CN103143677A

CN103143677A - Composite casting technology for hardening alkaline phenolic resin sand and water-glass sand by using CO2

Info

Publication number: CN103143677A
Application number: CN2013100753459A
Authority: CN
Inventors: 史东丽; 李震刚; 杨红霞; 马雪峰
Original assignee: Changzhou Vocational Institute of Mechatronic Technology
Current assignee: Changzhou Vocational Institute of Mechatronic Technology
Priority date: 2013-03-11
Filing date: 2013-03-11
Publication date: 2013-06-12

Abstract

The invention belongs to the field of sand mold cast steel molding materials, and particularly provides a composite casting technology for hardening alkaline phenolic resin sand and water-glass sand by using CO2. The composite casting technology comprises the following steps of: preparing materials, compositing, hardening, taking a mold, after painting coating, and closing a box for pouring. According to the technical scheme of the technology, the alkaline phenolic resin sand serves as surface layer sand, the water-glass sand serves as back layer sand, the advantages of the two molding materials are combined, and the alkaline phenolic resin sand and the water-glass sand are uniformly solidified by adopting CO2; the combination of the two molding materials can improve the dimensional accuracy and surface smoothness of casts under the condition of limited cost increment; as the usage amount of the surface layer land is little, expensive sand regenerative facilities do not need to be purchased by enterprises, and the surface layer alkaline phenolic resin sand has good collapsibility, so that the labor intensity in links such as sand removal, soldering and polishing can be reduced, and the loss of auxiliary materials is reduced; and small and medium-sized enterprises which adopt CO2 for hardening water-glass sand in past can adopt the composite casting technology for producing casts with high quality requirements under the condition that no facilities are added.

Description

Utilize CO 2The composite casting technology of Cured Alkali Phenol Resin and water-glass sand

Technical field

The invention belongs to sand mold cast steel Modeling Material field, particularly a kind of CO that utilizes ₂The composite casting technology of Cured Alkali Phenol Resin and water-glass sand.

Background technology

The Modeling Material that domestic medium and small sand mold cast steel corporate boss will adopt is water-glass sand, utilizes CO ₂Harden, this process costs is cheap, and sclerosis is fast, and operating process is simple, but water-glass sand is because the waterglass addition is large, and collapsibility is poor, and post processing link labour intensity is larger.Therefore, the surface quality of continuous castings that water-glass sand is produced is relatively relatively poor, Shortcomings during this technique is high in the production dimensional accuracy, surface smoothness is good high-end foundry goods.

The alkalescent phenol resin sand combination process is the new technology that development in recent years is got up, this explained hereafter surface finish of casting out is high, dimensional accuracy is high, the crackle tendency is little, the alkalescent phenol resin sand collapsibility is good, gas forming amount is little, is the comparatively ideal Modeling Material of present sand mold cast steel, domestic massive casting enterprise such as wide weight, the employing such as double be the technique of ester cured alkaline phenol resin; But the alkalescent phenol resin sand cost is higher, also need to purchase expensive sand regeneration treatment facility, so medium-sized and small enterprises seldom adopts this technique.

Summary of the invention

The technical problem to be solved in the present invention is: in the situation that the increase of sand cost is limited, provide a kind of composite casting technology that improves casting dimension accuracy and surface smoothness.

The technical solution used in the present invention is: a kind of CO that utilizes ₂The composite casting technology of Cured Alkali Phenol Resin and water-glass sand has following process:

⑴ material is prepared

Prepare alkalescent phenol resin sand, the mass ratio of its medium sand and alkalescent phenol resin is 100:(2.0～2.2); Alkalescent phenol resin is the Ecolotec650-CO of Foseco company ₂Cured alkaline phenol resin, sand adopts 40/70 purpose silica sand; The sand mulling craft of alkalescent phenol resin sand is: sand is dry mixed 0.5～1min in mixing and blending machine, then adds alkalescent phenol resin to continue mixed system 1.5～2min, last discharging is the facing sand moulding as early as possible within the up time after discharging.

Prepare water-glass sand, waterglass adopts modulus 2.4～2.6, density 1.48～1.52, it is 100:(6～8 that sand adopts the mass ratio of 40/70 its medium sand of purpose silica sand and waterglass); The sand mulling craft of water-glass sand is: sand is dry mixed 0.5～1min in mixing and blending machine, then adds waterglass to continue mixed system 1～2min, last discharging is contained in sand hopper covered with plastic film standby.

(2) compound with alkalescent phenol resin sand as surface layer sand, guarantee that the thickness of surface layer sand is 30～40mm, smear one deck releasing agent on mould, default gagger in sand mold, heap sand, consolidation is smash even; Water-glass sand as backing layer sand, is full of sandbox, fills out tight;

(3) after the sclerosis, delivery is at sand mold upper surface venting, and spacing 150mm blows CO to casting mold ₂Make sand mold sclerosis, until the sand mold rear delivery that fully hardens; Described CO ₂Throughput is 0.7～0.9m ³/ h, gassing time is 50～90Sec;

(4) coat after rear mould assembling cast delivery and to coat half an hour, mould assembling cast after 4 hours.

CO ₂The mechanism of solidifying alkalescent phenol resin is: contain resol and inorganic solidification agent in alkalescent phenol resin, it is both at CO ₂Effect under, resol and acid ion carry out cross-linking reaction makes adhesive cures; CO ₂The mechanism of hardened sodium silicate sand is: CO ₂Gas and water glass solution hydrolysate NaOH effect produce salt and water, and constantly NaOH is removed and impel waterglass to be hydrolyzed into the silicic acid molecule, the intermolecular continuous dehydration condensation of silicic acid forms silica sol, and Sol-gel Coated forms certain intensity at sand grain surface thereby sand grains is bonded together.

Surface layer sand in technical solution of the present invention adopts alkalescent phenol resin sand, and backing layer sand adopts water-glass sand, combines the advantage of these two kinds of Modeling Materials, the unified CO that adopts ₂Solidify; In the situation that the increase of sand cost is limited, two kinds of Modeling Materials of the present invention are in conjunction with improving casting dimension accuracy and surface smoothness; Because surface layer sand sand using amount is little, enterprise need not purchase expensive sand reclaim equiment, and the collapsibility of surface layer alkalescent phenol resin sand is good, can alleviate the labour intensity of the links such as sand removal, soldering, polishing and reduce the loss of auxiliary material; Adopt in the past CO ₂The medium-sized and small enterprises of hardened sodium silicate sand can adopt the higher foundry goods of some quality requirements of this explained hereafter in the situation that do not need to increase any equipment, and the profit that the high request foundry goods brings is enough to offset the limited value added of sand cost.

Description of drawings

The present invention is further described below in conjunction with drawings and Examples;

Fig. 1 is the structural representation that adopts the mould of casting technique of the present invention;

In figure, 1. mould, 2. lead to CO ₂Tracheae, 3. surface layer sand, 4. backing layer sand, 5. sandbox.

The specific embodiment

Embodiment one

A kind of CO that utilizes ₂The composite casting technology of Cured Alkali Phenol Resin and water-glass sand has following process:

⑴ material is prepared

Prepare alkalescent phenol resin sand, the mass ratio of its medium sand and alkalescent phenol resin is 100:2.2; Alkalescent phenol resin is the Ecolotec650-CO of Foseco company ₂Cured alkaline phenol resin; The sand mulling craft of alkalescent phenol resin sand is: sand is dry mixed 0.5～1min in mixing and blending machine, then adds alkalescent phenol resin to continue mixed system 1～2min, last discharging; Prepare water-glass sand, the mass ratio of its medium sand and waterglass is 100:8; The sand mulling craft of water-glass sand is: sand is dry mixed 0.5～1min in mixing and blending machine, then adds alkalescent phenol resin to continue mixed system 1～2min, last discharging.

(2) be compounded in mould 1, as surface layer sand 3, the thickness of described surface layer sand 3 is 40mm with alkalescent phenol resin sand; Smear one deck releasing agent on mould 1, default gagger in sand mold, heap sand, consolidation is smash even, and water-glass sand as backing layer sand 4, is tamped in sandbox 5, fills tight;

(3) after the sclerosis, delivery is at sand mold upper surface venting, and spacing 150mm is to the logical CO of casting mold ₂Tracheae 2 blow CO ₂Make the sand mold sclerosis, delivery after the sand mold sclerosis; Described CO ₂Throughput is 0.9m ³/ h, gassing time is 90Sec;

Claims

1. one kind is utilized CO ₂The composite casting technology of Cured Alkali Phenol Resin and water-glass sand is characterized in that: have following process:

⑴ material is prepared

Prepare alkalescent phenol resin sand, the mass ratio of its medium sand and alkalescent phenol resin is 100:(2.0～2.2), sand is 40/70 purpose silica sand; The sand mulling craft of alkalescent phenol resin sand is: sand is dry mixed 0.5～1min in mixing and blending machine, then adds alkalescent phenol resin to continue mixed system 1.5～2min, last discharging;

Prepare water-glass sand, waterglass adopts modulus 2.4～2.6, density 1.48～1.52, and sand adopts 40/70 purpose silica sand, the mass ratio of its medium sand and waterglass is 100:(6～8); The sand mulling craft of water-glass sand is: sand is dry mixed 0.5～1min in mixing and blending machine, then adds waterglass to continue mixed system 1～2min, it is standby that last discharging is contained in sand hopper covered with plastic film;

(2) compound with alkalescent phenol resin sand as surface layer sand, guarantee the minimum thickness 30～40mm of facing sand, smear one deck releasing agent on mould, default gagger in sand mold, heap sand is smash even consolidation; Then add water-glass sand as backing layer sand, be full of sandbox, fill out tight;

(3) the sclerosis delivery is at sand mold upper surface venting, and spacing 150m blows CO to casting mold ₂Make sand mold sclerosis, until the sand mold rear delivery that fully hardens;

2. the CO that utilizes according to claim 1 ₂The casting technique of Cured Alkali Phenol Resin and water-glass sand is characterized in that: CO in described step (3) ₂Throughput is 0.7～0.9m ³/ h, gassing time is 50～90Sec.