CN1507545A

CN1507545A - Gland packing and method for the production thereof

Info

Publication number: CN1507545A
Application number: CNA028094743A
Authority: CN
Inventors: T・克伦克; T·克伦克; 乜; U·利特克; 茨; F·舒尔茨; 穸�; R·沃格尔
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 2001-05-07
Filing date: 2002-03-12
Publication date: 2004-06-23
Anticipated expiration: 2022-03-12
Also published as: EP1386101A1; JP4310110B2; CN100339615C; CA2446268C; CA2446268A1; DE10122094B4; WO2002090803A1; DE10122094A1; JP2004525320A

Abstract

The invention relates to a gland packing made of a non-woven fabric, which is impregnated with an active substance, particularly PTFE, and which serves as a sealing element that can be pressed into annular gaps between a stationary and a moving machine part, whereby the sealing element (1) consists of at least two layers, which are radially wrapped around one another and pressed together and which are made of a non-woven fabric strip that is impregnated with the active substance.

Description

Stuffing box packing part and manufacture method thereof

Technical field

The present invention relates to the seal element in the annulus between the mechanical parts that a kind of conduct can be pressed into a static and motion, by a kind of usefulness one effectively/active material, the particularly stuffing box packing part (Stopfbuchspackung) made of the impregnated nonwoven fabric of polytetrafluoroethylene (PTFE), and a kind of method of making the sealing packing element.

The stuffing box packing part usually by special fabric in rope form or braided fabric ring, extrude ring or compacting ring is formed.Main graphite, PTFE, lamination coating, carbon, metal or these materials of using makes up accordingly as filler.Wherein lamination coating can also be provided with special impregnating agent.For requiring at high temperature to have simultaneously the sealing that high chemical stability becomes reconciled and the stuffing box packing part of frictional behaviour, PTFE can be used as raw material.But particularly when being woven into rope form sealing fabric with the PTFE yarn, the manufacturing of PTFE stuffing box packing part is relatively costly.

Background technique

By the known stuffing box packing part that forms by ring segment of DE 4423043 C2, this ring segment by compressible band of narrow fabric cut form and with a kind of effective material for example the PTFE solid particle flooded.This ring segment is being dried under about 105 ℃ temperature behind the dipping, is squeezed into a seal then in a squeezing unit.Can realize a kind of stuffing box packing part that has high-fire resistance in low friction moment and little leakage simultaneously by this way.A kind ofly also can be used as planar textile structures with the impregnated nonwoven fabric of PTFE and be applied in the sealing packing element.Because a lot of waste materials of generation in the cutting of described ring segment, this manufacture method is uneconomic.Also can between stuffing box packing part and affiliated axle, form uneven sealing surface by the horizontal slice face structure (Schichtebene) that stacks single ring segment formation mutually.

Summary of the invention

The objective of the invention is to, design a kind of stuffing box packing part that when having good frictional behaviour, has high sealing performance.

Above-mentioned purpose according to the present invention realizes like this that with a kind of stuffing box packing part that starts described type promptly described seal element comprises the layer that at least two radially mutual loopings and the nonwoven fabric band by the effective material dipping of a kind of usefulness that compresses are mutually made.Replace the axial ring segment that stacks mutually and be pressed into, the nonwoven fabric bands that a kind of radially looping used according to the invention becomes a plurality of layers and pushes subsequently.When radially layering is provided with the nonwoven fabric band, can in extrusion process, realize good sealing material interior solid, have well hook knot mutually simultaneously between the impregnated nonwoven fabric band.Determine that simultaneously be absorbed in the surface that effective dipping material in the nonwoven fabric band partly is pressed onto seal element when extruding, the accumulation herein of limited like this dipping material forms a smooth especially surface.Forming one thus has the smooth especially of optimal seal and frictional behaviour and does not have the sealing surfaces that construct on the surface.

When enforcement is of the present invention, if the looping terminal of the looping top of nonwoven fabric band first layer and last one deck so that finish the part or the analog that can not occur thickening on the seal element of extruding, then is favourable with its correspondingly overlapping placement of cutting edge.If wherein the rake of the oriented gradually closing of edge tool (auslaufend) also just upwards forms homogeneous thickness in whole week by this way in the looping process, then is particularly advantageous.The number of plies changes between at least 2 to maximum 200.

In order to realize that effectively dipping material is admitted on the highland as far as possible,, then be favourable if nonwoven fabric has high opening (Offenheit) and permeability/porosity (Por sit  t).This can realize thus, promptly described nonwoven fabric be a kind of mechanical connection, fiber length be 3 to 20mm and surface density be 20 to 200g/m ²The nonwoven fabric made of aramide-fibre.At this, short length of staple causes strong permeability.Aramide-fibre is particularly suitable at high temperature using.But also can replace aramide-fibre to use various fiber or the fibre mixture that for example has high strength and be suitable for the high temperature application.The combination of nonwoven fabric is that mechanical type is realized, for example by water spray set or pinprick reinforcement method (Nadeln).

Because the mechanical type set is opposite with a kind of chemical bond, at high temperature also has high stability, be significant therefore.

For the seal element of annulus between the mechanical component of making a this and motion static as one, by a kind of effective material of a kind of usefulness, the stuffing box packing part made of the nonwoven fabric of PTFE dipping particularly, use a kind of method, what flood a kind of mechanical connection with a kind of effective material in the method is the nonwoven fabric band that 3 to 100mm fiber is made by length of staple, next this nonwoven fabric is dried, then it being cut into its single width is the nonwoven fabric band of 1.5 to 5 times cut-out of described seal element preset thickness; And in the method, with single described nonwoven fabric band respectively looping it is being squeezed on one core bar and in a squeezing unit described seal element.The width of nonwoven fabric band determines according to later situation, particularly the hardness that should have according to the seal element of stuffing box packing part.Squeeze pressure along the direction of extrusion also depends on this (hardness).The hardness of wishing seal element is high more, and the squeeze pressure of selection is also high more, and the width of nonwoven fabric band is also big more.

Described nonwoven fabric band itself has 2.5mm, is preferably 0.5 to 1.25mm thickness.The endurance of impregnation bath is depended on degree of steeping and employed effective material of hope.This effective material is preferably made by a kind of moisture PTFE suspension or a kind of moisture bulking agent PTFE suspension that has.

For oozing of preventing to flood, the oven dry of impregnated nonwoven fabric band is preferably carried out in a straight-through type stove/continuous furnace (Durchlaufofen) with about 30 to 300 ℃ temperature.

Usually with described nonwoven fabric band dipping to maximum saturation ratio, promptly to the content share of the effective material of 95-98%.But for example for the reason with respect to the serviceability of sealability, fibre content share higher in seal element also can meet expectation.In order to realize this point simultaneously also in order to reach the good especially distribution in seal element of effective material, can one be connected the back take off in the material workshop section (Abstreifstrecke) between two rollers once more with impregnating agent partly from the nonwoven fabric band extruding come out.

Axial squeeze pressure is 5 to 50MPa in the squeezing unit.Can determine that by experiment the sealing material interior solid that this squeeze pressure can form has realized also that simultaneously impregnated nonwoven fabric band meets good the interconnecting of material behavior.The endurance of extruding is several seconds to 2 minute according to the compactness extent of hope.Higher squeeze pressure can form very hard seal element usually, and the sealing element needs very high axle envelope pushing force (Stopfbuchsbrillenkraft) to be used for sealing in the installation in seal space of face afterwards.

Show that under some special use condition it is favourable that the seal element that pushed is carried out a sintering with higher temperature and higher pressure.In addition, in order to reach better frictional behaviour, also can make the described Sealing of impregnated with lubricant in case of necessity.

Brief description of drawings

Described seal element shown in the drawings and the squeezing unit that is used for its manufacturing.

Wherein:

Fig. 1 illustrates the plan view of a seal element,

Fig. 2 illustrate according to the cross section of the seal element of Fig. 1 and

Fig. 3 illustrates the sectional view of the squeezing unit of putting into seal element.

Concrete form of implementation

Shown in Fig. 1 is the plan view that is used as the seal element 1 of stuffing box packing part.Sealing element 1 comprises three radially

mutual layers

2,3 and 4 of making of the nonwoven fabric band by a kind of effective material dipping of a kind of usefulness of looping.The looping top 10 of the first layer 2 of nonwoven fabric band and the looping terminal 11 of final layer 4 are with its 12 and 13 overlapped placements of cutting edge.Described

side cut

12 and 13 is provided with the rake of gradually closing.Cutting surface that passes seal element 1 of reference number 14 expressions.Axially separated at this (cutting surface) position seals element 1,, make it easy to put axle to be sealed from side direction with by seal element 1 being opened to excurvation.

Fig. 2 illustrates a section that passes seal element 1 by A-A line among Fig. 1.Wherein visible

single layer

2,3 and 4 radially.

Fig. 3 illustrates squeezing unit 20, the off-the-shelf seal element 1 that extrusion impregnating is crossed in this device.This squeezing unit 20 comprises a die 21 and a drift 24 with a core body 22 and a housing 23.Be embedded under the present case seal element of forming by layer 2 to 81 shown in left side among the figure in the space 25 between core body 22 and the housing 23.After this with drift 24 along the axis of orientation shown in arrow among the figure 26 and 27 in being pressed into opening 25.Shown in right side among the figure, this can cause the compression of described seal element 1.This axial extruding causes, the internal layer of seal element 12 and outer 8 within it or outer surface obtain a smooth especially structure.This (kind structure) is important for later seal process as the stuffing box packing part.Simultaneously, shown in the zigzag structure that passes through layer 3 to 7 among the figure, realized well hook knot mutually between each layer.After extrusion process, from squeezing unit 20, take out seal element 1, and can be used as the stuffing box packing part and come into operation.

Claims

A conduct can be pressed into the seal element in the annulus between the mechanical parts of a static and motion, by a kind of usefulness one effective material stuffing box packing part of making of the impregnated nonwoven fabric of polytetrafluoroethylene (PTFE) particularly, it is characterized in that described seal element (1) comprises the layer that at least two radially mutual loopings and the nonwoven fabric band by the effective material dipping of a kind of usefulness that compresses are mutually made.
2. according to the stuffing box packing part of claim 1, it is characterized in that the looping terminal (11) of the looping top (10) of the first layer of described nonwoven fabric band (2) and last one deck (4) is with the correspondingly overlapping placement of its side cut (12,13).
3. according to the stuffing box packing part of claim 2, it is characterized in that described side cut (12,13) is provided with the rake of gradually closing.
4. according to each stuffing box packing part in the claim 1 to 3, it is characterized in that, described nonwoven fabric be a kind of mechanical bond, fiber length be 3 to 100mm be in particular 3 to 20mm and surface density be 20 to 200g/m ²Nonwoven fabric.
5. according to the stuffing box packing part of claim 4, it is characterized in that the mechanical type of described nonwoven fabric is realized in conjunction with reinforcing by water spray.
6. according to the stuffing box packing part of claim 4, it is characterized in that described nonwoven fabric is by needle punching mechanical consolidation.
7. make according to each one of conduct in the claim 1 to 6 seal element of annulus between static and movable machinery element, by a kind of effective material of a kind of usefulness method of the stuffing box packing part made of the nonwoven fabric of PTFE dipping particularly, it is characterized in that, what flood a kind of mechanical connection with a kind of effective material is 3 to 100mm to be in particular the nonwoven fabric band that 3 to 20mm fiber is made by length of staple, next this nonwoven fabric is dried, then it being cut into its single width is the nonwoven fabric band of 1.5 to 5 times cut-out of described seal element preset thickness; With described nonwoven fabric band respectively looping it is being squeezed on one core bar and in a squeezing unit (20) described seal element (1).
8. according to the method for claim 7, it is characterized in that described fiber is an aramide-fibre.
9. according to the method for claim 7, it is characterized in that described nonwoven fabric is made by other fiber or the fiber blends made by polyimide (PI), polybenzimidazoles (PBI), polyester (PES), glass fibre (GF) or aramide-fibre (AF).
10. according to the method in the claim 7 to 9, it is characterized in that described nonwoven fabric band has 2.5mm, be preferably 0.5 to 1.25mm thickness.
11., it is characterized in that described effective material is made by a kind of moisture PTFE suspension or a kind of moisture PTFE suspension that has bulking agent according to each method in the claim 7 to 10.
12., it is characterized in that described effective material is made by a kind of grease-graphite mixture that has other bulking agent according to each method in the claim 7 to 10.
13., it is characterized in that described effective material is preferably made by a kind of elastomeric adhesives that has bulking agent according to each method in the claim 7 to 10.
14. according to each method in the claim 7 to 13, it is characterized in that, in a continuous furnace, carry out the oven dry of impregnated described nonwoven fabric band with 30 to 300 ℃ temperature.
15., it is characterized in that the squeeze pressure in the described squeezing unit is 5 to 50MPa according to each method in the claim 7 to 14.
16. according to each method in the claim 7 to 15, it is characterized in that, when it applies the pressure of higher temperature and Geng Gao, the described seal element that pushed carried out sintering or makes it crosslinked.