JPH05124103A - Method of coating plastic-coated metal pipe - Google Patents
Method of coating plastic-coated metal pipeInfo
- Publication number
- JPH05124103A JPH05124103A JP3291474A JP29147491A JPH05124103A JP H05124103 A JPH05124103 A JP H05124103A JP 3291474 A JP3291474 A JP 3291474A JP 29147491 A JP29147491 A JP 29147491A JP H05124103 A JPH05124103 A JP H05124103A
- Authority
- JP
- Japan
- Prior art keywords
- coating
- semi
- resin temperature
- molten plastic
- metal pipe
- 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.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts
- B29C48/151—Coating hollow articles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/07—Flat, e.g. panels
- B29C48/08—Flat, e.g. panels flexible, e.g. films
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/92—Measuring, controlling or regulating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92009—Measured parameter
- B29C2948/92209—Temperature
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92323—Location or phase of measurement
- B29C2948/92428—Calibration, after-treatment, or cooling zone
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92504—Controlled parameter
- B29C2948/92704—Temperature
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92819—Location or phase of control
- B29C2948/92923—Calibration, after-treatment or cooling zone
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Lining Or Joining Of Plastics Or The Like (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、鋼管、銅管、あるい
は、アルミ管等の金属管で、特に外面に管軸方向の溶接
ビードを有する金属管のプラスチック被覆方法に関する
ものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic coating method for metal pipes such as steel pipes, copper pipes, aluminum pipes, etc., particularly metal pipes having weld beads in the pipe axial direction on the outer surface thereof.
【０００２】[0002]
【従来の技術】従来、金属管の外面にプラスチック被覆
を行なう方法としては、多くの方法が知られているが、
比較的大径の金属管の場合は、生産性、コスト及び防食
性等の面から、一般に押出機から連続して押し出された
半溶融プラスチック帯状体を回転しながら、管軸方向に
移送する金属管の外面に螺旋状に巻き付けて被覆する方
法が用いられている。2. Description of the Related Art Conventionally, many methods have been known as a method for coating the outer surface of a metal tube with plastic.
In the case of a relatively large-diameter metal tube, in terms of productivity, cost, corrosion resistance, etc., the metal that is transferred in the axial direction of the tube while rotating the semi-molten plastic strip that is generally continuously extruded from the extruder. A method has been used in which the outer surface of the tube is spirally wound and coated.
【０００３】この方法で金属管に半溶融プラスチック帯
状体を被覆した場合、被覆後の金属管の溶接ビード部と
母材部とのプラスチック被覆は図４に示すが如く、同一
条件で被覆した場合、金属管１の母材部２におけるプラ
スチック被覆４の厚みｔ1 と溶接ビード部３におけるプ
ラスチック被覆４の厚みｔ2 とは常にｔ1 ＞ｔ2 の関係
と成り、均一な厚みのプラスチック被覆が得られないと
いう欠点がある。このようにｔ1 ＞ｔ2 の関係すなわち
溶接ビード部の被覆厚みが薄くなる現象は、押出機から
押し出された半溶融プラスチック帯状体を金属管の外面
に螺旋状に巻き付けてプラスチック被覆を行なう際、被
覆直後の溶接ビード部の被覆厚みは母材部の被覆厚みと
同等であるが、その後の工程において被覆直後の半溶融
プラスチック帯状体を弾性体から成る圧着ロールにより
圧着させる為に溶接ビード部の被覆がその圧着ロールに
よって多少延伸されることと、圧着後の冷却過程で溶接
ビードの被覆は母材部より肉厚が厚い溶接ビードからの
伝熱で冷却されるので母材部の被覆よりも冷却速度が遅
く、このため溶接ビード部の被覆の冷却は冷却における
被覆の収縮に伴い、母材部の被覆から引張りを受けるこ
とに起因するものと考えられる。そこで、従来より、該
欠点を補う方法として、押出機と金属管との間の適宜の
位置に設けた膜厚調整装置により、溶接ビード部に被着
される部分の半溶融プラスチック帯状体の厚みを局部的
に厚くして被着することにより、被覆後の溶接ビード部
の薄肉現象を防止する事等を提案してきた（特開昭５６
−７５８２７号，特公昭６１−１４９３０号）。When the metal tube is coated with the semi-molten plastic strip by this method, the plastic coating of the weld bead portion and the base material portion of the coated metal tube is performed under the same conditions as shown in FIG. , become always relationship t 1> t 2 is the thickness t 2 of the plastic coating 4 and the thickness t 1 of the plastic coating 4 in the base metal portion 2 of the metal tube 1 in the weld bead portion 3, the plastic coating of uniform thickness There is a drawback that you cannot get it. As described above, the relationship of t 1 > t 2 , that is, the phenomenon that the coating thickness of the weld bead portion becomes thin, is caused when the semi-molten plastic strip extruded from the extruder is spirally wound around the outer surface of the metal tube to perform the plastic coating. The coating thickness of the weld bead portion immediately after coating is equal to the coating thickness of the base metal portion, but in the subsequent process the weld bead portion is used to crimp the semi-molten plastic strip immediately after coating with a crimping roll made of an elastic body. The coating of the welding bead is slightly stretched by the crimping roll, and the coating of the welding bead is cooled by heat transfer from the welding bead whose thickness is thicker than the base metal during the cooling process after crimping. Since the cooling rate is slow, it is considered that the cooling of the coating of the weld bead portion is caused by the pulling from the coating of the base metal portion as the coating contracts during cooling. Therefore, conventionally, as a method of compensating for the drawback, the thickness of the semi-molten plastic strip at the portion adhered to the weld bead portion is adjusted by a film thickness adjusting device provided at an appropriate position between the extruder and the metal tube. It has been proposed to prevent the thinning phenomenon of the weld bead portion after coating by locally thickening and depositing it (JP-A-56).
-75827, Japanese Patent Publication No. 61-14930).
【０００４】[0004]
【発明が解決しようとする問題点】然し乍ら、特開昭５
６−７５８２７号に示された方法の場合、半溶融プラス
チック帯状体の厚みを膜厚調整装置で連続的に検出し、
ビード部上に被覆される部分のみの膜厚を上昇させる為
には、被覆される金属管の管径、周速、搬送速度及びビ
ード巾等を各々考慮し、且つ押出機の半溶融プラスチッ
クの押出量も制御しなければならない。又、特公昭６１
−１４９３０に示された方法の場合、ポリエチレン被覆
層の最内周層の冷却速度が１０℃／分以上にするという
非常に厳しい特定の条件でのみ成り立ち、且つ金属管被
覆の生産性を向上させる為、内面冷却開始を急ぎすぎる
と、金属管と該被覆材との接着養生時間が不足して、逆
に、接着力の低下を招く事に成る。これらの理由によ
り、公知の何れの方法でも、実際の連続的な操業時にお
ける対応が難しい欠点が有り、連続的な操業時における
対応が容易な溶接ビード部の薄肉現象を防止する金属管
のプラスチック被覆方法の開発が望まれている。[Problems to be Solved by the Invention]
In the case of the method shown in 6-75827, the thickness of the semi-molten plastic strip is continuously detected by a film thickness adjusting device,
In order to increase the film thickness of only the portion coated on the bead portion, consider the diameter of the metal pipe to be coated, the peripheral speed, the conveying speed, the bead width, etc., and consider the semi-molten plastic of the extruder. The extrusion rate must also be controlled. In addition, Japanese Patent Publication Sho 61
In the case of the method shown in No. 14930, it is possible only under a very severe specific condition that the cooling rate of the innermost peripheral layer of the polyethylene coating layer is 10 ° C./min or more, and the productivity of the metal pipe coating is improved. Therefore, if the cooling of the inner surface is started too quickly, the adhesive curing time between the metal tube and the coating material will be insufficient, and conversely the adhesive strength will be reduced. For these reasons, any of the known methods has a drawback that it is difficult to cope with the actual continuous operation, and the plastic of the metal pipe that prevents the thin wall phenomenon of the weld bead, which is easy to cope with during the continuous operation. It is desired to develop a coating method.
【０００５】[0005]
【課題を解決するための手段】発明者らは、上述の問題
点を解決すべく鋭意検討した。その結果、半溶融のプラ
スチックの被覆時の樹脂温度を制御する為の樹脂温度制
御ロールを押出機と金属管との間に設置した方法を用い
る事によって、前述の問題点を解決できる事を見出し、
本発明に至った。Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems. As a result, it was found that the aforementioned problems can be solved by using a method in which a resin temperature control roll for controlling the resin temperature during coating of semi-molten plastic is installed between the extruder and the metal tube. ,
The present invention has been reached.
【０００６】即ち、本発明の要旨とするところは、外面
に管軸方向の溶接ビードを有し、回転しながら管軸方向
に移送される金属管の外面に半溶融プラスチック帯状体
を螺旋状に巻き付けて被覆する金属管のプラスチック被
覆する方法において、半溶融のプラスチックの被覆時の
樹脂温度を制御する為の樹脂温度制御ロールを押出機と
金属管との間に設置した事を特徴とするプラスチック被
覆金属管の被覆方法にある。That is, the gist of the present invention is that the outer surface has a weld bead in the axial direction of the pipe, and the semi-molten plastic strip is spirally formed on the external surface of the metal pipe that is transported in the axial direction of the pipe while rotating. In a method of coating a metal pipe wrapped by winding, a plastic is characterized in that a resin temperature control roll for controlling a resin temperature during coating of a semi-molten plastic is installed between an extruder and the metal pipe. It is a method of coating a coated metal tube.
【０００７】即ち、本発明は図１に示すが如く、外面に
管軸方向の溶接ビードを有し、回転しながら管軸方向に
移送される金属管の外面に半溶融プラスチック帯状体を
螺旋状に巻き付けて被覆する金属管のプラスチック被覆
する方法に関するものである。That is, according to the present invention, as shown in FIG. 1, a welded bead in the pipe axial direction is provided on the outer surface, and a semi-molten plastic strip is spirally formed on the outer surface of a metal pipe which is transferred in the pipe axial direction while rotating. The present invention relates to a method of plastic coating a metal tube which is wound around and coated.
【０００８】以下、本発明につき詳細に説明する。ま
ず、本発明に用いる金属管とは、鋼、銅、あるいはアル
ミなどで成形された金属管などで、特に外面に管軸方向
の溶接ビードを有する金属管の総称である。The present invention will be described in detail below. First, the metal pipe used in the present invention is a metal pipe formed of steel, copper, aluminum, or the like, and is a generic term for metal pipes having a weld bead in the pipe axial direction on the outer surface.
【０００９】次に、本発明の方法を図１に基づき、詳細
に説明する。図１は、本発明の方法の１実施例を示す側
面図で、図２は、図１に示す実施例の平面図である。図
において、５は押出機、６は半溶融プラスチック帯状
体、７は金属管、８は溶接ビード、９-1，９-2は樹脂温
度制御の上下ロール、１０は圧着ロールである。Next, the method of the present invention will be described in detail with reference to FIG. FIG. 1 is a side view showing an embodiment of the method of the present invention, and FIG. 2 is a plan view of the embodiment shown in FIG. In the figure, 5 is an extruder, 6 is a semi-molten plastic band, 7 is a metal tube, 8 is a weld bead, 9 -1 and 9 -2 are upper and lower rolls for controlling the resin temperature, and 10 is a pressure bonding roll.
【００１０】本発明の方法においては、要は押出機５か
ら連続的に半溶融プラスチック帯状体が押出され、溶接
ビード８を有する金属管７に被覆される間に、半溶融プ
ラスチック帯状体の樹脂温度を制御する為の樹脂温度制
御ロール９-1，９-2を介して被覆するという事が骨子で
あり、図１の金属管の表面に亜鉛、アルミニウム、クロ
ム、ニッケル等のメッキ層、亜鉛−鉄、亜鉛−ニッケル
−コバルト等の合金メッキ層、メッキ層あるいは合金メ
ッキ層中にシリカ、アルミナ、シリカ・アルミナ、酸化
チタン、シリコンカーバイド、窒化ホウ素等の無機微粒
子を分散させた分散メッキ層が存在しても本発明の主旨
をいささかも損なうものではない。また、半溶融プラス
チック帯状体を２層構造として、この上層に繊維強化
材、微粉末、あるいは、リン片状強化材を含有する半溶
融プラスチック、下層に半溶融プラスチックを設けたも
のでもよい。In the method of the present invention, in short, the semi-molten plastic strip is continuously extruded from the extruder 5 and is coated on the metal tube 7 having the weld beads 8 while the resin of the semi-molten plastic strip is being coated. The essence is that coating is performed via resin temperature control rolls 9 -1 , 9 -2 for controlling the temperature, and the surface of the metal tube in FIG. 1 is plated with zinc, aluminum, chromium, nickel, etc. -An alloy plating layer of iron, zinc-nickel-cobalt or the like, or a dispersion plating layer in which inorganic fine particles such as silica, alumina, silica-alumina, titanium oxide, silicon carbide or boron nitride are dispersed in the plating layer or alloy plating layer. The existence thereof does not in any way impair the gist of the present invention. Alternatively, the semi-molten plastic band-shaped body may have a two-layer structure in which a semi-molten plastic containing a fiber reinforcing material, a fine powder or a flaky reinforcing material is provided on the upper layer, and a semi-molten plastic is provided on the lower layer.
【００１１】次に、本発明の半溶融プラスチック帯状体
の樹脂温度を制御する為の樹脂温度制御ロールは、押出
機５から押出された半溶融プラスチック帯状体の樹脂温
度（２００℃から２５０℃）を１００℃から２００℃の
適宜の樹脂温度に低下させる事が骨子であり、該樹脂温
度制御ロールの温調制御方法が該ロール内に温度調節し
た冷媒を循環させる方法、あるいは該樹脂温度制御ロー
ル内部に、電気的に制御可能なヒーター板を埋め込む方
法等の何れの公知の方法を用いても本発明の主旨をいさ
さかも損なうものではない。尚、上記の半溶融プラスチ
ック帯状体の樹脂温度を１００℃未満に制御する事は、
半溶融プラスチック帯状体と金属管との接着性が著しく
低下する為、更に、螺旋状に半溶融プラスチック帯状体
を被覆する際のラップ部における半溶融プラスチック帯
状体同志の相溶性が著しく低下する為、むしろ望ましく
ない。又、上記の半溶融プラスチック帯状体の樹脂温度
を２００℃より高い温度に制御する事は、溶接ビード部
の被覆厚みが薄くなる現象が著しく発現する為、望まし
くない。Next, the resin temperature control roll for controlling the resin temperature of the semi-molten plastic strip of the present invention is a resin temperature of the semi-molten plastic strip extruded from the extruder 5 (200 ° C. to 250 ° C.). The main point is to reduce the temperature of the resin to an appropriate resin temperature of 100 ° C. to 200 ° C., and the method of controlling the temperature of the resin temperature control roll is to circulate a temperature-controlled refrigerant in the roll, or the resin temperature control roll. Any known method, such as a method of embedding an electrically controllable heater plate inside, does not impair the gist of the present invention. In addition, controlling the resin temperature of the above-mentioned semi-molten plastic strip to less than 100 ° C.
Because the adhesiveness between the semi-molten plastic strip and the metal pipe is significantly reduced, and further, the compatibility between the semi-melted plastic strips in the wrap when the semi-molten plastic strip is spirally coated is significantly reduced. , Rather undesirable. Further, it is not desirable to control the resin temperature of the above-mentioned semi-molten plastic strip to a temperature higher than 200 ° C., because the phenomenon that the coating thickness of the weld bead portion becomes thin significantly appears.
【００１２】[0012]
【作用】以上の様にして得た本発明の方法は、押出機５
から連続して押出される半溶融プラスチック帯状体６
を、外面に管軸方向に移送される金属管７の外面に螺旋
状に巻き付けて被覆する際に、図１，図２に示すごとく
押出機５と金属管７との間の適宜の位置に設けた樹脂温
度制御ロール９-1，９-2により半溶融プラスチック帯状
体の樹脂温度を低下させて被覆する方法である。The method of the present invention obtained as described above is the same as the extruder 5
Semi-molten plastic strip 6 continuously extruded from
When spirally winding and covering the outer surface of the metal tube 7 which is transferred to the outer surface in the tube axis direction, as shown in FIGS. 1 and 2, at an appropriate position between the extruder 5 and the metal tube 7. In this method, the resin temperature of the semi-molten plastic strip is lowered by the provided resin temperature control rolls 9 -1 , 9 -2 to cover the semi-molten plastic strip.
【００１３】又、図中９-1，９-2の半溶融プラスチック
帯状体の樹脂温度制御ロールでの温度制御範囲として、
１００℃から２００℃の範囲であれば、溶接ビード部の
被覆厚みが薄くなる現象は起らず、良好な結果が得られ
る。以下、実施例により、本発明を具体的に説明する。Further, as the temperature control range of the resin temperature control roll of the semi-molten plastic strips 9 -1 , 9 -2 in the figure,
Within the range of 100 ° C. to 200 ° C., the phenomenon that the coating thickness of the weld bead portion becomes thin does not occur and good results are obtained. Hereinafter, the present invention will be specifically described with reference to examples.
【００１４】[0014]
【実施例】実施例及び比較例において、接着力は、被覆
金属管からプラスチック層の一部を引き剥がし、その１
部引き剥がした部分を保持して金属管の外周の接線方向
に引張って、さらに被覆層を引き剥がすのに要する力
（ｋｇ／ｃｍ）で示し、偏肉率（薄化率）Ａは、次式の
ようにプラスチックを被覆した金属管１の母材部のプラ
スチック被覆層の厚さｔ1 から溶接継目部分のプラスチ
ック層の厚さｔ2 を差し引いた値を、前記の溶接継目部
分以外の母材部のプラスチック層の厚さｔ1 で割って、
さらに１００倍して得られる値である。 Ａ＝（ｔ1 −ｔ2 ）／ｔ1 ×１００［％］。EXAMPLES In the examples and the comparative examples, the adhesive force was obtained by peeling off a part of the plastic layer from the coated metal tube.
The peeled portion is held and pulled in the tangential direction of the outer circumference of the metal tube, and the force required to peel off the coating layer (kg / cm) is shown. The uneven thickness ratio (thinning ratio) A is The value obtained by subtracting the thickness t 2 of the plastic layer at the weld seam portion from the thickness t 1 of the plastic coating layer at the base metal portion of the metal pipe 1 coated with plastic as shown in the formula Dividing by the thickness t 1 of the plastic layer of the material,
It is a value obtained by further multiplying by 100. A = (t 1 −t 2 ) / t 1 × 100 [%].
【００１５】実施例１〜５及び比較例１〜５ 鋼管の外径が１４２２ｍｍであり、鋼管の厚さが１９ｍ
ｍであり、しかも長さが１２ｍである鋼管を２５０℃に
予熱し、ポリエチレン系接着剤を被覆し、次いで直鎖上
ポリエチレン（密度：０．９２５ｇ／ｃｍ3 、Ｍｌ：
０．１５ｇ／１０分）９７．５重量％及びカーボンブラ
ック２．５重量％を含有するポリエチレン組成物を使用
して、押出成形機のＴダイから２５０℃の吐出温度で押
出した半溶融プラスチック帯状体（鋼管に巻き付け時の
厚さ約１．５ｍｍ、巾約５００ｍｍ）を、前記予熱鋼管
に巻き付けて一部帯状体物を重ね合わせながら螺旋状に
被覆した。Examples 1 to 5 and Comparative Examples 1 to 5 The outer diameter of the steel pipe is 1422 mm, and the thickness of the steel pipe is 19 m.
A steel tube having a length of 12 m and a length of 12 m is preheated to 250 ° C., coated with a polyethylene adhesive, and then linear polyethylene (density: 0.925 g / cm 3 , Ml:
0.15 g / 10 min) A semi-molten plastic strip extruded from a T-die of an extruder at a discharge temperature of 250 ° C. using a polyethylene composition containing 97.5% by weight and 2.5% by weight of carbon black. A body (thickness of about 1.5 mm when wrapped around a steel pipe, width of about 500 mm) was wrapped around the preheated steel pipe, and a part of the band-shaped material was overlapped and spirally covered.
【００１６】図１，図２に示すような方法で、表１に示
すような押出機吐出樹脂温度、樹脂温度制御ロール温度
で、前述のポリエチレン被覆金属管を製造した。その結
果、ポリエチレン被覆層の外観、接着力、及び偏肉率を
表１に示す。尚、ポリエチレン被覆層の全体の厚さは、
約３ｍｍであった。The above-mentioned polyethylene-coated metal pipe was manufactured by the method shown in FIGS. 1 and 2 at the extruder discharge resin temperature and the resin temperature control roll temperature shown in Table 1. As a result, Table 1 shows the appearance, adhesive strength, and wall thickness deviation of the polyethylene coating layer. The total thickness of the polyethylene coating layer is
It was about 3 mm.
【００１７】[0017]
【表１】 [Table 1]
【図１】本発明の方法の１実施例を示す側面図。FIG. 1 is a side view showing an embodiment of the method of the present invention.
【図２】図１に示す実施例の平面図。FIG. 2 is a plan view of the embodiment shown in FIG.
【図３】本発明法による溶接ビード部の被覆状態を示す
断面図。FIG. 3 is a cross-sectional view showing a covering state of a weld bead portion according to the method of the present invention.
【図４】従来法による溶接ビード部の被覆状態を示す断
面図。FIG. 4 is a sectional view showing a covering state of a weld bead portion by a conventional method.
１…金属管 ２…金属管の母材部 ３…金属管の溶接ビード部 ４…プラスチック被
覆部 ５…押出機 ６…半溶融プラスチ
ック帯状体 ７…金属管 ８…溶接ビード部 ９-1…樹脂温度制御上ロール ９-2…樹脂温度制御
下ロール １０…圧着ロールDESCRIPTION OF SYMBOLS 1 ... Metal tube 2 ... Base material part of metal tube 3 ... Weld bead part of metal tube 4 ... Plastic coating part 5 ... Extruder 6 ... Semi-molten plastic strip 7 ... Metal tube 8 ... Weld bead part 9-1 ... Resin Temperature control upper roll 9 -2 ... Resin temperature control lower roll 10 ... Crimping roll
───────────────────────────────────────────────────── フロントページの続き (72)発明者 石田雅己 君津市君津１番地 新日本製鐵株式会社君 津製鐵所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masami Ishida 1 Kimitsu, Kimitsu City Nippon Steel Corporation Kimitsu Steel Works
Claims (1)
転しながら管軸方向に移送される金属管の外面に半溶融
プラスチック帯状体を螺旋状に巻き付けて被覆する金属
管のプラスチック被覆する方法において、半溶融のプラ
スチックの被覆時の樹脂温度を制御する為の樹脂温度制
御ロールを押出機と金属管との間に設置した事を特徴と
するプラスチック被覆金属管の被覆方法。1. A plastic coating for a metal pipe, which has a weld bead in the pipe axial direction on its outer surface, and which coats a metal pipe that is transported in the pipe axial direction while rotating by winding a semi-molten plastic strip spirally around the outer surface. In the above method, a resin temperature control roll for controlling the resin temperature at the time of coating the semi-molten plastic is installed between the extruder and the metal tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3291474A JPH05124103A (en) | 1991-11-07 | 1991-11-07 | Method of coating plastic-coated metal pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3291474A JPH05124103A (en) | 1991-11-07 | 1991-11-07 | Method of coating plastic-coated metal pipe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05124103A true JPH05124103A (en) | 1993-05-21 |
Family
ID=17769345
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3291474A Withdrawn JPH05124103A (en) | 1991-11-07 | 1991-11-07 | Method of coating plastic-coated metal pipe |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05124103A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5771114A (en) * | 1995-09-29 | 1998-06-23 | Rosemount Inc. | Optical interface with safety shutdown |
| CN102756476A (en) * | 2012-07-26 | 2012-10-31 | 北京市塑料研究所 | Machining method and device of plastic full-coating corrosion resisting metal pole |
-
1991
- 1991-11-07 JP JP3291474A patent/JPH05124103A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5771114A (en) * | 1995-09-29 | 1998-06-23 | Rosemount Inc. | Optical interface with safety shutdown |
| CN102756476A (en) * | 2012-07-26 | 2012-10-31 | 北京市塑料研究所 | Machining method and device of plastic full-coating corrosion resisting metal pole |
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|---|---|---|---|
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