CN101104789A - Nontoxic high-pressure resistant sealing material - Google Patents

Abstract

The invention discloses a non- toxin sealing material with high pressure-resistance, belonging to polymer composites. The sealing material is prepared by mixing the following materials by weight: 65-85 portions of High Molecular Weight Polyethylene UHMWPE, 10-20 portions of copper powder, 2-6 portions of graphite powder, 2-6 portions of carbon fiber, 1-5portions of silica gel. The invention has the advantages of low friction coefficient which is about 0.2 at normal and less than 0.06 in the presence of lubricating fluid, high mechanical strength, good abrasion resistance and corrosion-resistance, low production cost, a high ratio of quality to cost and being nontoxic.

Description

Nontoxic high-pressure resistant sealing material

Technical field

The invention belongs to polymer composites, specifically is a kind of nontoxic high-pressure resistant sealing material

Background technology

Sealing article is the important foundation element of all kinds of machineries, and nearly all industrial sector all be unable to do without it.The quality of sealing element how, is directly connected to the work-ing life and the operating reliability of machine.If sealing member is with low quality, gently then bring loss and trouble, heavy then can cause serious accident.

The mechanical means of industry such as food-processing, pharmacy because its special industry needs, not only requires the sealing element good sealing effect, and abrasion resistance properties is strong, but also requires sealing material to have characteristics such as nontoxic, odorless.Sealing element in the mechanical means of these industries, the operating ambient temperature height, it is big to bear load, and often needs dynamic seal in the use.The domestic systematic study of also not carrying out this respect at present, employed moulding product mostly are that elastomeric material is made, better practical requirement.With the high pressure food machinery is example, because operating pressure is higher in the production process, the load that sealing-ring bore is bigger, in equipment running process, often run into the sealing member damaged condition, the sealing member that has can only use 1～2 month, even the shorter time, just need to change, brought trouble for the continuous production of enterprise.And because equipment often leaks, have little time to change, severe contaminations such as the gas of leakage, material operating environment, destroyed stable production situation.Therefore, present actual production scene presses for and a kind ofly can stably realize the non-toxic material oil-free lubricatoin high pressure seal, that meet health, physical and chemical standards under the long cycle.

Summary of the invention

The objective of the invention is to overcome the above-mentioned deficiency of prior art, a kind of nontoxic high-pressure resistant sealing material is provided, with UHMWPE is matrix, add polymkeric substance, carbon fiber and small amounts of inorganic composition granule as toughener, with UHMWPE thorough mixing compression molding, form the ultra high molecular polyethylene UHMWPE base composite sealing material of nontoxic high-pressure resistant with excellent sealing performance and friction and wear behavior.

Ultra high molecular polyethylene (UHMWPE) is the novel visco-elasticity macromolecular material that grows up on the polyethylene basis, the general polyethylene of molecular weight ratio exceeds several magnitude, twine between the molecular chain, form physical crosslinking, relaxed stress effectively has high impact properties, good wear resistance and biocompatibility.But pure UHMWPE water-absorbent is stronger, and creep resisting ability is poor, and this makes its mechanical property reduce, and dimensional stability is affected, and has limited giving full play to of its premium properties to a certain extent.For further improving material property, overcome the deficiency, people add various fillers to strengthen its performance in pure UHMWPE.Filler commonly used at present is particles of inorganic material and each fibrid.Because can be by to the assurance of raw-material selection, each component distribution design and processing condition etc. during Composite Preparation, make the complementation of stock blend material advantage, thereby the matrix material after strengthening can be when keeping the UHMWPE premium properties, improve its physical strength and creep resisting ability greatly, present excellent comprehensive performances.

Technical scheme of the present invention is as follows: a kind of nontoxic high-pressure resistant sealing material is prepared from by the raw material of following weight parts is mixing:

Ultra high molecular polyethylene UHMWPE:65～85 part,

The copper powder massfraction: 10～20 parts,

Graphite Powder 99: 2%～6%,

Carbon fiber: 2%～6%,

Silica gel: 1%～5%;

Described copper powder and Graphite Powder 99 are copper powder and the Graphite Powder 99s of handling through silane coupling agent.

Described copper powder size range is 10～24 μ m, and the Graphite Powder 99 size range is 15～30 μ m.

Described carbon fibrous body toughener is to place air through the PAN base carbon fibre after the oxide treatment, also claims PAN-based carbon fiber,

Concrete preparation method is as follows:

1.. the silane coupling agent that copper powder Cu and the size range 15～30um Graphite Powder 99 of size range 10～24um added quality 1.5～2% respectively and greater than sonic oscillation behind the acetone of material volume more than one times 30 minutes, put into 50～90 ℃ of loft drier then, treat to take out grinding and cross 200 mesh sieves after the acetone evaporated, standby;

2. .PAN base carbon fibre oxide treatment in air is standby;

3.. by mass parts: 65～85 parts of ultra high molecular polyethylene UHMWPE, 10～20 parts of copper powders, 2～6 parts of Graphite Powder 99s, after 2～6 parts on carbon fiber and 1～5 part of mixing of silica gel in ball mill batch mixing 6～8 hours solid mixture;

4.. solid mixture is placed mould internal heating to 200～220 ℃, pressurization 10～15MPa moulding;

5.. moulding product is placed in the loft drier, under 80～100 ℃ of temperature, be incubated 2～4 hours, eliminate the product internal stress.

The present invention is body material with the ultra high molecular polyethylene, the polymkeric substance, carbon fiber and the small amounts of inorganic composition granule that add nontoxic and stable performance strengthen body, copper powder is the creep resistance agent, it is good that graphite is that anti-friction composition is developed a kind of moulding process, has the high pressure resistant high score subclass composite seal of excellent sealing performance and friction and wear behavior.Such material has improved its hardness, Young's modulus and antifatigue polishing machine when keeping the UHMWPE premium properties.Compare with existing other sealing material, such matrix material has no side effect, and the mechanical strength height, frictional coefficient is low, antiwear property is strong, can effectively prolong the work-ing life of air locking under the High Temperature High Pressure working conditions.Such material estimates will have bright development prospect in industries such as food, medicine.

The present invention has the following advantages:

1, frictional coefficient is little, be about generally speaking about 0.2, when having lubricating fluid to exist less than 0.06;

2, the physical strength height is wear-resistant;

3, cost is low, has the good ratio of performance to price;

4, nontoxic, corrosion resistance nature is good.

Embodiment

Further specify the solution of the present invention below in conjunction with embodiment.

Embodiment

With copper powder (Cu, size range 10～24um) and Graphite Powder 99 (size range 15～30um) add the silane coupling agent of quality 1.5～2% respectively and be equivalent to the acetone of 2 times of copper powder or Graphite Powder 99 volumes after sonic oscillation 30 minutes, put into 80 ℃ of loft drier then, treat to take out grinding and cross 200 mesh sieves after the acetone evaporated.PAN base carbon fibre oxide treatment in air.Press the massfraction copper powder: 15 parts, Graphite Powder 99: 4 parts, carbon fiber: 2 parts, silica gel: 2 parts are mixed back batch mixing 8 hours in ball mill with 77 parts of ultra high molecular polyethylene UHMWPE, place mould internal heating to 220 ℃ then, pressurization 15MPa places product in the loft drier after the cooling, insulation is 4 hours under 100 ℃ of temperature, can obtain the finished product.

Claims (4)

1. nontoxic high-pressure resistant sealing material is characterized in that: be prepared from by the raw material of following weight parts is mixing:

Ultra high molecular polyethylene UHMWPE:65～85 part

The copper powder massfraction: 10～20 parts,

Graphite Powder 99: 2%～6%,

Carbon fiber: 2%～6%,

Silica gel: 1%～5%;

Copper powder and Graphite Powder 99 are copper powder and the Graphite Powder 99s of handling through silane coupling agent.

2. a kind of nontoxic high-pressure resistant sealing material according to claim 1 is characterized in that: described copper powder size range is 10～24 μ m, and the Graphite Powder 99 size range is 15～30 μ m.

3. a kind of nontoxic high-pressure resistant sealing material according to claim 1 is characterized in that: described carbon fibrous body toughener is to place air through the PAN base carbon fibre after the oxide treatment.

4. the preparation method of the described nontoxic high-pressure resistant sealing material of claim 1, it is characterized in that: concrete steps are as follows:

1.. the silane coupling agent that copper powder Cu and the size range 15～30um Graphite Powder 99 of size range 10～24um added quality 1.5～2% respectively and greater than sonic oscillation behind the acetone of material volume more than one times 30 minutes, put into 50～90 ℃ of loft drier then, treat to take out grinding and cross 200 mesh sieves after the acetone evaporated, standby;

2. .PAN base carbon fibre oxide treatment in air is standby;

3.. by mass parts: 65～85 parts of ultra high molecular polyethylene UHMWPE, 10～20 parts of copper powders, 2～6 parts of Graphite Powder 99s, after 2～6 parts on carbon fiber and 1～5 part of mixing of silica gel in ball mill batch mixing 6～8 hours solid mixture;

4.. solid mixture is placed mould internal heating to 200～220 ℃, pressurization 10～15MPa moulding;

5.. moulding product is placed in the loft drier, under 80～100 ℃ of temperature, be incubated 2～4 hours, eliminate the product internal stress.