DE2835219C2 - Securing the load in a transport unit - Google Patents

Description

Packaged goods and examples of improvements for some upholstery fabrics ", Verpackungs-Rundschau 1 (1971) 1/9.

The novel securing system only makes sense when the space to be filled between the cargo has a minimum width, for example 15 cm. The use of a foam filling body with a specific energy absorption capacity between 40 and 60 KJ / m ³ is particularly preferred. If the value of the specific energy absorption capacity is below 30 KJ / m ³ , the foam is no longer suitable because the load no longer remains adequately locked in the event of 5 stronger impacts and it cannot prevent the load from colliding with each other (breakdown). If the specific energy absorption is above 80 KJ / m ³ , then the foam filler body is too "rigid" and the cargo is damaged if it is hit, since too little energy is destroyed in the foam filler body.

The special advantages of the new load securing can be seen "on site". Today it is visual foam systems and transportable foaming machines with suitable mixing heads known, so that the foaming per se does not cause any particular difficulties. The new load securing can be carried out by underqualified personnel run properly.

When it is produced, the foam filler body adapts very well to the space that has remained free. He even pushes something into the gaps between the load.

A crucial point is that the foam fillings function properly even after a severe impact, the fixation and the shock absorption, still largely retained. The foam fillers are several times durable. In many cases they can also be used for other purposes; a recycling of the polyurethane foams is also possible.

The use of the foam described for securing loads is shown as an example in the drawing shown:

The figure shows a railway wagon 1 which is loaded with barrels 2. The wagon 1 has a dead weight of 14 t. It is loaded with 96 filled 200-liter barrels 2. The wagon 1 was loaded from the middle through the sliding door 3 to both sides. There was a free hold about 50 cm wide in the middle. This free space was filled with four polyethylene bags filled with the said polyurethane foam. Since the reaction mixture was poured into the polyethylene bags 4 on the spot, the resulting filler bodies 4 lay on the barrels as foam pads made to measure and partially also fill the gussets between the barrels 2.

With such a loaded wagon were in the presence of representatives of the German Federal Railroad Attempts at impact between 9.6 and 13.8 km / h.

Results with different polyurethane foams and a standard wooden lock at 9.8 km / h Impact velocities are summarized in the table. The locking with square timbers was after Regulations of the German Federal Railroad have been created. It broke on the first impact. The barrels have been dented severely by the splintered beams.

The reaction systems or foams used are described in more detail below; you are not Subject of the patent application, but of the state of the art.

Foam packing 1 There were

75 parts by weight of propoxylated sucrose-glycerol polyether, OH number 380;

15 parts by weight of amine-containing, alkylated phosphoric acid ester, OH number 450;

10 parts by weight of castor oil, OH number 175;

1.5 parts by weight of polysiloxane polyether;

2 parts by weight of nonionic emulsifier;

1 part by weight of 50% solution of the sodium salt of sulfonated! Castor oil in water;

1.2 parts by weight of triethylamine;

28 parts by weight of monofluorotrichloromethane;

110 parts by weight technical 4,4'-diphenylmethane diisocyanate, NCO content 31%

mixed with a commercially available two-component foaming machine and filled the liquid reaction mixture into polyethylene bags. The discharge rate was 7.5 kg per minute. The foaming process started after 35 seconds. The setting time was 160 seconds. A closed-cell, tough rigid polyurethane foam with a bulk density of around 30 kg / m ^{3 was obtained} . The compressive strength was 0.2 MPa, the cushioning factor 4 g (g = 9.81 m / s ² ) and the specific energy absorption 106 Kj / m ³ . (The cushioning factor and specific energy consumption were determined on a 10 cm thick plate at a height of 0.6 m.)

Foam filler 2

There were

65 parts by weight of ether, propoxylated 1,1,1 -trimethylolpropane polyether, OH number 35;

10 parts by weight of phthalic anhydride ethylene glycol polyester? '-, OH number 280:

10 parts by weight of 1,3-butanediol, OH number 1250;

10 parts by weight of ethoxylated polypropylene glycol polyester, OH number 49;

10 parts by weight of propoxylated sorbitol-propylene glycol polyether, OH number 480;

7.5 parts by weight of propoxylated l, l, l-trimethylolpropane polyether, OH number 550;

7 parts by weight of water;

2 parts by weight stabilizer;

2 parts by weight of 1-methylimidazole;

124 parts by weight of technical 4,4'-diphenylmethane diisocyanate, NCO content 31%

mixed with a commercially available two-component foaming machine and poured the liquid reaction mixture into polyethylene bags. The discharge rate was 8 kg per minute. Foaming started after 20 seconds. The setting time was 60 seconds. An open-cell, semi-rigid foam with a bulk density of 23 kg / m ^{3 was obtained} . The compressive strength at 40% deformation was 54 kPa, the cushioning factor

3.1 g, the specific energy absorption 55 KJ / m ³ . (The cushioning factor and specific energy consumption were determined as described in Example 1.)

Foam filler 3 There were

80 parts by weight of ethoxylated polypropylene glycol polyether, OH number 87;

15 parts by weight of phthalic acid-adipic acid-oleic acid polyester, OH number 370;

5 parts by weight of water;

4 parts by weight of N-methylmorpholine;

1 part by weight foam stabilizer;

0.5 part by weight of dodecylbenzenesulfonic acid;

106 parts by weight of technical 4,4'-diphenylmethane diisocyanate, NCO content 31%

mixed with a commercially available two-component foaming machine and poured the liquid reaction mixture into polyethylene bags. The discharge rate was 8 kg / min. After 14 seconds the foaming started; the setting time was 80 seconds. A strongly open-cell, semi-rigid foam with a bulk density of 25 kg / m ^{3 was obtained} . The compressive strength at 40% deformation was 40 kPa, the cushioning factor 2.8 g, the specific energy consumption 32KJ / m ³ . (The cushioning factor and specific energy consumption were determined as described in Example 1.)

Foam packing 4 There were

45 parts by weight of eth-, propoxylated 1,1,1-trimethylolpropane polyether, OH number 35;

10 parts by weight of propoxylated ammonia, OH number 590;

10 parts by weight of propoxylated sucrose-glycerine polyether, OH number 370;

10 parts by weight of f-caprolactam and water in a ratio of 80/20;

20 parts by weight of water;

4 parts by weight of dimethylbenzylamine;

0.5 part by weight of polysiloxane polyether;

100 parts by weight technical 4,4'-diphenylmethane diisocyanate, NCO content 31%

mixed with a commercially available two-component foaming machine and poured the liquid reaction mixture into polyethylene bags. The discharge rate was 8 kg / min. Foaming started after 14 seconds. The setting time was 35 seconds. An open-cell, semi-rigid polyurethane foam with a bulk density of 9 kg / m ^{3 was obtained} . The compressive strength at 40% deformation was 10 kPa, the cushioning factor

3.2 g. The specific energy absorption 12.4 KJ / m ³ .

The polyethylene sacks were filled with foam in the car between the barrels. The filling time was like that dimensioned so that the rising foam reached about barrel height.

When impact tests were carried out at an impact speed of approx. 9.8 km / h, only the polyurethane foam fillers 2 and 3 meet the requirements. The results are summarized in the table.

Tabel

Load securing through

spec. Energy-charge shift assessment

absorption capacity

Wooden lock

Foam filler 1 Foam filler 2

Foam filler 3 foam filler 4

Broken wood wedging 106kJ / m ³ 13 cm

55 kj / m ³

18 cm

32 kj / m ³ 23 cm

12.4 kj / m ³ penetration

negative; Dents in the barrels

negative; Rigid foam presses strong dents in barrels and barrel edges
very good; no damage, even after the 2nd impact the semi-rigid foam was still flawless
Well; If the foam was a little harder, the displacement would be smaller
negative; Foam battered and splintered; Dents in the barrels.

1 sheet of drawings

Claims (1)

Claim: Use of open-cell, semi-rigid polyurethane foam with a poister factor between 2.6 and 3.4 g and a specific energy absorption between 30 and 80 KJ / m ³ , preferably between 40 and 60 KJ / m ³ , when filling the remaining free cargo space with fillers (4) from this foam, to secure the cargo (2) in a transport unit (1). When securing the load - for example hobboks, barrels, sacks, pallets or boxes, usually with a weight between 50 and 1000 kg - in a transport unit - for example in railway wagons, Lorries or containers - it is not enough to fix the load; there must also be precautionary measures be met that by the inevitable horizontal and vertical shocks during transport Packaging and / or the transported goods are not damaged. For example, damage in transit often occurs as a result of rapid braking of the truck or when maneuvering railway wagons when the overrun speed 9 km / h or more The cargo space is bought in a transport unit, in which in many cases it is used for general cargo, in particular in the case of mixed shipments, the loading volume cannot be completely filled, against predominantly horizontal impacts protected by being in the remaining free space between two landing sets or a support made of squared timber is installed as a final safeguard. Such a wooden construction must be Be created on-site specifically tailored to the load and the transport units. Have so z. B. the railway administrations issue very detailed regulations on how a support must be carried out, how thick the squared timbers have to be, how many nails are to be used etc. Such load securing according to the state of the art are able to fix the charge sufficiently; after overuse, they fall but mostly the same completely in their function. A splintered beam or nail will damage it a barrel or a sack generally more than if the barrels or sacks had no storage security were clashed. It is also known (DE-OS 25 32 867), the remaining space between cargo in small containers with prefabricated Padding made of polyurethane foam to be filled. However, due to the variety of cargo, it is not practicable to manufacture and in stock suitably constructed cushions for all different needs to keep. It is also known (DE-OS 22 39 154), when packing objects in containers, the gaps to be filled between the packaged object and the container by filling bodies, which are made of a collapsible cover (foil bag) with foamed polyurethane foam. The foam systems used for this fulfill their purpose in small containers. For modes of transport like railway wagons and trucks, they fail because there are much stronger, dynamic loads, especially shock loads occur. In addition, there are not individual items of cargo in their placement with one another or with the walls are to be secured, but between stacks of loads of the same type there are often free spaces or residual spaces to be filled in for the adjacent stack. Since such stacks, which are movable in themselves, have their own dynamics, Increased demands are made on the upholstery, which were previously used for packaging purposes Polyurethane foams can not be met. The task is to create a load securing system for the stated purpose, which can also be used several times protects against occurring, unpredictable bumps. The solution consists in the use of open-cell, semi-rigid polyurethane foam with a cushioning factor between 2.6 and 3.4 g and a specific energy absorption between 30 and 80 KJ / m ³ , preferably between 40 and 60 KJ / m ³ , in the Filling the remaining free cargo space with fillers made of this foam to secure the cargo in a transport unit. The filler body must be supported by a bellows for shaping when it is formed. The shape of the The bellows is preferably sack-like, rectangular or egg-shaped. A polyethylene bottom bag, for example, is suitable. It is possible that the foamable reaction mixture also enters the bellows outside of the carrier unit is given. Immediately afterwards you bring the bellows between the cargo, where the reaction mixture is foams and hardens in the bellows. The more common way, however, will be that the bellows immediately between the Load is filled with the foam components and that a system is used that is fast foams and hardens quickly. The specific energy absorption of foam cushions is not an absolute value, but the measured value depends within limits on the measurement conditions. It is understood that the preferred range of the specific Energy absorption of a suitable foam filler may be slightly different if the measurement conditions are changed. The measurement of the padding factor and the specific energy absorption are on a padding sample of 0.1 m To determine the thickness at a height of fall of 0.6 m. The problem that arises is for example in the following writings in more detail: J. Penzkofer, reflections on the properties and methods that are decisive for shock absorption their measurement, Verpackungs-Rundschau 8 (1960) 77; J. Hohmann, J. Penzkofer, R. Heiss, "on the evaluation of the shock-absorbing properties of upholstery materials for the packaging of compact and oscillatable goods", Verpackungs-Rundschau 4 (1965) 25/33;
J. Penzkofer, G. Reif, R. Heiss, »Procedure for the dimensioning of upholstery fabrics for the dispatch of rigid