THE INSULATION METAL PIPE WITH FOAMING PLASTIC COVER AND ITS MANUFACTURE PROCESS

ISOLANT EN MOUSSE PLASTIQUE POUR COUVRIR LES TUYAUX EN METAL, ET PROCEDE DE FABRICATION

English Abstract

One type of metal pipe with plastic foaming consists of metal pipe, plastic
foaming layer and plastic protection layer from inside to outside. It is
produced by
extruder. The extruder extrudes the foaming layer and the protection which are
pressed onto the metal pipe by compound mould, the product is completed
immediately. The invention has the advantages in: good insulation, moisture-
proof, flame-proof, stable quality, and long life of usage. With use of this
pipe, the
installation time of insulation pipe will be shortened, and the force of
labors will
be reduced.

Claims

Patent Indication
1. One type of metal pipe with plastic foam cover, has the feature of that
there is plastic
foam layer between the metal pipe and the protection.
2. The metal pipe with plastic foam cover stated in item 1 has the feature of
that it
can be all types of metal pipes or metal hoses.
3. The metal pipe with plastic foam cover stated in item 1 has the feature of
that
the main raw materials of plastic foam layer (2) can be polyvinyl chloride
(PVC), polystyrene, polyethylene, polyaminester, polypropylene, or
acrylonitrile-butadiene-styrene copolymer, or copolymer of ethylene-vinyl
acetate.
4. The metal pipe with plastic foam cover has the feature of the main raw
materials of the protection (3) can be polyvinyl chloride (PVC), polystyrene,
polyethylene, polyaminester, polypropylene, or acrylonitrile-butadiene-styrene
copolymer, or copolymer of ethylene-vinyl acetate.
5. According to the manufacture process for metal pipe with plastic foam as
stated in item 1, the feature involves the following steps:
1)surface treatment of metal pipe: removal of mud, dust and grease;
2) the make-up of raw materials for plastic foam, mixing in the extruder, heat-
melting, foaming;
3) the make-up of raw materials for the protection, mixing in the extruder,
heat-
melting;
4) pre-heating of metal pipe;
5) the extruder extrudes the melted plastic foams and compound onto the
metal pipe;
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6) the extruder extrudes the melted protection plastic, and compound onto the
plastic foaming layer.
7) Cooling and finalize the design
6. The manufacture process for metal pipe with plastic foaming as stated in
item
5. has the feature of: the fourth, fifth, and sixth steps are completed in the
compound mould at first time.
7. The manufacture process for metal pipe with plastic foaming as stated in
item
6, has the features of the said compound mould consists of lock nut(01 ),
mandrel(02), mould parent(03), machine neck-first(04), large aperture
mould(05), lock net (06), mandrel(07), sleeve body (08), small aperture mould
(09), machine neck (013) and heater (015) , and connected by screw (011 )
and adjust screw (012, 014). The mould stream is formed between mould
parent (03), machine neck (04), mandrill (07), large aperture mould (05), and
S2 stream is formed by sleeve body (08), machine neck (013) and large
aperture mould (05).
8. The manufacture process for metal pipe with plastic foaming, has the
feature
of : the said metal pipe(1) is melted under preheating of heater(015), the
plastic
foaming is conducted into mould stream (S1) through machine neck(04) pressed
by extruder. The melted plastic protection is also conducted into mould stream
(S2) by extruder through machine neck (013), and compound onto the metal pipe
at the mould outlet. The product of metal pipe(1) with plastic foaming
layer(2) and
plastic protection layer (3) is finished.
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Description

CA 02356451 2001-08-22
Description of Patent
The insulation metal pipe with foaming plastic cover
and its manufacture process
This invention involves with metal pipe, especially one type of insulation
metal
pipe with foaming plastic cover.
The existing insulation of metal pipe is usually done by wrapping the
insulation
material manually on the metal pipe or putting it on the surface of metal
pipe,
finally wrapping the protection cloth outside of insulation material. It costs
a lot
of manpower, material resources. Not only does it require big labour forces,
but
also arouses the problem of safety. The material waste is often occurred by
improper manual operation, and the effect of insulation is also affected,
which
caused the loss on economics and energy resource. The economic loss is also
often caused by improper use of material or malfunction of the protection
layer.
There is one metal pipe with plastic warping protection, but this structure
still can
not reach the good insulation effect. The metal pipe with manual insulation is
with
low strength, easy damaged, poor insulation effect, because of the foaming
exposures outside.
The purpose of this invention is to overcome the above shortages, to provide
the
insulation metal pipe with foaming plastic cover, to create the conditions of
large
scale commercial production.
The metal pipe with foaming plastic cover, consists of metal pipe, plastic
foaming layer and plastic protection layer from inside to outside.
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CA 02356451 2001-08-22
The said metal pipe could be all types of metal pipes or metal hoses
The said plastic foaming layer has the main raw materials such as polyvinyl
chloride (PVC), polystyrene, polyethylene, polyaminester, polypropylene, or
acrylonitrile-butadiene-styrene copolymer, or copolymer of ethylene-vinyl
acetate.
The raw materials of plastic protection layer could be polyvinyl chloride
(PVC),
polystyrene, polyethylene, polyaminester, polypropylene, or acrylonitrile-
butadiene-styrene copolymer, or copolymer of ethylene-vinyl acetate.
The manufacture process of metal pipe with said foaming plastic cover includes
the following steps:
1 ) the surface treatment, removing of mud, dust and grease.
2) The make up of the plastic foaming raw material, mixed up in the extruder,
heated and melted, foaming;
3) The make up of raw material for plastic protection, mixed in the extruder,
heated and melted;
4) Preheating of metal pipe;
5) The extruder extrudes the melted plastic foaming, and compound onto the
surface of metal pipe.
6) The extruder extrudes the melted plastic protection, and compound with the
plastic foaming;
7) Cooling and finalizing.
The above steps of 4, 5, and 6 are produced in the compound mould at the first
time.
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CA 02356451 2001-08-22
The compound mould are composed of lock nut, mandrel, mould parent,
machine neck-first, large aperture mould, lock net, mandrel, sleeve body,
small
aperture mould, machine neck and heater , and connected by screw and adjust
screw. The mould stream is formed among mould parent , machine neck ,
mandrill , large aperture mould, and S2 stream is formed among sleeve body,
machine neck and large aperture mould.
The said metal pipe is melted under preheating, and the foaming plastic is
conducted into the streams of mould S1 through machine neck by extruder, the
melted plastic protection is conducted into the stream of mould S2, and
compound with metal pipe at the outlet, to become the completed product at the
first time.
The further description is given based on the figures attached.
Figure 1 is the structure drawing of the insulation metal pipe with plastic
foaming
cover.
Figure 2 is the structure cutaway view of the compound mould for this
invention.
In the drawing: 1-metal pipe; 2-heat prevention plastic foam; 3-
protection
01-lock nut 02- mandrel 03- parent
04-machine neck 05- large aperture06- lock nut
first
07-mandrel 08- sleeve body 09- small aperture
mould
011-screw 012 -adjust screw013 -machine neck
014-adjust screw 015-heater
The structure of the metal pipe is shown in Figure 1. The inner layer is metal
pipe1, the middle is the plastic foaming layer2, the outer layer is plastic
protection
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CA 02356451 2001-08-22
3. The said metal pipe can be the various types of metal pipes or metal hoses.
The main raw materials of the said plastic foaming can be polyvinyl chloride
(PVC), polystyrene, polyethylene, polyaminester, polypropylene, or
acrylonitrile-
butadiene-styrene copolymer, or copolymer of ethylene-vinyl acetate. The main
raw materials of the said plastic protection layer can use either of the
following
materials: polyvinyl chloride (PVC), polystyrene, polyethylene, polyaminester,
polypropylene, or acrylonitrile-butadiene-styrene copolymer, or copolymer of
ethylene-vinyl acetate. Of course, during selection of the raw materials for
foaming and protection, it is expected that the melting temperatures of both
are
close. It is better if the materials are the same.
The manufacture process for the insulation metal pipe with plastic foaming
includes the following steps:
The surface treatment of metal pipe for mud , dust and grease; the make up of
the plastic foaming raw materials, mixed in the extruder, heated and melted,
foaming; the make up of plastic protection raw materials, mixed in the
extruder,
heated and melted; preheating of metal pipe; the extruder extrudes the plastic
foaming which is compounded onto the surface of metal pipe; the extruder
extrudes the melted plastic protection, and compound with foaming plastic;
cooling and finalize.
The figure 2 is the structure cutaway view of the compound mould for this
invention.
This compound mould consists of lock nut(01 ), mandrel(02), mould parent(03),
machine neck-first(04), large aperture mould(05), lock net (06), mandrel(07),
sleeve body (08), small aperture mould (09), machine neck (013) and heater
(015) , and connected by screw (011 ) and adjust screw (012, 014). The mould
stream is formed among mould parent (03), machine neck (04), mandrill (07),
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CA 02356451 2001-08-22
and large aperture mould (05), for foaming plastic moving through machine neck
(04) press and S2 stream is formed by sleeve body (08), machine neck (013) and
large aperture mould (05), for melted protection plastic moving through
machine
neck(013) press.
We will give one example to explain the feasibility and technical effects for
this
invention and manufacture process.
To select PVC as main raw material of foaming material, the recipe is as
following:
Raw Material Gravity Ratio
PVC 100
Stability Agent 10.2
Polyethylene Wax 1.3
Ozokerite 14
Stearic Acid Calcium 3.g
Filling 6.3
Foaming Agent O.g
Protection Layer (Select PVC as
main raw
material)
PVC 100
Stability Agent 12.0
Polyethylene Wax 1.3
Ozokerite g,0
Stearic Acid Calcium 2.5
Plasticizer 1 g
Filling 6.0
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CA 02356451 2001-08-22
Fire retardant 15.0
Ageing Resistant 3.3
pigment 0.2
The temperature of extruder casing is 150°C, the temperature of mould
is 140°C,
the turning speed of the screw stem is 45/min, the head pressure is 12 Mega-
Pa,
the traction speed of copper pipe is 5 m/second, under above operation
parameters, the metal pipe with foaming plastic cover is made at the first
time.
Through tests, the features and advantages of the insulation metal pipe with
foaming plastic are:
(1) low heat conductivity, at the average temperature of 0 °C , the
heat
conductivity of the pipe is <0.03 w.m.k, only one-tenth of conductivity index
for traditional insulation pipe; under the same circumstance, the amounts of
insulation material needed for same insulation effect is decreased by more
than 50%.
(2) Closed insulation layer, the moisture is hard to permeate to the material,
not
only to keep warm but also become moisture- proofed. Moisture-proofed
factor ,5000.
(3) Because of fire retardant and preservative etc.added, the plastic
protection
layer is fire proofed, the 02 index is as high as 28; it is high preservative,
the
elongation strength , 10 mega Pa, the compressive strength and anti-
damage strength are high, the life of usage ,30 years. It is suitable for
using
in building and relevant facilities.
(4) Easy installation, it will shorten the project schedule considerably, and
can
lower the manpower forces greatly.
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CA 02356451 2001-08-22
The advantages of this invention manufacture process:
(1)The heat prevention pipe can be produced commercially, and suitable for any
insulation treatment of metal pipe. According to the insulation requirement,
the process can be adjusted and the insulation thickness can be changed to
meet the requirement of the market.
(2) The manual insulation of pipes has been changed to machine equipment,
whose process parameters and performance are matched well, the quality is
guaranteed.
(3) The manufacture process is reasonable, particular style in compound mould
structure and shaping, three layers of material are produced into one
compound product at the first time using plastic melted features, the product
is stable.

Representative Drawing