CN204414493U - The mould of the auxiliary injection mo(u)lding of water - Google Patents

Abstract

The utility model is the mould of the auxiliary injection mo(u)lding of a kind of water, relates to the device of polymer material molding technical field, specifically a kind of water aided injection forming mould.The utility model at least comprises dynamic model (1a), cover half (1b), is fixed on mould and introduces squirt mechanism (3), the current limiting element (4a) of current; Wherein, form the die cavity (2) of shaping hollow product (6), material overflow cavity (5), interface channel (4) between die cavity (2) and material overflow cavity (5) together with squirt mechanism (3) after dynamic model (1a) and cover half (1b) are closed, the current output of squirt mechanism (3) is arranged in die cavity (2), and current limiting element (4a) is arranged on the interface channel (4) between die cavity (2) and material overflow cavity (5).The utility model has the advantages that, by the interface channel between mold cavity and material overflow cavity arranges current limiting element, reduce and eliminate the shrinkage cavity and porosity defect in goods wall, and achieving goods fully copying and hollow space Die cavity profile.

Description

The mould of the auxiliary injection mo(u)lding of water

Technical field

The utility model relates to the device of polymer material molding technical field, specifically a kind of water aided injection forming mould.

Background technology

Water-assisted Injection Molding, is a kind of control fluid (water), is injected into the specific melt region of product to form hollow technology.Utilize liquid drugs injection to its core injection water after injection molten thermoplastic melt, the forward position of water acts on the molten core of product, and the changeover portion from the forward position of water to melt have cured the plastic foil that one deck is very thin, promote polymer melt, filling mold cavity is to obtain hollow product.Compared with gas assisted Injection Molding Technology, water aided injection forming has cool time and molding cycle is shorter, product inner surface is more smooth, thickness evenly, production cost reduction, the advantage such as production efficiency increase.

But be also very easy in the resin cross section of the hollow product of water shaping at discovery shrinkage cavity or shrinkage defect, and the incomplete defect of goods filling in die cavity.This is mainly because the difference of the physical characteristic of foaming with gas medium (being generally high pressure nitrogen) used and water aided injection forming medium (water) used causes, such as when gas assistant injection molding, when high pressure nitrogen promotes melten gel formation hollow because the thermal capacity of nitrogen is low, the inwall of hollow can not solidify immediately, but cool from the goods outer wall contacted with mold cavity wall to hollow wall, simultaneously because nitrogen has compressibility, namely nitrogen has the bulbs of pressure to promote melten gel to mould to die cavity wall motion complementary contraction with fully fill die cavity, even if adopt the defects such as high pressure nitrogen pressurize operation also can eliminate shrinkage porosite and cavity filling is incomplete after completing hollow molding, and when adopting water shaping, thermal conductivity due to water is 40 times of nitrogen, the thermal capacity of water is 4 times of nitrogen, the inwall of ducted body can form hard cured layer rapidly, the outer wall meanwhile contacted with mold cavity wall also forms hard cured layer rapidly under the cooling of mould, but glassware for drinking water has Incoercibility, if mean flowing stowing operation in do not have enough resistances just can not form enough hydraulic pressure to act on resinite, after coagulation part between two-layer hard cured layer is so just caused to produce the defect such as shrinkage cavity or shrinkage porosite, and can not promote not solidify the thin-wall construction in the complete filling die cavity of melten gel.

In granted patent application 201210010667.0 " forming method of thermoplastic resin hollow product ", the method that the utility model people proposes to adopt gases at high pressure oppositely to pressurize in melten gel filling process solves the problems such as shrinkage cavity existing in water shaping, although there is good effect, but find the seal request of mold cavity higher in implementation process, the more high deficiency of implementation cost.

Utility model content

The utility model object is the deficiency existing for above-mentioned existing water shaping hollow product, provides a kind of die device, makes water shaping hollow product quality higher.

The utility model at least comprises dynamic model 1a, cover half 1b, be fixed on mould and introduce squirt mechanism 3, the current limiting element 4a of current; Wherein, form the die cavity 2 of shaping hollow product 6, material overflow cavity 5, interface channel 4 between die cavity 2 and material overflow cavity 5 together with squirt mechanism 3 after dynamic model 1a and cover half 1b closes, the current output of squirt mechanism 3 is arranged in die cavity 2, and current limiting element 4a is arranged on the interface channel 4 between die cavity 2 and material overflow cavity 5.

The utility model has the advantages that, by the interface channel between mold cavity and material overflow cavity arranges current limiting element, reduce and eliminate the shrinkage cavity and porosity defect in goods wall, and achieving goods fully copying and hollow space Die cavity profile.

Accompanying drawing explanation

Fig. 1 the utility model structural representation;

Fig. 2 uses the utility model to fill molten thermoplastic resin's schematic diagram;

Current limiting element enlarged drawing in Fig. 3 the utility model;

Current limiting element enlarged drawing in Fig. 4 the utility model;

Fig. 5 uses the utility model to water filling schematic diagram in molten resin body;

Fig. 6 uses view before the utility model die sinking;

Fig. 7 uses the utility model aft-loaded airfoil and hollow product schematic diagram.

Detailed description of the invention

As Fig. 1-7 illustrates, the label in figure represents respectively: 1-mould, 1a – cover half, 1b – dynamic model, 2-mold cavity, 3-squirt mechanism, 4 – interface channels, 4a – current limiting element, 5-material overflow cavity, 6 – hollow products, 6b – goods material overflow cavity end technique clout, the external stability syndeton of 6c – goods, 7-water, 8-cast gate, 8a-runner system, 9-nozzle.

A kind of hollow product 6 manufactured experimently in this specific embodiments as shown in Figure 7, resin material used is nylon 66+30%fiberglass reinforced (PA66+30%GF), resin density is 1.35g/cm ³, wherein, this water pipe external diameter is 20mm, and the hollow tube internal diameter expected is 15mm ± 0.5mm.

Figure 1 shows that the structural configuration of a set of injection forming mold made according to the technical solution of the utility model, comprise dynamic model 1a, cover half 1b, squirt mechanism 3, current limiting element 4a etc.; Squirt mechanism is fixed on cover half, and is connected with homemade water assistant controller, can inject water according to desired water speed and volume in the resinite in die cavity.After dynamic model closes with cover half, together form mold cavity 2, material overflow cavity 5 with squirt mechanism, be communicated with the interface channel 4 of die cavity 2 and material overflow cavity 5; The current output of squirt mechanism is arranged in die cavity 2, and after inject molten thermoplastic resin in die cavity, this current output will be completely coated by melten gel; For forming required goods hollow space, current output and the interface channel 4 of squirt mechanism are arranged on the boot segment of corresponding position, institute's moulded products hollow space two ends or correspondence in die cavity 2.For the hollow tube goods 6 that the present embodiment is produced, owing to having stricter requirement to the shape at hollow tube two ends and latus rectum, can one of them termination of straight forming hollow tube by the current output of squirt mechanism, but the other end of hollow tube needs to increase boot segment so that water column is derived the internal diameter required by could being formed, and this boot segment can be considered as a part for mold cavity 2.The interface channel 4 offered is connected with this boot segment, is so just communicated with material overflow cavity 5 by mold cavity 2.When injection mo(u)lding is complete, after excising in boot segment and follow-up interface channel and material overflow cavity material and the technique clout 6b shown in Fig. 6 and cast gate after die sinking, final hollow tube goods just can be obtained.For ensureing the complete external stability syndeton 6c of shaping hollow tube goods 6 and the compactness of goods inside, mould is provided with current limiting element 4a on interface channel 4; Current limiting element 4a can the interface channel 4 directly between die cavity 2 in a mold and material overflow cavity 5 be offered out, as shown in Figure 3; Current limiting element also can be removable inserted current limiting element block, is arranged on interface channel 4, as shown in Figure 4; In order to set up sufficient pressure to the molten resin in die cavity, the latus rectum of current limiting element 4a is at least less than 1/3 of the hollow tube latus rectum of expectation, is preferably less than and expects 1/4 of hollow tube latus rectum.For reducing the workload when adjusting current limiting element latus rectum, adopt removable inserted current limiting element block by more convenient.Fig. 2, Fig. 5 to Fig. 7 illustrate the several steps in forming process; Concrete forming method is as follows:

Close die, makes squirt mechanism 3 in the closed position; The molten thermoplastic resin of predetermined is injected in the die cavity 2 of mould 1, the molten thermoplastic resin's volume injected can fully fill mold cavity 2, be filled at most the entrance of current limiting element 4a, the resin blocking having avoided current limiting element before water filling to be solidified; Complete in the die cavity 2 of mould 1, fill the molten thermoplastic resin of predetermined while or delay scheduled time, open squirt mechanism 3 and in the molten thermoplastic resin's body in die cavity 2, inject water 7 by the volume flow rate preset and injected slurry volume, promote the not solidified thermoplastic resin of core and enter into material overflow cavity 5 by current limiting element 4a, meanwhile, under the effect of current limiting element 4a, set up sufficient pressure in molten thermoplastic resin's body in die cavity 2, make resin energy fully copy mold die cavity; After completing the water injecting predetermined in the resinite in die cavity 2, stop water filling, and pass through the deadweight of water or by Compressed Gas, the water in hollow product after cooled and solidified discharged; Goods are taken out in die sinking.The hollow resin body machine of taking-up or instrument are carried out following process by technique clout 6b and cast gate excision, obtain hollow product 6.In the present embodiment, the utility model people is according to such scheme, according to the physical property of thermoplastic resin (PA66+30GF), the temperature of dynamic model 1a and cover half 1b is set and controls at 100 DEG C, the temperature of water controls at 70 DEG C, contrast test has been carried out, by dissecting the state of the defects such as the shrinkage cavity and porosity checked in goods wall and goods hollow hole for current limiting element 4a pore size.Result of the test is as shown in table 1.

Table 1 current limiting element size comparison tests

Current limiting element size	Shaping hollow products	Shrinkage cavity	Shrinkage porosite
				Without current limiting element	Be difficult to uniform in shaping runner	More	More
Φ5（mm）	Shaping comparatively uniform flow path	Few	Few
				Φ4.5（mm）	Shaping comparatively uniform flow path	Less	Less
Φ4（mm）	Uniform in shaping runner	Nothing	Nothing
				Φ3.5（mm）	Uniform in shaping runner	Nothing	Nothing
Φ3（mm）	Uniform in shaping runner	Nothing	Nothing
				Φ2.5（mm）	Uniform in shaping runner	Nothing	Nothing
Φ2（mm）	Uniform in shaping runner	Nothing	Nothing

As can be seen from the result of table 1, the latus rectum size of current limiting element and selection current limiting element is set, is beneficial to product molding and obtains uniform hollow duct, and reduce and eliminate the appearance of the defects such as goods shrinkage cavity shrinkage porosity.

Although below done to elaborate to the design according to the utility model object with reference to accompanying drawing; but those skilled in the art will recognize that; under the precondition not departing from claim limited range; still can make various improvement and conversion to the utility model, and this improvement and conversion still should belong to protection domain of the present utility model.

Claims (1)

1. a mould for the auxiliary injection mo(u)lding of water, is characterized in that, at least comprises dynamic model (1a), cover half (1b), is fixed on mould and introduces squirt mechanism (3), the current limiting element (4a) of current; Wherein, form the die cavity (2) of shaping hollow product (6), material overflow cavity (5), interface channel (4) between die cavity (2) and material overflow cavity (5) together with squirt mechanism (3) after dynamic model (1a) and cover half (1b) are closed, the current output of squirt mechanism (3) is arranged in die cavity (2), and current limiting element (4a) is arranged on the interface channel (4) between die cavity (2) and material overflow cavity (5).