WO2008019458A1

WO2008019458A1 - Expanded polypropylene foam

Info

Publication number: WO2008019458A1
Application number: PCT/BR2007/000205
Authority: WO
Inventors: Maria Isabel Pinto Koleski; Luciana Bedendo Prates
Original assignee: Maria Isabel Pinto Koleski; Luciana Bedendo Prates
Priority date: 2006-08-14
Filing date: 2007-08-14
Publication date: 2008-02-21
Also published as: BRPI0603479A

Abstract

The present patent describes a process of light polypropylene foam manufacture expanded with density in bulk reduced, varied and differentiated of the existing ones in the market. The in bulk product formed by small foam can vary its density between 8 and 14g/l, and when formatted (compacted) it stays around 10 to 14 g/l.

Description

"EXPANDED POLYPROPYLENE FOAM"

FIELD OF THE INVENTION

The present patent relates to the field of polypropylene foam manufacture processes which were developed for industrial application in the automobile, furniture, civil, nautical and aeronautical fields.

BACKGROUND OF THE INVENTION

The light polypropylene foams are known and their manufacturing processes are well spread in the market.

The expanded polypropylene foam (Expanded Poly Propylene - EPP) is compounded of expanded cellular plastic particles which cells are predominantly closed.

The blocks that are injected in expanded polypropylene are produced through high pressure and temperature injection in last generation equipment making possible the production of ideal rectangular blocks for lamination operations destined to applications as spacers, chocks for packing, shock absorbing plates, etc.

The manufacturing process of molded expanded polypropylene parts includes neither the pre-expansion phase, nor the intermediate ensilage, for there are no expanding agents here. The molding process is carried through by compression of particles inside the molds because, as related above, the expansion of expanded polypropylene particles is not possible.

The technique parts laminated in expanded polypropylene offers the possibility of combining or not the raw material with the sticking/ adhesivation process which basic configuration is defined without outlines (when the product can be defined from three basic measures: length/height/width without sticker/adhesive) or when using adhesive and/or if the configuration is more complex through outlines.

These related parts are obtained from expanded polypropylene injected blocks cut in special machines for obtaining the final measures.

The technique parts molded in expanded polypropylene allow them to serve as protectors, tool-holders, anti-noise, sealers, spacers, impact absorbents, chocks, etc., with a format outline-defined and which can be obtained through injection molds. The required properties are usually defined according to the application it is destined to, which requires a case to case application analysis.

Patent Pl 9900674-0, entitled Polypropylene or expanded polyethylene and its application in therapeutic, orthopedic or similar devices for human body rest, was idealized in order to promote greater durability, resistance, flexibility and slightness to the therapeutic mattresses, orthopedic mattresses and similar devices, making its handling and transportation easier, as well as diminishing stages and costs for industrial feasibility and, furthermore, due to being constituted with the use of plate form polypropylene or expanded polyethylene to be applied as an intermediate layer on the mattresses, being this later "under-lapped" and overlapped by layers of foam or just generally queued, such order is determined according to the purpose and necessity mattress usage, the process generates less pollutants in the plant's environment in its elaboration.

Patent Pl 0001497-4, entitled Diverse Vehicles Seat Headrest

(head restraint) Improvement, made of two parts or distinct pieces. The first part is called molded body with or without external covering, and the second is called structure, the last made of metallic material while the first is molded in expanded polypropylene foam in accordance to a desired density and by a known injection process made by specific injectors and vapor, considering the mentioned structure presents two stretches in the shape of vertical rods with or without plastic covering. In both cases they present diverse teeth and a funneled inferior tip, the last is "cooperative" so that the set can be put together in an adjustable way on the top any seat which is prepared to receive such accessory.

Patent Pl 0305173-0, entitled Beret for polishing with polypropylene foam cubes, allows the use of a flexible rubber disc that has a fabric which purpose is to guarantee the polishing disc fixation to a rotating tool through a string and also the polypropylene foam fixation cut in form of cubes which are passed over and stuck on that fabric. They increase the product's lifespan at over a hundred times consequently considerably lowering it usage costs and also preventing inconveniences such as the removal of car doors latches or locks for executing polishing processes because of the its material resistance.

Patent Pl 8706052-3, entitled Process for the obtention of stabilized polypropylene against oxidant degradation. A polyolefin is stabilized against oxidant degradation by the inclusion of a stabilizer amount of a stabilizing mixture that includes: a) at least one "diarilamina" substituted with "arilalcoilos"; e b) at least a phenol sterically blocked.

Thus, the existing system main disadvantages must be presented:

• Weight varying from 11 to 80 g/l;

• It does not use expanding agent;

This way the technique state was presented. The next item shows the present patent's brief description. BRIEF SUMMARY OF THE INVENTION

The present patent describes a process of light polypropylene foam manufacture expanded with density in bulk reduced, varied and differentiated of the existing ones in the market. One of the objectives of the invention is to reduce its weight and, consequently, its density for the same volume.

Another objective refers to diminishing the consumption of energy in its manufacturing process.

And furthermore another objective is the insertion of an expanding agent in a plalene. stic-type polypropy

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING Figure 1 shows the present patent's graphical representation in blade form.

DETAILED DESCRIPTION OF THE INVENTION

The present patent describes the manufacturing process of expanded polypropylene light foam manufacture with "in bulk" density reduced, varied, and differentiated from the ones existing in the market.

The expanded polypropylene is obtained through an injection (impregnation) of an expanding agent in a polypropylene-type plastic through the impregnation methods that are known to the state of technique. The in bulk product formed by small foam can vary its density between 8 and 14g/l, and when formatted (compacted) it stays around 10 to 14 g/l.

These small foams (in bulk) are formatted in injection machines which are used in the following fields: automobile industries, furniture, civil, nautical and aeronautical. Therefore, the advantages of the patent are shown as follows:

• Rather reduced Weight that can vary from 8 to14 g/l in bulk and from 14g/l to 10g/l when formatted;

• Low energy consumption in the manufacturing; • Polypropylene-type Injection (impregnation) of expanding agent in the plastic;

• Great capacity of energy absorption;

• Good behavior of elastic recovery when subject to static and dynamic loads; • Absorption of substantially unchanged energy when subject to multiple impact efforts;

• Isotropic Behavior of deformation independently of the impact direction;

• Reduced water absorption; • Good resistance to temperature and low thermal conductivity;

• Chemical and solvent products resistance;

• Environment friendly and recyclable in many ways.

Although the description above has many specifications, they should not be interpreted as limitations to the invention purpose; they merely aim to give simplified illustrations of one of this patent's preferred configurations.

Thus, the purpose must be determined by the attached claims and its legal equivalents.

Claims

1) EXPANDED POLYPROPYLENE FOAM, characterized for being manufactured through impregnation and drawing process.

2) EXPANDED POLYPROPYLENE FOAM, according to claim 1 , characterized for possessing rather reduced weight when in bulk, varying preferably from 8 to 14 g/l.

3) EXPANDED POLYPROPYLENE FOAM, according to claim 1 , characterized for the fact to possess rather reduced weight when formatted, varying preferably from 10 to 14 g/l. 4) EXPANDED POLYPROPYLENE FOAM, according to claim 1 , characterized reducing the consumption of energy for its manufacture.

5) EXPANDED POLYPROPYLENE FOAM, according to claim 1 , characterized for allowing the injection (impregnation) of an expanding agent in the plastic type polypropylene