JPH03114808A - Manufacture of resin molded item with no silver streak - Google Patents
Manufacture of resin molded item with no silver streakInfo
- Publication number
- JPH03114808A JPH03114808A JP25405289A JP25405289A JPH03114808A JP H03114808 A JPH03114808 A JP H03114808A JP 25405289 A JP25405289 A JP 25405289A JP 25405289 A JP25405289 A JP 25405289A JP H03114808 A JPH03114808 A JP H03114808A
- Authority
- JP
- Japan
- Prior art keywords
- resin
- mold
- sheet
- gas
- sheet material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229920005989 resin Polymers 0.000 title claims abstract description 103
- 239000011347 resin Substances 0.000 title claims abstract description 103
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 title claims abstract description 21
- 229910052709 silver Inorganic materials 0.000 title claims abstract description 21
- 239000004332 silver Substances 0.000 title claims abstract description 21
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 239000000463 material Substances 0.000 claims abstract description 75
- 238000002347 injection Methods 0.000 claims abstract description 16
- 239000007924 injection Substances 0.000 claims abstract description 16
- 239000007788 liquid Substances 0.000 claims abstract description 8
- 230000009969 flowable effect Effects 0.000 claims abstract description 6
- 238000009413 insulation Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 abstract description 7
- 239000012466 permeate Substances 0.000 abstract description 4
- 239000000047 product Substances 0.000 description 28
- 239000011148 porous material Substances 0.000 description 6
- 230000013011 mating Effects 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000001746 injection moulding Methods 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- 229920003002 synthetic resin Polymers 0.000 description 3
- 239000000057 synthetic resin Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- -1 polypropylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 238000010107 reaction injection moulding Methods 0.000 description 1
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は合成樹脂の射出成形により樹脂成形品を製造
する際、シルバーストリーク（銀条）の発生しない樹脂
成形品の製造方法に関するものである。[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a method for producing a resin molded product that does not generate silver streaks when the resin molded product is manufactured by injection molding of synthetic resin. .
合成樹脂の射出成形を行うと、成形品の表面に樹脂の流
れた方向に沿って、シルバーストリークと呼ばれる白銀
色のすじ状の模様が発生し、商品価値を低下させること
がある。このシルバーストリークは、線状になった微細
な溝によって形成されており、射出された樹脂に含まれ
るガス、または樹脂と型面の間に瞬間的に発生したガス
が樹脂の流動とともに型面に沿って移動する際、樹脂が
型面に熱を奪われて固化することにより発生するとされ
ている。このようなガスが発生する原因は。When injection molding of synthetic resin is performed, silver streaks may appear on the surface of the molded product in the direction in which the resin flows, reducing the product value. These silver streaks are formed by fine linear grooves, and the gas contained in the injected resin or the gas instantaneously generated between the resin and the mold surface hits the mold surface as the resin flows. It is said that this occurs when the resin absorbs heat from the mold surface and solidifies as it moves along the mold. What causes this kind of gas?
樹脂中に含まれる水分、型面に付着または発生した水分
、樹脂中の揮発成分などによるものと推定されている。It is estimated that this is due to moisture contained in the resin, moisture attached to or generated on the mold surface, volatile components in the resin, etc.
従来シルバーストリークの発生を防止する方法としては
、型面の温度を上げること、型面を清浄にすることなど
があげられているが、操作、制御等が書難であるにも拘
らず、完全な防止策とはいえなかった。Conventional methods for preventing the occurrence of silver streaks include raising the temperature of the mold surface and cleaning the mold surface. It could not be called a preventive measure.
一方、ウェルドラインの発生を防止する方法として、射
出成形型のウェルドラインの発生する個所に予め熱可塑
性樹脂のシートまたはフィルムを装着して樹脂を射出し
、一体成形する方法が提案されているが（例えば特開昭
６０−２６０３１３号）、シルバーストリークの防止に
は役立っていない、また耐候性等に優れた樹脂成形品の
製造方法として、耐候性等に優れた皮膜または加工を施
した熱可塑性樹脂からなるシート状材料を、射出成形型
の型面に装着して樹脂を射出し、一体成形する方法が提
案されているが（例えば特開昭６０−２５０９２５〜６
号。On the other hand, as a method to prevent the occurrence of weld lines, a method has been proposed in which a sheet or film of thermoplastic resin is attached in advance to the part of the injection mold where weld lines occur, and the resin is injected to perform integral molding. (For example, Japanese Patent Laid-Open No. 60-260313), which is not useful for preventing silver streaks, and is a method for manufacturing resin molded products with excellent weather resistance, etc. A method has been proposed in which a sheet-like material made of resin is attached to the mold surface of an injection mold and the resin is injected to form an integral mold (for example, Japanese Patent Laid-Open No. 60-250925-6
issue.
同６０−２５３５１８〜９号）、いずれもシルバースト
リークについては示唆されていない。No. 60-253518-9), none of them suggest silver streaks.
本発明の目的は、従来の射出成形型を用いて。 The object of the invention is to use conventional injection molds.
簡単な操作により完全にシルバーストリークを防止し、
シルバーストリークのない樹脂成形品の製造方法を提案
することである。Completely prevents silver streaks with simple operations,
The purpose of the present invention is to propose a method for manufacturing resin molded products without silver streaks.
（１１題を解決するための手段〕
本発明は、剛性を有する硬質材料からなる射出成形型の
型面に、前記硬質材料よりも断熱性が高いガス透過性の
シート状材料を載置した後、キャビティに液状の樹脂を
射出して、樹脂がシート状材料に接触しかつ型面に直接
接触しないように充填し、樹脂が流動可能状態にある間
に加圧して。(Means for Solving the 11 Problems) The present invention provides a method for placing a gas-permeable sheet-like material having higher heat insulating properties than the hard material on the mold surface of an injection mold made of a rigid hard material. , by injecting liquid resin into the cavity, filling the cavity so that the resin contacts the sheet material but not directly against the mold surface, and pressurizes the resin while it is in a flowable state.
シート状材料を通して樹脂側のガスを排出し、樹脂をシ
ート状材料に密着させることを特徴とするシルバースト
リークのない樹脂成形品の製造方法である。This method of manufacturing a resin molded product without silver streaks is characterized by discharging gas from the resin side through the sheet material and bringing the resin into close contact with the sheet material.
本発明において使用するシート状材料は、射出成形型の
材料より断熱性が高く、かつ加圧時におけるガス透過性
が高い材質からなるもので、−船釣には射出樹脂の融点
よりも高い融点を有する合成樹脂からなるシート、フィ
ルム、その他のシート状のものが使用できる。シート状
材料の厚さは特に制限されないが１作業性および取扱性
の面から０．１〜１■程度が好ましく、ガス透過性およ
び断熱性の面から０．２〜０．７閣が特に好ましい、シ
ート状材料の材質としてはポリカーボネート樹脂、＾Ｂ
Ｓ樹脂、 ｐｐｏ樹脂、ポリアミド樹脂、ポリプロピレ
ン樹脂などが使用できる。The sheet material used in the present invention is made of a material that has higher thermal insulation properties than the injection mold material and has higher gas permeability when pressurized. Sheets, films, and other sheet-like materials made of synthetic resins having the following properties can be used. The thickness of the sheet-like material is not particularly limited, but is preferably about 0.1 to 1 inch in terms of workability and handling, and particularly preferably 0.2 to 0.7 inch in terms of gas permeability and heat insulation. , the material of the sheet material is polycarbonate resin, ^B
S resin, PPO resin, polyamide resin, polypropylene resin, etc. can be used.
本発明のシルバーストリークのない樹脂成形品の製造方
法においては、射出成形型の型面にガス透過性のシート
状材料を載置した後、キャビティに液状の樹脂を射出し
て、樹脂がシート状材料に接触しかつ型面に直接接触し
ないように充填し、樹脂が流動可能状態にある間に加圧
して、シート状材料を通して樹脂側のガスを透過させて
排出し。In the method of manufacturing a silver streak-free resin molded product of the present invention, a gas-permeable sheet-like material is placed on the mold surface of an injection mold, and then liquid resin is injected into the cavity to form a sheet-like resin. It is filled so that it contacts the material but does not directly contact the mold surface, and while the resin is in a flowable state, it is pressurized to allow the gas from the resin side to permeate through the sheet-like material and be discharged.
樹脂をシート状材料に密着させて、シルバーストリーク
のない樹脂成形品を製造する。To produce a resin molded product without silver streaks by bringing resin into close contact with a sheet material.
このとき、加熱溶融した高温の樹脂はゲートを介してキ
ャビティ内に射出されるが、射出された樹脂は成形型の
型面に直接接触することがないため、急激な温度低下は
なく、成形品の表面を形成する樹脂は、断熱性の高いシ
ート状材料を介して型面に密着しているので、温度低下
は緩やかである。At this time, the heated and molten high-temperature resin is injected into the cavity through the gate, but since the injected resin does not come into direct contact with the mold surface of the mold, there is no sudden temperature drop and the molded product Since the resin that forms the surface of the mold is in close contact with the mold surface via a highly heat-insulating sheet-like material, the temperature decreases slowly.
従って、型面に水分が付着していても、水分はシート状
材料と型面との間に介在し、溶融した樹脂とは直接接触
しないので、急激に水蒸気となることはない、また緩や
かに加熱されて水蒸気となっても、吸引路や型の合せ面
から排出されたり、あるいは一部分がシート状材料と型
面との間に残留していても、成形品表面に影響を与える
ことはない。Therefore, even if moisture adheres to the mold surface, the moisture will be present between the sheet-like material and the mold surface and will not come into direct contact with the molten resin, so it will not suddenly turn into water vapor and will gradually Even if it is heated and turns into water vapor, it will not affect the surface of the molded product even if it is discharged from the suction path or the mating surface of the mold, or even if a portion remains between the sheet material and the mold surface. .
また樹脂から発生するガス（水蒸気を含む）は大部分が
樹脂の流動により型の合せ面から排出される。そしてシ
ート状材料と溶融樹脂との間にガスが残留したとしても
、キャビティ内に樹脂が充填され、流動可能な保圧状態
のときに、１ｄ当り数十〜数百−相当の圧力がかかるの
で、ガスはシート状材料を通して型面側に透過し、排出
される。Further, most of the gas (including water vapor) generated from the resin is discharged from the mating surface of the mold due to the flow of the resin. Even if gas remains between the sheet material and the molten resin, when the cavity is filled with resin and the pressure is maintained so that it can flow, a pressure equivalent to tens to hundreds of units is applied per 1 d. , the gas permeates through the sheet material to the mold surface side and is discharged.
これに伴いガスが存在した部分の凹みは、ガス排出に伴
ってその部分を埋めるように樹脂が流動し。As a result, the resin flows to fill the dents in the areas where the gas was present as the gas is discharged.
シート状材料面に密着する。Closely adheres to the sheet material surface.
一般にシート状材料は温度および圧力が高いほどガス透
過性が高くなるから、保圧時においてガスはほぼ完全に
透過して排出され、シート状材料と樹脂の間に残留する
ことはない、この間シート状材料の型面側は型面に接触
して熱を奪われるため、溶融することなく、固形状態を
保つ。In general, the higher the temperature and pressure of a sheet material, the higher the gas permeability. Therefore, during pressure retention, gas almost completely permeates and is discharged, and does not remain between the sheet material and the resin. The mold surface side of the shaped material comes into contact with the mold surface and loses heat, so it does not melt and remains solid.
従ってシート状材料の内面および外面においてシルバー
ストリークが発生することはなく、均一な表面を有する
成形品が得られる。またシート状材料は断熱性を有する
ため、型面に近い部分で樹脂が局部的に固化することな
く、キャビティ全体に樹脂が行きわたり１表面等に欠陥
のない成形品が得られる。そしてシート状材料は全体が
樹脂製の成形型より薄肉に形成できるから、成形品の冷
却も容易である。Therefore, silver streaks do not occur on the inner and outer surfaces of the sheet material, and a molded product having a uniform surface can be obtained. Furthermore, since the sheet-like material has heat insulating properties, the resin does not locally solidify near the mold surface, and the resin spreads throughout the cavity, resulting in a molded product with no defects on one surface or the like. Moreover, since the sheet-like material can be formed thinner than a mold made entirely of resin, cooling of the molded product is also easier.
以下、本発明の実施例を図面に基づいて説明する。 Embodiments of the present invention will be described below based on the drawings.
第１図は実施例における射出成形型の断面図、第２図お
よび第３図は射出成形中の状態を示す第１図の部分拡大
図、第４図は樹脂成形品の断面図である。FIG. 1 is a sectional view of the injection mold in the example, FIGS. 2 and 3 are partially enlarged views of FIG. 1 showing the state during injection molding, and FIG. 4 is a sectional view of the resin molded product.
図において、１は射出成形型で、金属製のキャビティ型
２およびコア型３間に形成されたキャビティ４内にラン
ナー５からゲート６を通して液状の樹脂が射出されるよ
うになっている。キャピテイ型２およびコア型３のキャ
ビティ４に面した型面７，８には細孔９ａ、 １０ａを
介して吸引路９，１０が開口し、型面７．８にガス透過
性のシート状材料１１．１２を装着できるようになって
いる。In the figure, reference numeral 1 denotes an injection mold, and liquid resin is injected from a runner 5 through a gate 6 into a cavity 4 formed between a metal cavity mold 2 and a core mold 3. Suction passages 9 and 10 are opened through pores 9a and 10a in the mold surfaces 7 and 8 of the cavity mold 2 and the core mold 3 facing the cavity 4, and gas-permeable sheet-like material is provided on the mold surfaces 7.8. 11.12 can be installed.
シート状材料１１．１２は、成形型１の材質よりも断熱
性が高く、また射出する樹脂と同一または高い融点を有
するガス透過性の熱可塑性樹脂シートからなり、実施例
では射出する樹脂とは相溶性を有しない樹脂が使用され
ている。またシート状材料１１．１２は、型面７．８に
対応する形状に曲げ成形したものを用いるのが好ましい
が、可撓性により型面に沿った変形が可能な場合、ある
いは型面７．８が平坦な面である場合には予め曲げ成形
しなくてもよい。The sheet material 11.12 is made of a gas-permeable thermoplastic resin sheet that has higher heat insulation properties than the material of the mold 1 and has the same or higher melting point as the resin to be injected, and in the examples, the resin to be injected is Incompatible resins are used. The sheet material 11.12 is preferably bent into a shape corresponding to the mold surface 7.8, but if it is flexible and can be deformed along the mold surface, or if the sheet material 11. If 8 is a flat surface, it is not necessary to bend it in advance.
シルバーストリークのない樹脂成形品の製造方法は、ま
ず第１図に示すように、射出成形型１の型面７．８に、
ガス透過性のシート状材料１１．１２を載置し、吸引路
９，１０およびこれに接続する細孔９ａ、１０ａから吸
引して型面７．８に装着する。The method for producing a resin molded product without silver streaks begins with the mold surface 7.8 of the injection mold 1, as shown in FIG.
A gas permeable sheet material 11.12 is placed and attached to the mold surface 7.8 by suction through the suction channels 9, 10 and the pores 9a, 10a connected thereto.
そして型閉めした後、第２図に示すように、ランナー５
からゲート６を通してキャビティ４に液状の樹脂１３を
射出して、樹脂１３がシート状材料１１．１２に接触し
かつ型面７．８に直接接触しないようにキャビティ４に
充填する。そして第３図に示すように、樹脂１３が流動
可能状態にある間に加圧して、シート状材料１１．１２
を通して樹脂１３側のガス１４を型面７．８側に透過さ
せ、細孔９ａ、 ｌｏａを介して吸引路９，１０から排
出し、樹脂１３をシート状材料１１．１２に密着させて
、シルバーストリークのない樹脂成形品１５を製造する
。After closing the mold, as shown in Figure 2, the runner 5
A liquid resin 13 is injected into the cavity 4 through the gate 6 and filled into the cavity 4 such that the resin 13 contacts the sheet material 11.12 and does not directly contact the mold surface 7.8. Then, as shown in FIG. 3, while the resin 13 is in a flowable state, the sheet material 11.12 is
The gas 14 on the resin 13 side is permeated to the mold surface 7.8 side through the pores 9a and loa, and is discharged from the suction paths 9 and 10, and the resin 13 is brought into close contact with the sheet material 11.12, and the silver A streak-free resin molded product 15 is manufactured.
このとき、加熱溶融した高温の樹脂１３はゲート６を介
してキャビティ４内に射出されるが、射出された樹脂１
３は成形型１の型面７．８に直接接触することがないた
め、急激な温度低下はなく、成形品１５の表面を形成す
る樹脂１３は、断熱性の高いシート状材料１１．１２を
介して型面７．８に密着しているので、温度低下は緩や
かである。従って。At this time, the heated and melted high temperature resin 13 is injected into the cavity 4 through the gate 6, but the injected resin 1
3 does not come into direct contact with the mold surface 7.8 of the mold 1, so there is no sudden temperature drop, and the resin 13 that forms the surface of the molded product 15 is made of sheet-like material 11. Since the mold surface 7.8 is in close contact with the mold surface 7.8, the temperature decreases slowly. Therefore.
型面に水分が付着していても、水分はシート状材料１１
．１２と型面７．８との間に介在し、溶融した樹脂１３
とは直接に接触しないので、急激に水蒸気となることは
ない、また緩やかに加熱されて水蒸気となっても、細孔
９ａ、１０ａを介して吸引路９．１０から、または型の
合せ面１６から排出されたり。Even if moisture adheres to the mold surface, the moisture will be removed from the sheet material 11.
．． 12 and the mold surface 7.8, the molten resin 13
Since it does not come into direct contact with the mold, it will not suddenly turn into water vapor, and even if it is heated slowly and turns into water vapor, it will be released from the suction path 9.10 through the pores 9a and 10a, or from the mating surface 16 of the mold. or discharged from.
あるいは一部分がシート状材料１１．１２と型面７゜８
との間に残留しても、成形品１５の表面に影響を与える
ことはない。Or a part of the sheet material 11.12 and mold surface 7°8
Even if it remains between the two, it will not affect the surface of the molded product 15.
また樹脂１３から発生するガスは大部分が樹脂１３の流
動により型の合せ面１６から排出される。そしてシート
状材料１１，１２と樹脂１３との間にガス１４が残留し
たとしても、キャビティ４内に樹脂１３が充填され、流
動可能な保圧状態のときに、１−当り数十〜数百−相当
の圧力がかかるので、ガス１４はシート状材料１１．１
２を通して型面７．８側に透過し、細孔９ａ、 １０ａ
を介して吸引路９．１０から、または型の合せ面１６か
ら排出される。これに伴い、ガス１４が存在した部分の
凹みはガス排出に伴ってその部分を埋めるように樹脂１
３が流動し、シート状材料１１．１２の面に密着する。Further, most of the gas generated from the resin 13 is discharged from the mating surface 16 of the mold due to the flow of the resin 13. Even if the gas 14 remains between the sheet materials 11 and 12 and the resin 13, when the resin 13 is filled in the cavity 4 and is in a fluidized pressure state, it is possible to - Due to the considerable pressure applied, the gas 14 is transferred to the sheet material 11.1
2 to the mold surface 7.8 side, and the pores 9a, 10a
from the suction channel 9.10 or from the mating surface 16 of the mold. Along with this, the dent in the part where the gas 14 existed is filled with resin 1 as the gas is discharged.
3 flows and adheres closely to the surface of the sheet material 11, 12.
一般にシート状材料１１．１２は温度および圧力が高い
ほどガス透過性が高くなるから、保圧時においてガス１
４はほぼ完全に透過して排出され、シート状材料１１．
１２と樹脂１３の間に残留することはない、この間シー
ト状材料１１．１２の型面７，８側は型面７．８に接触
して熱を奪われるため、溶融することなく、固形状態を
保つ。In general, the higher the temperature and pressure of the sheet material 11.12, the higher the gas permeability.
4 is almost completely permeated and discharged, and the sheet material 11.
During this time, the mold surfaces 7 and 8 of the sheet-like material 11.12 are in contact with the mold surface 7.8 and heat is removed, so the sheet material 11.12 remains in a solid state without melting. keep it.
従ってシート状材料１１．１２の内面および外面におい
てシルバーストリークが発生することはなく。Therefore, no silver streaks occur on the inner and outer surfaces of the sheet material 11, 12.
均一な表面を有する成形品１５が得られる。またシート
状材料１１，１２は断熱性を有するため、型面７．８に
近い部分で樹脂１３が局部的に固化することなく、キャ
ビテイ４全体に樹脂１３が行きわたり、表面等に欠陥の
ない成形品１５が得られる。そしてシート状材料１１，
１２は全体が樹脂製の成形型１より薄肉に形成できるか
ら、成形品１５の冷却も容易である。A molded article 15 with a uniform surface is obtained. In addition, since the sheet materials 11 and 12 have heat insulating properties, the resin 13 is not locally solidified near the mold surface 7.8, and the resin 13 is distributed throughout the cavity 4, ensuring that there are no defects on the surface, etc. A molded article 15 is obtained. and sheet material 11,
Since the mold 12 can be made thinner than the mold 1, which is entirely made of resin, the molded product 15 can be cooled easily.
こうして得られた樹脂成形品１５は、第４図に示すよう
に、成形型１から取出し、シート状材料１１゜１２を剥
離し、ゲート部１７をＸ方向に切断して製品を得る。こ
の場合、成形品１５の剥離性を良くするため、シート状
材料１１．１２の表面に鉱油等の剥離剤を塗布しておく
ことができる。As shown in FIG. 4, the resin molded product 15 thus obtained is taken out from the mold 1, the sheet materials 11 and 12 are peeled off, and the gate portion 17 is cut in the X direction to obtain a product. In this case, in order to improve the releasability of the molded article 15, a release agent such as mineral oil may be applied to the surface of the sheet material 11.12.
成形品１５の表面は、シート状材料１１．１２の内面に
よってのみ左右されるので、鏡面状の平滑さが要求され
るものでも、平滑面を有するシート状材料１１．１２を
使用すればよく、成形型１の型面７゜８を鏡面仕上加工
する必要はない、逆にシート状材料１１，１２と型面７
．８との間に僅かなガスの通過する間隙があったほうが
、ガスを容易に排出するという作用からは好ましい、こ
のため、型面７゜８は第２図および第３図に示すように
、荒ないし中仕上げの粗面とすることができる。The surface of the molded product 15 is determined only by the inner surface of the sheet material 11.12, so even if mirror-like smoothness is required, a sheet material 11.12 with a smooth surface may be used. There is no need to mirror-finish the mold surface 7°8 of the mold 1; conversely, the sheet materials 11, 12 and the mold surface 7
．． It is preferable that there be a small gap between the mold surface 7.8 and the mold surface 7.8 for the gas to pass through from the viewpoint of easily discharging the gas.For this reason, the mold surface 7.degree. It can have a rough or semi-finished rough surface.
上記の実施例では、シート状材料１１．１２は成形品１
５から剥離するため、樹脂１３と相溶性を有しない樹脂
により構成しているが、樹脂１３と相溶性を有する樹脂
からなるものを使用して樹脂１３と一体成形してもよい
、この場合両者間に接着剤を介在させてもよい。In the above example, the sheet material 11.12 is the molded article 1
Although it is made of a resin that is not compatible with the resin 13 in order to separate it from the resin 13, it is also possible to use a resin that is compatible with the resin 13 and mold it integrally with the resin 13. In this case, both An adhesive may be interposed between them.
また上記実施例ではシート状材料１１．１２をキャビテ
ィ４の両側に装着するようにしたが、成形品１５の外表
面となる面のみに装着してもよい、成形品１５が透明な
場合は両側に装着するのが好ましい。Further, in the above embodiment, the sheet-like materials 11 and 12 are attached to both sides of the cavity 4, but they may also be attached only to the outer surface of the molded product 15. If the molded product 15 is transparent, the sheet-like materials 11 and 12 It is preferable to attach it to
さらに上記実施例では加熱溶融した樹脂１３を射出する
例を示したが、樹脂１３として反応性の樹脂を用いる反
応射出成形（ＲＩＭ）でもよい。Further, in the above embodiment, an example was shown in which heated and melted resin 13 was injected, but reaction injection molding (RIM) using a reactive resin as the resin 13 may also be used.
以上の通り、本発明によれば、射出成形型の型面に、断
熱性が高いガス透過性のシート状材料を載置した後、キ
ャビティに液状の樹脂を射出して充填し、樹脂が流動可
能状態にある間に加圧して、シート状材料を通して樹脂
側のガスを排出し、樹脂をシート状材料に密着させるよ
うにしたので。As described above, according to the present invention, a gas permeable sheet material with high heat insulation properties is placed on the mold surface of an injection mold, and then liquid resin is injected and filled into the cavity, and the resin flows. While the resin is in a ready state, it is pressurized to exhaust the gas on the resin side through the sheet-like material, so that the resin adheres to the sheet-like material.
従来の射出成形型を用いて、簡単な操作により完全にシ
ルバーストリークの発生を防止し、シルバーストリーク
のない樹脂成形品を製造することができる。Using a conventional injection mold, it is possible to completely prevent the occurrence of silver streaks and produce resin molded products without silver streaks through simple operations.
第１図は実施例における射出成形型の断面図、第２図お
よび第３図は射出成形中の状態を示す第１図の部分拡大
図、第４図は樹脂成形品の断面図である。
各図中、同一符号は同一または相当部分を示し、１は射
出成形型、４はキャビティ、７．８は型面、９．１０は
吸引路、９ａ、１０ａは細孔、１１．１２はシート状材
料、１３は樹脂、１４はガス、１５は樹脂成形品である
。FIG. 1 is a sectional view of the injection mold in the example, FIGS. 2 and 3 are partially enlarged views of FIG. 1 showing the state during injection molding, and FIG. 4 is a sectional view of the resin molded product. In each figure, the same reference numerals indicate the same or equivalent parts, 1 is the injection mold, 4 is the cavity, 7.8 is the mold surface, 9.10 is the suction path, 9a, 10a are the pores, and 11.12 is the sheet. 13 is a resin, 14 is a gas, and 15 is a resin molded product.
Claims (1)
に、前記硬質材料よりも断熱性が高いガス透過性のシー
ト状材料を載置した後、キャビティに液状の樹脂を射出
して、樹脂がシート状材料に接触しかつ型面に直接接触
しないように充填し、樹脂が流動可能状態にある間に加
圧して、シート状材料を通して樹脂側のガスを排出し、
樹脂をシート状材料に密着させることを特徴とするシル
バーストリークのない樹脂成形品の製造方法。(1) After placing a gas-permeable sheet material with higher heat insulation properties than the hard material on the mold surface of an injection mold made of a rigid hard material, injecting liquid resin into the cavity, The resin is filled in such a way that it contacts the sheet material and does not directly contact the mold surface, and while the resin is in a flowable state, it is pressurized to exhaust gas from the resin side through the sheet material.
A method for producing a resin molded product without silver streaks, characterized by closely adhering resin to a sheet material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25405289A JP2785385B2 (en) | 1989-09-29 | 1989-09-29 | Method for manufacturing resin molded product without silver streak |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25405289A JP2785385B2 (en) | 1989-09-29 | 1989-09-29 | Method for manufacturing resin molded product without silver streak |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03114808A true JPH03114808A (en) | 1991-05-16 |
| JP2785385B2 JP2785385B2 (en) | 1998-08-13 |
Family
ID=17259565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25405289A Expired - Fee Related JP2785385B2 (en) | 1989-09-29 | 1989-09-29 | Method for manufacturing resin molded product without silver streak |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2785385B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4719022B2 (en) * | 2006-02-08 | 2011-07-06 | 日鐵住金建材株式会社 | Road guard fence connection structure and road guard beam material |
-
1989
- 1989-09-29 JP JP25405289A patent/JP2785385B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4719022B2 (en) * | 2006-02-08 | 2011-07-06 | 日鐵住金建材株式会社 | Road guard fence connection structure and road guard beam material |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2785385B2 (en) | 1998-08-13 |
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