CN101508176A - Composite material pulling and extruding molding method by heating baking-path to solidify - Google Patents

Abstract

The invention discloses a pultrusion molding method for a drying tunnel-assisted post-cured composite material, which belongs to the technical field of composite material molding. The method is characterized by comprising the following steps that: (1) reinforced fibers are released through a yarn releasing device and enter a steeping vat through a guide device; (2) fibers impregnated with resin are cured in a hot mold into a gel state; (3) the gel-like composite material product out of the mold is cured in a heating drying tunnel; and (4) the cured composite material is coiled by a coiling device under the traction of a traction unit. The method solves the problem of the prior method that the friction in the curing area of a pultrusion mold is overlarge to cause dead mold, and is particularly applicable to pultruded products with a large specific surface area.

Description

The composite material pultrusion method that adopts the auxiliary back of drying tunnel to solidify

Technical field

The present invention relates to a kind of composite material pultrusion method that adopts the auxiliary back of drying tunnel to solidify, belong to technical field of composite material molding.

Background technology

Pultrude process is the moulding process that automaticity is the highest in the composite material forming method, production efficiency is the highest, is applicable to the production of the continuous composite material goods with constant cross-section shape.As " the fiberglass optical cable strengthens the development of core fast pultrusion technology " (Shen Huiping, Pei Hong, Gao Xudong etc. glass fibre, 2004, (1): 18-19.) ... introduced a kind of typical composite material drawing and extruding technical process: fiber is put yarn and entered the steeping vat impregnating resin, enter heated mold and solidify after preformed, the composite product of curing is through the draw-gear traction continuous rolling of depanning or cut.There is certain defective in this technology: the higher temperature of needs when resin solidifies in mould, resin solidification is emitted a large amount of heat simultaneously, thereby this composite product thermal expansion that causes having cured produces very big frictional resistance in the resin solidification district, expensive mould, the damage goods mechanical property of wearing and tearing causes dead mould to reduce pultrusion production efficiency easily.Especially have bigger specific area when product, the frictional resistance that produces in the mold cured district even can surpass the limit breaking load of product cause product can't adopt pultrude process production.Particularly have continuous pultrusion than the bigger serface goods for finishing composite product, a kind of method that can effectively reduce curing area frictional resistance is demanded invention urgently.

Summary of the invention

Purpose of the present invention, provide a kind of composite material pultrusion method that adopts the auxiliary back of drying tunnel to solidify, to solve the excessive difficult problem that causes dead mould easily of pultrusion die curing area frictional resistance, particularly solution has the difficulty that is difficult to realize pultrusion production than the bigger serface product.

A kind of composite material pultrusion method that adopts the auxiliary back of drying tunnel to solidify is characterized in that process is as follows:

1), fortifying fibre is put yarn and is entered steeping vat through guider by putting yarn feeding device;

2), pitch based fiber is cured to gel state through preformed by heated mold;

3), the composite product that reaches gel state of depanning is finished curing by the heating drying tunnel;

4), under the traction of draw-gear through the wrap-up rolling.

The steeping vat temperature is controlled in the proper range in the said method, and resin viscosity can kept more than 3 hours between 0.5Pa.s～2Pa.s.Mould adopts the low heating-up temperature of more typical pultrusion method, regulates pultrusion speed according to mold temperature simultaneously, and resin reaches gel state when making depanning, can possess stable shape.Drying tunnel adopts higher temperature, and the composite product of gel is solidified rapidly.Drying tunnel two ends open-ended adopts the low higher thermograde form of medium temperature of two ends temperature simultaneously.For the drying tunnel inlet, this thermograde can make the curing degree of composite product improve gradually, and the unexpected temperature of avoiding being in gel state of goods raises, and causes alteration of form; For the drying tunnel outlet, this thermograde can make composite product cool off gradually, avoids too fast cooling to cause very big internal stress influence product properties.That the present invention has is low to extruding equipment repacking cost, the pultrude process parameter is regulated simple advantage.

For the bigger pultrusion product of specific area, i.e. the long-pending ratio A of the area that contacts with die cavity of goods and article cross sections ₁/ A ₂Bigger, in the thermal expansion strain stress _HeatUnder the identical condition, can produce bigger cavity pressure P, thereby produce bigger frictional resistance f.Strength of materials σ at goods _bUnder certain condition, goods specific area A ₁/ A ₂Big more, f/F _MaxBig more, work as f/F _Max〉=1 o'clock, the frictional resistance of these goods in die cavity was enough to make the goods fracture, can't be by pultrude process production.The present invention can effectively reduce the thermal expansion strain stress of goods in the mold cured district _Heat, be specially adapted to have pultrusion than the bigger serface goods.

f＝μ×P (1)

P＝σ _heat×A ₁ (2)

σ _heat＝E×ε _heat (3)

F _max＝σ _b×A ₂ (4)

$\frac{f}{F_{\max }}=\frac{\mathrm{\&mu;E}}{{\mathrm{\&sigma;}}_b}\&times;\frac{A_1}{{\mathrm{<figure-callout\; id="2"\; label="A"\; filenames="A200910024649E00061.png"\; state="\{\{state\}\}">A</figure-callout>}}_2}\&times;{\mathrm{\&epsiv;}}_{\mathrm{heat}}---\left(5\right)$

In the following formula: f---pultrusion frictional resistance; Coefficient of friction between μ---die cavity and goods; P---cavity pressure; σ _Heat---the goods thermal expansion stress; A ₁---goods and die cavity contact area; E---goods elastic modelling quantity; ε _Heat---the thermal expansion strain; F _Max---goods can bear ultimate load; σ _b---product tensile strength; A ₂---article cross sections is long-pending.

Description of drawings

Fig. 1 is the present device structural representation.

Fig. 2 is a drying tunnel temperature distribution schematic diagram of the present invention.

Label title among Fig. 1: 1. put yarn feeding device; 2. guider; 3. steeping vat; 4. pre-shaping device 5. moulds; 6. drying tunnel; 7. draw-gear; 8. wrap-up.

The specific embodiment

Adopt the composite pole of FW-77 hot setting system epoxy resin and T300 carbon fiber pultrusion diameter 0.3mm.

1, the steeping vat temperature determines

Determine that according to sticking temperature test steeping vat can make resin keep viscosity 0.5Pa.s～2Pa.s3 hour, sets 35 ℃ of steeping vat temperature in 35 ℃ ± 2 ℃ scopes.

2, mold temperature determines

Through overtesting, choosing mold temperature is 140 ℃, neither makes mould produce bigger pultrusion resistance and can make PhastGel in the resin short time again, improves pultrusion speed.

3, determining of pultrusion speed

Under 140 ℃ of mold temperatures, select the pultrusion speed of 0.75m/min, can control and reach gel state after resin goes out mould.

4, drying tunnel temperature determines

Under above-mentioned pultrusion speed, adopt 175 ℃ drying tunnel temperature that resin is solidified in drying tunnel fully.

Claims (2)

1, a kind of composite material pultrusion method that adopts the auxiliary back of drying tunnel to solidify is characterized in that process is as follows:

(1), fortifying fibre is put yarn and is entered steeping vat through guider by putting yarn feeding device;

(2), pitch based fiber is cured to gel state through preformed by heated mold;

(3), the composite product that reaches gel state of depanning is finished curing by the heating drying tunnel;

(4), under the traction of draw-gear through the wrap-up rolling.

2, the composite material pultrusion method of employing drying tunnel according to claim 1 auxiliary back curing, it is characterized in that: (3) goes on foot described drying tunnel, high thermograde form in the middle of its temperature employing two ends are low.

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