Daehwa Precision

Injection
Method

Water stop grouting Method Reinjector Injection Method Syringe Injection Method DH Acrylic Seal Injection method

대화정밀공업은 최고 품질의 자재를 생산하기 위해 노력합니다.: Water stop grouting Method

Polyurethane Injection (Packer 3D) Polyurethane Injection (Packer 3D)

Polyurethane Injection (Packer)
Polyurethane Injection (Packer)

Various Types of Polyurethane Foam Resin

Polyurethane based 'Flexible Foam' (DHP-1000, DHP-3000)
It is the single-component hydrophilic resin that hardens by reacting to water and forms soft,open celled foam of high density by discharging Co2. It becomes highly elastic after hardening and has a strong adhesive strength for wet surface.
Polyurethane based 'Hard Foam' (DHP-2000, DHP-4000)
It is the single-component hydrophobic resin that forms hard, closed celled foam which is not resilient to deformation. The hardened substance by foaming does not shrink.
Polyurethane based 'Hard Solid' (Ultra Con)
It is the dual component resin that requires different hardening time and shows high tensile,compression, adhesive strength after hardening.
Polyurethane based 'Flexible Solid' (Ultra Pack)
It is the dual component resin that requires different hardening time and shows high tensile,adhesive strength and elongation.

Comparison of properties of Polyurethane Foam Resin

Comparison of properties of Polyurethane Foam Resin
Classification	DHP-1000	DHP-2000	DHP-3000	DHP-4000
Classification	Flexible Foam	Rigid Foam	High Elasticity Foam	Semi-Rigid Foam
Mixing ratio	Single component	Single component	Single component	Duel component
Main raw material	T. D. I (Toluene Discoyanate)	M. D. I (Methylene Diphenyl Disocyanate)	M. D. I (Methylene Diphenyl Disocyanate)	M. D. I (Methylene Diphenyl Disocyanate)
Type of foam	Flexible Foam	Rigid Foam	High Elasticity Foam	Semi-Rigid Foam
Tensile strength	2.3kgf/㎠	16.5kgf/㎠	6.2kgf/㎠	9.3kgf/㎠
Elongation	Over 150%	Under 30%	Over 80%	Under 50%
Rate of foaming	1200%	3300%	800%	3000%
Application	Prevention of water leakage from cracks of concrete structure with vibration	Prevention of water leakage from cracks of concrete structure with minor vibration	Prevention of water leakage from cracks of concrete structure with vibration	Prevention of water leakage from cracks of concrete structure with minor vibration

Comparison of properties of Polyurethane Foam Resin
Classification	Ultra Con	Ultra Pack
Classification	No shrinkage high strength polyurethane	No shrinkage high elasticity polyurethane
Mixing ratio	Dual component	Dual component
Main raw material	M. D. I (Methylene Diphenyl Disocyanate) (Toluene Discoyanate) + (Polyether Polyol)	M. D. I (Methylene Diphenyl Disocyanate) (Toluene Discoyanate) + (Modifiled Polyether Polyol)
Type of hardened substance	No shrinkage high strength polyurethane	No shrinkage high elsticity polyurethane
Adhesive strength	9.5 N/㎟	3.4 N/㎟
Elongation	Under 10%	Over 50%
Rate of foaming	100% ~ 200%	100% ~ 200%
Application	Prevention of water leakage from cracks of concrete structure with minor vibration	Prevention of water leakage from cracks of concrete structure with vibration

Injection method for polyurethane resins

Polyurethane foam resin has a low viscosity, so you can inject it completely into the cracks or minute air voids in which water leakage is progressing by using high pressure injection pump.You are recommended to drill holes on the areas of water leakage at regular intervals and to use the packer with high pressure nozzle that we have developed to ensure that the foam resin makes a perfect infiltration into cracks or minute air voids. You can choose from a variety of packers depending upon the site condition.

Using Materials

It is specially designed to endure high pressure that is applied. Injected resin won't flow backward and this packer is also specially designed not to leak resin around stabilized and fixed packer.
This is 1 component type high-pressure injection equipment that is specially manufactured to fill on a leakage and fracture spot by using polyurethane foam and epoxy injection material.

How to drill holes and set the injection packer on crack

After installing the packer, the drilling of the concrete surface must be cracked to be equal to or greater than 60 degrees, as can be seen in the picture above. The location of the drilling must be 10cm from the area of leakage to ensure that even the smallest spaces of the central crack can be entirely blocked. (According to the construction site, the angle or location of drilling may differ) The intervals between the drilling must be adjusted according to the width of the crack or the amount of water leakage. The drilling must be done in a zigzag shape from the crack. The intervals between the drilling must not exceed 20cm.

Polyurethane Foam Resin Grouting Method

01. Checking the crack and leakage status

Examine the concrete structure's thickness, crack status (width depth), and leakage status prior to deciding the engineering plan.

02. Drilling

if the concrete thickness is 10cm or less, perform drilling directly on the crack part.
if the concrete is 10cm~50cm thick, perform drilling on the area away from the crack part by 1/5 of concrete thickness, maintaining 60ºangle. If the concrete thickness is over 50cm, perform drilling on the area 20cm~30cm away from the crack part, maintaining 60ºangle.
Perform drilling in accordance with given interval (5~6 holes per meter in general).

03. Packer installation

Make the inside of holes clean with an air-compressor. Install the packer such that the packer's rubber sleeve and the nut's cutoff line are buried under the concrete surface.
Fasten the packer with a T-wrench completely.
(Excessive fastening may damage the packer.)

04. Injection

Inject the urethane resin using a high pressure device or a grease gun. Perform initial injection with the pressure of around 40kg/cm, and then slowly increment the pressure by the 10kg/cm unit until the resin overflows the crack. Water overflows the crack first, followed by resin foam and finally the resin. Verify that the resin, not the resin foam, overflows the crack, prior to working on the next packer.