JPS5822433B2 - Plastic bag with filling valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic bag having a fill valve and an air permeable dust filtration layer that allows air to be evacuated from the interior of the bag.

Plastic bags with fill valves are commonly known in the art.

In known plastic bags, the filling valve is placed on one side of the bag, and at the same end of the bag as the filling valve, but in the opposite corner from the filling valve, there is a provision for discharging air from the interior of the bag. An air permeable dust filtration layer is placed.

Such known bags have the disadvantage that the air permeable dust filtration layer constitutes the outside of the bag and is susceptible to damage.

Particularly with plastic bags, it is even more difficult to achieve the proper combination of a homogeneous air permeable dust filtration layer with the plastic bag.

Even more disadvantageous is that the bag as a whole is susceptible to damage since grasping the bag at the dust filtering air permeable layer will damage this air permeable layer.

The construction of such bags therefore suggests that the dust filtration air permeable layer should have great strength properties, but in some cases this becomes a drawback that impedes the air permeability of the layer.

In bags of this type, the presence of trapped air is essential if very fine powders have to be packed into such bags.

This is because the absence of such air adversely affects proper stacking of the bags.

However, particles also tend to be ejected through the dust filtration layer,
This must be avoided.

This is because powder discharged from the bag together with air during or after filling the bag tends to adhere to the outside of the bag due to electrostatic charge, making the accumulated bag particularly prone to slipping. It is.

The object of the present invention is to provide a plastic bag with a fill valve, which is characterized in that the above-mentioned disadvantages are alleviated.

A further object of the invention is to provide a bag characterized in that the gas-permeable layer is covered at least in part by an impermeable covering layer.

The gas permeable layer is a layer of material that is integral with the bag.

Preferably, it is at least partially covered by at least one bag.

In this way, the gas-permeable layer is never exposed to the surrounding atmosphere, so that a person handling the bag cannot grasp any relevant parts thereof.

Preferably, the bag material that is integral with the layer of material forming the bag forms the bag bottom layer.

In this way, on the one hand, the filling valve can be formed in one corner of the bag, and on the other hand, the dust-filtering air-permeable layer can be simultaneously attached to the other corner, and then the bottom is formed. .

The gas permeable layer suitably extends from both the edges of the inner corner flaps of the bag and the edges of the bottom portion of the bag located opposite the corner flaps.

A very convenient embodiment is protected by a corner flap located on the inside of the bottom and on its underside, and opposite the filling valve, whereby a pocket of gas-permeable material is provided at least in the corner flap. It extends to the inner edge.

in a gas permeable layer that forms small pockets.

The pocket of air permeable material may extend beyond the inner edge of the corner flap.

The above embodiment of forming pockets of gas permeable material has the great advantage that the bag can be easily removed from the filling nozzle of the filling machine after filling.

This is because even a normally flat plastic bag can be manipulated and grasped by the aforementioned pockets of air permeable material.

This one in particular appears to be delicate.

On the other hand, however, pockets of gas-permeable material have the great advantage that air can be easily evacuated from the interior of the bag.

The gas-permeable material is conveniently constituted by a felt or non-woven thermoplastic fabric, in particular of polyester or polyethylene fibres.

Conveniently, the fill valve consists of a tube section which is fixed to the bag bottom and has a protruding part that can be folded back inward to seal the fill valve.

FIG. 1 shows a plastic bag 1 in which a front foil layer and a rear foil layer form a clearly tubular foil.

The bag has a first bottom flap 3 and a second bottom flap 4.
and a bottom part 2 formed by being joined together by adhesive bonding or heat sealing 5.

The first and second bottom flaps 3 and 4 include bottom flap edges 8 and 9.

first and second corner flaps 11 while forming a bottom;
and 12 are also formed at the same time.

The first corner flap 11 is the first corner flap located inside the bag.
- with corner flap edges 14;

The second corner flap 12 has an edge 13 .

After folding the corner flap parts 11 and 12, the valve pipe part 6 is placed in the position of the corner flap 11, after which the end part 16 is folded back towards the projecting end 17 of the valve pipe part.

The valve tube section 6 forms a fill valve end 18 which is located within the bag and extends further into the bag than the end edge 14 of the first corner flap section 11 .

On the other hand, the free end edge 17 of the filling valve tube part 6 projects outside the bag.

Adhesive joints or heat seals 19 and 20 join the valve tube ends to the corner flaps 11 and the bottom covering foil layer 21, which in turn connects to the folded bottom flap 3.
and fixed along 4.

On the other hand, an air permeable pocket 22 is attached to the second corner flap 12.
Fixed.

This pocket forms an air permeable junction between the interior and exterior of the bag.

This pocket 22 is preferably of such length that it extends inside the bag beyond the edge 13 of the second corner flap 12.

In the vicinity of the free end 23, the pocket 22 has a bottom covering foil layer covering the bottom flaps 3 and 4 which are folded towards each other and the part of the second corner flap 12 which is arranged directly below them. 21 by adhesive or heat sealing.

It is clear that a dust-filtering but air-permeable pocket 22 of felt or non-woven fabric connects the inside of the bag with the outside, allowing air trapped inside the bag to be evacuated. be.

The air permeable pocket 22 is comprised of layers 22a and 22b whose ends are interconnected to form the air permeable or non-woven pocket 22.

During the period that the bag is being filled by the filling machine, the bag is suspended from the filling machine by means of the filling valve 6, but once the filling has been completed, the bag can be easily removed from the filling machine.

This is because, by placing a hand into the air permeable pocket 22, the normally smooth plastic bag 1 can be easily grasped and removed from the filling machine.

For this purpose, the mouth 26 of the air-permeable pocket is open and the hand is placed in the pocket 2 until it reaches the bottom 15 of the pocket.
It can be placed in 2.

As can be seen from the drawings, said bottom 15 extends into the bag beyond the edge 13 of the second corner flap 12.

The second corner flap 12 and the bottom covering foil 21 cannot be brought into contact with each other to ensure optimal degassing.

Although pocket 22 has been defined as an air permeable pocket in the foregoing description, it is clear that this pocket is also permeable to other gases.

As mentioned above, pocket 22 is preferably on the same end of the bag as the valve.

As can be seen from the figure, the part 24a of the adhesive l-IJ tab
and 24b join the pocket layer 22a with the folded bottom flap portions 3 and 4.

To fill the bag, the mouth 10 of the filling valve 6 is opened.

FIG. 3 shows that parts 20a and 20b of the adhesive strip are placed between the tubular strut 6 and the inside of the folded bottom flaps 3 and 4.

The area 27 of the folded portion of the tubular thread is glued to the covering layer 21 so that there are no unbonded parts of the covering layer.

If desired, the cover layer 21 can be omitted, in which case the bottom can be formed by providing a tubular bag foil with incisions and folding the bottom flap as described in GB 1,072,856. I can do it.

In particular, it should be noted that in an air-permeable layer as shown in the figures, air or other gases are allowed to flow out from the interior of the bag to the exterior, parallel to the bottom.

Although preferred embodiments of the invention have been described above, it will be apparent to those skilled in the art that various improvements and modifications may be made in practicing the invention as set forth in the claims.

[Brief explanation of the drawing]

1 is a partial view of a plastic bag with a filling valve according to the invention; FIG. 2 is a partial view of a plastic bag with a gas-permeable layer in the form of a non-woven pocket located opposite the filling valve; Figure 3 is similar to Figure 1 and 2.
FIG. 4 shows a top view of the bottom with fill valve and gas permeable pocket according to the figures; FIG. 4 shows a cross-sectional view of the fill valve and air permeable layer; 1... Plastic bag, 2... Bottom of bag, 3... First bottom flap, 4...
...Second bottom flap, 5, 19, 20...
・Adhesive bonding or heat sealing, 6... Valve pipe part of filling valve, 8, 9... Bottom flap edge part, 10.
...Mouth of filling valve, 11...First corner flap, 12...Second corner flap, 13...
... Second corner flap edge, 14... First corner flap edge, 15... Pocket bottom, 16... Valve pipe portion. End, 17... Filling valve protrusion, 18... Filling valve end, 21...
... bottom covering foil layer, 22 ... air permeable pocket, 23 ... free end of pocket, 26 ...
...One pocket opening

Claims (1)

Claims: 1. A plastic bag having a filling valve and a gas-permeable dust filtration layer, preferably located at the same bag end as said filling valve, for discharging gas from the interior of the plastic bag, comprising: Plastic bag, characterized in that the gas permeable layer is at least partially covered by at least one impermeable coating layer. 2. Plastic bag according to claim 1, characterized in that the gas permeable layer is partially covered by at least one bag, which is a layer of material that is integral with the bag. 3. A plastic bag according to claim 2, characterized in that the covering layer is the bottom layer of the bag. 4. characterized in that said gas permeable layer forms a pocket which is secured to the inside of the bottom layer of the bag and to a corner flap portion located on the underside of the bottom layer of said bag opposite the filling valve. A plastic bag according to claim 1. 5. A plastic bag according to claim 4, wherein the pocket of gas permeable material extends at least to the inner edge of the corner flap portion. 6. The plastic bag of claim 4, wherein the pocket of gas permeable material extends beyond the inner edge of the corner flap portion. T. The plastic bag according to claim 1, wherein the gas permeable material is made of a thermoplastic nonwoven fabric. 8. The plastic bag according to claim 7, wherein the gas permeable material is made of a nonwoven fabric of polyester fibers or polyethylene fibers or felt. 9. A plastic bag as claimed in claim 1, characterized in that the filling valve comprises a valve tube section glued to the bottom wall of the bag and to a first corner flap section located below it. 10 The valve tube portion is bent at one end toward the protruding free end of the valve tube portion, and is folded backward [the covered valve tube portion is located at the bottom wall of the bag and the first corner thereof] 10. The plastic bag according to claim 9, wherein the plastic bag is adhesively bonded to the front flap portion.