Product Overview

The KR‑404A analog pointer‑operated tear‑strength tester follows the classic Elmendorf pendulum principle for measuring propagation‑tear resistance of paper and lightweight paper‑board. Pre‑notched specimens are secured in paired clamps. When the weighted pendulum swings downwards from the defined initial angle, its stored potential energy is consumed to extend the pre‑made slit. The mechanical pointer reads energy loss directly from the calibrated scale, giving tear‑strength values in mN.

This cost‑effective benchtop unit meets ISO 1974 and GB/T 455.1 requirements. It is widely adopted by pulp‑paper mills, packaging‑factories, research institutes and official quality‑supervision laboratories for routine incoming‑material inspection and physical‑property QC of various paper grades and low‑strength paper‑board.

Core Product Competitive Advantages

1. Precision Pendulum Kinematics with Standard‑Compliant Geometry Tear‑arm length is strictly kept at 104 ± 1 mm, pendulum initial swing angle at 27.5 ± 0.5°, and standard tear travel reaches 43 ± 0.5 mm. Low‑friction pivot bearings minimise unwanted energy dissipation during swing, laying reliable foundations for repeatable test outcomes.
2. Two‑Range Dual‑Scale Measuring Setup Built‑in dual‑graduation scales deliver two measuring spans: 100‑8000 mN (100 mN resolution) and extended‑range 100‑16000 mN (200 mN resolution). Operators select the suitable scale according to specimen toughness, covering ordinary paper up to heavier lightweight board without extra pendulum‑weight replacement.
3. Controlled‑Accuracy Mechanical Pointer Indication Within 20‑80 % of full‑scale, indication error stays ≤±1 % and repeatability error ≤±1 %; outside this band, performance is controlled within ±0.5 % full‑scale. Robust mechanical scale avoids electronic‑circuit drift, ideal for stable long‑term production‑lab usage.
4. Standard‑Dimension Specimen‑Clamping Assembly Paper‑holding clamps are machined to 25 × 15 mm gripping size, with clamp‑to‑clamp gap held at 2.8 ± 0.3 mm. Quick manual clamping simplifies specimen mounting; no complicated auxiliary fixtures are required.
5. Robust All‑Mechanical Compact Desktop Layout Pure‑mechanical core structure reduces dependence on electronic components. The compact footprint occupies minimal lab‑bench space. Designed for easy cleaning and basic maintenance, suitable for high‑frequency daily quality‑control workflows.

Complete Technical Parameter Table

表格

Compliance Standards: ISO 1974, GB/T 455.1

Standard Complete Test Operating Workflow

1. Pre‑Test Preparation Set the instrument on rigid, vibration‑free laboratory bench. Level the equipment. Cut paper‑board specimens and make standard pre‑cut slit; condition samples under specified temperature‑humidity. Confirm pointer zero‑position before starting tests.
2. Specimen Mounting Insert conditioned specimen between upper‑and‑lower clamping jaws, fasten clamps firmly. Ensure specimen sits flat without twisting or offset, and the pre‑cut slit aligns with standard tear‑trajectory.
3. Pendulum Lock‑in‑Place Lift pendulum and lock it at the 27.5° initial standby‑angle. Reset pointer to the starting scale mark. Verify no obstacles block pendulum swing path.
4. Execute Tear‑Strength Measurement Release pendulum manually. The pendulum swings freely and tears the pre‑notched specimen. After swing completes, read tear‑strength value directly from the mechanical pointer‑scale.
5. Batch‑Sample Repetition & Record Release clamps and remove torn‑out sample. Repeat test for multiple parallel specimens. Record scale readings and calculate average tear‑strength for quality‑evaluation.
6. Post‑Test Tidying Clear paper scraps from clamping jaws. Return pendulum to resting home‑position. Keep instrument in dry clean location. Perform regular pendulum‑friction inspection and scale zero‑check.

KR-404B Microcomputer Control Cardboard Paper Tearing Strength Test Machine

Wide Industrial Application Scenarios

Pulp‑Paper Manufacturing Plants

Routine tear‑resistance QC for printing‑paper, wrapping‑base‑paper and lightweight paper‑board; assess fibre‑bonding toughness for production‑process adjustment.

Packaging‑Material R&D Departments

Compare tear‑performance of different pulp‑formula paper grades, support packaging‑material formulation research.

University Paper‑Science Laboratories

Mechanical‑property teaching‑experiment apparatus for paper‑packaging majors.

Third‑Party Accredited‑Testing‑Organizations

Conduct ISO 1974 / GB/T 455.1‑compliant tear‑strength evaluation and issue formal inspection‑documents for material‑certification audits.

Standard Factory‑Full‑Delivery Kit

1. KR‑404A pointer‑type Elmendorf tear‑strength‑tester main‑unit
2. Standard specimen pre‑cut auxiliary tool
3. Multilingual printed‑operation‑manual complying with ISO 1974, GB/T 455.1
4. Factory‑issued performance‑inspection‑certificate

Global Distributor & After‑Sales‑Support

We deliver remote‑one‑on‑one operational guidance covering specimen‑clamping, pendulum‑handling and routine zero‑point‑verification. Spare‑parts stock includes clamp‑jaws and pivot‑bearing components. Bulk‑order customers can request custom‑voltage variants for overseas‑market deployment. Regional‑exclusive‑agent privileges contain priority‑production‑scheduling, OEM private‑branding‑services and complete‑set high‑definition product‑marketing‑image‑resources.

Product‑Banner‑Marketing‑Slogan

KR‑404A Analog Pointer‑Type Tear‑Strength Tester | ISO‑GB‑Compliant Elmendorf Pendulum Instrument For Paper & Light‑Board Tear‑Resistance‑Testing

Core‑Feature‑Labels‑For‑Product‑Images

Dual‑Measuring‑Range Scale | Precision Pendulum‑Mechanism | Analog Pointer Read‑Out | 100‑16000 mN Measuring‑Scope | Standard‑Specimen‑Clamp Assembly | All‑Mechanical Stable‑Structure | Compact Benchtop‑Design | ISO1974‑GB/T455.1‑Compliant

Safety‑Operation‑Reminder

Keep hands away from pendulum swing area while releasing pendulum. Keep clamping jaws clean of paper fragments. Avoid strong external vibration during testing; perform periodic zero‑position and friction‑performance inspection.