Description:The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION:

The present invention relates to the field of plastic bag making machines. The present invention more particularly relates to the field of BOPP bag machines.

BACKGROUND OF THE INVENTION:

BOPP film is inter alia used to make bags meant for jewelry which are typically small sized bags compared to plastic bags meant for other applications. BOPP film characteristic is a memory retention that is good for a short period compared to most other plastic films. As a result, BOPP film has an inherent tendency to unfold and open.
Utility Model CN216579437U seeks to address the problem that the BOPP material plastic is uneven in slitting. The plastic bag splitting machine disclosed in the said Utility Model comprises a splitting machine body and a storage box arranged outside the splitting machine body. A supporting plate is arranged on the upper surface of the splitting machine body, a cross beam is arranged on the upper surface of the supporting plate, a telescopic movement mechanism is arranged at the bottom of the cross beam, and a telescopic pressing assembly is arranged at the bottom of the telescopic movement mechanism. A reciprocating motion mechanism is arranged at the bottom of the telescopic motion mechanism, a plastic cutting mechanism is arranged at the bottom of the telescopic motion mechanism and fixedly connected with the reciprocating motion mechanism, and a conveying belt is arranged at the top of the splitting machine body. A telescopic pressing assembly is arranged at the bottom of the telescopic movement mechanism, so that the situation that a notch is uneven due to the fact that the plastic bag deviates in the cutting process of the plastic bag is prevented, a plastic cutting motor and a cutting blade are arranged on a movable block, and the cutting blade rotates under rotation of the plastic cutting motor; therefore, the plastic bag is cut, and the problem that the BOPP material plastic is uneven in slitting is effectively solved. While the Utility Model may address the unevenness of BOPP while slitting, it does not disclose a machine to produce 4 up BOPP bags.
US 20170157882A1 discloses an uninterrupted bag making and folding machine that includes multiple server power sources electrically connected to a control unit, which instructs a conveyance unit to deliver a film tube through a sealing unit, a perforating unit and a waste breaking device for processing into finished bags, and a folding unit for folding each finished bag to reduce the size for storage. The invention enables the film tube to be continuously delivered at a constant speed and processed through a sealing process, a waste breaking process and a finished bag folding process, accelerating the finished bag fabrication speed and improving the production capacity. While this invention discloses accelerated finished bag fabrication speed and improved production capacity, but it does not address the issue of BOPP film memory retention that is good only for a short period and therefore, the invention may not be adequate for producing BOPP bags.
Manufacturers of bags out of BOPP film first need to fold the BOPP film into tube. Tubes of folded BOPP film are then used to make bags. Thus, two steps are required. Also, most machines that make BOPP bags have a large foot print in order to accommodate multiple tubes of BOPP film. The larger the machine, the greater is the wastage of BOPP film during set up.
Conventional BOPP bag making machines produce bags that cannot be stacked well and instead, get dumped into a sack and later, the bags, without getting properly stacked, end up being sold by weight and not by quantity.
The present invention seeks to address these issues while providing an economically significant solution.
OBJECTS OF THE INVENTION:
An object of the present invention is to provide a machine to manufacture BOPP bags that folds the BOPP film online and that obviates the need to have the conventional two-step process.
Another object of the present invention is to provide up to 4 lanes of BOPP bags from a single BOPP sheet.
Yet another objective of the present invention is to provide a BOPP film making machine that has a small footprint compared to conventional machines.
An additional advantage of the present invention is that it uses forming assembly for folding BOPP film and avoids or minimizes scratches on BOPP bags.
Still another advantage of the present invention is that Pearl film can be inserted in BOPP bags.

ADVANTAGES OF THE INVENTION:
An advantage of the present invention is that it does not require offline folding of BOPP film.
Another advantage of the present invention is that it provides for BOPP bag making machine that has a small footprint.
Further advantage of the present invention is that it reduces wastage of BOPP film during set up.
Yet another advantage of the present invention is that it avoids or reduces scratches on BOPP bags.
Still another advantage of the present invention is that it requires only one worker per machine who can easily stack final bags and make bunches out of them to be able to sell bags by quantity.
STATEMENT OF THE INVENTION:

The present invention discloses a machine that has multiple lanes up to 4 up bags from single BOPP sheet which folds BOPP sheet online.

BRIEF DESCRIPTION OF THE DRAWINGS:

Fig.1 represents a conventional pre-folding system to make pre-folded BOPP tubes.

Fig. 2 represents side view of the conventional machine to produce BOPP bags from pre-folded BOPP tubes.

Fig. 3 represents side view of the machine to produce BOPP bags in accordance with the present invention.

DESCRIPTION OF THE INVENTION:

As shown in Fig. 1, in conventional pre-folding system to make pre-folded BOPP tubes, an unwinder (10) unwinds BOPP sheet (15) using a film folding device (30) to fold the BOPP sheet (15) into BOPP tube (20). This forms the first step in the conventional manufacture of BOPP bags.

The second step uses conventional BOPP bag making machine (40) that uses BOPP tubes (20) as shown in Fig. 2. As can be seen in Fig. 2, there are 4 lanes of BOPP tubes (20) that produces 4 up BOPP bags. Such conventional BOPP bag making machine (40) is approximately 7.5 metres long for the second step only. This requires a fairly large foot print.

Thus, conventional manufacturing of BOPP bags requires a two-step process and a pre-folding system shown in Fig. 1 separate from the conventional BOPP bag making machine (40) shown in Fig. 2.

Now, referring to Fig. 3, it shows the BOPP bag making machine (50) in accordance with the present invention. In the present invention, there is no need to offline produce BOPP tube (20) and up to 4 up BOPP bags can be produced directly from BOPP sheet (15) that is folded online.

In accordance with the present invention, unwinder (110) unwinds the BOPP sheet (15). The two ‘C’ forming assemblies (70) form two ‘C’ shaped BOPP tubes. Pre-heater (80) pre-heats the ‘C’ shaped BOPP tubes. The two centre slitting blades (90) slit the pre-heated ‘C’ shaped BOPP tubes. The sealing cutting blade (100) seals and cuts into 4 up BOPP bags the slit and pre-heated ‘C’ shaped BOPP tubes.

BOPP bag making machine (50) also includes four strip insertion assemblies (60) to produce BOPP bags with Pearl film. Two Pearl strips are inserted inside each of the two ‘C’ shaped BOPP tubes.

BOPP bag machine (50) is at most 4.5 metres long and requires a fairly small foot print compared to the conventional BOPP bag making machine (40).

BEST METHOD OF PERFORMING THE INVENTION:

Fig. 3 shows the BOPP bag making machine (50) in accordance with the present invention. In the present invention, there is no need to offline produce BOPP tube (20) and up to 4 up BOPP bags can be produced directly from BOPP sheet (15) that is folded online.

In accordance with the present invention, unwinder (110) unwinds the BOPP sheet (15). The two ‘C’ forming assemblies (70) form two ‘C’ shaped BOPP tubes. Pre-heater (80) pre-heats the ‘C’ shaped BOPP tubes. The two centre slitting blades (90) slit the pre-heated ‘C’ shaped BOPP tubes. The sealing cutting blade (100) seals and cuts into 4 up BOPP bags the slit and pre-heated ‘C’ shaped BOPP tubes.

BOPP bag making machine (50) also includes four strip insertion assemblies (60) to produce BOPP bags with Pearl film. Two Pearl strips are inserted inside each of the two ‘C’ shaped BOPP tubes.

BOPP bag machine (50) is not longer than 4.5 metres in length and requires a fairly small foot print compared to the conventional BOPP bag making machine (40). , Claims:We Claim:
1. A BOPP bag making machine (50) to make 4 up BOPP bags comprising:
a. an unwinder (110) for BOPP sheet (15);
b. two ‘C’ forming assemblies (70);
c. a pre-heater (80);
d. two centre slitting blades (90); and
e. a sealing cutting blade (100).

2. The BOPP bag making machine (50) as claimed in Claim 1 having four Pearl strip insertion assemblies (60).

3. The BOPP bag making machine (50) as claimed in Claim 1 whose overall length is not greater than 4.5 metres.

4. A method to make 4 up BOPP bags comprising:
a. unwinding BOPP sheet (15) from unwinder (110) of the BOPP bag machine (50);
b. forming two ‘C’ shaped BOPP tubes using the two ‘C’ forming assemblies (70);
c. pre-heating the ‘C’ shaped BOPP tubes using the pre-heater (80);
d. slitting the pre-heated ‘C’ shaped BOPP tubes using the two centre slitting blades (90); and
e. sealing and cutting the pre-heated ‘C’ shaped BOPP tubes using the sealing cutting blade (100) into 4 up BOPP bags.

5. The method to make 4 up BOPP bags as claimed in Claim 3 wherein two Pearl strips are inserted inside each of the two ‘C’ shaped BOPP tubes.