
Product Introduction
The KR-728 manual profiling dumbbell specimen cutter is dedicated laboratory pre-processing equipment for plastic tensile test samples. It adopts mature profiling milling technology, converting rotary cutter motion into stable linear feed movement, and rapidly mills standard dumbbell tensile strips and rectangular Vicat test blanks from plastic sheets, pipes and flat slabs. Uniform sample geometry eliminates manual cutting dimensional deviation, laying reliable foundation for accurate tensile strength, elongation and thermal deformation test data.
Fully compliant with domestic plastic material testing standards including GB/T 1040, GB/T 8802, GB/T 8804 series specifications, this bench machine matches universal tensile testers, Vicat softening point instruments and heat deformation testing equipment. It is widely adopted by plastic pipe factories, modified composite material labs, masterbatch manufacturers, university material teaching rooms and third-party polymer inspection stations.

Core Product Highlights
- Fixed Profiling Mold Design, No Repeated Tool Setting
Custom profiling fixtures lock the sample forming contour permanently. Operators only fix raw blanks before milling, no repeated calibration of cutter position during batch preparation, greatly boosting daily lab sample-making efficiency and cutting down repeated adjustment labor cost.
- Smooth Burr-Free Milling, Avoid Test Data Interference
High-hardness integral spiral milling cutter runs at constant high speed, producing neat, burr-free sample edges without micro cracks or notches on the gauge section. It eliminates abnormal fracture caused by rough cutting surfaces during tensile testing, ensuring consistent test repeatability between parallel specimens.
- Thickness Wide Compatibility & Adjustable Fixture
Clamping structure supports raw material thickness from 1mm up to 30mm, compatible with thin plastic film, medium-thickness sheet and thick engineering plastic slabs. Modular fixture assembly can be customized into Type 1 / Type 2 / Type 5 multi-spec dumbbell molds according to different standard requirements, supporting both polyolefin pipe and rigid PVC raw material sample preparation.
- Built-In Dust Collection Matching, Clean Working Environment
Reserved interface for matched vacuum dust cleaner, which instantly sucks plastic milling debris during processing, preventing powder accumulation on the workbench and cutter surface, reducing frequent equipment cleaning frequency and protecting lab operators from plastic dust inhalation.
- Dial Indicator Auxiliary Positioning, Ultra-High Dimensional Consistency
Equipped precision dial gauge above the milling head to monitor cutter feed depth in real time, effectively controlling dimensional tolerance of the sample gauge length and transition arc. Uniform specimen size eliminates test error differences caused by inconsistent manual cutting techniques.
- Compact Desktop Integrated Layout
Integrated cabinet structure occupies limited countertop area, fitted with anti-slip adjustable foot pads to stabilize the machine during high-speed milling vibration. Standard single-phase 220V power supply requires no industrial special wiring, suitable for small QC rooms and teaching labs with limited space.



Complete Technical Parameter Table
| Parameter Item |
KR-728 Standard Specification |
| Milling Cutter Rotation Speed |
2800 r/min constant speed |
| Standard Cutter Effective Length |
30 mm |
| Processable Sample Thickness Range |
1 ~ 30 mm |
| Maximum Sample Total Length |
≤ 170 mm |
| Applicable Sample Width |
16 ~ 30 mm |
| Main Power Input |
AC220V 50Hz (380V optional) |
| Complete Machine Net Weight |
60 KG |
| Overall Outer Dimension |
400 × 400 × 500 mm |
| Standard Configuration |
Dial positioning gauge, profiling fixture, spiral alloy cutter |
| Optional Accessory |
Vacuum debris suction cleaner |
Supported Standard Specimen Types
- GB/T 1040 Type 1 / Type 2 / Type 5 dumbbell tensile samples for general plastic sheets
- GB/T 8804.2 Type 1&2 samples for PVC-U / PVC-C plastic pipes
- GB/T 8804.3 dumbbell specimens for PE, PP polyolefin pipelines
- Rectangular standard blanks for Vicat softening point & thermal deformation tests (GB/T 1633, GB/T 8802)
- Custom special-shaped test strips per customer material inspection requirements

Standard Full Sample-Making Operation Steps
-
Equipment Pre-Checking
Power on the machine and run idle milling for 1 minute to check cutter rotation stability and dial indicator normal reading; connect the vacuum cleaner if dust removal is needed.
- Raw Material Clamping
Cut plastic slab/pipe blank into rough size slightly larger than standard specimen, loosen fixture bolts, place the blank flat in the profiling mold cavity and lock the clamping assembly tightly to avoid shifting during milling.
- Milling Feed Operation
Rotate the manual feed handwheel to drive the high-speed cutter along the profiling mold contour for automatic shaping, keep steady feed speed to ensure smooth sample surface.
- Specimen Taking & Inspection
Complete one-cycle milling, retract the cutter and loosen fixture to take out finished dumbbell strip, visually check for burrs, cracks or dimensional out-of-tolerance defects.
- Debris Cleaning & Continuous Production
Start the vacuum cleaner to clear accumulated plastic chips on the workbench and cutter, install new raw blanks to carry out batch sample preparation.
- Equipment Shutdown Maintenance
Cut off power supply after daily use, fully clean cutter, mold and workbench with soft brush, store the machine in a dust-proof environment.

Widely Applicable Industry Scenarios
Plastic Pipe Production Enterprises
HDPE, PP, PVC-U, CPVC pipeline raw material tensile sample preparation, batch incoming material mechanical performance inspection before factory delivery.
Modified Plastic & Masterbatch Factories
Glass fiber reinforced plastics, flame retardant composite sheets, color masterbatch blending slabs; tensile, elongation test specimen pre-processing for formula optimization.
Biodegradable Material R&D Labs
PLA, PBAT degradable film and sheet sample making, standard tensile strip preparation for material degradation performance research.
University Material Science Teaching Labs
Plastic mechanics experiment supporting equipment, student tensile test sample making tool for teaching demonstration and graduation project research.
Third-Party Polymer Testing Institutions
Standard specimen preparation for product market access compliance testing, uniform-size samples to ensure test report authenticity and comparability.
Standard Factory Delivery Kit
- KR-728 main manual profiling dumbbell sample cutter host
- High-hardness integral spiral alloy milling cutter
- Multi-spec interchangeable profiling fixture set (Type1/Type2 standard molds)
- Precision dial positioning gauge assembly
- Adjustable clamping bolt set and specimen cleaning brush
- On-off control button assembly and complete power cord
- Multilingual operation manual matching GB plastic test standards
- Factory dimensional calibration inspection certificate
- Optional matched vacuum dust suction cleaner

Global Distributor & After-Sales Support
We provide remote one-on-one sample-making operation training and mold parameter guidance, with long-term stable supply of spare alloy milling cutters and customized profiling fixtures. Overseas 60Hz voltage conversion versions and special ultra-thick sample upgraded fixtures are available for bulk orders. Exclusive regional agent policies include priority production scheduling, OEM private brand customization and full HD product marketing image packages.
English Overlay Text For All Product Pictures
Main Banner Title: KR-728 Manual Profiling Dumbbell Specimen Cutter
Control Panel Tags: POWER ON / POWER OFF / FEED HANDWHEEL
Feature Overlay Tags: Profiling No Re-Calibration / 1-30mm Sample Thickness / Dial Positioning Gauge / Burr-Free Specimen / Vacuum Cleaner Optional
Safety Operation Tip: Do Not Touch Rotating Milling Cutter During Equipment Operation