Claims
- 1. A process for producing pipe sections in a rotary mold drum comprising:
- rotating the rotary mold drum to provide centrifugal forces to an inner mold drum surface and during rotation performing the steps of:
- introducing onto the inner mold drum surface a protective layer of moldable plastic in a liquid state, said moldable plastic being free of fiber reinforcing material;
- allowing said moldable plastic to cure to a hardened state by addition of a hardening agent;
- applying a first reinforcing layer of fiber-reinforced plastic in a liquid state to said hardened protective layer;
- applying a first connecting layer of fiber free plastic in a liquid state to the first reinforcing layer;
- allowing said first connecting layer to cure to a partially hardened pasty state by addition of a hardening agent;
- applying a central layer of inorganic material to the first connecting layer while the first connecting layer is in said partially hardened pasty state;
- allowing said central layer of inorganic material to partially set;
- applying a second connecting layer of fiber free plastic in a liquid state to be the central layer of inorganic material after the central layer of inorganic material is partially set;
- allowing said second connecting layer to cure to a partially hardened pasty state by addition of a hardening agent; and
- applying a second reinforcing layer of fiber-reinforced plastic in a liquid state to said partially hardened pasty second connecting layer.
- 2. A process according to claim 1 further including a step of allowing said second reinforcing layer to cure to a hardened state by addition of a hardening agent, and a step of applying a protective plastic layer for corrosion protecting purposes to said hardened second reinforcing layer, said protective plastic layer being essentially free of fiber-reinforcing material.
- 3. The process according to claim 1 further including steps of forming the first and second reinforcing layers by admixing fibers with the plastic prior to application thereof.
- 4. The process according to claim 1, wherein the first, liquid connecting layer is applied to the first reinforcing layer before the first reinforcing layer hardens.
- 5. The process according to claim 1 further including curing the pipe section in said rotary mold drum.
- 6. The process according to claim 1 wherein said step of applying a central layer of inorganic material comprises applying a central layer of concrete.
- 7. The process according to claim 1 wherein said step of applying a central layer of inorganic material comprises applying a central layer of mortar essentially free of mineral fillers.
- 8. The process according to claim 1 wherein said step of applying a central layer of inorganic material comprises applying a central layer of mortar having mineral fillers.
Priority Claims (1)
Number |
Date |
Country |
Kind |
243/84 |
Jan 1984 |
CHX |
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Parent Case Info
This application is a continuation of application Ser. No. 687,016, filed Dec. 28, 1984, now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (6)
Number |
Date |
Country |
2352843 |
Apr 1975 |
DEX |
2068167 |
Mar 1972 |
FRX |
53-117065 |
Oct 1978 |
JPX |
56-142034 |
Nov 1981 |
JPX |
804456 |
Feb 1981 |
SUX |
910631 |
Nov 1962 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
687016 |
Dec 1984 |
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