical properties of the requirements.

Liquid products are generally also used in 3~4 layers of material structure, to protect the product transport and use for the main purpose of process design, the use of NY/NY/PE, PET/NY/PE and other structures are mostly used to pack daily chemical laundry detergent, juice, beverages, and even some alcohol, water and other products. Of course, some lightweight liquid nozzle pouches, there are also two-layer material structure design, such as 100ml below the product, there will be NY/PE or PET/PE structure products.

In the above structure, we found that there is no use of CPP as the base material, this is because of the limitations of CPP, but also the nozzle bags need to pay special attention to the place. Currently the industry as well as the consumer side, public welfare organisations and the government level in the promotion of single material packaging, such as PE/PE or BOPP/CPP structure products, nozzle products in the use of a single material, may be more inclined to choose PE//PE structure.

Second, the control points of the production process of the nozzle bag

1, raw materials

In terms of raw material process design, fabrics according to conventional process design, fabrics must be high temperature, pressure resistance, the pressure resistance, mainly refers to the pressure in the pressure mouth, can withstand the pressure and high temperature, and for a single material suction nozzle bag, need to pay special attention to the temperature resistance of the fabrics, or else it is easy to be rotted, the substrate, according to conventional, the substrate of the heat sealing temperature is relatively low, the more conducive to the bag body and the suction nozzle of the heat sealing performance. The lower the heat sealing temperature of the base material, the more favourable the heat sealing performance of the bag body and nozzle.

2.Printing

Ink needs to use high temperature resistance, especially in the position of the pressure nozzle, the relevant colour ink, if necessary, need to increase the curing agent to improve the temperature resistance of its pressure nozzle position.

If the product is designed with matte oil, generally the position of the pressure nozzle will be designed in the non-matte oil position.

Some people may wonder why the nozzle position is usually not printed with matte oil. This is because there are differences in the temperature resistance of some domestic matte oils, and many matte oils are prone to anti-sticking under the high temperature and pressure of the heat sealing position. At the same time, the heat sealing knife of the general hand press nozzle is not glued with high temperature cloth, and the back-stickiness of the matte oil is easy to pile up on the sealing knife of the press nozzle.

Therefore, in general, the design of the nozzle position is more conducive to the production control of non-mute oil position.

3、Composite

Composite need to use high-temperature resistant glue, of course, the high temperature here does not mean high-temperature cooking glue, but suitable for high-temperature glue pressure mouth. Of course, for the need to carry out high-temperature cooking nozzle bag, glue must choose high-temperature cooking grade glue. Add the nozzle of the high-temperature cooking bag, we as producers, we must understand clearly the customer's requirements. Because once the bag with a nozzle, the same cooking conditions, it is likely that because the last pressure relief in the cooking process is unreasonable or insufficient pressure, it will be in the bag body and the nozzle of the combination of the position, resulting in expansion of the bag and lead to bag breakage, because of bag breakage are mainly concentrated in the combination of soft and hard position of the weakest position. Therefore, for the addition of nozzle high-temperature cooking bags, we must be especially careful when taking orders, we must ask the customer's requirements, otherwise it is easy to lead to the waste of bulk products.

4, bag making

For the manual pressure mouth products, we should pay special attention to the size control of the pressure nozzle position, general nozzle position size has a certain size space range, if the space range is too narrow, the nozzle is difficult to put it in, it may support the bag body, and if the space range is too large, put the nozzle, and easy to drop the nozzle, and easy to press the wrong position. Therefore, when designing the space range for the nozzle, the mould must reserve a good size range so that the manual pressure nozzle will be smoother after the process.

5、Pressing nozzle

There are two main production modes of nozzle pressing, one is purely manual mode, and the other is automatic nozzle pressing machine automation mode.

Manual pressure mouth, generally we need to pay attention to the same three elements of bag making: time, temperature, pressure, pressure mouth will pay more attention to temperature and pressure. For matte OPP or OPP fabric or PE fabric products, the staff of the nozzle presser must pay special attention to the control of the temperature and pressure of the nozzle presser, with matte OPP fabric or OPP, PE fabric products always have poor temperature resistance, very easy to rot, but also very easy to produce false seals when the temperature is not enough, so the temperature range of such products will be smaller, the production of which needs to be very careful. Therefore, the temperature range of this kind of products will be smaller, and we need to be very careful when producing. For this kind of products, we need to pay special attention to the design of raw materials and technology, the fabrics try to improve the temperature resistance, the base material try to reduce the starting temperature of its heat sealing temperature, and the same nozzle also need to try to reduce the starting temperature of its sealing temperature, in order to better with the body of the bag heat sealing, in order to improve the range of the temperature difference.

Automatic sealing machine is better control than manual press mouth, automatic sealing machine will generally have preheating knife and cooling knife, can be like a bag making machine through multiple sealing pressure, better heat sealing of the nozzle and the bag body. But the automatic pressure mouth need to pay attention to is the hot knife, preheating knife and cold sealing knife pressure matching to be effectively coordinated, so the main concern of the automatic pressure mouth way is the matching of pressure and temperature, in view of each equipment manufacturer's process design is not the same or the same manufacturer's equipment models are not the same, need to operate the staff to differentiate between them.

6, process testing

The main test bag-making process and finished products and pressure nozzle process.

In the bag-making process, to test in the absence of pressure nozzle, the physical properties of the product is over. For example, test the bag drop performance, within the scope of the national standard whether to achieve the national standard height and the number of falls, not broken and not leakage, and then further test whether to meet the customer's drop requirements. Test qualified, before further production or make production adjustments. If the drop performance is not up to standard when there is no pressure nozzle, it will be more difficult to meet the relevant requirements after the pressure nozzle. Pressure resistance performance is the same, to be tested before the pressure nozzle to achieve the national standard pressure resistance index or to meet the customer's requirements of the pressure resistance index.

After the pressure mouth of the finished product should also be drop resistance and pressure resistance test, especially the nozzle and the bag body of the hot joint position, is the whole bag is sealed by the heat extrusion, the thickness of the biggest difference between the link position, in the test drop or pressure resistance, but also the most prone to break the position of the bag.

Conclusion

Suction nozzle bags have their own uniqueness, so to efficient, high-quality production of suction nozzle bags, from raw materials, structure to the production process and testing, need to take into account the characteristics of the suction nozzle bags, in general bag products based on the process design, to make adjustments.