Process and apparatus for preheating a composite film for bag making

Abstract

The present application relates to the field of composite film bag making machine, especially to a kind of composite film preheating bag making process and its equipment, including the preheating step and the hot pressing step for combining first composite film and second composite film, the preheating step is located before the hot pressing step, process steps include parameter determination, preheating, transmission and forming. First preheater and second preheater respectively preheat first heat sealing layer and second heat sealing layer, then drive first composite film and second composite film to the first heating assembly and the second heating assembly by the transmission assembly, then heat first composite film and second composite film by the first heating assembly and the second heating assembly respectively, avoid the situation that the heat transfer efficiency is low and the production efficiency is difficult to improve due to the indirect heating of first heat sealing layer and second heat sealing layer between the first heating assembly and the second heating assembly.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite film bag making machine, in particular to a composite film preheating bag making process and equipment thereof. BACKGROUND

[0002] The composite film bag making process is a process for making soft packaging of plastic film or paper plastic film. In the existing composite film bag making process, the process of "partial completion of pressing and sticking, heat transfer, temperature rise, and hot pressing and sticking" is usually used for the step of hot pressing and sticking. The composite film is composed of a surface layer substrate on the outer layer and a heat sealing layer on the inner layer. In the production of the traditional process, the heating of the heat sealing layer needs to be conducted through the heat transfer of the surface layer substrate. This indirect heating method requires a long temperature rising time, which makes it difficult to improve the production efficiency. SUMMARY

[0003] Therefore, the present application provides a composite film preheating bag making process and equipment thereof which can improve the production efficiency.

[0004] The technical scheme of the present application is as follows: a composite film preheating bag making process, which comprises a preheating step and a hot pressing step for combining a first composite film and a second composite film. The preheating step is arranged before the hot pressing step. First and second preheating components are arranged at a position between the paths of the first and second composite films in the preheating step. In the preheating step, the first and second preheating components directly heat the heat sealing layer substrate on the inner surface of the first and second composite films, respectively, to improve the initial temperature of the composite film in the hot pressing step. The process comprises the following steps:

[0005] Parameter determination: the first preheating temperature T1 is determined according to the material of the first heat sealing layer of the first composite film, the second preheating temperature T2 is determined according to the material of the second heat sealing layer of the second composite film, the first heating temperature T5 is determined according to the first surface layer material of the first composite film and the total thickness of the first composite film, and the second heating temperature T6 is determined according to the second surface layer material of the second composite film and the total thickness of the second composite film. When the first preheating temperature T1 and the second preheating temperature T2 are used, neither the first heat sealing layer nor the second heat sealing layer is melted;

[0006] Preheating: in the preheating step, the first preheating component heats the first heat sealing layer to the first preheating temperature T1, and the second preheating component heats the second heat sealing layer to the second preheating temperature T2;

[0007] Transmission: the first composite film and the second composite film are moved to the position of the hot pressing step by the transmission component, and the first composite film and the second composite film are adhered under the action of the transmission component;

[0008] Forming: in the hot-pressing step, the initial temperatures of the first and second heat-seal layers are the first and second hot-pressing initial temperatures T3 and T4, the first and second heating assemblies heat the first and second heat-seal layers to the first and second target temperatures T7 and T8, and the first and second composite films are hot-pressed and bonded under pressure.

[0009] Optionally, between the step of preheating and the step of parameter determination, the following step is further included:

[0010] Sample trial: under the conditions of the current temperature parameters, the current transmission assembly running speed v1, the first heating assembly heat transfer time t1 to the first composite film, and the second heating assembly heat transfer time t2 to the second composite film, a sample is tried.

[0011] Optionally, between the step of preheating and the step of sample trial determination, the following step is further included:

[0012] Parameter adjustment: according to the permission of the mechanical speed, the running speed of the transmission assembly is increased according to the following formula:

[0013] v2 = v1 +△v, where v2 is the adjusted running speed of the transmission assembly, v1 is the running speed of the transmission assembly before adjustment,△v is the single increment of speed, after adjustment, the hot-pressing firmness and apparent quality of the sample are checked again, if the hot-pressing firmness and apparent quality meet the standards, then v2 is assigned to v1, and the cycle debugging is performed.

[0014] If the hot-pressing firmness or apparent quality does not meet the standards, the first preheating temperature T1 and the second preheating temperature T2 are increased, the first hot-pressing initial temperature T3 and the second hot-pressing initial temperature T4 are increased, so as to improve the hot-pressing firmness and apparent quality, and then the running speed of the transmission assembly is adjusted to obtain the maximum value of v1.

[0015] If the transmission adhesion phenomenon of the composite film heat-seal layer occurs after the first preheating temperature T1 and the second preheating temperature T2 are increased, the values of T1, T2 and v1 before the increase are returned.

[0016] Optionally, the initial value of the first preheating temperature T1 is T1 = X1*T9, and the initial value of the second preheating temperature T2 is T2 = Y1*T10, where the values of X1 and Y1 are both between 0.75 and 0.85, and T9 and T10 are the melting temperatures of the first and second heat-seal layers, respectively; the first heating target temperature T7 = X2*T9, and the second heating target temperature value T8 = Y2*T10, where the values of X2 and Y2 are both between 0.85 and 1.05.

[0017] Optionally, between the step of parameter determination and the step of preheating, the following content is further included:

[0018] The first heating component includes a first supplementary heat source and a first hot knife, and the second heating component includes a second supplementary heat source and a second hot knife. The temperature of the first hot knife is determined according to the material of the first surface substrate, and the temperature of the second hot knife is determined according to the material of the second surface substrate. The correction values ​​ΔT5 and ΔT6 of the first hot knife and the second hot knife are determined according to the respective thicknesses of the first composite film and the second composite film. The set temperature of the first hot knife is the first heating temperature T5 and T5 = T11 + ΔT5, and the set temperature of the second hot knife is the second heating temperature T6 and T6 = T12 + ΔT6.

[0019] Optionally, the initial operating speed v1 of the transmission assembly is negatively correlated with the length of the bag and the delivery distance.

[0020] Optionally, the first preheating temperature T1 and the second preheating temperature T2 are automatically controlled using one of the following three methods:

[0021] Method 1: The first preheating temperature T1, the second preheating temperature T2, the first heating temperature T5, and the second heating temperature T6 are controlled independently;

[0022] Method 2: The first preheating temperature T1 and the first heating temperature T5 are linked and controlled together; the second preheating temperature T2 and the second heating temperature T6 are linked and controlled together.

[0023] Method 3: The first preheating temperature T1, the second preheating temperature T2, the first heating temperature T5, and the second heating temperature T6 are linked and controlled.

[0024] Another objective of this embodiment is to provide a composite film preheating bag making device, including the first preheating component, the second preheating component, the first heating component, the second heating component and the transmission component described above, wherein the first composite film and the second composite film are provided with a separation portion, a transition portion and a joining portion in sequence along the extension direction of the forward direction of the transmission component.

[0025] The first preheating component is disposed at the separation portion of the first composite film, the second preheating component is disposed at the separation portion of the second composite film, the first heating component is disposed at the bonding portion of the first surface substrate of the first composite film on the side away from the first heat-sealed layer, and the second heating component is disposed at the bonding portion of the second surface substrate of the second composite film on the side away from the second heat-sealed layer.

[0026] Optionally, the transmission assembly includes at least two first rollers and at least two second rollers, with the at least two first rollers respectively disposed on opposite sides of the separation portions of the first composite film and the second composite film, and the at least two second rollers respectively disposed on the outer side of the transition portion of the first surface substrate and the second surface substrate.

[0027] Compared with the prior art, implementing the embodiments of the present invention has the following beneficial effects:

[0028] The composite film preheating bag making process and equipment of the present invention preheat the first heat-sealing layer and the second heat-sealing layer by using a first preheater and a second preheater respectively, and then transmits the first composite film and the second composite film to the space between the first heating component and the second heating component by a transmission component. The first heating component and the second heating component then heat the first composite film and the second composite film respectively. This avoids the situation where the first heat-sealing layer and the second heat-sealing layer are indirectly heated between the first heating component and the second heating component, resulting in low heat transfer efficiency and difficulty in improving production efficiency. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the composite film preheating bag making equipment described in Embodiment 1 of the present invention.

[0030] Figure 2 This is a flowchart of a sample trial of the composite film preheating bag making process described in Embodiment 1 of the present invention.

[0031] Figure 3 This is a schematic diagram of the structure of the composite film preheating bag making equipment described in Embodiment 2 of the present invention.

[0032] Figure 4 This is a schematic diagram of the structure of the composite film preheating bag-making equipment described in Embodiment 3 of the present invention.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. First composite film; 11. First surface substrate; 12. First heat-sealing layer;

[0035] 2. Second composite film; 21. Second surface substrate; 22. Second heat-sealing layer.

[0036] 3. First preheating component,

[0037] 4. Second preheating component,

[0038] 5. First heating element; 51. First supplementary heat source; 52. First hot knife.

[0039] 6. Second heating element; 61. Second supplementary heat source; 62. Second hot knife.

[0040] 7. First roller,

[0041] 8. Second roller,

[0042] A. Separation section, B. Transition section, C. Joint section.

[0043] T1, First preheating temperature,

[0044] T2, the second preheating temperature,

[0045] T3, Initial temperature of the first pressing.

[0046] T4, initial temperature of the second pressing.

[0047] T5, First heating temperature,

[0048] T6, Second heating temperature,

[0049] T7, First target temperature,

[0050] T8, the second target temperature.

[0051] T9, the melting temperature of the first heat-sealed layer.

[0052] T10, the melting temperature of the second heat-sealed layer

[0053] T11, First heating blade temperature,

[0054] T12, the second hot knife temperature. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0057] Furthermore, the terms "first," "second," etc., are used in this invention to describe various types of information, but these terms should not be limited to them; they are only used to distinguish information of the same type from one another. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information.

[0058] Example 1:

[0059] ReferenceFigure 1 and Figure 2 This embodiment provides a process and equipment 100 for preheating composite film to make bags, including a preheating step and a pressing step for combining a first composite film 1 and a second composite film 2. The preheating step is set before the pressing step. A first preheating component 3 and a second preheating component 4 are arranged between the paths of the first composite film 1 and the second composite film 2 in the preheating step. In the preheating step, the first preheating component 3 and the second preheating component 4 respectively preheat the heat-sealing layer substrate on the surface of the first composite film 1 and the inner surface of the second composite film 2 in this step, so that the temperature of the heat-sealing layer substrate is close to its heat-melting temperature, thereby increasing the initial temperature of the composite film in the pressing step. The process includes step parameter determination, preheating, transmission, and forming.

[0060] The parameter determination includes determining a first preheating temperature T1 based on the material of the first heat-sealing layer 12 of the first composite film 1, determining a second preheating temperature T2 based on the material of the second heat-sealing layer 22 of the second composite film 2, determining a first heating temperature T5 based on the first surface material 11 and the total thickness of the first composite film 1, and determining a second heating temperature T6 based on the second surface material 21 and the total thickness of the second composite film 2. When the first preheating temperature T1 and the second preheating temperature T2 are used, neither the first heat-sealing layer 12 nor the second heat-sealing layer 12 melts.

[0061] The preheating process includes heating the first heat-sealed layer 12 to a first preheating temperature T1 by the first preheating component 3, and heating the second heat-sealed layer 22 to a second preheating temperature T2 by the second preheating component 4.

[0062] The transmission includes moving the first composite film 1 and the second composite film 2 to the position of the hot pressing step through the transmission component, so that the first composite film 1 and the second composite film 2 are bonded together under the action of the transmission component.

[0063] The molding process includes, in the hot pressing step, the initial temperatures of the first heat-sealed layer 12 and the second heat-sealed layer 22 are respectively the first hot pressing initial temperature T3 and the second hot pressing initial temperature T4, the first heating component 5 and the second heating component 6 heat the first heat-sealed layer 12 and the second heat-sealed layer 22 to the first target temperature T7 and the second target temperature T8, and the first composite film 1 and the second composite film 2 are hot-pressed and bonded under pressure.

[0064] After the first heat-sealing layer 12 and the second heat-sealing layer 22 are preheated by the first preheating component 3 and the second preheating component 4 respectively, the first composite film 1 and the second composite film 2 are then transmitted between the first heating component 5 and the second heating component 6 by the transmission component. The first heating component 5 and the second heating component 6 then heat the first composite film 1 and the second composite film 2 respectively. This avoids the situation where the first heat-sealing layer 12 and the second heat-sealing layer 22 are indirectly heated between the first heating component 5 and the second heating component 6, resulting in low heat transfer efficiency and difficulty in improving production efficiency.

[0065] Better, refer to Figure 1 and Figure 2 In this embodiment, between the preheating step and the parameter determination step, there is also a sample trial run step, wherein...

[0066] Sample testing includes testing samples under the following conditions: current temperature parameters, current transmission component operating speed v1, heat transfer time t1 of the first heating component 5 to the first composite film 1, and heat transfer time t2 of the second heating component 6 to the second composite film 2. Through sample testing, it can be confirmed whether the samples produced under the current parameters meet the requirements of the first heat-sealing layer 12, the second heat-sealing layer 22 not adhering to the transmission component, the heat-pressing adhesion of the first composite film 1 and the second composite film 2, and the appearance quality.

[0067] Better, refer to Figure 1 and Figure 2 In this embodiment, between the preheating step and the sample trial determination, the step parameter adjustment is also included, wherein,

[0068] Parameter adjustments include increasing the operating speed of the transmission components according to the following formula, based on the permissible speed of the machinery:

[0069] v2 = v1 + Δv, where v2 is the adjusted speed of the transmission component, v1 is the original speed of the transmission component, and Δv is the speed increment per cycle. After adjustment, the heat-pressing firmness and appearance quality of the sample are checked again. If the heat-pressing firmness and appearance quality meet the standards, v2 is assigned to v1 and cyclic debugging is performed.

[0070] If the heat sealing adhesion or appearance quality does not meet the standards, the first preheating temperature T1 and the second preheating temperature T2 are increased, thereby raising the first initial heat sealing temperature T3 and the second initial heat sealing temperature T4, thus improving the heat sealing adhesion and appearance quality. Then, the operating speed of the transmission component is adjusted to obtain the highest value of v1. Specifically, in this embodiment, the initial value of the first preheating temperature T1 is T1 = X1 * T9, and the initial value of the second preheating temperature T2 is T2 = Y1 * T10, where the values ​​of X1 and Y1 are both between 0.75 and 0.85. T9 and T10 are the melting temperatures of the materials of the first heat-sealing layer 12 and the second heat-sealing layer 22, respectively. The first heating target temperature T7 = X2 * T9, and the second heating target temperature T8 = Y2 * T10, where the values ​​of X2 and Y2 are both between 0.85 and 1.05. If adhesion occurs in the composite film heat-sealing layer after increasing the first preheating temperature T1 and the second preheating temperature T2, then revert to the original values ​​of T1, T2 and v1.

[0071] With the temperature parameter at its upper limit, increasing heat transfer efficiency reduces heat transfer time, and then adjusting the operating speed of the transmission components yields the highest value of v1. This achieves the highest operating efficiency for the current equipment and operating environment.

[0072] Better, refer to Figure 1 and Figure 2 In this embodiment, the step parameter determination and step preheating also include the following:

[0073] The first heating component 5 includes a first supplementary heat source 51 and a first hot knife 52. The second heating component 6 includes a second supplementary heat source 61 and a second hot knife 62. The temperature of the first hot knife is determined according to the material of the first surface substrate 11, and the temperature of the second hot knife is determined according to the material of the second surface substrate 21. The correction values ​​ΔT5 and ΔT6 of the first hot knife 52 and the second hot knife 62 are determined according to the respective thicknesses of the first composite film 1 and the second composite film 2. The set temperature of the first hot knife 52 is the first heating temperature T5 and T5 = T11 + ΔT5. The set temperature of the second hot knife 62 is the second heating temperature T6 and T6 = T12 + ΔT6.

[0074] Preferably, in this embodiment, the initial operating speed v1 of the transmission component is negatively correlated with the length of the bag and the delivery distance.

[0075] Better, refer to Figure 1 and Figure 2 In this embodiment, the first preheating temperature T1 and the second preheating temperature T2 are automatically controlled using one of the following three methods:

[0076] Method 1: The first preheating temperature T1, the second preheating temperature T2, the first heating temperature T5, and the second heating temperature T6 are controlled independently;

[0077] Method 2: The first preheating temperature T1 and the first heating temperature T5 are linked and controlled together; the second preheating temperature T2 and the second heating temperature T6 are linked and controlled together.

[0078] Method 3: The first preheating temperature T1, the second preheating temperature T2, the first heating temperature T5, and the second heating temperature T6 are linked and controlled.

[0079] Normally, the first heat-sealed layer 12 and the second heat-sealed layer 22 are made of the same material. This allows the first preheating temperature T1 to be the same as the second preheating temperature T2, and the first heating temperature T5 to be the same as the second heating temperature T6. Adjusting to mode two or mode three reduces the number of steps required by the operator. Specifically, in this embodiment, when the first heat-sealed layer 12 and the second heat-sealed layer 22 are made of PE substrate, T5 = T6 = 100℃; when the first heat-sealed layer 12 and the second heat-sealed layer 22 are made of CPP substrate, T5 = T6 = 160℃. When the first heat-sealed layer 12 and the second heat-sealed layer 22 are not made of the same material, the operator can handle the special production situation using mode one.

[0080] Another objective of this embodiment is to provide a device for preheating composite film to make bags, including the first preheating component 3, the second preheating component 4, the first heating component 5, the second heating component 6 and the transmission component mentioned above. The first composite film 1 and the second composite film 2 are each provided with a separation part A, a transition part B and a connecting part C in sequence along the forward extension direction of the transmission component.

[0081] The first preheating component 3 is disposed at the separation part A of the first composite film 1, the second preheating component 4 is disposed at the separation part A of the second composite film 2, the first heating component 5 is disposed at the side away from the first heat-sealing layer 12 at the bonding part C of the first surface substrate 11, and the second heating component 6 is disposed at the side away from the second heat-sealing layer 22 at the bonding part C of the second surface substrate 21.

[0082] Better, refer to Figure 1 In this embodiment, the transmission assembly includes at least two first rollers 7 and at least two second rollers 8. The at least two first rollers 7 are respectively disposed on opposite sides of the separation portion A of the first composite film 1 and the second composite film 2, and the at least two second rollers 8 are respectively disposed on the outer side of the transition portion B of the first surface substrate 11 and the second surface substrate 21. The first rollers 7 and the second rollers 8 can limit the positioning of the first composite film 1 and the second composite film 2, thereby forming the separation portion A, the transition portion B, and the joint portion C while driving the first composite film 1 and the second composite film 2 to move.

[0083] Better, refer to Figure 1In this embodiment, the first preheating component 3 is disposed on the side of the first heat-sealed layer 12 away from the first surface substrate 11, and the second preheating component 4 is disposed on the side of the second heat-sealed layer 22 away from the second surface substrate 21. The first heat-sealed layer 12 and the second heat-sealed layer 22 are directly heated by the first preheating component 3 and the second preheating component 4 through electric heating, ensuring the accuracy of heating the first heat-sealed layer 12 and the second heat-sealed layer 22.

[0084] Example 2:

[0085] Better, refer to Figure 3 In this embodiment, the first preheating component 3 is disposed on the side of the first surface substrate 11 away from the first heat-sealing layer 12, and the second preheating component 4 is disposed on the side of the second surface substrate 21 away from the second heat-sealing layer 22. By indirectly heating the first heat-sealing layer 12 and the second heat-sealing layer 22 by heating the first surface substrate 11 and the second surface substrate 21, the power required by the first heating component 5 and the second heating component 6 can be reduced.

[0086] Example 3:

[0087] Better, refer to Figure 4 In this embodiment, the first preheating component 3 and the second preheating component 4 are disposed on the outer periphery of the first roller 7 and the second roller 8. The first roller 7 and the second roller 8 are bonded to the first heat-sealing layer 12 through the first preheating component 3, and the first roller 7 and the second roller 8 are bonded to the second heat-sealing layer 22 through the second preheating component 4. The heat source for the first preheating component 3 and the second preheating component 4 is a high-temperature liquid. By disposing the first preheating component 3 and the second preheating component 4 on the first roller 7 and the second roller 8 respectively, the first composite film 1 and the second composite film 2 can be heated simultaneously during movement, thereby improving work efficiency.

[0088] In other embodiments, the above process can also be applied to a multilayer composite film in which an intermediate substrate is provided between the first heat-sealing layer 12 and the first surface substrate 11, and the total thickness of the first composite film is the sum of the thicknesses of the intermediate substrate, the first heat-sealing layer 12 and the first surface substrate 11.

[0089] The process and equipment for preheating composite film bag making in this embodiment are used with the example of different materials for the first and second composite films:

[0090] The first preheating temperature T1 is determined based on the material of the first heat-sealing layer 12 of the first composite film 1, and the second preheating temperature T2 is determined based on the material of the second heat-sealing layer 22 of the second composite film 2. The first initial pressing temperature T3 and the second initial pressing temperature T4 are set. The first heating temperature T5 is determined based on the first surface material 11 of the first composite film 1 and the total thickness of the first composite film 1. The second heating temperature T6 is determined based on the second surface material 21 of the second composite film 2 and the total thickness of the second composite film 2. The temperature of the first heating component 5 is set to the first target temperature T7, and the temperature of the second heating component 6 is set to the second target temperature T8.

[0091] Under the conditions of current temperature parameters, current transmission component operating speed v1, heat transfer time t1 of the first heating component 5 to the first composite film 1, and heat transfer time t2 of the second heating component 6 to the second composite film 2, a sample is made. Through sample making, it can be confirmed whether the sample made under the current parameters meets the requirements of the first heat-sealing layer 12, the second heat-sealing layer 22 not adhering to the transmission component, the heat-pressing adhesion of the first composite film 1 and the second composite film 2, and the appearance quality.

[0092] Based on the permissible speed of the machinery, increase the operating speed in increments of (5-10) times / minute. After adjustment, recheck the pressing adhesion and surface quality. If the pressing adhesion or surface quality does not meet the standards, increase the first preheating temperature T1 and the second preheating temperature T2 to raise the first initial pressing temperature T3 and the second initial pressing temperature T4, thereby improving the pressing adhesion and surface quality. Then adjust the operating speed of the transmission component to obtain the highest value of v1. The initial setting value of the first preheating temperature T1 is T1 = (0.75-0.85) * T9, and the initial setting value of the second preheating temperature T2 is T2 = (0.75-0.85) * T10. T9 and T10 are the melting temperatures of the materials of the first heat-sealed layer 12 and the second heat-sealed layer 22, respectively. The first heating target temperature T7 = (0.85-1.05) * T9, and the second heating target temperature T8 = (0.85-1.05) * T10. If adhesion occurs in the composite film heat-sealing layer after increasing the first preheating temperature T1 and the second preheating temperature T2, then revert to the original values ​​of T1, T2 and v1.

[0093] After debugging, the first heat-sealing layer 12 is heated to a first preheating temperature T1 by the first preheating component 3, and the second heat-sealing layer 22 is heated to a second preheating temperature T2 by the second preheating component 4. Then, the transmission component moves the first composite film 1 and the second composite film 2, causing them to adhere together under the action of the second roller 8. Finally, the adhered first composite film 1 and the second composite film 2 are heated to a first target temperature T7 and a second target temperature T8 respectively by the first heating component 5 and the second heating component 6, and then pressed together under pressure. This completes the bag-making process of the composite film, avoiding the low heat transfer efficiency and difficulty in improving production efficiency caused by indirect heating between the first heating component 5 and the second heating component 6 for the first heat-sealing layer 12 and the second heat-sealing layer 22.

[0094] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A process for preheating composite film to make bags, characterized in that, The process includes a preheating step and a heat-pressing step for combining a first composite film and a second composite film. The preheating step is performed before the heat-pressing step. A first preheating component and a second preheating component are positioned between the paths of the first and second composite films in the preheating step. In the preheating step, the first and second preheating components directly preheat the heat-sealing layer substrate on the inner surface of the first and second composite films, respectively, thereby increasing the initial temperature of the composite film in the heat-pressing step. The process includes the following steps: Parameter determination: The first preheating temperature T1 is determined based on the material of the first heat-sealing layer of the first composite film; the second preheating temperature T2 is determined based on the material of the second heat-sealing layer of the second composite film; the first heating temperature T5 is determined based on the material of the first surface layer of the first composite film and the total thickness of the first composite film; and the second heating temperature T6 is determined based on the material of the second surface layer of the second composite film and the total thickness of the second composite film. When the first preheating temperature T1 and the second preheating temperature T2 are used, neither the first heat-sealing layer nor the second heat-sealing layer melts. Preheating: In the preheating step, the first heat-sealed layer is heated to a first preheating temperature T1 by the first preheating component, and the second heat-sealed layer is heated to a second preheating temperature T2 by the second preheating component; Transmission: The transmission component drives the first composite film and the second composite film to move towards the hot pressing step, and causes the first composite film and the second composite film to adhere under the action of the transmission component; Molding: In the hot pressing step, the initial temperatures of the first heat-sealed layer and the second heat-sealed layer are the first hot pressing initial temperature T3 and the second hot pressing initial temperature T4, respectively. The first heating component and the second heating component heat the first heat-sealed layer and the second heat-sealed layer to the first target temperature T7 and the second target temperature T8, and the first composite film and the second composite film are hot-pressed and bonded under pressure. Between the preheating step and the parameter determination step, the following steps are also included: Sample trial production: Under the conditions of current temperature parameters, current transmission component operating speed v1, heat transfer time t1 of the first heating component to the first composite film, and heat transfer time t2 of the second heating component to the second composite film, a sample trial production was carried out. Between the preheating process and the sample trial determination, the following steps are also included: Parameter adjustment: Based on the permissible speed of the machinery, increase the operating speed of the transmission components according to the following formula: v2 = v1 + Δv, where v2 is the adjusted speed of the transmission component, v1 is the original speed of the transmission component, and Δv is the speed increment per cycle. After adjustment, the heat-pressing firmness and appearance quality of the sample are checked again. If the heat-pressing firmness and appearance quality meet the standards, v2 is assigned to v1 and cyclic debugging is performed. If the heat pressing firmness or appearance quality does not meet the standards, the first preheating temperature T1 and the second preheating temperature T2 are increased, so that the first heat pressing initial temperature T3 and the second heat pressing initial temperature T4 are increased, thereby improving the heat pressing firmness and appearance quality. Then, the running speed of the transmission component is adjusted to obtain the highest value of v1. If adhesion of the composite film heat-sealing layer occurs after increasing the first preheating temperature T1 and the second preheating temperature T2, then revert to the original values ​​of T1, T2 and v1.

2. The process for preheating and bag making of composite film according to claim 1, characterized in that, The initial value of the first preheating temperature T1 is T1=X1*T9, and the initial value of the second preheating temperature T2 is T2=Y1*T10, where the values ​​of X1 and Y1 are both between 0.75 and 0.85, and T9 and T10 are the melting temperatures of the first and second heat-sealing layer materials, respectively; the first target temperature T7=X2*T9, and the second target temperature T8=Y2*T10, where the values ​​of X2 and Y2 are both between 0.85 and 1.

05.

3. The process method for preheating composite film to make bags according to claim 2, characterized in that, The process between determining the parameters and preheating includes the following: The first heating component includes a first supplementary heat source and a first hot knife, and the second heating component includes a second supplementary heat source and a second hot knife. The temperature of the first hot knife is determined according to the material of the first surface substrate, and the temperature of the second hot knife is determined according to the material of the second surface substrate. The correction values ​​ΔT5 and ΔT6 of the first hot knife and the second hot knife are determined according to the respective thicknesses of the first composite film and the second composite film. The set temperature of the first hot knife is the first heating temperature T5 and T5 = T11 + ΔT5, and the set temperature of the second hot knife is the second heating temperature T6 and T6 = T12 + ΔT6.

4. The process method for preheating composite film to make bags according to claim 1, characterized in that, The initial speed v1 of the transmission component is negatively correlated with the length of the bag and the delivery distance.

5. The process method for preheating composite film to make bags according to claim 1, characterized in that, The first preheating temperature T1 and the second preheating temperature T2 are automatically controlled using one of the following three methods: Method 1: The first preheating temperature T1, the second preheating temperature T2, the first heating temperature T5, and the second heating temperature T6 are controlled independently; Method 2: The first preheating temperature T1 and the first heating temperature T5 are controlled in conjunction with each other, and the second preheating temperature T2 and the second heating temperature T6 are controlled in conjunction with each other. Method 3: The first preheating temperature T1, the second preheating temperature T2, the first heating temperature T5, and the second heating temperature T6 are linked and controlled.

6. An apparatus for preheating composite film bags, applied to the process of preheating composite film bags according to any one of claims 1-5, characterized in that, The system includes the first preheating component, the second preheating component, the first heating component, the second heating component, and the transmission component. The first composite film and the second composite film are provided with a separation part, a transition part, and a joint part in sequence along the extension direction of the forward direction of the transmission component. The first preheating component is disposed at the separation portion of the first composite film, the second preheating component is disposed at the separation portion of the second composite film, the first heating component is disposed at the bonding portion of the first surface substrate of the first composite film on the side away from the first heat-sealed layer, and the second heating component is disposed at the bonding portion of the second surface substrate of the second composite film on the side away from the second heat-sealed layer.

7. The composite film preheating bag-making equipment according to claim 6, characterized in that, The transmission assembly includes at least two first rollers and at least two second rollers. The at least two first rollers are respectively disposed on opposite sides of the separation portion of the first composite film and the second composite film, and the at least two second rollers are respectively disposed on the outer side of the transition portion of the first surface substrate and the second surface substrate.

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