SE455086B - Bag of plastics lined paper - Google Patents

Abstract

One edge zone of the paper sheet is without plastics lining for a greater part than is required for an adhesive seam, whilst the other edge zone, completely lined with plastics, overlaps that which is unlined. During filling of the bag, air can penetrate in between the edge zones in the overlapped area and out through pores in the unlined part.

Description

455 086 2 When the bag is filled, the air will be forced out through the paper layer 2 in g the edge zone 4 and further between the outside of this layer 2 and the plastic layer 3 in it overlapping edge zone 7 and further out between the point-by-point adhesive yarns 6, as shown by the arrows.

Figure 2 also shows the invention applied to a single-bladed sack, but instead a blade with a plastic-free edge zone (4 in figure 1) a blade 8 is used with plastic coating 9 all the way to the edges, which blade is extended by a non plastic-coated paper strip lU which is attached with the adhesive joint ll in the lower edge of the blade 8 and with the adhesive joint 12 in its upper edge zone 13. When filling the bag penetrates air out the path shown by the arrows, ie the same path as in the construction in the figure 1.

Figure 3 shows a part of a two-bladed bag with deaeration according to the invention. 15 is the paper layer of the outer blade 14. 16 is its plastic layer. 17 is the inner blade, consisting of paper without a plastic layer. 18 and 19 are adhesive joints. When the bag is filled the air will be forced through the inner blade ll and in between the overlapping ones edge zones 2D and 21 on the outer blade 14 and through the outer edge zone 21 as in its outer part is without plastic coating. The overlap is so wide that the edge zone 20 goes a bit below the plastic-coated part of the edge zone 21.

Figures 4, 5 and 6 show different bag types.

Figure 4 shows a valve bag with top 22 and bottom 23 of canister type. Figure 5 shows an open sack with the bottom of canister type 24 and figure 6 an open sack with sewn bottom 25. The invention can also be applied to bags with a "pinch" bottom.

In the following exemplary embodiment, single-bladed valve bags are compared according to the embodiment form of the invention as Figure 1 shows with those of conventional design.

Measured height 5D cm width 40 cm thickness 9 cm Material kraft paper basis weight llU g / mz with on one side a polyethylene layer, basis weight lÜ g / mz. In one experiment the bag material was but in a second experiment with microperformance rering. '

Claims (1)

455 086 The test was carried out so that air was led into the bag through a hose, which passed tightly through the valve, until the intended overpressure was obtained in the bag. The air flow required to maintain the overpressure was measured in the inlet hose. Results Experiment Test Sack design Air flow at l kPa single-leaf overpressure liter - minute - mz A. without perforation l Conventional 23.0 2 According to invention 57.5 B. with perforation 3 Conventional 195 (in According to invention 218 invention 1 experiment A 'is the increase in infmöde: from sample 1: in sample 2 34.5 more - rnin'1 -nfz nen in experiment B from sample 3: in sample 4 23 iiler- min * -rn'2. _ Patent claim l. Sack of plastic-coated paper, designed to facilitate the expulsion of air from the bag when it is filled, characterized by the following: a. On the sheet (1, 8) or the outermost (14) of the sheets forming the bag, the edge zones (4,7) overlap 10, lll; 20, 21) each other considerably more than is necessary for the adhesive joint which is to hold the sack tube together b. On the leaf (1, B) or the outermost (14) of the leaves forming the sack, one edge is (11, 10, Z1) without plastic coating where the two edge zones (4,7; 10, 14; 20, 21) overlap each other 455 086 Sack-like collar characterized in that it is made of e blade (1, 8) and that the edge of the outer part of the blade (1, 8) in the overlap is attached to the inner part of this blade (1, 8) in the overlap with many short adhesive joints (6) with intermediate non-stick areas. the edge of the inner part of the blade (1, B) in the overlap is fastened with an adhesive joint (5, 12) running along the entire edge, the edge zone (11, 10) which constitutes the inner overlapping part of the blade (1, 8) also constitutes the edge zone without plastic coating. Sack according to claims 1 and Z, characterized in that the non-plastic-coated edge zone is obtained by extending a plastic-coated sheet (8) all the way to the edges with a strip (10) of non-plastic-coated paper, which strip (10) is attached to the plastic-coated sheet. (8) with an adhesive joint (ll) between the edges of the blade (8) and the strip (10). Bag claim characterized in that it is made of two or more sheets (14, 17) of which one intermediate sheet or the outermost sheet (14) is of plastic-coated paper and the inner sheet or sheets (17) of non-plastic-coated paper, the plastic-free edge zone (Z1) in the plastic coated sheet (1b) is in the outer overlapping portion of this sheet (III), the fully plastic coated edge zone (20) constituting the inner overlapping portion of the outer sheet (1a) extends a bit below the plastic coating in the outer overlapping portion, the edge of the outer overlapping part of the outer blade (14) is glued to the inner overlapping part of this blade (III) with a cohesive adhesive joint (18).